On the induction of mood

Clinical Psychology R&w, Vol. 10, pp. 669-697, Printed in the USA. All rights reserved.

1990 Copyright

0272-7358/90 $3.00 + .oo 0 1990 Pergamon Press plc

ON THE INDUCTION OF MOOD Maryanne University

Martin of Oxford

ABSTRACT. Increasing interest in the relation between emotion and cognition has led to the development of a range of laboratory methodsfor inducing temporary mood states. Sixteen such techniques are reviewed and compared on a range of factors including success rate, the possibility of demand effects, the intensity of the induced mood, and the range of different moods that can be induced. Three diff erent cognitive models (self-schema theory, semantic network theory, and fragmentation theory) which have been successfully used to describe long-term mood states, such as clinical depression, are elaborated to describe the process of temporary mood induction. Finally, the use of mood induction is contrasted with alternative m.ethods(such as the study of patients suffering from depession) for investigating emotion.

There has been a growing awareness among psychologists that emotion and thought are strongly interactive in human beings. For a considerable period in the history of academic psychology each has been studied independently as if one were by and large irrelevant to the understanding of the other. This has been achieved by three means. First, there has been a tendency in research on emotion towards using animals as subjects, where the role of thought processes is less obvious. Second, there has been a tendency in studies of thought toward testing humans in a neutral emotional state. Third, there has been a tendency in such studies to choose material devoid as far as possible of emotional content. Over the last decade a considerable change of emphasis has occurred, making the relation between thought and emotion one of the most active areas of research in psychology. This increased effort is reflected in the growth of academic journals (e.g., Cognitive Therapy and Research, Cognition and Emotion, and to a lesser degree Social Cognition) devoted to this issue. In some respects, the historical separation of emotion and thought may not have been a bad thing, as it has allowed considerable advances to be made in each area, The author is grateful to David M. Clark and Kathy Clayden the Medical Research Council and the Leverhulme Trust for Correspondence should be addressed to Maryanne Martin, Psychology, University of Oxford, South Parks Road, Oxford 669

for helpful comments and to their financial support. Department of Experimental OX1 3UD, England.

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M. Martin

in both theories and techniques. One of the stumbling-blocks to progress until recently has been the lack of suitable methodology for studying emotion in humans in the laboratory. The purpose of this article is to review a range of methods which have sought to overcome this problem by inducing mood states in a controlled way. These new methods should help us to gain insight into the questions of how mood affects thought patterns, and how thought patterns affect mood. Answers to such questions will entail a further broadening of the scope of information processing models in cognitive psychology and a test of their underlying principles. So far, some cognitive models have been adapted to account for the effects of long-term mood states, most commonly clinical depression. This article will examine how three of the most popular approaches, schema theory, semantic network theory and fragmentation theory, can be extended in order to account for the temporary induction of mood states as well as the presence of persistent mood states. It is hoped that the study of mood induction will also lead to improved understanding of issues such as why some individuals are much more vulnerable to clinical mood disorders, together with the development of successful new therapies for mood disorders and the refinement of existing ones. The development of cognitive therapy for depression (Beck, 1976; Beck, Rush, Shaw, Jc Emery, 1979) and more recently anxiety (Beck, Emery, & Greenberg, 1985; Clark, 1986a, 1986b) has provided a strong impetus to the search for effective mood induction techniques to be used in investigating the relation between emotion and cognition. At our present state of knowledge, there is no unequivocal taxonomy of induction procedures and induced moods. Some of the procedures induce a variety of moods; others attempt to be more specific. This article reviews 16 such mood induction procedures; it then evaluates and compares them along a number of dimensions including the percentage of individuals successfully induced, the presence of demand effects, and the intensity of the induced mood. The second half of the article reviews the mechanisms by which these mood induction.procedures may work. Three active components of the procedures are The cognitive component is then isolated: cognitive, somatic, and emotional. explored in depth. Three different theories are adapted from the literature on clinical depression to account for temporary induction of moods in cognitive terms. The 16 types of procedure utilize either self-statement, music, incremental music, hypnotic suggestion, facial expression, game feedback, social feedback, solitary recollection, social recollection, autobiographical recall, imagery, empathy, experimenter behavior, film, threat, and public speaking. Clearly some of these methods are closely related to one another (e.g., the solitary recollection, social recollection, and autobiographical recall procedures all affect mood by manipulating the content of recall). However, it seems best to consider them separately at this stage, since apparently minor differences in procedure may turn out in practice to have important empirical consequences. MOOD

INDUCTION

PROCEDURES

The procedure developed by Velten (1968) is the most widely used of the mood induction techniques (Goodwin 8c Williams, 1982). Indeed, a review which dealt solely with this procedure and the Music procedure noted that more than 30

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studies have employed the Self-Statement technique, or minor variants of it (Clark, 1983b). The induction into either depressed or elated mood involves the use of 60 self-referent mood-statements of the relevant type (or 60 neutral sentences for a neutral mood). The relevant set is read silently and then aloud by the subject, who is urged to try to feel the mood suggested by the statements. For the depression induction, most of the statements fall into two categories: those concerned with self-devaluation and those which contain suggestions of the somatic states characteristic of depression (Frost, Graf, & Becker, 1979). Examples of the first type include, “I’m discouraged and unhappy about myself,” while examples of the second type include, “Every now and then I feel so tired. and gloomy that I’d rather just sit than do anything,” and, “I feel worn out, my health might not be as good as it’s supposed to be.” A shortened version consisting of 12 self-referent mood-statements of the relevant type has been successfully used for inducing depressed and elated mood by Teasdale and Russell (1983). Orton, Beiman, La Pointe, and Lankford (1983) extended the Velten technique to anxiety mood induction by developing 50 self-referent statements based on suggestions from Beck (1976). The statements fall into three categories: Those concerned with the anticipation of danger or unpleasantness (e.g., “What if I lose control of my an feelings”), catastrophes (e.g., “This is awful”), and statements describing anxious state (e.g., “I’m feeling more and more jittery”). Music In this procedure, mood-suggestive music is played to subjects, who are asked to use the music as a background to their own efforts to get into the depressed, elated, or neutral mood. It is explained that the music alone may not automatically induce the desired mood state, and subjects are asked to use any other means they find effective to get into the appropriate mood. In the first study of the musical induction procedure (Sutherland, Newman, & Rachman, 1982) subjects were able to choose among several different pieces of music, but subsequent studies by Oxford workers have used the same piece of music for all subjects allocated to a particular mood (e.g., Clark dc Teasdale, 1985; Clark, Teasdale, Broadbent, & Martin, 1983; Teasdale 8c Spencer, 1984). For the depression induction “Russia under the Mongolian Yoke” from the film “Alexander Nevsky,” composed by Prokofiev and recorded at half-speed, was chosen. The music for the elated mood induction was the mazurka from “Coppelia” by Delibes, while the music for the neutral induction was the electronic “Pocket Calculator” by Kraftwerk. Incremental Music Pignatiello, Camp, and Rasar (1986) have introduced a variant technique in which subjects are not informed that the music expected to change their mood. Consistent with this, induction pieces of music which all start with the same neutral segment become increasingly more elating or depressing, or else remain Hypnotic

of the preceding they will hear is utilizes composite and then either neutral.

Suggestion

For this induction, only those subjects who are highly hypnotizable (e.g., as measured by the Stanford Hypnotic Susceptibility Scale, Form C, of Weitzenhoffer

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& Hilgard, 1962) are selected. Subjects are instructed to relax and a hypnotic trance is induced using an eye-closure technique (see Weitzenhoffer 8c Hilgard, 1962). When deep trance is reached, the appropriate mood (sad, happy, or angry) is induced by asking subjects to recall a relevant emotional event from their lives. They are to replay this memory in their imagination and to re-experience the associated emotion. The subjects are then requested to experience this emotion in isolation (i.e., detached from the original event) and to increase its intensity until the mood is intense but not overwhelming. This emotional state is to be maintained during the experimental task. This technique has been used primarily by Bower and his colleagues (e.g., Bower, 1981, 1983; Bower & Cohen, 1982; Bower, Gilligan, & Monteiro, 1981; Bower, Monteiro, & Gilligan, 1978). Facial Expression Laird, Wagener, Halal, and Szegda (1982) manipulated facial expression to induce a sad, angry, fearful, or happy mood. To obscure the purpose of the facial subjects were told that the study was concerned with measuring expression, muscular activity during cognitive and perceptual tasks. This cover story was successful in 85-90s of cases, in that the subjects were unaware of the true purpose of the experiment. Before the trial, the experimenter manipulates the subject’s face by asking (e.g., for sadness), “Draw your eyebrows down, but not together, and push your lower lip up against the upper lip and out.” Game Feedback Subjects perform a task and are then given feedback on their performance. They may be told either that they did badly (failure feedback) or well (success feedback). It has been assumed that failure feedback will induce a negative mood. Unfortunately, mood measures were not taken in the well-known study by Isen, Clark, Shalker, and Karp (1978) which gave preprogrammed failure on a video wargame. Social Feedback This type of induction is similar to the game feedback technique in that subjects are given feedback on a simulated social skills task. In a recent study, Martin and Clark (in preparation-a) employed a computer simulation of a dyadic interaction based on a program by Berry and Broadbent (1984). The subject interacts with a series of preprogrammed “computer persons.” The subjects are informed that this is a social skills training program, and that their task is to make each computer person respond in the most friendly way using a range of responses. The more this is achieved, the higher the popularity score the subject receives. There are 12 possible grades of behavior: Very Rude, Rude, Very Cool, Cool, Indifferent, Polite, Very Polite, Friendly, Very Friendly, Affectionate, Very Affectionate, and Loving. In the depressed mood induction, subjects are informed that they have scored below the average popularity score and are given a further opportunity to succeed. After this, subjects are again informed that their popularity is below average. Solitary Recollection Subjects are asked to write down four events of a particular type (e.g., unhappy) which have happened to them over the past year and to rank order them in terms

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of unhappiness. They are then instructed to think of their two unhappiest events for two consecutive S-minute periods. They are asked to think of the events in detail, remembering how they felt and what happened. The technique was developed by Martin, Argyle, and Crossland (1990). Social Recollection This technique starts in the same way as the Solitary Recollection technique with two separate subjects each writing down four unhappy events which have happened to them over the past year, and rank ordering them in terms of unhappiness. When both subjects have finished the ratings they are each instructed to talk about the event which had made them the unhappiest. They talk in turn for 3 minutes about their particular event. When it is not their turn to talk they are asked to act as a good, sympathetic listener to the other subject who is talking. The listener is instructed to ask questions about the event, encourage the speaker to talk, and ask the speaker how they had felt. Subjects then write an outline of the major points they covered when talking about their event and an outline of the major points the other subject covered when talking about their own event. This technique was also developed by Martin et al. (1990). Autobiographical Recall Subjects are asked to close their eyes and to recall three autobiographical moodevoking events that made them feel lonely, rejected, defeated, or hurt. The three events are to be progressively sadder and more unpleasant. This technique has been used by Brewer, Doughtie, and Lubin (1980) and was originally described by Mosak as part of the clinical practice of Adlerian psychotherapy (Mosak & Dreikurs, 1973). A similar procedure was developed by Barlett, Burleson, and Santrock (1982) from a technique used by Moore, Underwood, and Rosenhan (1973) with young children instead of adults. Subjects are first asked to recall an experience that makes them sad (or happy), and then to think about the experience while getting “a picture in your head of everything that happened and how you felt.” In further similar studies, children have been asked to think, while staring at a plain grey box for 30 seconds, about happy, sad, or neutral events they had experienced (Barden, Garber, Duncan, 8c Masters, 198’1; Masters, Barden, & Ford, 1979). Imagery Subjects listen to a tape-recording instructing them to relax, make themselves comfortable, and focus their attention on the instructions they are about to hear. Subjects are instructed to imagine situations that would leave them feeling either sad, happy, or neutral. They are told that they can either imagine hypothetical situations or real events in their past, and are then requested to generate vivid imagery of the events. They are told to think the thoughts that they would actually think and to feel the same (happy, sad, neutral) feelings that they would actually feel if they were in the situations. This technique was developed by Wright and Mischel (1982). Empa thy This technique was developed by Thompson, Cowan, and Rosenhan (1980) in the USA and modified for use with a British population by Williams (1980). The

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subject is asked to become emotionally involved in a tape-recorded story in which a friend becomes ill and is eventually diagnosed as having an incurable disease. The tape focuses on the subject’s own feelings of helplessness and loneliness. In a related technique, subjects read a brief newspaper report of a tragic event (e.g., death caused by leukemia, homicide or fire), imagining how they would feel if they had read the story in their local paper (Johnson 8c Tversky, 1983). A form of this procedure for use with children has been developed by Barden, Garber, Leiman, Ford, and Masters (1985). Children hear a story concerning a situation either of social acceptance or of social rejection, and are told something similar could happen to them or to their peers at school. Experimenter Behavior In this technique the experimenter spends about 3 minutes acting in a happy (or sad) manner and then tells a story which is happy (or sad). The procedure was developed by Barlett and Santrock (1979) for use with children. In a similar procedure developed by Barden et al. (1985), the experimenter behaves in either a socially accepting or a socially rejecting way toward the child subject. Film Film has been used to induce mood by various investigators. Marston, Hart, Hileman, and Faunce (1984) asked subjects to view an edited version (lasting 55 minutes) of the film “The Champ.” The film centers on an 8-year-old boy’s love for his father, an ex-boxer, who raised him, and the efforts of his mother to re-establish contact. In the final scenes the father dies after a successful but brutal return to the ring. The subjects were told the film was selected to elicit emotions and that they were to, “Let yourself experience whatever emotions you have, as fully as you can. Don’t try to hold back or hold in your feelings.” Similarly, Isen and Gorgolione (1983) have subjects view 5-minute segments of films. A comedy film entitled “Gag Reel” was used for positive mood induction. The segment shown was composed of “out-takes” (scenes with errors in them that were not shown to the public) of the old “Gunsmoke” television series, and also a skit from “The Red Skelton Show.” The film entitled “Run” was used for negative affect (anxiety) induction. It depicts a man running away from something unseen, panting and seeming anxious (frequently turning to look behind him) as he runs. In the end, the audience discovers that it is himself from whom he is running, and he falls into his grave. Finally, Barden et al. (1985) showed children color videotapes, shot with child actors, either of a sad scene in which a child is socially rejected or of a happy scene in which a child is socially accepted. Threat A technique which has been used for inducing anxiety in the laboratory is to threaten subjects with painful electric shock (e.g., Herman & Polivy, 1975; Polivy, 1981; Schacter, 1959). Polivy (1981) told subjects: “The stimulation you will be receiving is electric shock. It will be quite painful but harmless and will result in no tissue damage. In order to comply with University regulations, I had to administer the same level shock you will get to myself. As I said, it was very painful but

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tolerable, and as you can see, caused no permanent damage. However, to ensure safety would you please remove all rings, bracelets, watches, etc.? Since the shock will be painful, I would like to remind you that it is your prerogative to decide whether or not you want to go on, but I would appreciate it very much if you would stay. The research is very important and has serious implications for education and business. Your participation would be extremely valuable.” Anxiety induction continued with subjects signing a consent form, being seated in front of a shock generator set to the second-to-highest level and having electrodes from the generator attached to their nonpreferred hand. Public Speaking A recent technique for inducing anxiety is to inform subjects that at a later stage in the experiment they will be asked to speak in front of an audience on a specified topic (Martin, 1990). In addition, subjects may be told that their talks will be video recorded, with video cameras and other recording equipment being on view. EVALUATION

OF MOOD INDUCTION

PROCEDURES

Certain common features which contribute to the shift in mood can be detected among the 16 induction procedures. A considerable number use the subject’s own efforts to change his or her mood. These efforts are aided by the experimenter or by experimental materials which range from verbal statements, through imagery and music to stories and film. In other cases, however, the mood is manipulated by the experimenter without the subject’s awareness, for example in the case of the Facial Expression, Incremental Music, Threat, Game Feedback, Social Feedback, Experimenter Behaviour, and Public Speaking procedures. The inductions may be evaluated by their standings on a number of different criteria. Those to be considered here comprise Range, Measurement, Intensity, Specificity, Success Rate, Administration Time, Group Administration, Individual Differences, Demand Effects, and Ethics. Range The range of different moods for which mood induction procedures have thus far been utilized is fairly restricted. As shown in Table 1, 14 of these methods have been employed for depression (reflecting research interest in clinical depression), 12 for elation, 6 for anxiety, and 2 for anger (together with 7 for neutral mood). In principle, it seems feasible that most of the procedures could be adapted to include at least elation and neutral mood. Measurement One of the main problems in evaluating the relative merits of induction procedures is the shortage of articles which consider more than one technique (for exceptions see Chartier & Ranieri, 1989; Clark, 1983b; Martin, 1985a). Further, there is the lack of a single generally adopted measure of mood and mood change. The studies considered here have made use of a variety of self-report and physiological measures. In some studies no specific measures of mood were taken 1981; Bartlett et al., 1982), although the (e.g., Bower, Gilligan, & Monteiro,

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TABLE 1. Types of Mood Induced by Each Procedure Depressed

Anxious

Angry

Happy

Neutral

Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No No

Yes No No Yes Yes No No No No No No No No Yes Yes Yes

No No No Yes Yes No No No No No No No No No No No

Yes Yes Yes Yes Yes Yes No Yes Yes Yes Yes No Yes Yes No No

Yes Yes Yes Yes No No No No No Yes Yes Yes No No No No

Self-Statement Music Incremental Music Hypnotic Suggestion Facial Expression Game Feedback Social Feedback Solitary Recollection Social Recollection Autobiographical Recall Imagery Empathy Experimenter Behaviour Film Threat Public Speaking behavior

of subjects

following

hypnotic

suggestion

did seem

to be influenced

by

In other studies utilizing behavioral criteria, Masters and his colleagues have recorded children’s facial expressions. When these expressions were rated according to the categories devised by Ekman, Friesen, and Ellsworth (197 l), significant changes were found following use of the Autobiographical Recall technique (Barden et al., 1981; Masters et al., 1979) and Empathy, Experimenter Behaviour, and Film techniques (Barden et al., 1985). Standardized measures such as the Depression Adjective Check List (DACL: Lubin, 1967) and the State-Trait Anxiety Inventory (STAI: Spielberger, Gorsuch, & Lushene, 1970) have been used in the evaluation of the Self-Statement, Incremental Music, Autobiographical Recall, Empathy, and Public Speaking procedures. The Self-Statement, Music, Solitary and Social Recollection, Empathy, Social Feedback, and Public Speaking procedures have been compared on visual analogue scales of mood. These are linearly arranged categories that run from “I do not feel at all X” to “I feel extremely X,” where X is a mood adjective. The Self-Statement and Music procedures have also been assessed using psychomotor measures known to be affected by depression. Velten (1968) used writing speed, distance approximation, decision time, word association, and spontaneous verbalization to measure change of mood due to Self-Statement induction, and found significant differences between elated and depressed groups on all measures. Count times (viz., the time taken to count aloud from 1 to 10) has also been found to be significantly affected by the Self-Statement and Music procedures (Clark & Teasdale, 1985; Clark et al., 1983; Teasdale & Fogarty, 1979; Teasdale, Fogarty, & Williams, 1980). However, there is as yet no single measure on which the majority of mood inductions have been compared. mood,

as judged

both by observers

and the subjects

themselves.

Intensity

One criticism that has been made of mood induction techniques (e.g., Marston et al., 1984), is that only a low level of intensity of mood is produced. This criticism

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TABLE 2. Mean Scores (Maximum 100) on Mood Judgements for Clinical Depression and Induced Depression Procedures

Depressed

Type

Mood ludgement Anxious

Happy

Clinicaldepression 53.8

42.5

30.3

70.0 35.0

58.3 43.3

23.5 42.0

Self-Statement Teasdale & Fogarty (1979) Teasdale & Russell (1983) Teasdale & Taylor (1981) Teasdale, Taylor & Fogarty (1980)

43.9 50.8 48.4 44.8

29.4 24.5 21.0 28.5

41.4 50.8 29.8 37.0

Mean

47.0

25.9

39.8

60.0

26.8

31.0

54.0

39.0

39.0

59.0 (17.0)

41.0 (36.0)

33.0 (61.0)

Mean

57.7

35.6

34.3

Social Recollection Martin, Argyle, & Crossland (1990) Criterion group Whole group

48.6 29.7 (20.0)

28.6 24.7 (37.3)

45.0 59.3 (66.7)

Solitary Recollection Martin, Argyle, & Crossland (1990) Criterion group Whole group

47.5 43.3 (17.0)

30.8 32.0 (23.7)

40.0 44.3 (66.6)

Empathy Williams (1980)

60.0

57.0

35.0

Social Feedback Martin & Clark (in preparation-a) Criterion group Whole group

52.3 40.7 (25.9)

52.8 42.7 (30.5)

45.0 49.2 (63.8)

Clark (1983a) Clark & Teasdale (1982) More depressed occasion Less depressed occasion

Induced depressionprocedures

Music Clark & Teasdale (1985) Clark, Teasdale, Broadbent, & Martin (1983) Martin, Harrison, & Clark (in preparation)

Note. Scores in parentheses

refer to preinduction

data.

could be particularly important if studies using experimental mood induction were related to the phenomenon of clinical depression. It seems likely that the effects of mood vary quantitatively as well as qualitatively with type of mood. Nevertheless, it would be of interest to compare the intensity of naturally occurring clinical depression with that of an equivalent induced state. Two induction procedures whose effects have been compared with those of clinical depression in a number of contexts are the Self-Statement and Music techniques. Clark (1983b) reviewed evidence for similar effects of these procedures over a wide range of behavior,

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M. Martin

including psychomotor retardation, loss of pleasure and incentive, disturbed appetite, indecisiveness, persistence in the face of frustration, facial electromyography, hemispheric lateralization, illusion of control, helpfulness, behavior in social situations, and ease of retrieval of positive and negative material from memory. One method of assessing mood intensities which has been used by workers in Oxford for a wide range of induction procedures is that of visual analogue scaling. Depression, anxiety, and happiness have been judged on these scales by depressed patients and by normal people both prior to mood induction and following the Self-Statement, Music, Solitary and Social Recollection, Social Feedback, and Empathy procedures. The results for a number of studies are shown in Table 2 and follow a consistent pattern. All six mood induction procedures give rise to a level of reported depressed/despondent emotion equivalent to an intermediate clinical level. Table 2 includes for comparison the levels for a group of depressed patients studied by Clark (1983a), and for both the less depressed and the more depressed phases of the depressed patients in the study of diurnal mood variation by Clark and Teasdale (1982). Both groups of depressed psychiatric patients met the Research Diagnostic Criteria for Unipolar Major Depressive Disorder (Spitzer, Endicott, & Robins, 1978), and had Beck Depression Inventory (BDI: Beck, Ward, Mendelson, Hock, & Erbaugh, 1961) scores of 20 or above. With the exception of Social Recollection and Social Feedback induction, all of these procedures also give rise to a mean level of happiness at intermediate clinical levels. The level of anxiety was less than that for depressed patients for all procedures except Empathy and Social Feedback. Before leaving Table 2, one further issue should be noted. Most studies of mood induction report the mean mood measures only for a criterion group of subjects who changed mood in the expected direction by some predesignated amount. However, for the Social and Solitary Recollection and the Social Feedback studies, values are given in Table 1 not only for data derived in this way (viz., sampling only subjects with IO-point shifts in depression in the expected direction), but also those averaged over the whole group of subjects who were tested. Where differences between the two groups are small, it of course indicates that almost the whole group satisfied this criterion. Turning to anxiety induction, in the few cases where there are data, it appears that anxiety induced subjects temporarily experience a reasonable level of anxiety. In Table 3 it can be seen that subjects who experienced the Public Speaking Induction obtain Spielberger State anxiety scores comparable to a group of Generalized Anxiety Disorder Patients and to a group of nonpatients experiencing a naturally occurring stressful situation (the interview procedure for selection for places to read for undergraduate degrees at Colleges of Oxford University). Similarly, Table 3 reveals that following anxiety induction, scores on the visual analogue scales of mood are indistinguishable from the levels of anxiety experienced in a naturally occurring anxious situation (Martin, 1990). Unfortunately, the visual analogue measures were not administered to the patient sample. Specificity

How pure are the mood states produced by different induction procedures? It should be noted first that the question of specificity is an important issue not only

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TABLE 3. Mean Mood Scores of Generalized Anxiety Disorder Patients, Naturally Occurring Anxiety, Induced Anxiety, and Neutral Situations from Martin (1990) Mood Judgement Anxious

State Anxiety

Type

Depressed

Clinical anxiety (n = 14)

No data

No data

No data

48.2

Naturally Occurring Anxiety (n = 33)

34.5

57.4

52.0

49.2

Induced Anxiety (n = 40)

25.1 (23.5)

46.1 (30.3)

53.4 (62.7)

49.2 (39.7)

Neutral Situation (n = 105) (n = 86)

29.7 27.8

36.4 34.5

57.7 62.4

40.6 38.9

Note. Scores in parentheses refer to preinduction

Happy

data.

induction, but also with naturally occurring emotional disorders. By the mid- 197Os, the consensus of opinion in psychiatry was that anxiety and depression were separate but related disorders. Anxious and depressed patients could be discriminated with respect to symptomatology, personality, past history, and treatment response. However, several more recent clinical, family and treatment studies have raised the possibility that depressive and anxiety disorders share a common diathesis (see Greenberg, Vazquez, & Alloy, 1988). One proposal (Ellis, 1962) is that irrational beliefs produce a general arousal and global “upsetness,” whereas a converse position (Beck, 1976) is that there is considerable specificity with emotional states directly linked to the type of cognition present (e.g., depression is postulated to result from thoughts involving unfulfilled expectations, loss, and failure, whereas anxiety results from thoughts that anticipate danger or unpleasantness). Within cognitive psychology, Oatley and Johnson-Laird (1987) propose that sadness and anxiety are distinct basic emotions which arise at different junctures of an individual’s current plan. For example, sadness occurs when there is failure of a major plan or loss of an active goal, whereas anxiety occurs when the self-preservation goal is threatened. They propose that, in general, emotions inhibit one another, although they allow for oscillations between two emotions. Whatever the outcome of this theoretical debate, it is certainly the case that in clinical practice it can be difficult to distinguish between depressive and anxious states. Indeed, it has been suggested that in primary care most patients experience a mixed affective disorder rather than pure anxiety or depression (Goldberg & Huxley, 1980). Overt anxiety is commonly found in reactive and neurotic depression, but infrequently observed in psychotic, bipolar, and other more severe forms of depression (see Greenberg et al., 1988). Moreover, in college samples it is unusual to be able to identify a substantial number of subjects who are depressed but not anxious (see Dobson, 1985; Greenberg et al., 1988). There is evidence that some anxiety induction techniques (Public Speaking, Film) induce anxiety without increasing depression. Also, some depression induction techniques (Music, Facial Expression) increase depression without increasing with

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anxiety. Other depression techniques (Empathy, Social Feedback, Autobiographic Recall) increase depression and anxiety. The depression Self-Statement technique induces depression sometimes without an increase in anxiety (see Table 2, Brewer et al., 1980; Frost et al., 1979; Polivy, 1981; Polivy 8c Doyle, 1980; Sutherland et al., 1982), and sometimes with an increase in anxiety (see Strickland, Hale & Anderson, 1975; Wilson & Krane, 1980). Another approach to the question of specificity in mood induction is to compare different procedures with each other in order to ascertain whether they induce indistinguishable moods. Unfortunately, there are few studies of this type. Isen and Gorgolione (1983) compared positive and negative Velten and film inductions with a neutral condition showing reasonable specificity of induction compared with the neutral condition. Unfortunately, for our purposes, no statistical comparisons among induction procedures are reported, so it is not possible to ascertain if, for example, the two negative inductions differed from each other. Moreover, Barden et al. (1985) have examined the effects of different types of positive remediation after children had experienced negative versions of the Empathy, Experimenter Behavior, or Film induction procedures. They found that there were some differences in their effects among the positive remediation procedures as a function of the identity of the preceding negative induction procedure. Nevertheless, it is of course possible that these differences were mediated by means of the relations between the first and second procedures on dimensions other than those pertaining to induced mood itself.

When experimental resources are limited, the percentage of subjects susceptible to a particular form of induction is likely to be an important variable. If only 50% of people are susceptible to a particular mood induction technique it will be necessary to test twice as many subjects as might otherwise be necessary. With some techniques -(e.g., hypnotic suggestion), only 15% of cases meet the selection criterion. In this case a sample size of well over 300 people is likely to be necessary in order to find 50 suitable subjects. Such large sample sizes can cause considerable practical problems when, for example, new subjects are required for each experiment. In addition, there is perhaps the more serious issue of generalizability from experimental results to the population as a whole. This is called into question when the experiment proper is restricted to only a small subset of the population, selected according to a particular characteristic. For example, results obtained using the Hypnotic Suggestion technique may in principle be applicable only to persons who are highly susceptible. There is considerable variability in the success rate of different mood induction techniques. Some successfully induce the required mood in more than 75% of cases (e.g., Music, Autobiographical Recall, Solitary Recollection, Film). Several procedures achieve approximately 50% success (e.g., Self-Statement, Social Recollection, Facial Expression, Social Feedback). In a series of studies by Bower and his colleagues, Hypnotic Induction is used only for people who fall into the top 15 percent of the college population for hypnotic susceptibility. However, caution should be exercised in comparing techniques where different criteria of success have been employed. As yet there is no single agreed standard for inferring that a mood has been successfully induced in an individual experi-

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mental subject. One criterion used in a number of the studies reviewed here is that a change in mood from pre-induction to post-induction of at least 10 percentage points using a visual analogue scale of instantaneous mood is required for the technique to be deemed successful. More generally, the success rate criteria cited here are those reported in the individual studies concerned (see also the Measurement section). Administration Time The time to administer each of the techniques to a subject varies considerably. The longest time has been employed by one of the Film techniques, taking 55 minutes (an abbreviated 15-minute form has also been suggested); the Social Feedback and Incremental Music techniques take about 20 minutes to conduct; Self-Statement also takes 20 minutes for the full version and 7 minutes for the shortened version; Social and Solitary Recollection, Autobiographical Recall, Empathy, and Game Feedback each take about 10 minutes; Music, Hypnotic Suggestion, Threat, Facial Expression, Public Speaking and one of the Film techniques each take less than 10 minutes. Group Administration Most of the mood induction techniques have been applied to subjects individually rather than to groups, though the Self-Statement procedure has sometimes been used in a group administration form (e.g., Coleman, 1975; Brewer et al., 1980), as has the Autobiographical Recall method (Brewer et al., 1980) and the Public Speaking method (Martin, 1990). Individual testing is usually favored by experimenters as some people may be inhibited from entering a specified mood if they can be observed by other subjects. Individual Differences A relatively neglected topic at present is the question of individual differences in susceptibility to different induction procedures. However, there is some evidence of systematic variation among people in their susceptibility to particular forms of induction. Laird and Crosby (1974) found that subjects who responded to the Facial Expression form of mood induction displayed distinctive reports of everyday emotional experience. Their everyday mood changes were reported to be controlled by self-produced rather than situational cues. It has also been reported (Gouaux & Gouaux, 1971) that women are more susceptible than men to the effects of the Self-Statement induction procedure, although subsequent research has not provided much further support for this hypothesis (see Clark, 1983b). It is proposed that an individual is much more likely to be susceptible to a particular mood induction technique if the contents focus on one of their current concerns. There is some support for this hypothesis. Individuals who judged themselves to be more afraid of public speaking increased more in anxiety in response to a subsequent Public Speaking induction (Martin, 1990). Those who scored higher on the Social Interest Scale (Crandall, 1975) became relatively significantly more depressed following the Social Recollection rather than the Solitary Recollection induction (Martin et al., 1990). Individuals who are selfreflective and introspective as measured by the Private Self-Consciousness scale

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(PSC: Fenigstein, Scheier, 8c Buss, 1975) are relatively more depressed by negative information about the self which is new, as provided in the Self-Statement technique (Scheier 8c Carver, 1977), but significantly less affected by negative self-information which they generated in the Solitary and Social Recollection procedures (Martin et al., 1990), presumably because it is already so familiar to them. Further, those who are more concerned about interpersonal relations are more emotionally susceptible to subsequent negative interpersonal life events, whereas those who are more achievement-oriented are more susceptible to failure in life events (Hammen, 1988; Hammen, Marks, Mayol, & deMayo, 1985). Demand Effects It has recently been suggested that the effects observed with the Self-Statement mood induction may be artifactual in that subjects may not really change mood but simply report doing so in order to comply with experimental demands (Buchwald, Strack, & Coyne, 1981; Polivy & Doyle, 1980). The same criticism could perhaps be levied against some of the other techniques as well. With the exception of the Facial Expression, Game Feedback, Social Feedback, Incremental Music, Threat, and Public Speaking procedures, subjects could possibly guess the type of mood effect that the experimenter might be expecting. The problem is perhaps most pressing with the Self-Statement technique, where the self-statements themselves may give information which could be useful in simulating mood. One type of evidence against the demand-effects hypothesis is the occurrence of mood effects that subjects are unlikely to simulate. As one example, Natale and Gur (1980), using the Self-Statement procedure, found differences in conjugate eye movements between depressed and elated mood-induced groups. Similarly, Teasdale and Bancroft (1977) found that corrugator electromyographic activity (EMG) was higher in depressed patients when they were instructed to generate unhappy rather than happy thoughts. Furthermore, significant positive correlations between self-reported depressed mood and corrugator EMG were obtained. Consistent with this, Sirota and Schwartz (1982) found that normal subjects given Self-Statement depression induction showed higher levels of corrugator muscle activity than subjects given either the corresponding neutral or elation version, and Haney and Euse (1976) found heightened heart rate and skin conductance reactivity for negative visual imagery relative to neutral imagery (though there was no difference between positive and negative imagery). In addition, psychomotor tasks reveal a decrease in speed when subjects are induced into a depressed mood and an increase in speed when they are induced into an elated mood. In particular, Johnson’s number-writing task is sensitive to Self-Statement induction (Alloy, Abramson, Se Viscusi, 1981; Hale & Strickland, 1976; Natale, 1977a, 1977b, 1978; Natale 8c Hantas, 1982; Velten, 1968) and Incremental Music induction speed is sensitive to Music induction (Pignatiello et al., 1986), while counting-aloud (Clark & Teasdale, 1985; Clark et al., 1983; Sutton, 1985). Similar considerations apply to the use of inconspicuous videotaping of children’s facial expressions by Barden and his colleagues, and to changes observed in subjects’ voices by Bugental and Moore (1979) since there is evidence that speakers generally have little awareness of voice intonation (Holzman & Ronsey, 1966). Another type of evidence against the demand-effects hypothesis is the occurrence of mood effects even when subjects are unlikely to know that their behavior

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is being observed. For example, Frost, Goolkasian, Ely, and Blanchard (1982) found an effect of mood induction when the experimenter was out of the room. Individuals who scored highly on a dietary restraint questionnaire, when induced into a depressed mood, ate more sweets from a nearby bowl than did other high-restraint subjects with induced neutral or elated moods. Similarly, Coleman (1975) found that subjects who had received depressed or elated induction could be distinguished outside the laboratory on the basis of general demeanor, even though the subjects thought that the experiment had finished and were unaware of being observed. Alloy et al. (1981) provided further evidence against the demand-effects hypothesis. They compared subjects receiving depression induction, neutral induction, and instructions to simulate depression on three measures of mood: self-reported depression, writing speed, and “illusion of control.” On the more easy-to-fake self-report measure, the simulators significantly overestimated their responses compared to the depression induction group, whereas on the two more difficult-to-fake measures, writing speed and “illusion of control,” simulators’ responses were significantly weaker than those of the depression induction group. This study, therefore, provides good evidence against explanations of the results obtained with mood induction entirely in terms of demand effects, since this would have predicted that the simulators would be indistinguishable from the mood-induced group. The demand-effects hypothesis is also particularly implausible in the case of recall experiments (which have employed the Self-Statement, Music, and Hypnotic Mood induction procedures). This is because subjects are asked to respond as fast as possible or to recall as much as possible in all cases. So the demand hypothesis has no convincing explanation why the time taken to retrieve pleasant memories in response to a prompt (relative to the time taken to retrieve unpleasant memories) is significantly longer when subjects are depressed than when they are happy (Teasdale & Fogarty, 1979), why subjects recall a higher ratio of negative to positive material when sad than when happy (Bower, 1981, 1983; Martin 8c Clark, in preparation-b), and why this pattern of recall is found for material pertaining to the self, but not to others (Martin & Clark, in preparation-b). Furthermore, Teasdale and Spencer (1984) demonstrated that retrospective estimates of success on an experimental task varied with mood only if the subjects had previously been given feedback as to their success rate on that task. Again a demand-effects hypothesis would have predicted that previous feedback should be irrelevant and that mood congruency should have been observed either in both conditions or in neither. Ethics It is of paramount importance that consideration be given to the ethical implications of any mood-induction procedure before it is put into use. In general, there is little concern about inducing positive moods. Perhaps more problematic is the induction of negative moods. However, many mood induction procedures give rise to moods which are very short-lived, often only lasting a matter of minutes (see Argyle, 1987; Frost 8c Green, 1982; Isen 8c Gorgoline, 1983). It has even been suggested that there are some beneficial effects of swings of mood in everyday life. For example, in the case of individuals who live in very stable environments mood swings may foster novel planning (Mayer, 1986). The tech-

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niques for inducing depression and anxiety discussed in this review appear by and large to be regarded as ethical by many practitioners in the field. It is, of course, important for each study to receive individual ethical assessment (see American Psychological Association, 1981). Some general considerations that might be thought to be appropriate would include using only individuals who have volunteered to take part in mood induction studies; screening out from negative mood-induction any people who have had episodes of clinical depression or anxiety, or are very depressed or anxious just before the experiment; thoroughly debriefing subjects at the end of the study; and checking that a subject’s mood has returned to normal at the end of the study. It may also be prudent for individuals without clinical training or experience to work with clinical colleagues.

Perhaps the most important single distinction which emerges for the different techniques which have been described here is that between techniques where the subjects are aware that a particular mood is being induced, and those where this is not so. The majority of techniques falls into the first group, for which subjects can either infer what their likely target mood is or else may be explicitly informed of it. The second group, where the target mood may be unknown to subjects, is limited probably to the Facial Expression, Game Feedback, Social Feedback, Incremental Music, Threat, and Public Speaking techniques, although even with these techniques some subjects may be able to infer target moods. The two groups of techniques differ generally in at least three important ways: on success rate, on ethics, and on demand effects. On success rate, the first group of techniques appears to be particularly effective. Ethically, they also have the advantage that the subject is aware of the way in which his or her mood is being manipulated. As reviewed here, the second group of techniques appears in general to be less reliable than the first group in their effects upon mood, and also does not provide subjects with such a direct opportunity for informed consent prior to their mood manipulation, but does provide less opportunity for subjects to display demand effects on tasks for which these are in principle possible. THEORIES OF MOOD

INDUCTION

It is unlikely that all mood induction procedures work in exactly the same way, just as different people do not appear to become depressed naturally in exactly the same way. It is nevertheless possible that the procedures share certain common features. One of these is the importance of negative cognitions. According to cognitive models of depression (e.g., Beck, 1967; Beck & Rush, 1978; Beck et al., 1979), negative cognitions can play a causal role in producing symptoms of depression, rather than being themselves merely a symptom of depression as has often been assumed (see Wilner, 1985). Negative cognitions are attributed to both of these roles in what may be termed the vicious circle model (Bower, 198 1; Clark & Teasdale, 1982, 1985; Teasdale, 1983b, 1988; Teasdale & Fogarty, 1979). The vicious circle hypothesis is that negative cognitions lead to depression, which leads to changes in accessibility within memory, resulting in negative cognitions, and so on, in a cyclic progression. Obviously, the process is constrained somehow in most people as otherwise, once a person became depressed, they would continue to

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TABLE 4. The Primary Focus of the Different Mood Induction Procedures

Type of Induction

Cognitive

Self-Statement Music Incremental Music Hypnotic Suggestion Facial Expression Game Feedback Social Feedback Solitary Recollection Social Recollection Autobiographical Recall Imagery Empathy Experimental Behaviour Film Threat Public Speaking

Yes Yes No? Yes No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes

Focus of Induction Emotional Somatic Yes Yes Yes? No Yes No No No No No No No No No No No

Yes Yes No Yes No No No Yes Yes Yes Yes Yes No Yes No No

spiral on downwards indefinite1 y. It is hypothesized that the circle can be broken by distraction, sleep, positive life events, mood-elevating drugs, and belief modification. It may be that mood induction generally involves the construction of a vicious circle which involves a reciprocal relationship between emotion and cognition similar to that in naturally occurring emotional states. However, mood induction procedures do not necessarily all have their primary focus at the same point of the vicious circle. Three different components may be distinguished: cognitive, via thought processes; somatic, via bodily sensations; and emotion, via an intention on the behalf of a subject to feel a specified emotion. The cognitive route involves increased accessibility of negative cognitions and forms the core of three influential theoretical accounts of depression which will be discussed later. The somatic route involves changes in bodily state as a result of a physical manipulation or verbal instruction. The emotion route may be a separate route from the cognitive and somatic routes or, in practice, it may be simply a free choice on the part of the individual to use the cognitive and/or somatic routes. Table 4 shows that some mood induction procedures focus primarily on the cognitive part of the vicious circle (e.g., Game Feedback, Social Feedback, Experimenter Behavior, Threat and Public Speaking). In a further group of inductions, subjects are also instructed to feel an emotion in addition to the cognitive component (e.g., Hypnotic Suggestion, Social and Solitary Recollection, Autobiographical Recall, Imagery, Empathy and Film). In contrast, in some inductions there is no obvious direct cognitive component (Incremental Music; Facial Expression). In these procedures mood is cued by bodily state, for example, the positioning of facial muscles in the Facial Expression induction. Finally, it is proposed that two of the most widely used techniques, Self-Statement and Music, have cognitive, somatic and emotional components. The notion of increased accessibilty of negative cognitions is central to three

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(a) Schema Theory

(b) Semantic Network Theory

(c) Fragment Theory

FIGURE 1. Graphical representation of (a) Schema Theory, (b) Semantic Network Theory, and (c) Fragmentation Theory accounts of induced depressed mood. major cognitive approaches to the understanding of naturally occurring depression: schema theory, semantic network theory, and fragmentation theory (see Martin, 1985b). In the following sections, we explore the possible extension of each of the three types of cognitive model to the domain of mood induction. Schema Theory Since the pioneering work of Bartlett (1932), the notion of schema has become an important element in cognitive theorizing (see Alba & Hasher, 1983), and has been widely utilized by Beck and his colleagues (e.g., Beck 8c Rush, 1978; Beck et al.,

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1979) and many others (e.g., Alloy, Hartlage, 8c Abramson, 1988; Dobson, 1985; Evans & Hollon, 1988) in describing cognitive structures and processes in depression and anxiety. The schema is an organized cluster of stored knowledge, beliefs, and assumptions. The content of each schema is built up and organized from an individual’s lifetime of experiences, and is used to perceive and evaluate current information. The self-schema is used in the same way by the depressed and anxious, although the content of these schemata is specific to the disorder. The depressive’s schema centers upon themes of personal deficiency, worthlessness, self-blame, guilt, deprivation and rejection, whereas the anxious individual’s schema centers upon themes of threat, danger and uncertainty. Kovaks and Beck (1978, pp. 528-529) write, “A schema is a relatively enduring structure that functions like a template; it actively screens, codes, categorises, and evaluates information. By definition, it also represents some relevant prior experience.” It is the depressive schema that is responsible for the systematic negative biases reported in depression. Beck (1967, 1988) suggests that the schemata that are prepotent in depression seem to be relatively dormant when the depression is not present, although specific experiences of deprivation or defeat may activate them even during the nondepressed period. During depression the negatively toned schemata emerge from the predepressive personalities of the patients. This view would suggest that only those people who already possess negative selfschemata will be susceptible to negative mood induction procedures. Further, the extent of the mood change will be greater the closer the match between the specific content of the mood induction procedure and the content of the selfschema. The schema (see Figure 1) can be activated in two main ways (Beck et al., 1979, pp. 16-20). First, activation may be by events which resemble those on which the schema was originally based. The Game and Social Feedback induction procedures provide good potential instances of this form of activation, since they could reinstate cognitive failure experiences that have often in the past co-occurred with depression and become embedded within negative schemata. Similarly, the Public Speaking induction procedure may resemble sufficiently other anxiety-provoking social situations where anxiety schemata have become established and hence elicit these schemata, which in turn lead to the individual experiencing anxiety. A second form of activation may be instigated by depression itself, irrespective of how the depression is precipitated. The Self-Statement and Music induction procedures provide good potential instances of this form of activation, since individuals are specifically requested to try and get into a depressed mood. In the Self-Statement procedure, for example, statements are read containing suggestions of the somatic states characteristic of depression (e.g., Frost et al., 1979). Presumably, the other procedures which involve remembering past emotional experiences (Hypnotic Suggestion, Social and Solitary Recollection, Autobiographical Recall, and Imagery) also elicit depression, which in turn gives rise to maladaptive schemata. Similarly, the sad content of the stories of the Empathy, Experimenter Behavior, and Film procedures give rise to depression and thus to the maladaptive schemata. It is also possible that there is direct activation of these schemata by overlap of their content with that of the elicited memories or the presented stories. Semantic Network Theory One of the more influential classes of theories in cognitive psychology consists of semantic network models of memory. Although there are a number of different

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network theories, they share major features in common (see Johnson-Laird, Herrmann, & Chaffin, 1984). Let us consider the model originally proposed by Anderson and Bower (1973) and subsequently developed by Anderson (1976, 1983). Here, an individual’s knowledge is represented by a set of nodes linked together within a network, such nodes representing perceptual categories, theories, words, and emotions. The links between nodes in this network may vary in strength over time, and the extent of the spread of activation at any time will be dependent on the current strength of the various links. Moreover, only a section of the network is active at any time, with activation spreading from one node to another within this section, and there is a general dampening of activation to prevent it from going out of control. When one node is activated, the activation spreads to other related nodes. Consequently, excitation of the contents of a node can act as a cue for the recall of material that has been previously associated with them. In addition, the spread of activation leads to a general priming (or increase in the resting level of excitation) of related nodes. A number of theorists have proposed that a depressed mood activates the “depression” node, which in turn leads to activation of nodes closely related to it, thereby leading to recall of material previously associated with depression (Bower, 1981; Clark & Teasdale, 1985; Gilligan & Bower, 1984; Teasdale, 1983a, 1983b, 1988). As it is very likely that negative experiences and depressed mood have occurred together more often than positive experiences and depressed mood, strong links should be built in the network between the depression node and nodes that represent negative experiences. Thus, it is expected both that depressed mood will give rise to negative thoughts and vice versa. Negative thoughts can result both directly and indirectly from memories of past negative events. Directly, they may arise through straitforward association with the memories of negative events. Indirectly, they may arise because the memories’ increased accessibility can bias the interpretation of ambiguous events towards the negative, thus influencing predictions about the future toward the pessimistic. On this account, a negative view of the self and the world is again likely to occur in depression, irrespective of whether the depression be naturally occurring or artificially induced. Within the semantic network, emotion, somatic states and negative thoughts are each represented by equivalent nodes which are linked together in the network (see Figure 1). Thus, a mood induction will be successful if it excites any of the types of node (emotion, somatic states, thoughts) that are connected to the appropriate emotion node. The closeness of the exact content of the mood induction procedure to the circumstances surrounding previously experienced emotion is much less important here than in the Schema approach. Further, it seems probable that related emotions will prime each other. It would be expected that once a negative emotion node such as depression is excited, then other related negative emotion nodes will also become excited, leading to the lack of specificity in mood induction observed following some techniques (see Specificity). This contrasts with Oatley and JohnsonLaird’s (1987) proposal that the basic emotions, such as anxiety and sadness, inhibit each other. Fragmentation

Theory

This approach provides an alternative to the spreading-activation semantic network theory. Here, the long-term associative memory

approach of store support-

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ing a person’s knowledge of the world is composed of a large number of rather than of a single network within which each independent fragments, emotion is represented by a solitary node (e.g., see Bruce, 1980; Jones, 1976, 1983, 1984, 1987; Le Voi & Rawles, 1979; Martin, 1984b; Rubin & Wallace, 1989). The fragment account has been incorporated by Broadbent (1983, 1984) into the Maltese Cross model he has advanced as a general framework within which to consider human cognition. Each fragment in memory originates as the encoding, to a variable degree of completeness, of an individual experience. Because the memory store is particulate, rather than forming a single network, the same relating to a mood state) may be element of information (e.g., information represented in a number of independent fragments (see Figure 1). As it is more likely that depressed mood has occurred more frequently with negative events than positive events in the past, there are probably a greater number of fragments with depressed mood state linked to negative items than fragments with depressed mood state linked to positive items. There is also considerable evidence that information corresponding to each element of a memory fragment can act as an effective cue for recalling the remainder of that experience (Jones, 1983). Thus, if a depressed mood occurs, irrespective of whether it occurs naturally or as a result of laboratory induction, it acts as a cue for the retrieval of the remainder of the fragment, which is likely to be negative in nature. Alternatively, if a current experience resembles a previous one (such as one concerned with failure) that is likely to be represented in memory in a fragment in which depression also is represented, the likelihood is that it also will conversely elicit this depressed mood state. Comparison of the Theories The differences among the theories lie not so much in terms of structure as the psychological processes associated with them. A problem for both schema and semantic network models concerns experimental observations of induced moodrelated intrusion errors in recall. Both theories attribute enhanced levels of negative recall in depression to facilitation of all material associated with a depressive schema or node. In contrast, the particulate structure of memory posited by fragmentation theory suggests that facilitation will be restricted to only those individual memory fragments that possess not only appropriate emotional but also appropriate contextual components. The fragmentation theory, unlike the other two, predicts therefore that mood-congruent facilitation of intrusion errors should not occur in a manner analogous to that for correct recall. This prediction has been tested in a recent study (Martin & Clark, in preparation-b) in which a list of positive and negative words was presented to subjects in neutral mood and recalled following mood induction. Contrary to the schema and network theories, but in accord with the fragmentation theory, no increase in negative intrusion errors due to induced depression was observed, although an increase was observed in correct recall of negative words. A futher difficulty for schema and network models concerns their predictions about the effects of mood on perceptual aspects of cognition. In particular, work on word recognition (e.g., see Martin, 1977, 1984a) and on lexical decision times (i.e., latencies for deciding whether or not strings of letters form words) appears to offer the opportunity to distinguish more decisively among the three models

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(Martin, 1984b). By virtue of their fundamental assumption of activation spreading from one node to another (albeit an assumption explicitly rejected by Ratcliff & McKoon, 1981), network theories assert that mood (or personality) should be capable of exerting facilitatory effects upon perception that are similar to those for memory. Similarly, schema theory asserts that perceptual performance should be affected in the same way as memory performance for material that can be assimilated to mood-related schemata. In contrast, memory fragments reside in a long-term associative store that does not interface directly with perceptual systems (Broadbent, 1983, 1984), and thus fragment theory does not predict effects of mood on perception similar to those in memory. In practice, attempts to demonstrate with mood induction the occurrence of perceptual mood-congruency effects analogous to those found in recall have been unsuccessful both with wordrecognition thresholds (Gerrig & Bower, 1982) and with lexical decision times (Clark et al., 1983; Martin, Harrison, & Clark, in preparation). A disadvantage of the semantic network theory, compared with the fragment and schema theories, is the difficulty in explaining why it is possible to think, talk or write about depression without feeling depressed. Presumably, the depression node is active, but somehow it is possible to interrogate one’s academic knowledge on a topic without spreading activation from that node, so that one feels the emotion. This problem does not arise in fragment theory, as it is plausible to assume that academic knowledge of the literature on depression is stored in different fragments from the fragments which contain one’s own personal experiences of depression. Similarly, it is probable that experts on depression have an academic schema containing knowledge about the literature on depression. This is likely to be quite distinct from a depressive self-schema. Kuiper and Olinger (1986), in their self-worth contingency model of depression, propose that nondepressed individuals, whether they are vulnerable to depression or not, have positive self-schemata, whereas mildly depressed individuals have positive and negative self-schemata and the clinically depressed individuals have only negative self-schemata. The self-schema is strong for the nonvulnerable nondepressed and the clinically depressed. In contrast, vulnerable individuals who are either nondepressed or mildly depressed have weak self-schemata. These weak self-schemata are poorly integrated and lack cohesion. Processing of both positive and negative self-referent material is inefficient and inconsistent. If the contents and strength of the self-schema are determining factors in depression, then it follows that the clinically depressed will be most susceptible to the effects of negative mood induction, followed by the mildly depressed, then the vulnerable nondepressed, and finally the nonvulnerable nondepressed. The exact opposite pattern of susceptibility to positive mood induction is predicted. In both positive and negative inductions the effects will be strongest where there is greatest overlap in content between the schema and the induction procedure. In addition, a distinction between episode and vulnerability schematas has been proposed by Kuiper and his colleagues (Kuiper & Olinger, 1986; Kuiper, Olinger, & Macdonald, 1988; Kuiper, Olinger, Macdonald, & Shaw, 1985; Kuiper, Olinger, & Martin, in press). An episode schema refers to the maladaptive cognitive structures that become available only after the onset of a depressive episode. The episode schema is thought to be involved in such tasks as self-referencing judgements on trait words and their subsequent recall. Vulnerability schematas are presumed to play a causal role in the onset of depression. The content of

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vulnerability schemata may include more general beliefs and assumptions ranging from Beck et al.‘s (1979) dysfunctional attitudes to Lewinsohn, Steinmetz, Larson, and Franklin (1981) irrational beliefs as well as general social perceptions. In particular, Kuiper and his colleagues (Kuiper, et al., 1988; Kuiper, Olinger, & Swallow, 1987) suggest that increased public self-consciousness and social anxiety would be vulnerability cognitions, whereas increased private self-consciousness (i.e., self-focused attention) would be a concomitant or episodic cognition. This proposal was not supported by results of a study examining the effectiveness of the Social Recollection induction. All three factors predicted mood shift (Martin et al., 1990). The lack of differentiation among the factors is not surprising given that the three factors themselves were intercorrelated between .3 and .4 in this study, a result which has been commonly observed in other recent studies (see Piliavin & Charing, 1988). Support for a related view (Martin, 1985b; Teasdale, 1988) that higher levels of the personality variable, neuroticism, predispose individuals to depression is supported by a finding of Teasdale and Dent (1987) that recovered depressed patients have significantly elevated neuroticism scores compared to matched controls who had never suffered from depression. PURPOSEOF MOOD INDUCTION As already mentioned, one of the strongest impetuses for work on mood induction comes from the development of cognitive therapy for disorders such as those of depression and anxiety (see Beck, 1976; Beck et al., 1985; Clark & Beck, 1988). It is hoped that mood induction studies will extend our knowledge of depression and anxiety in a way which would allow the development of new treatments and would help refine existing ones, for example, by allowing the isolation of their effective components. Furthermore, they may assist in the indentification of those individuals who are at high risk of clinical mood disorders. For example, those individuals who are more vulnerable to emotional disorders following severe life events may also prove to be those who are more susceptible to the effects of particular mood induction procedures in the laboratory. After many years of neglect, there is also a growing interest in the relation between emotion and cognition in the normal population (e.g., Mandler, 1975; Zajonc, 1984). A greater understanding in this area may lead to advances in many fields varying from personnel selection, where it is often important to assess a person’s likely response to emotional situations, through to counselling, where the existence of normative data would be very valuable. At first sight, it might seem that a simple way of carrying out clinical research is to take a group of patients suffering from a mood disorder and to compare them with a control group (e.g., another class of patients, people who have recovered from a mood disorder, or normal people matched on relevant dimensions). However, in such comparisons there are numerous potentially confounding variables concerning, for example, the presence/nonpresence of drugs, psychotherapy, or institutionalism. Similarly, for research entirely on the normal population a simple method is to divide a subject sample into those who are naturally in the required mood at the time of testing and those who are not. Although these can be valuable experimental designs, they have the drawback of confounding state and trait effects, with the effects of transient mood states potentially masked by those of long-lived personality traits. For example, it is well-established that

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neuroticism and depression are highly correlated in their distributions within both patient populations (Christie 8c Venables, 1973; Costa 8c McCrae, 1980; Lloyd & Lishman, 1975) and normal populations (Martin, 1985b; Martin, Ward, Jc Clark, 1983; Mayo, 1983; Williams, 1981); see also Garber, Miller, and Abramson (1980) and Martin (1985) for reviews. For this reason it is difficult to interpret the results of studies which use this type of between-subjects design, because any effects observed may be attributable not to the subjects’ current mood states but rather to their underlying personalities. The distinction between state and trait provides an important point of divergence between different current cognitive theories of the development and maintenance of clinical depression and other emotional disorders. These theories differ in whether a cognitive predisposition to such a disorder is viewed as an enduring characteristic that is always evident (e.g., Martin, 1985b) or alternatively as a latent characteristic that is only evident under certain circumstances (e.g., Kovacs 8c Beck, 1978; Teasdale, 1983b). I have proposed, for example, that the effects of depression and of neuroticism upon cognition are distinct but interrelated in that, acting in a similar direction, one may reinforce the other. It is hypothesized (Martin, 1985) that a clinical problem is especially likely to result from the combination of a high neuroticism individual (as assessed by the Eysenck Personality Questionnaire) with a mood-depressing circumstance. In addition, mood-induction procedures are more generally of service in resolving theoretical issues concerning emotion and cognition. A good example is provided by work investigating the effects of depression on memory. In this area it is important to separate the effects of mood at encoding from those at retrieval (Martin & Clark, 1986a, 1986b), and mood induction procedures have been instrumental in achieving this. Note that this type of discrimination is not possible if depressed patients are compared with controls, because the patients are likely to bein a depressed mood at both encoding and retrieval, whereas the controls are likely to be in a neutral mood on both occasions. But using mood induction, it has been found both that depressed mood at the time of encoding results in superior learning of negative information (e.g., Bower et al., 1981), and also that depressed mood at the time of retrieval leads to improved recall of negative self-relevant information (e.g., Martin & Clark, in preparation-b; Teasdale & Russell, 1983). This latter finding is particularly important because it appears to rule out simple state-dependent learning as an explanation of all mood effects in memory. That is, it appears to demonstrate that recall may be enhanced even if learning and recall do not share the same distinctive context, as required by simple state dependency (e.g., Bower, 1981; Teasdale 8c Fogarty, 1979). However, it remains entirely possible that a more subtle form of state dependency is operating, as has been advocated by Clark and Teasdale (1982, 1985), Teasdale and Russell (1983), and Teasdale (1983a, 1983b). In this account, the crucial assumption is that negative material, though encoded within the experiment in neutral mood, is likely to have been encoded previously (in earlier encounters) in depressed mood, and that state-dependent facilitation is operating at this extra-experimental level. REFERENCES Alba, J. W., & Hasher, L. (1983). Is memory schematic? Psychological Bulletin, 93, 203-231. Alloy, L. B., Abramson, L. Y., & Viscusi, D. (1981). Induced mood and the illusion of control. Journal of Personality and Social Psychology, 41, 1129-l 140. Alloy, L. B., Hartlage, S., & Abramson, L. Y. (1988). Testing the cognitive-diathesis stress theories of

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693

depression: Issues of research design, conceptualization, and assessment. In L. B. Alloy (Ed.), Cognitive processes in depression (pp. 31-73). New York: The Guilford Press. American Psychological Association. (1981). Ethical principles ofpsychologists. Washington, DC: Author. Anderson, J. R. (1976). Language, memory, and thought. Hillsdale,NJ: Erlbaum. Anderson, J. R. (1983). The architecture of cognition. Cambridge, MA: Harvard University Press. Anderson, J. R., & Bower, G. H. (1973). Human associative memo?. Washington, DC: Winston. Argyle, M. (1987). The psychology of happiness. London: Methuen. Barden, R. C., Garber, J., Duncan, S. W., & Masters, J. C. (1981). Cumulative effects of induced affective states in children: Accentuation, inoculation, and remediation. Journal of Personality and Social Psychology, 40, 750-760. Barden, R. C., Garber, J., Leiman, B., Ford, M. E., & Masters, J. C. (1985). Factors governing the effective remediation of negative affect and its cognitive and behavioural consequences. Journal of Personality and Social Psychology, 49, 1040-1053. Bartlett, F. C. (1932). Remembering. Cambridge, England: Cambridge University Press. Bartlett, J. C., & Santrock, J. W. (1979). Affect-dependent episodic memory in young children. Child Development, 50, 513-518. Bartlett, J. C., Burleson, G., & Santrock, J. W. (1982). Emotional mood and memory in young children. Journal of Experimental Child Psychology, 34, 59-76. Beck, A. T. (1967). Depression: Clinical, experimental, and theoretical aspects. New York: Hoeber. Beck, A. T. (1976). Cognitive therapy and the emotional disorder. New York: American Library. Beck, A. T. (1987). Cognitive models of depression. Journal of Cognitive Psychotherapy, 1, 5-38. Beck, A. T., Emergy, G., & Greenberg, R. L. (1985). Anxiety and phobius: A cognitive perspective. New York: Basic Books. Beck, A. T., & Rush, A. J. (1978). Cognitive approaches to depression and suicide. In G. Serban (Ed.), Cognitive defects in the development of mental illness (pp. 235-257). New York: Brunner Mazel. Beck, A. T., Rush, A. J., Shaw, B. F., & Emery, G. (1979). Cognitive therapy of depression (pp. 291-331). New York: Guilford Press. Beck, A. T., Ward, C. H., Mendelson, M., Hock, J., & Erbaugh, J. (1961). An inventory for measuring depression. Archives of General Psychiatry, 4, 561-571. Berry, D. C., & Broadbent, D. E. (1984). On the relationship between task performance and associated verbalizable knowledge. The Quarterly Journal of Experimental Psychology, 36A, 209-23 1. Bower, G. H. (1981). Mood and memory. American Psychologist, 36, 129-148. Bower, G. H. (1983). Affect and cognition. Philosophical Transactions of the Royal Society of London, B302, 387-402. Bower, G. H., & Cohen, P. R. (1982). Emotional influences in memory and thinking: Data and theory. In M. S. Clark & S. T. Fiske (Eds.), Affect and cognitiopz.Hillsdale, NJ: Erlbaum. Bower, G. H., Gilligan, S. G., & Monteiro, K. P. (1981). Selectivity of learning caused by affective states. Journal of Experimental Psychology: General, 110, 451-473. Bower, G. H., Monteiro, K. P., & Gilligan, S. G. (1978). Emotional mood as a context for learning and recall. Journal of Verbal Learning and Verbal Behavior, 17, 573-585. Brewer, D., Doughtie, E. B., & Lubin, B. (1980). Induction of mood and mood shift. Journal of Clinical Psychology, 36, 215-226. Broadbent, D. E. (1983). The functional approach to memory. Philosophical Transactions of the Royal Society of London, B302, 239-249. Broadbent, D. E. (1984). The Maltese cross: A new simplistic model for memory. Behavioral and Brain Sciences, 7, 55-94. Bruce, D. (1980). Single probes, double probes, and the structure of memory traces. Journal of Experimental Psychology: Human Learning and Memory, 6, 276-292. Buchwald, A. M., Strack, S., & Coyne, J. C. (1981). Demand characteristics and the Velten mood induction procedure. Journal of Consulting and Clinical Psychology, 49, 478479. Bugental, D. B., & Moore, B. S. (1979). Effects of induced moods on voice affect. Developllentul Psychology, 15, 664-665. Chartier, G. M., & Ranieri, D. J. (1989). Comparison of two mood induction procedures. Cognitive Tkapy and Research, 13, 275-282. Christie, M. J., & Venables, P. H. (1973). Mood changes in relation to age, EPI scores, time and day. British Journal of Social and Clinical Psychology, 12, 61-72. Clark, D. M. (1983a). differential effects of mood on the accessibility of positive and negative information. Unpublished doctoral dissertation, University of Oxford.

694

M. Martin

Clark, D. M. (1983b). On the induction of depressed mood in the laboratory: Evaluation and comparison of the Velten and musical procedures. Advances in Behavior Research and Therapy, 5, 27-49. Clark, D. M. (1986a). A cognitive approach to panic. Behaviour, Research and Therapy, 4, 461-470. Clark, D. M. (1986b). Cognitive therapy for anxiety. Behuviourul Psychotherapy, 14, 283-294. Clark, D. M., & Beck, A. T. (1988). Cognitive approaches. In C. Last & M. Hersen (Eds.), Handbook of anxiety disorders (pp. 362-385). New York: Pergamon. Clark, D. M., & Teasdale, J. D. (1982). Diurnal variation in clinical depression and accessibility of memories of positive and negative experiences. Journal of Abnormal Psychology, 91, 87-95. Clark, D. M., & Teasdale, J. D. (1985). Constraints of the effects of mood on memory. Journal of Personality and Social Psychology, 48, 1595-1608. Clark, D. M., Teasdale, J. D., Broadbent, D. E., & Martin, M. (1983). Effect of mood on lexical decisions. Bulletin of the Psychonomic Society, 21, 175-178. Coleman, R. E. (1975). Manipulation of self-esteem as a determinant of mood of elated and depressed women. Journal of Abnormal Psychology, 84, 693-700. Costa, P. T., & McCrae, R. R. (1980). Influence of extraversion and neuroticism on subjective well-being: Happy and unhappy people. Journal of Personality and Social Psychology, 38, 668-678. Crandall, J. E. (1975). A scale for Social Interest. Journal of Individual Psychology, 31, 187-195. Dobson, K. S. (1985). The relationship between anxiety and depression. Clinical Psychology Review, 5, 307-324. Ekman, P., Friesen, W. V., & Ellsworth, P. (1971). Emotion in the human face: Guidelines for research and integration of findings. New York: Pergamon Press. Ellis, A. (1962). Reason and emotion to psychotherapy. New York: Lyle Stuart Press. Evans, M. D., & Hollon, S. D. (1988). Patterns of personal and causal inference: Implication for the cognitive therapy of depression. In L. B. Alloy (Ed.), Cognitive processes in depression (pp. 344-377). New York: The Guilford Press. Fenigstein, A., Scheier, M. F., & Buss, A. H. (1975). Public and private self-consciousness: Assessment and theory. Journal of Consulting and Clinical Psychology, 43, 522-527. Frost, R. O., Goolkasian, G. A., Ely, R. J., & Blanchard, F. A. (1982). Depression, restraint, and eating behavior. Behaviour Research and Thera$y, 20, 113-123. Frost, R. 0.. Graf, M., & Becker, J. (1979). Self-devaluation and depressed mood. Journal of Consulting and Clinical Psychology, 47, 958-962. Frost, R. O., & Green, M. L. (1982). Duration and post-experimental removal of Velten mood induction procedure effects. Personality and Social Psychology Bulletin, 8, 341-347. Garber, J., Miller, S. M., & Abramson, L. Y. (1980). On the distinction between anxiety and depression: Perceived control, certainty and probability of goal attainment. In J. Garber & M. E. 0. Seligman (Eds.), Human helplessness: Theory and applications (pp. 131-169). London: Academic Press. Gerrig, R. J., & Bower, G. H. (1982). Emotional influences on word recognition. Bulletin of the Psychonomic Society, 19, 197-200. Gilligan, S. G., & Bower, G. H. (1984). Cognitive consequences of emotional arousal. In C. E. Hard, J. Kagan, & R. B. Zajonc (Eds.) Emotions, cognition, and behaviour. Cambridge, England: Cambridge University Press. Goldberg, D., & Huxley, P. (1980). Mental illness in the community. London: Tavistock. Goodwin, A. M., & Williams, J. M. G. (1982). Mood induction research its implications for clinical depression. Behuviour Research and Therapy, 20, 373-382. Gouaux, C., & Gouaux, S. M. (1971). The influence of induced affective states on the effectiveness of social and non-social reinforcers in an instrumental learning task. Psychonomic Science, 22, 34 l-343. Greenberg, M. S., Vazquez, C. V., & Alloy, L. B. (1988). Depression versus anxiety: Differences in selfand other-schemata. In L. B. Alloy (Ed.), Cognitive pocesses in depression. New York: The Guilford Press. Hale, W. D., & Strickland, B. R. (1976). Induction of mood states and their effect on cognitive and social behaviours. Journul of Consulting and Clinical Psychology, 44, 155. Hammen, C. (1988). Depression and cognitions about personal stressful life events. In L. B. Alloy (Ed.), Cognitive p-ocesses in akpression (pp. 77-108). New York: The Guilford Press. Hammen, C., Marks, T., Mayol, A., & deMayo, R. (1985). Depressive self-schemas, life stress and vulnerability to depression. Journal of Abnormal Psychology, 94, 308-319. Haney, J. N., & Euse, F. J. (1976). Skin conductance and heart rate responses to neutral, positive and negative imagery: Implications for covert behavior therapy procedures. Behavior Therapy, 7, 494 503.

Induction of Mood

695

Herman, C. P., & Polivy, J. (1975). Anxiety, restraint, and eating behavior. Journal of Abnormal Psychology, 84, 666-672. Holzman, P. S., & Ronsey, C. (1966). The voice as a percept. Journal of Personality and Social Psychology, 4, 78-86. Isen, A. M., Clark, M., Shalker, T. E., & Karp, L. (1978). Affect, accessibility of material in memory, and behavior: A cognitive loop? Journal of Personality and Social Psychology, 36, 11-12. Isen, A. M., & Gorgolione, J. M. (1983). Some specific effects of four affect-induction procedures. Personality and Social Psychology Bulletin, 9, 136-143. Johnson, E. J., & Tversky, A. (1983). Affect, generalization, and the perception of risk. Journal of Persona& and Social Psychology, 45, 20-3 1. Johnson-Laird, P. N., Hermann, D. J., & Chaffin, R. (1984). Only connections: A critique of semantic networks. Psychological Bulletin, 96, 292-3 15. Jones, G. V. (1976). A fragmentation hypothesis of memory: Cued recall of pictures and of sequential position. Journal of Experimental Psychology: General, 105, 277-293. Jones, G. V. (1983). Structure of the recall process. Philosophical Transactions of the Royal Society of London, B302, 373-385. Jones, G. V. (1984). Fragment and schema models for recall. Memory and Cognition, 12, 250-263. Jones, G. V. (1987). Independence and exclusivity among psychological processes: Implications for the structure of recall. Psychological Review, 94, 229-235. Kovaks, M., & Beck, A. T. (1978). Maladaptive cognitive structures in depression. American Journal of Psychiatry, 135, 525-533. Kuiper, N. A., & Olinger, L. J. (1986). Dysfunctional attitudes and self-worth contingency model of depression. Advances in Cognitive-Behavzoural Research and Therapy, 5, 115-142. Kuiper, N. A., Olinger, L. J., & Macdonald, M. R. (1988). Vulnerability and episodic cognitions in a self-worth contingency model of depression. In L. B. Alloy (Ed.), Cognitive processes in depression (pp. 289-309). New York: Guilford Press. Kuiper, N. A., Olinger, L. J., Macdonald, M. R., & Shaw, B. F. (1985). Self-schema processing of depressed and non-depressed content: The effect of vulnerability on depression. Social Cognition, 5, 77-93. Kuiper, N. A., Olinger, L. J., & Martin, R. A. (in press). Are cognitive approaches to depression useful? In C. D. McCann & N. S. Endler (Eds.), Depression: New directions in theory, research and practice. Toronto: Wall and Thompson. Kuiper, N. A., Olinger, L. J., & Swallow, S. R. (1987). Dysfunctional attitudes, mild depression views of self, self-consciousness, and social perceptions. Motivation and Emotion, 11,37940 1. Laird, J., & Crosby, M. (1974). Individual differences in self-attribution of emotion. In H. London & R. Nisbett (Eds.), Thought and feeling: The cognitive alteration offeeling states (pp. 44-59). Chicago: Aldine. Laird, J. D., Wagener, J. J., Halal, M., & Szegda, M. (1982). Remembering what you feel: Effects of emotion on memory. Journal of Personality and Social Psychology, 42, 646-657. Le Voi, M. E., & Rawles, R. E. (1979). Backward recognition failure: A case of retrieval success. Quarterly Journal of Experimental Psychology, 31, 609-620. Lewinsohn, P. M., Steinmetz, J. L., Larson, D. W., & Franklin, J. (1981). Depression-related cognitions: Antecedent or consequence? Journal of Abnormal Psychology, 90, 2 13-2 19. Lloyd, G. G., & Lishman, W. A. (1975). Effect of depression on the speed of recall of pleasant and unpleasant experiences. Psychological Medicine, 5, 173-180. Lubin, B. (1967). Manual for the depession adjective checklists. San Diego, CA: Educational and Industrial Testing Service. Mandler, G. (1975). Mind and emotion. New York: Wiley. Marston, A., Hart, J., Hileman, C., & Faunce, W. (1984). Toward the laboratory study of sadness and crying. American Journal of Psychology, 97, 127-131. Martin, M. (1977). Reading while listening: A linear model of selective attention. Journal of Verbal Learning and Verbal Behaviour, 16, 453463. Martin, M. (1984a). Attentional constraints in the detection of brief auditory targets: Temporally fine-grained processing in speech perception. Journal of Experimental Psychology: Human Perception and Performance, 10,794-811. Martin, M. (1984b). Memory and mood. The Behavioral and Brain Sciences, 7, 75. Martin, M. (1985a). Induction of depressed mood in the laboratory. American Journal of Psychology, 98, 635639. Martin, M. (1985b). Neuroticism as predisposition toward depression: A cognitive mechanism. Personality and Individual Differences, 6, 353-365.

696

M. Murtin

Martin, M. (1990). Cognitive basis of anxiety. In P. J. D. Drenth, J. A. Sergent, & R. J. Takens (Eds.), European perspectives in psychology (Vol. 2, pp. 269-283). New York: John Wiley & Sons. Martin, M., Argyle, M., & Crossland, J. (1990). A trouble shared is a trouble halved: Social and solitary, positive and negative mood induction. Manuscript submitted for publication. Martin, M., & Clark, D. M. (1986a). On the response bias explanation of selective memory effects in depression. Cognitive Therapy and Research, 10, 267-270. Martin, M., & Clark, D. M. (1986b). Selective memory, depression, and response bias: An unbiased response. Cognitive Therapy and Research, 10, 275-278. Martin, M., & Clark, D. M. (in preparation-a). Neuroticism as predictor of mood shft following a failure experience. Martin, M., & Clark, D. M. (in preparation-b). Recall as a function of self-reference in depressed mood. Martin, M., Harrison, S., & Clark, D. M. (in preparation). Depression and the perceptual processing of positive and negative personality znformution. Martin, M., Ward, J. C., & Clark, D. M. (1983). Neuroticism and the recall of positive and negative personality information. Behaviour Research W Therapy, 21, 495-503. Masters, J. C., Barden, R. C., & Ford, M. E. (1979). Affective states, expressive behavior, and learning in children. Journal of Personality and Social Psychology, 37, 380-390. Mayer, J. D. (1986). How mood influences cognition. In N. E. Sharkey (Ed.), Advances in cognitive science (Vol. 1). Chichester: Ellis Norwood. Mayo, P. T. (1983). Personality traits and the retrieval of positive and negative memories. Personality and Individual Differences, 4, 465-47 1. Moore, B., Underwood, B., & Rosenhan, D. L. (1973). Affect and altruism. Developmental Psychology, 8, 99-104. Mosak, H. H., & Dreikurs, R. (1973). Adlerian psychotherapy. In R. Corsini (Ed.), Current psychotherapies. Hasca, IL: FE Peacock. Natale, M. (1977a). Effects of induced elation-depression on speech in the internal-external locus of control. Journal of Consulting and Clinical Psychology, 45, 45-52. Natale, M. (1977b). Induction of mood states and their effects on gaze behaviours. Journal of Consulting and Clinical Psychology, 45, 560. Natale, M. (1978). Effect of induced elation and depression on internal-external locus of control. Journal of Psychology, 100, 3 15-32 1. Natale, M., & Gur, R. (1980). Differential hemispheric lateralization of positive and negative emotions. International Neuropsychological Sociely Bulletin, March, 2 1. Natale, M., & Hantas, M. (1982). Effect of temporary mood states on selective memory about the self. Journal of Personality and Social Psychology, 42, 927-934. Oatley, K., & Johnson-Laird, P. N. (1987). Towards a cognitive theory of emotions. Cognition and Emotion, 1, 29-50. Orton, I. K., Beiman, I., La Pointe, K., & Lankford, A. (1983). Induced states of anxiety and depression: Effects on self-reported affect and tonic psychophysiological response. Cognitive Therapy and Research, 7, 233-244. Pignatiello, M. F., Camp, C. J., & Rasar, L. A. (1986). Muscial mood induction: An alternative to the Velten technique. Journal of Abnormal Psychology, 95, 295-297. Piliavin, J. A., & Charing, H. (1988). What is the factorial structure of the private and public self-conscious scales? Personality and Social Psychology Bulletin, 14, 587-595. Polivy, J. (1981). On the induction of emotion in the laboratory: Discrete moods or multiple affect states? Journal of Personality and Social Psychology, 41, 803-817. Polivy, J., & Doyle, C. (1980). Laboratory induction of mood states through the reading of self-referent mood statements: Affective changes or demand characteristics? Journal of Abnormal Psychology, 89, 286-290. Ratcliff, R., & McKoon, G. (1981). Does activation really spread? Psychological Review, 88, 454-462. Rubin, D. C., & Wallace, W. T. (1989). Rhyme and reason: Analyses of dual retrieval cues. Journal of Experimental Psychology: Learning, Memory, and Cognition, 15, 698-709. Schacter, S. (1959). The psychology of affiliation. Stanford, CA: Stanford University Press. Scheier, M. F., & Carver, C. S. (1977). Self-focused attention and the experience of emotion: Attraction, repulsion, elation, and depression. Journal of Personality and Social Psychology, 35, 625-636. Sirota, A. D., & Schwartz, G. E. (1982). Facial muscle patterning and lateralization during elation and depression imagery. Journal of Abnormal Psychology, 91, 25-34. Spielberger, C. D., Gorsuch, R. L., & Lushene, R. E. (1970). Manual for the state-trait anxiety inventory.

Induction

of Mood

697

Palo Alto, CA: Consulting Psychologists Press. Spitzer, R. L., Endicott, J., & Robins, E. (1978). Research diagnostic criteria for a selected group of functional disorders. New York: Biometric Research Unit, New York State Psychiatric Institute. Strickland, B. P., Hale, W. D., & Anderson, L. K. (1975). Effect of induced mood states on activity and self reported affect. Journal of Consulting and Clinical Psychology, 43, 587. Sutherland, G., Newman, B., & Rachman, S. (1982). Experimental investigations of the relations between mood and intensive unwanted cognitions. British Journal of Medical Psychology, 55, 127-138. Sutton, L. (1985). Effects of d ep essed mood on remembering and perceiving pleasant and unpleasant material. Unpublished master’s thesis, University of Oxford, Oxford, England. Teasdale, J. D. (1983a). Affect and accessibility. Philosophical Transactions of the Royal Society of London, Series B, 302, 403-412. Teasdale, J. D. (1983b). Negative thinking in depression: Cause, effect, or reciprocal relationship? Advances in Behavaour, Research and Therapy, 5, 3-25. Teasdale, J. D. (1988). Cognitive vulnerability to persistent depression. Cognition and Emotion, 2, 247-274. Teasdale, J. D., & Bancroft, J. (1977). Manipulation of thought content as a determinant of mood and corrugator electromyographic activity in depressed patients. Journal of Abnormal Psychology, 86, 235-241. Teasdale, J. D., & Dent, J. (1987). Cognitive vulnerability to depression: an investigation of two hypotheses. British Journal of Clinical Psychology, 26, 113-126. Teasdale, J. D., & Fogarty, S. (1979). Differential effects of induced mood on retrieval of pleasant and unpleasant events from episodic memory. Journal of Abnormal Psychology, 88, 248-257. Teasdale, J. D., Fogarty, S. J., & Williams, J. M. G. (1980). Speech rate as a measure of short-term variation in depression. British Journal of Social and Clinical Psychology, 19, 271-298. Teasdale, J. D., & Russell, M. L. (1983). Differential effects of induced mood on the recall of positive, negative and neutral words. British Journal of Clznical Psychology, 22, 163-171. Teasdale, J. D., & Spencer, P. (1984). Induced mood and estimates of past success. British Journal of Clinical Psychology, 23, 149-150. Thompson, W. G., Cowan, C. L., & Rosenhan, D. L. (1980). Focus of attention mediates the impact of negative affect on altruism. Journal of Personality and Social Psychology, 38, 291-300. Velten, E. (1968). A laboratory task for induction of mood states. Behaviour Research and Therapy, 6, 473-482. Weitzenhoffer, A. M., & Hilgard, E. R. (1962). Stanford hypnotic suggestibilityscale, Form C. Palo Alto, CA: Consulting Psychologists Press. Williams, D. G. (1981). Personality and mood: State-trait relationships. Personality and Individual Dtfferences, 2, 303-309. Williams, J. M. G. (1980). Generalization in the effects of a mood induction procedure. Behaviour Research and Therapy, 18, 565-572. Wilner, P. (1985). Depression: A psychobiological synthesis. New York: John Wiley. Wilson, A. R., & Krane, R. V. (1980). Changes in self esteem and its effects on symptoms of depression. Cognitive Therapy and Research, 4, 419-421. Wright, J., & Mischel, W. (1982). Influence of affect on cognitive social learning variables. Journal of Personality and Social Psychology, 43, 90 l-9 14. Zajonc, R. B. (1984). On the primacy of affect. American Psychologist, 39, 117-123.

Received May 2, 1989 Accepted January 2, 1990