Comparing visual and auditory presentation for the modification of interpretation bias

J. Behav. Ther. & Exp. Psychiat. 40 (2009) 558–570

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Journal of Behavior Therapy and Experimental Psychiatry journal homepage: www.elsevier.com/locate/jbtep

Comparing visual and auditory presentation for the modification of interpretation bias Helen Standage*, Chris Ashwin, Elaine Fox University of Essex, Colchester, UK

a r t i c l e i n f o

a b s t r a c t

Article history: Received 10 December 2008 Received in revised form 23 July 2009 Accepted 28 July 2009

This experiment compares the effects of visual vs. auditory presentation of cognitive bias modification (CBM) training scenarios upon interpretation style and emotional vulnerability. For both modalities, negative, but not positive interpretation biases were successfully induced relative to a baseline. Mood declined for the auditory but not the visual group throughout the CBM procedure, irrespective of the valence of the CBM condition. This deterioration in mood raises an important methodological issue and indicates that the increased testing time brought about by auditory compared to visual presentation needs to be addressed. The CBM procedures did not influence emotional vulnerability as assessed by behavioural measures, but counter-to-prediction, CBM procedures did increase self-reported depression vulnerability for the positive but not negative CBM condition. Ó 2009 Elsevier Ltd. All rights reserved.

Keywords: Cognitive bias modification Interpretative bias Causality Anxiety

1. Introduction The cognitive bias modification (CBM) paradigm experimentally modifies cognitive biases, which in turn causally influence emotional vulnerability (Hirsch, Mathews, & Clark, 2007; Holmes, Lang, & Shah, 2009; Mackintosh, Mathews, Yiend, Ridgeway, & Cook, 2006; Murphy, Hirsch, Mathews, Smith, & Clark, 2007). Thus CBM has stimulated both theoretical and therapeutic interest. However, on a more practical level, little attention has been given to the most effective means of CBM administration. With respect to scenario-based CBM, presentation modality has been at times visual; text-based scenarios

* Corresponding author. Department of Psychology, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, UK. Tel.: þ44 (0)1206 874179; fax: þ44 (0)1206 873 801. E-mail address: [email protected] (H. Standage). 0005-7916/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbtep.2009.07.006

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read by participants (e.g., Mathews & Mackintosh, 2000; Salemink, van den Hout, & Kindt, 2007). Or the presentation modality has been auditory (e.g., Hirsch et al., 2007; Holmes et al., 2009) To date, no rigorous comparison has been made between the two presentation modalities. The primary purpose of this study was to examine the efficacy of CBM with visual vs. auditory presentation of CBM material. The Dual Coding Theory (Paivio, 1971, 1986) proposes that visual and verbal information are processed independently in two distinct channels with each channel having a limited cognitive capacity. Consistent with Dual Coding Theory is the ‘‘Modality Effect’’ or ‘‘Multimedia Learning Effect’’ (Mayer, 2001) which posits that learning performance is enhanced when instructional material is presented in dual modalities (e.g., pictures accompanied with an auditory rather than written narrative). Bi-modal presentation of material avoids overwhelming any single sensory processing channel. Stimulation of multiple sensory processing channels is thought to optimise learning performance because each processing channel operates concurrently yet independently without cross-channel interference. Further corroborating support for the Dual Coding Theory and Modality Effect comes from the model of Working Memory. This model includes two domain-specific processing ‘‘slave’’ systems: the visuo-spatial sketch-pad and phonological loop (Baddeley & Hitch, 1974). The distinction between the visual and phonological processing stores is based on findings from dual-task paradigms. Performance on simultaneous verbal and visual tasks is not compromised. Yet performance on simultaneous tasks sharing a single perceptual domain deteriorates compared to performance on each task undertaken individually (Baddeley & Andrade, 2000). These findings suggest that visual and verbal tasks resource two discrete cognitive abilities that operate in synchrony without reciprocal disruption. The implication is that the sum of exploiting both verbal and visual cognitive resources for a common task should augment performance on such a task (i.e., the Modality Effect). With respect to scenario-based CBM, typically, participants are requested to imagine the scenarios described. Previous research demonstrates that learning of verbal information is enhanced when paired with a visual image, and whether the visual image is perceived or imagined is irrespective to the learning outcome (Anderson & Bower, 1973). Likewise, research with PET scans and fMRI have shown that similar brain areas are activated for imagined and perceived events (Ganis, Thompson, & Kosslyn, 2004; Kosslyn, Thompson, & Alpert, 1997). A final point to mention is that reading is a visual task and interferes with visual imaging (Brooks, 1967, 1970; Unnava, Agarwal, & Haugtvedt, 1996). Based on the research and theory outlined above, the most appropriate presentation modality to optimise the effects of scenario-based CBM would be auditory, complemented by visual imagery of the scenarios. This method of auditory presentation combined with visual imaging of CBM scenarios has been used by Holmes et al. and reported to be more successful than auditory presentation without the visual imagery component (Holmes et al., 2009; Holmes & Mathews, 2005; Holmes, Mathews, Dalgleish, & Mackintosh, 2006). In sum, the evidence suggests that auditory presentation of CBM materials should increase the ‘‘training’’ effect of CBM scenarios, as visual presentation involving reading would interfere with the visual imaging of CBM scenarios. However, this question has yet to be empirically tested within the CBM domain. Furthermore, auditory as opposed to visual presentation of CBM material, is less convenient to administer. This is because the speed of presentation cannot be self-paced when using an auditory modality, which often results in prolonging the CBM procedure compared to visually presented scenarios (particularly for those who are quick readers). Given these administrative limitations, the beneficial ‘‘training’’ effects of auditory over visual CBM needs to be clearly demonstrated. A further important feature of the current study is the use of a baseline measure of interpretation bias, which has not been used in many interpretative CBM studies. A baseline measure of bias is necessary in order to establish the extent to which positive and negative CBM procedures are effective. Only three previous studies have reported a baseline measure of cognitive bias when both positive and negative conditions have been used. Experiment 3 from Mathews and Mackintosh (2000) and Experiment 4 from Grey and Mathews (2000) both measured baseline bias by using participants who had received no training and comparing them with participants from other experiments who had received valenced training. The results from each experiment were contradictory. Mathews and Mackintosh (2000) found that compared to a baseline measure, both positive and negative bias induction had equivalent but opposing effects. However, Grey and Mathews (2000) reported that compared to their baseline condition only negative CBM was effective. This efficacy of negative over positive CBM was also reported by

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Holmes and Mathews (2005, Experiment 2) who used a superior within-subjects design to test for changes in interpretative bias from pre to post-CBM. The present study also uses the more rigorous, within-subject design, to measure interpretation bias in the same group of participants both before and after the CBM manipulation. A replication of the findings of Holmes and Mathews is necessary, as the question of symmetry between positive and negative induction is important in terms of evaluating the clinical potential of CBM. For instance, if negative training is predominantly driving the modification of bias, then the clinical utility of CBM would be undermined. It is therefore important to establish that the positive interpretation CBM procedures are having an impact. The present study used a CBM paradigm that presented social training scenarios and a test of interpretation bias both before and after training. All materials were taken from Mathews and Mackintosh (2000) and presented either visually or aurally. With respect to emotional vulnerability, social training scenarios have been found to influence anticipated anxiety (Hirsch et al., 2007; Murphy et al., 2007) and also affect susceptibility to mood induction procedures (Holmes et al., 2009). Although important findings, these measures of emotional vulnerability are dependent on self-report alone (but see Hirsch, Hayes, & Mathews, 2009). The impact that social scenario-based CBM has on more objective indices of anxiety, such as behaviour during, for example a speech performance, is as yet unknown. The current study intends to address this void by including a stress task whereby participants have to give a speech into a camera. The purpose of the stress task was to test whether positive CBM can safeguard participants’ mood states, whilst undergoing a stressful experience, relative to negative CBM. Clear demonstrations that positive CBM can serve to protect mood state, when challenged by a stressful circumstance, are necessary if CBM is to be considered as a therapeutic tool. Behavioural signs of anxiety, together with self-report measures were recorded. 1.1. Experimental hypotheses The hypotheses of the present study were: (1) the induction of interpretation biases will be greater with auditory compared to visual presentation of CBM material, (2) based on the findings from Grey and Mathews (2000, Experiment 4) and Holmes and Mathews (2005, Experiment 2) negative CBM will be more effective than positive CBM and (3) positive CBM relative to negative CBM will reduce emotional vulnerability. 2. Method 2.1. Participants Forty-eight first year undergraduates took part in this study, with a gender distribution of 38 females and 10 males. The age range was 18–56 years with a mean of 22.08 years. They were drawn from a population of 139 students on an introductory Psychology course who all completed the Fear of Negative Evaluation Scale (FNE) (Watson & Friend, 1969). The mean (standard deviation) FNE score of the 139 undergraduates was 16.27 (6.57). Given that half of the participants were to receive negative CBM and all participants would be required to undergo the stress task of giving a speech into a camera, it was considered inappropriate to subject high-anxious participants to the experimental procedure. As such, the selection criteria for our sample was half a standard deviation above the introductory Psychology course population mean and one and a half standard deviations below the mean, as opposed to one standard deviation either side of the mean. This resulted in all participants’ FNE scores falling within a window of 7 and 19 points. All participants had normal or corrected-to-normal vision and hearing, and no history of psychiatric illness. Participants were given course credits or paid a small sum of money for their participation. The participants were assigned using pseudo-randomisation to four equal groups, with two groups trained using the auditory modality to have either a negative bias or a positive bias. The other two groups were trained using the visual modality in either a positive or negative direction. Before testing, one-way ANOVA’s showed that the four groups did not differ on FNE scores, state anxiety, state depression, cognitive bias, age or gender distribution (see Table 1).

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Table 1 Mean (standard deviation) of participants’ characteristics before CBM induction. Positive Visual Characteristic Age FNE State depression State anxiety Similarity ratings of positive sentences Similarity ratings of negative sentences Gender

24.75 12.92 7.58 10.25 2.81

(8.91) (4.94) (4.48) (6.20) (.440)

2.07 (.371) 2m vs. 10f

Negative Auditory

Visual

23.33 13.17 7.67 11.42 2.45

19.33 12.50 9.83 12.17 2.65

(10.74) (4.20) (4.70) (6.00) (.427)

2.18 (.325) 4m vs. 8f

F(3,47)

p

(4.60) (4.05) (4.97) (4.54) (.440)

1.28 0.28 1.39 0.96 1.87

>.05 >.05 >.05 >.05 >.05

2.20 (.405)

1.63

>.05

0.86

>.05

Auditory (2.23) (3.34) (6.63) (8.00) (.500)

2.40 (.402) 1m vs. 11f

20.92 14.00 5.75 8.08 2.44

3m vs. 9f

2.2. Materials The stimuli were based on those devised by Mathews and Mackintosh (2000), with some modifications.1 2.2.1. Training items A training scenario consisted of 3 lines of text presented as one unified paragraph. The social descriptions were identical for both the positive and negative training conditions, except for the final word, which defined the valence of what was a previously an emotionally ambiguous scenario. An example of a training item is as follows: ‘‘Your partner asks you to go to an anniversary dinner that their company is holding. You have not met any of their work colleagues before. Getting ready to go, you think that the new people you will meet will find you friendly/boring’’ A comprehension question followed the training scenario and required a yes/no answer. For the response to the comprehension question, buttons labelled as ‘‘YES’’ and ‘‘NO’’ appeared on the computer screen, which the participants were required to click using the mouse. For example, the comprehension question below corresponds to the scenario quoted above. ‘‘Will you be liked by your new acquaintances?’’ Yes/No There were 2 practice training items and 8 blocks of 10 training trials. The order of presentation of the trials within each block was randomised as were the blocks themselves. 2.2.2. Test items and recognition sentences The test items consisted of a title followed by three lines of text with the final word preserving the ambiguity of the scenario. The comprehension questions that accompanied each test scenario were also neutrally toned. An example of a test scenario with its accompanying comprehension question is as follows: ‘‘The Wedding Reception’’ ‘‘Your friend asks you to give a speech at her wedding reception. You prepare some remarks and when the time comes, get to your feet. As you speak, you notice some people in the audience start to laugh’’ ‘‘Did you stand up to speak?’’ Yes/No

1 After publication of the 2000 paper, Mathews and Mackintosh refined their pool of CBM training scenarios by excluding the least effective scenarios and replacing them with new and improved scenarios. The present study used the updated pool of scenarios from Mathews and Mackintosh.

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There were 4 recognition sentences pertaining to each test scenario, two positively valenced and two negatively valenced. Examples of the recognition sentences corresponding to the ‘‘Wedding Reception’’ test scenario are given below: The Wedding Reception As you speak, people in the As you speak, people in the As you speak, people in the As you speak, people in the

audience audience audience audience

laugh appreciatively. find your efforts laughable. applaud your comments. start to yawn.

For the response to the sentence recognition task, all participants were presented on the screen with four buttons labelled as ‘‘very different’’, ‘‘fairly different’’, ‘‘fairly similar’’ and ‘‘very similar’’ which represented a 4-point scale ranging from 1to 4 respectively. There were 10 ambiguous test scenarios and 4 recognition sentences to each test scenario. The order of presentation of the test scenarios was randomised for each participant. The recognition sentences were grouped into their respective sets of 4 and then each set was randomised, as was the order of presentation of the 4 sentences within each set. There were 2 administrations of the testing aspect of the experiment, once before the training items and then subsequent to training. 2.2.3. Visual analogue mood scales To assess current mood state two visual analogue mood scales (VAMS) were presented on the computer screen at various points throughout the experiment to all participants (instructions were either written or aural dependent upon group assignment). As with MacLeod, Rutherford, Campbell, Ebsworthy, and Holker (2002) each scale consisted of a 15 cm horizontal line with a 30-point scale. The terminal labels on one scale were relaxed and anxious and this was referred to as the anxiety scale. The terminal labels of the other scale were happy and depressed and this scale was referred to as the depression scale. Higher scores indicate a higher negative mood state. 2.3. Apparatus The stimuli were presented via an Apple Macintosh iMac (twenty inch two Giga Hertz core duo one Gigabite sd ram) using Supercard version 4.5 software. Sennheiser HD 212Pro headphones were used for the auditory presentation of the stimuli. The stimuli for the auditory group were recorded using sound studio software. The voice was spoken in a neutral expression without emotional intonation, and the sound files were not digitally edited in any way. A Sony handicam DCR-TRV 900 E PAL was used to record each participant’s speech, and footage was imported into iMovie on an Apple Macintosh iMac. 2.4. Procedure All participants were tested individually. Half the participants heard the stimuli and instructions via headphones, the remaining half read the instructions and stimuli from the computer screen. All participants used the mouse to make their responses. Participants first recorded their state anxiety and state depression using the two VAMS. Next participants were presented with two practice scenarios. The instructions advised participants, when reading/listening to these scenarios, to imagine themselves as the central character in the social situation.2 Having read/listened to the practice scenario, a comprehension question was heard after a one second pause for the participants in the auditory condition, and for those participants in the visual presentation group, they clicked on a continue button in order for the comprehension question to appear. There was no time limit to answer the comprehension question and feedback was given for both correct and incorrect answers. After a one second delay the next practice scenario automatically began.

2 An assumption is made that participants use visual rather than auditory, olfactory, gustatory, kinaesthetic or cutaneous imagery during scenario-based CBM. This is based on research showing visual imagery to be the dominant imaging modality (Brower, 1947; Intons-Peterson, 1980; White, Ashton, & Brown, 1977).

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All participants following the practice were presented with the 10 ambiguous test scenarios. The procedure for the test scenarios was the same as that of the practice scenarios. On completion of the test scenarios, subjects were given a speed of comprehension test for 2 min that served as an irrelevant filler task. This involved clicking on a ‘‘true’’ or ‘‘false’’ button in response to a mixture of short, true or false statements e.g., ‘‘rats have teeth.’’ Next the participants’ read/heard the 40 recognition sentences whereby they were instructed to rate how similar each sentence was to its corresponding test scenario. The sentences were presented individually and participants were asked to rate each sentence independent of all others. A second set of VAMS was completed before participants were presented with either 80 negative or positive training scenarios depending upon group allocation. The instructions and procedure for completing the training items was identical to that of the test and practice items. A third set of VAMS was undertaken and then the test aspect of the experiment was re-administered (using the same stimuli as the first test). There was a fourth set of VAMS followed by a break lasting 4 min (Stern, Ray, & Quigley, 2001). At the end of the break participants completed a fifth set of VAMS before being informed of a requirement to give a 4-min speech into a camera. A sixth set of VAMS was completed immediately after receiving this information. Participants were reminded that they could leave the experiment at any time. They were then given the topic of their talk: ‘‘The advantages and disadvantages of the death penalty’’ and told that they had a minute and a half to prepare. Participants were required to stand in front of a camera and speak for 4 min. On completion of the speech, a final set of VAMS was taken plus a self-rating of global speech performance. Participants were debriefed and offered the opportunity to watch a comedy sketch before leaving in order to eliminate any residual negative effects of the experimental training. 3. Results 3.1. Recognition ratings 3.1.1. Cognitive bias A four-way mixed design Analysis of Variance was performed with CBM Group (positive vs. negative) and Modality (visual vs. auditory) as the between subject factors and Sentence Valence (positive vs. negative) and Time (before vs. after) as within-subject factors. The dependent variable was the rating of how similar the recognition sentences were to the test items, with a higher rating indicating greater similarity. The analysis revealed a main effect of Sentence Valence [F(1,44) ¼ 18.24, p < .001, h2p ¼ 0.29] with similarity ratings for positively valenced sentences [2.59 (0.43)] being higher than similarity ratings for negatively valenced sentences [2.25 (0.38)]. There was a main effect of Modality [F(1,44) ¼ 4.68, p ¼ .036, h2p ¼ 0.09], showing that the visual group [2.50 (0.24)] was more likely than the auditory group [2.33 (0.28)] to rate sentences as similar to the test scenarios. There was a significant Sentence Valence  CBM Group interaction [F(1,44) ¼ 5.34, p < .05, h2p ¼ 0.11] which was further qualified by a Sentence Valence  CBM Group  Time interaction [F(1,44) ¼ 4.74, p < .05, h2p ¼ 0.10]. All other main effects and interactions were non-significant (all p > .05). The significant Sentence Valence  CBM Group  Time interaction was decomposed by performing two further two-way ANOVA’s at Time 1 and Time 2, with Sentence Valence and CBM Group as the factors. The Sentence Valence  CBM Group ANOVA at Time 1 revealed a main effect of Sentence Valence [F(1,46) ¼ 19.31, p < .001] with positively valenced sentences [2.59 (0.47)] having higher similarity ratings than negatively valenced sentences [2.21 (0.38)]. There was no main effect of CBM Group or a significant CBM Group  Sentence Valence interaction (all p > .05) (see Fig. 1a). The Sentence Valence  CBM Group ANOVA at Time 2 revealed a main effect of Sentence Valence [F(1,46) ¼ 13.30, p < .01] with similarity ratings for positive sentences [2.59 (0.42)] being higher than similarity ratings for negative sentences [2.28 (0.41)]. There was a Valence by CBM Group interaction [F(1,46) ¼ 7.82, p < .01]. Analyses of the simple main effects revealed that at Time 2 the positive group gave higher similarity ratings for positive sentences than negative sentences [F(1,46) ¼ 20.76, p < .001] but for the negative group similarity ratings were no different for positive and negative sentences

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Time 1

a

Time 2

b

Recognition ratings (1-4)

2.8

2.6

*

*

positive valence

*

positive valence

positive valence

2.4

positive valence

negative valence

negative valence

2.2

2

*

*

negative valence

negative valence

positive group

negative group

Training group

positive group

negative group

Training group

Fig. 1. Positive and negative CBM group ratings of positive and negative valenced sentences at: (a) Time 1 and (b) Time 2. Key: * indicates significant differences between conditions at p < .05 level.

[F < 1]. Similarity ratings for positive sentences were no different across the positive and negative groups [p > .05] but for negative sentences the negative group gave higher similarity ratings than the positive group [F(1,92) ¼ 6.25, p < .05] (see Fig. 1b). Analyses of the simple, simple main effects revealed a significant increase in similarity ratings for negative sentences by the negative group from Time 1 to Time 2 [F(1,46) ¼ 5.604, p < .05] (see Fig. 1a and b). All other simple, simple main effects were non-significant (all p > .05). 3.1.2. Presentation modality The Modality factor did not interact with any other factors in the four-way CBM Group  Modality  Time  Sentence Valence ANOVA. In order to further assess the influence of presentation modality on CBM there was a need to reduce and simplify the statistical design by eliminating any unnecessary factors. The Time factor was discarded by basing the presentation modality analyses on ratings at post-training only (where the significant CBM Group  Sentence Valence interaction occurred). The Sentence Valence factor was made into 2 dependent variables. This left two between subject factors: CBM Group (positive vs. negative) and Modality (visual vs. auditory).3 A two-way ANOVA was performed, firstly with similarity ratings for positive sentences as the dependent variable and then again with similarity ratings for negative sentences as the dependent variable. The CBM Group  Modality ANOVA with positive sentence similarity ratings as a dependent measure revealed a main effect of modality [F(1,44) ¼ 6.38, p < .05, h2p ¼ 0.13] with the visual group [2.73 (0.44)] giving higher similarity ratings than the auditory group [2.45 (0.34)]. There was no main effect of CBM Group (p > .05) nor was there a CBM Group  Modality interaction (p > .05). The CBM Group  Modality ANOVA with negative sentence similarity ratings as a dependent measure revealed a main effect of CBM Group [F(1,44) ¼ 6.54, p < .05, h2p ¼ 0.13] with the negative CBM Group [2.42 (0.41)] giving higher similarity ratings for the negative sentences than the positive CBM Group [2.13 (0.37)]. There was no main effect of Modality [p > .05] nor was there a CBM Group  Modality interaction (p > .05).

3 A power analysis showed that with 48 participants (12 per cell) and a large effect size (delta ¼ 0.75) power ¼ 0.96 (a ¼ .05). With a medium effect size (delta ¼ 0.5) power ¼ 0.69 (a ¼ .05). Available: http://www.math.yorku.ca/SCS/Online/power/.

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3.2. Mood measurements The VAMS were organised by considering the first four mood scales as part of the cognitive phase of the study and these scales measure how training directly affects mood. The last three mood scales were considered as part of the stress phase of the study and analysed separately. The scales in the stress phase measure emotional vulnerability. Higher scores indicate a higher negative mood state. 3.2.1. Mood during the cognitive phase There were four mood measurements during the cognitive phase of the study: (1) at the beginning of the experiment, (2) immediately prior to training, (3) immediately after training, and (4) following the post-training test of bias. A three-way ANOVA was performed on participants’ depression ratings with CBM Group (positive vs. negative) and Modality (visual vs. auditory) as between subject factors and Assessment Point (pt1 vs. pt2 vs. pt3 vs. pt4) as the within-subject factor. There was a significant main effect of Assessment Point [M (SD) ¼ 7.70 (4.97) vs. 8.63 (4.94) vs. 9.71 (5.45) vs. 9.73 (5.40)] F(3,132) ¼ 7.79, p < .001, h2p ¼ 0.15. The Tukey post-hoc test (a ¼ .05) revealed that the depression ratings at assessment point 1 were significantly lower than depression ratings at assessment points 3 and 4, while none of the other assessment points differed. There was a marginal Assessment Point  Modality interaction F(3,132) ¼ 2.21, p ¼ .09, h2p ¼ 0.05. Analysis of the effects within the interaction using the Tukey posthoc test (a ¼ 0.05) revealed that for the visual group there were no significant differences across the 4 assessment points. For the auditory group, depression ratings at assessment points 3 and 4 were significantly higher than depression ratings at assessment point 1 (all other differences at the level of the auditory group were non-significant). With regard to the simple main effects, there were no significant differences between the visual and auditory group at any of the 4 assessment points (all p > .05). All other interactions and main effects from the three-way ANOVA were non-significant (all p > .05). See Table 2 for the descriptive statistics. A further three-way ANOVA was performed with anxiety ratings replacing depression ratings as the dependent measure. There was a significant main effect of Assessment Point [M (SD) ¼ 10.48 (6.29) vs. 10.25 (5.43) vs. 10.13 (5.56) vs. 11.83 (6.21)] F(3,132) ¼ 3.43, p < .05, h2p ¼ 0.07. The Tukey post-hoc test (a ¼ .05) revealed that the anxiety ratings at assessment point 4 were significantly greater than ratings at assessment points 3 and 2, while none of the other assessment points differed. All other interactions and main effects from the three-way ANOVA were non-significant (all p > .05) (see Table 2). 3.2.2. Mood during the stress phase Six participants refused to give a speech in front of a camera. Therefore, data from 42 participants was analysed from the stress phase of the experiment with 8 participants in the positive/visual group, Table 2 Mean (standard deviation) of depression and anxiety ratings during the cognitive and stress phases. Phase

Cognitive

Modality

Visual

Auditory

Stress

Visual

Auditory

Assessment pt.

Positive CBM

Negative CBM

Depression

Anxiety

Depression

Anxiety

One Two Three Four One Two Three Four

7.58 7.92 7.50 8.33 7.67 9.50 10.50 10.83

(4.48) (5.00) (4.98) (5.18) (4.70) (4.66) (4.30) (4.30)

10.25 9.58 7.75 10.58 11.42 12.33 11.83 13.33

(6.20) (4.74) (3.82) (5.62) (5.98) (6.13) (6.51) (5.30)

9.83 9.58 11.58 11.17 5.75 7.50 9.25 8.58

(6.63) (5.45) (5.71) (5.34) (3.22) (4.91) (6.38) (6.60)

12.17 (8.00) 10.17 (5.91) 11.25(6.30) 13.17 (7.51) 8.08 (4.54) 8.92 (4.91) 9.67 (4.94) 10.25 (6.31)

Baseline Anticipatory Post-speech Baseline Anticipatory Post-speech

8.00 14.38 8.38 10.09 13.09 11.00

(4.72) (6.59 (3.58) (4.89) (4.95) (5.50)

8.75 18.38 9.88 13.00 18.00 16.18

(8.24) (8.91) (3.64) (5.33) (5.80) (6.35)

10.75 13.50 12.50 8.09 8.09 7.55

(4.83) (7.09) (6.86) (6.20) (4.99) (4.45)

10.83 16.33 14.67 8.64 12.27 10.55

(6.82) (9.03) (9.31) (6.76) (7.52) (6.82)

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11 participants in the positive/auditory group, 12 participants in the negative/visual group and 11 participants in the negative/auditory group. There were three mood measurements during the stress phase of the study: (1) immediately after the 4-min rest (baseline), (2) immediately after being informed of the requirement to give a speech (anticipatory), and (3) once the speech was over (post-speech). Planned comparisons between CBM groups at the baseline period were performed on both depression and anxiety ratings to establish that state mood was equivalent between both training groups before the stressor task was introduced. Independent samples t-tests showed no significant differences in depression [t < 1] or anxiety [t < 1] ratings between the positive group and the negative group at baseline. An Assessment Point (baseline vs. anticipatory vs. post-speech)  CBM Group (positive vs. negative)  Modality (visual vs. auditory) mixed design ANOVA was performed on the depression ratings and revealed a main effect of Assessment Point F(2,76) ¼ 11.47, p < .001, h2p ¼ 0.23. The Tukey post-hoc test (a ¼ .05) showed that the mean depression ratings for the anticipatory period [12.14 (6.25)] were significantly greater than the baseline [9.36 (5.17)], and post-speech [10.02 (5.59)] periods (p < .05). The critical Assessment Point  CBM Group interaction to see whether the CBM procedures had a causal impact on emotional vulnerability was significant [F(2,76) ¼ 4.04, p < .05, h2p ¼ 0.10]. Analysis of the effects within the CBM Group  Assessment Point interaction using the Tukey post-hoc test (a ¼ 0.05) revealed that the depression ratings from the positive group at the anticipatory assessment point were higher than depression ratings at the baseline and post-speech assessment points (the positive group’s ratings between baseline and post-speech did not differ significantly). There were no significant differences in depression ratings at the level of the negative group. With regard to the simple main effects there was a marginally significant difference between the positive and negative group at the anticipatory assessment point [F(1,58) ¼ 2.89, p ¼ .09]. However the direction of difference was against prediction with the positive CBM group showing greater depression ratings than the negative CBM group (see Fig. 2). Differences between the positive and negative group at baseline and post-speech assessment points were not significant (ps > .05). There were no further main effects or interactions from the three-way Assessment Point  CBM Group  Modality ANOVA on depression ratings during the stress phase of the study (all p > .05). See Table 2 for the descriptive statistics. A second Assessment Point  CBM Group  Modality ANOVA was performed with anxiety ratings as the dependent measure. There was a main effect of Assessment Point F(2,76) ¼ 16.13, p < .001, h2p ¼ 0.30. The Tukey post-hoc test (a ¼ .05) showed that all pairwise comparisons between anxiety ratings at baseline [10.43 (6.74)], anticipatory [16.10 (7.96)] and post-speech [13.07 (7.33)] assessment points were significantly different. There were no further main effects or interactions from the 17

Positive Group Negative Group

Depression ratings (0-30)

16 15 14 13 12 11 10 9 8

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Assessment Point Fig. 2. Depression ratings in response to the speech stress task for the positive and negative CBM groups.

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three-way ANOVA on anxiety ratings during the stress phase of the study (all p > .05). See Table 2 for the descriptive statistics. 3.2.3. Behavioural measures of anxiety Two independent assessors rated the participant’s speeches on video for behavioural signs of anxiety using the Timed Behavioural Checklist (TBCL) for performance anxiety (Paul, 1966) The TBCL lists 20 different molecular behaviours that signify performance anxiety e.g., speech stammers, extraneous hand movements, sways etc. Interrater reliability was assessed by means of an Intraclass Correlation (ICC) and produced a reliability coefficient of ICC ¼ 0.92. Given sufficient reliability between assessors, a between subjects ANOVA was performed with the CBM Group and Modality as factors. The dependent variable was the mean of both assessors’ total ratings for each participant. The analysis revealed no significant effects [all p > .05]. For global speech performance independent assessors gave a rating of between 1 and 10. Interrater reliability was assessed by means of an Intraclass Correlation and produced a reliability coefficient of ICC ¼ 0.97. Given that there was sufficient interrater reliability, the two assessors’ ratings were combined and compared to (1) the self-rating of global speech performance from the positive group, (2) the self-rating of global speech performance from the negative group, (3) assessors ratings were compared between the positive and negative CBM groups and (4) self-ratings were compared between the positive and negative groups. Four independent samples t-tests were conducted. The analyses produced no significant differences [all ts < 1]. 4. Discussion At odds with the first hypothesis was the finding that both auditory and visual presentation had comparable effects in altering interpretation bias using social scenarios. Consistent with the second hypothesis, the present study has shown that with a mid-range anxiety level sample, negative scenario-based CBM is effective, whereas positive CBM is not. Contrary to the third hypothesis, the negative shift in interpretation bias did not increase emotional vulnerability, relative to positive CBM, with respect to behavioural anxiety. Moreover, the positive CBM group reported experiencing increased depression levels whilst anticipating a speech task relative to a baseline, whereas the negative CBM group did not. While presentation modality did not affect the magnitude of change in interpretation bias, the mode of presentation did have a differential effect on mood during the CBM procedure. The auditory group reported an increase in depression ratings whilst the visual group did not. The differential influence of modality upon self-reported depression levels is difficult to explain. For the auditory group, a negative mood state progressively increased in spite of the valence of the CBM procedure, while the visual group’s depression levels remained constant. This deterioration in mood state for the auditory group may be due to the fact that auditory presentation extended the mean time of the experiment by 15 min, thus prolonging the task for participants. For the visual group the mean testing time was approximately 50 min. The advantage of reading over listening to the scenarios is that participants can progress through the experiment at their own personal speed and are not compelled to process the stimuli at a pre-set rate that is out of step with their own natural pace. It may be that presentation modality per se does not have a direct influence on mood but that the procedural advantages in terms of time and self-control that visual presentation offers over auditory presentation creates a differential mood effect. Given that the modality of presentation did not impact on the effectiveness of CBM, and for reasons of minimising participant fatigue and reducing testing time, we suggest that the visual modality is a better method of presenting scenarios for CBM paradigms. The equivalence of visual and auditory presentation modality with respect to cognitive induction does not fully accord with the Dual Coding Theory (Paivio, 1971, 1986), Multimedia Learning Effect (Mayer, 2001) and other research (Baddeley & Andrade, 2000; Brooks, 1967, 1970). Collectively, the above research would predict written presentation of scenarios as interfering with the visual imaging of scenarios thus making auditory presentation the more effective alternative for successful CBM induction. Interestingly though, the present study’s findings of comparability between visual and auditory presentation are consistent with the work of Tabbers, Martens, and Van Merrienboer (2001).

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Tabbers et al. reported that the learning advantage of bi-modal presentation (e.g., pictures with verbal narration) compared to visual-only (e.g., pictures with text) occurs only when information is ‘‘systempaced’’, i.e., the pace of presented information is pre-determined. When the presentation of to-belearned information is self-paced the modality effect disappears. In the present study, participants in the visual modality group were able to control the pace of the material given. This aspect of self-paced control may account for the lack of influence presentation modality had on CBM induction. Furthermore, as previously discussed, the self-paced feature may improve the whole CBM procedural experience for participants/clients with respect to positive mood state. In terms of clinical potential it is of some concern that the attempt to induce a positive interpretation bias was not successful. To illustrate, participants demonstrated a positive bias in their interpretation style at baseline. Following CBM, this propensity to disfavour negative interpretations was erased for the negatively trained group. In other words, following CBM the negative group was more balanced in their endorsement of positive and negative sentences. For the positive group, however, the natural predisposition to demonstrate a positive bias was barely affected by training. This asymmetry in the superior efficacy of negative over positive CBM is consistent with previous findings (Grey & Mathews, 2000; Holmes & Mathews, 2005; but see Mathews & Mackintosh, 2000). Since participants in the present and previous studies have generally been selected on the basis of mid-range self-reports of anxiety, it is possible that attempts to shift a positive bias in a more positive direction may be affected by ceiling effects. Attempts to induce a negative bias would not, of course, be constrained by these ceiling effects. In terms of clinical use it is likely that scenario-based CBM attempts to neutralize a negative bias (or induce a positive bias) may be more effective with a clinically high-anxious group who demonstrate an initial negative bias. Consistent with this, Murphy et al. (2007) and Mathews, Ridgeway & Cook (2007) both presented a scenario-based CBM procedure that was successful in inducing a positive interpretation bias in high-anxious participants. More research is needed to replicate the efficacy of scenario-based positive bias manipulation in high-anxious individuals. It is disappointing that the induction of a negative interpretation bias did not affect emotional vulnerability, relative to the positive CBM group, as measured by behavioural indices of anxiety. Previous research on speaking performance and social phobia has found that blind assessors often cannot discriminate between socially phobic and non-phobic speakers. Thus, it is not surprising that the assessors in the current study did not discriminate between the positive and negative CBM groups (but see Amir, Weber, Beard, Bomyea, & Taylor, 2008). However, past research has shown that at a global level, socially phobic individuals rate their own speech performance as significantly poorer than independent assessors’ ratings. This discrepancy between phobics’ self-ratings and the assessors’ ratings is a robust effect (Rapee & Lim, 1992; Stopa & Clark, 1993). Therefore if negative, social scenariobased CBM is thought to induce the biases that socially anxious individuals possess, and if these biases are predicted to causally contribute to the anxiety condition, then one would expect to see differences between self and assessor ratings for the negative CBM group, as found with genuinely socially anxious people. This was not the case and possible reasons are that the content of the CBM training scenarios did not specifically relate to public speaking, but rather, were about general and variable social situations. Alternatively the effects of social scenario-based CBM may not transfer to a behavioural domain. We would argue that it is important in terms of clinical utility, for future scenario-based CBM studies to demonstrate a robust influence of CBM effects on emotional vulnerability, across a wide range of measures including physiological and behavioural in addition to the more common self-report measures. Although the CBM induction did not differentially influence self-reported anxiety in response to the speech task, CBM training did have a differential impact on depression levels, with the positive group reporting marginally greater depression than the negative group whilst anticipating the speech task. A possible explanation for this unexpected result comes from social comparison research. To illustrate, social comparison research claims we automatically make other-self comparisons that can be contrasting rather than assimilative when personal identity is salient (Brewer & Weber, 1994; Gordijn & Stapel, 2006). With regard to CBM scenarios, participants are requested to imagine themselves as the central character, thus personal identity is primed. The very nature of the CBM training coerces participants to absorb consistently positive or negative social interpretations set by another individual that likely differ from their own natural thinking. These are perfect conditions to elicit an automatic

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social comparison with contrast effects. For the negative group the contrast will be downward (‘‘my social life is more successful than the situations described in these scenarios’’) thus bolstering selfesteem. However, for the positive CBM group the contrast will be upward resulting in a decrease in selfesteem and possibly engendering an increase in emotional vulnerability. Thus contrast effects are a potential explanation for the counter-to-prediction results obtained in this study with respect to depression vulnerability. Furthermore a social comparison process explanation of emotional vulnerability is reconcilable with other research. To illustrate, attentional CBM and interpretation CBM using homographs are unlikely to prime personal identity and elicit contrast effects. This is consistent with the emotional vulnerability effects found in the research of MacLeod et al. (2002) and Wilson, MacLeod, Mathews, and Rutherford (2006) who used attentional and homograph training respectively. Also Mackintosh et al. (2006) reported an emotional vulnerability effect but used physical as opposed to social scenarios, which are less likely to evoke social comparison responses. Finally Holmes et al. (2009) also report that unfavourable comparisons with highly positive material can reduce the efficacy of scenario-based CBM. To conclude, the current study demonstrates that both visual and aural presentation of CBM scenario material were equally effective in modifying interpretation style. In both presentation modalities, however, negative biases were induced whereas positive biases were not in individuals with mid-range social anxiety. More research is needed to determine whether this is also the case for high-anxious participants. If this is the case, then the potential use of the scenario-based CBM procedures for clinical use would be called into question. Against prediction, the anticipation of having to present a speech increased self-reported depression for the positive but not negative CBM group. Behavioural measures of emotional vulnerability did not differ between the different CBM conditions. There is clearly a need to establish that these scenario-based CBM procedures do influence other indices of emotional vulnerability and causally impact on self-reported emotional vulnerability in the predicted direction. Acknowledgements Chris Ashwin has now moved to the Department of Psychology, University of Bath, UK. The authors would like to thank Andrew Mathews and Bundy Mackintosh for providing us with their training and test materials. The authors would also like to thank two anonymous reviewers for their comments on an earlier draft of this manuscript and Kelly Garner for rating participants’ videoed speeches. This research formed part of a thesis submitted for the PhD degree at the University of Essex by Helen Standage and was supported by a Doctoral Training Grant from the Economic and Social Research Council. References Amir, N., Weber, J. G., Beard, C., Bomyea, J., & Taylor, C. (2008). The effect of a single session attention modification program on response to a public speaking challenge in socially anxious individuals. Journal of Abnormal Psychology, 117(4), 860–868. Anderson, J. R., & Bower, G. H. (1973). Human associative memory. Washington, DC: Winston. Baddeley, A. D., & Andrade, J. (2000). Working memory and the vividness of imagery. Journal of Experimental Psychology, 129, 126–145. Baddeley, A. D., & Hitch, G. J. L. (Eds.). (1974), Working memory, Vol. 8. New York: Academic Press. Brewer, M. B., & Weber, J. G. (1994). Self-evaluation effects of interpersonal versus intergroup social comparison. Journal of Personality and Social Psychology, 66, 268–275. Brooks, L. R. (1967). The suppression of visualization by reading. Quarterly Journal of Experimental Psychology, 19, 189–299. Brooks, L. R. (1970). An extension of the conflict between visualisation and reading. Quarterly Journal of Experimental Psychology, 22, 91–96. Brower, D. (1947). The experimental study of imagery. II. The relative predominance of various imagery modalities. Journal of General Psychology, 37, 199–200. Ganis, G., Thompson, W. L., & Kosslyn, S. M. (2004). Brain areas underlying visual mental imagery and visual perception: an fMRI study. Cognitive Brain Research, 20, 226–241. Gordijn, E. H., & Stapel, D. A. (2006). Behavioural effects of automatic interpersonal versus intergroup social comparison. British Journal of Social Psychology, 45, 717–729. Grey, S., & Mathews, A. (2000). Effects of training on interpretation of emotional ambiguity. Quarterly Journal of Experimental Psychology, 53A(4), 1143–1162. Hirsch, C., Hayes, S., & Mathews, A. (2009). Looking on the bright side: accessing benign meanings reduces worry. Journal of Abnormal Psychology, 118(1), 44–54.

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