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Subjective wellbeing and temporal patterns of sympathetic-adrenal medullary activity
Biological Psychology 4 (1976) 157-172 O North-Holland Publishing Company
SUBJECTIVE WELLBEING AND TEMPORAL PATTERNS OF SYMPATHETICA D R E N A L MEDULLARY A C T I V I T Y GUNN JOHANSSON Department o f Psychology, University o f Stockholm, P.O. Box 6706, S-113 85 Stockholm, Sweden Accepted for publication 13 April 1976
Sixteen male subjects performed an audiovisual-conflict test during 1 h of an ordinary day of work. Adrenaline and noradrenaline excretion and subjective reactions were measured before, during, and after the test period as well as at corresponding points in time in a control day of ordinary work without interruption. This program was carried out on two occasions, which were expected to differ with respect to the subjects' general mental condition and wellbeing. There were large intraindividual as well as interindividual variations in the rate at which adrenaline output decreased after the stress period. The results support the hypothesis that rapid recovery to baseline levels is positively related to a relaxed, alert and subjectively pleasant state of mind.
1. Introduction The activity o f the sympathetic-adrenal medullary system is enhanced by a variety of physical as well as psychosocial stimuli (for reviews see Frankenhaeuser, 1975; Johansson, 1973; Levi, 1972). In this investigation urinary excretion of adrenaline and noradrenaline were used as indices o f peripheral catecholamine secretion. It has long been known (Cannon, 1932) that the adrenaline secreted from the adrenal medulla is o f vital importance for mobilization of physical energy in emergency situations. By stimulating glycogenolysis, the activity of the heart and the dilation o f arterioles in the skeletal muscles, etc., adrenaline facilitates adjustment to demands for the physical environment. Noradrenaline, which is also released from the adrenal medulla but mainly at the sympathetic nerve endings, plays an important role in maintaining blood pressure homeostasis. The mobilization of catecholamines in response to psychosocial stressors has also been shown to have beneficial effects on adjustment to demands in the psychosocial environment. Several studies have demonstrated positive relations between mental performance and concurrent rate o f adrenaline output (Frankenhaeuser and Rissler, 1970; P~itkai, Frankenhaeuser, Rissler and Bjfrkvall, 1967). In a few investigations a positive correlation between mental performance and noradrenaline 157
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output has been found (Frankenhaeuser, Mellis, Rissler, Bj6rkvall and P~itkai, 1968). A similar, positive relationship between adrenaline output in a school situation and performance in standardized tests of school achievement has also been found (Johansson, Frankenhaeuser and Magnusson, 1973). These relationships have commonly been explained in terms of increased general arousal (P~itkai, 1970). Although the release of catecholamines, in some respects, appears to have beneficial effects in a short perspective, it is evident that frequent or prolonged adrenal medullary activity may insert an extra load on several physiological functions in a way that may be harmful to the individual. However, so far, only little empirical evidence is available to test the validity of this assumption. Even less is known about possible mechanisms by which disease might develop (cf. Levi, 1972). When both the harmful and tile beneficial effects of adrenal medullary activity are taken into consideration it seems natural that the temporal pattern of adrenaline response should be one important part of the adjustment to external demands. A pattern of rapid mobilization in response to stressful experiences and, likewise, a rapid demobilization after elimination of the stressor would be the most 'economic' reaction and, thus, could be expected to promote optimal adjustment. Until recently, little attention has been focussed on the process of adrenaline 'recovery', i.e. return to baseline levels after exposure to a stressor. In a previous investigation in our laboratory (Johansson and Frankenhaeuser, 1973) considerable interindividual variation was found in the rate of adrenaline decrease. It was also demonstrated that subjects who performed well and who had low neuroticism scores showed the most 'economic' adrenaline response, i.e. their adrenaline excretion decreased rapidly. The noradrenaline excretion was not significantly affected by the stressor. The classification of subjects into slow and rapid 'decreasers' is of interest under the assumption that slow demobilization of adrenaline is, in some respect, undesirable. Equally important, from a prophylactic point of view, would be to explore intraindividual variations in rate of adrenaline decrease, since this may provide a possibility to specify the conditions under which individual subjects exhibit a rapid versus slow decrease. The aim of the present study was to explore intraindividual variation in the rate of adrenaline decrease after stress. By analogy with earlier findings concerning differences between rapid and slow decreasers, it was postulated that the time pattern of adrenaline release indicating optimal adjustment, i.e. the most rapid adrenaline decrease, would occur when the individual is in a relaxed, emotionally balanced and subjectively satisfactory mental condition. Therefore two situations, assumed to differ clearly in these respects, were chosen: a job setting before and after a period of vacation. It was known that the industry where the study was to be carried out reported less absence from work and less complaints about health problems during the period following summer vacations than during the rest of the year. On the basis of the above considerations, it was predicted that adrenaline excre-
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tion would return to baseline level after a period of_stress more rapidly after than before vacation.
2. Methods 2.1. Subjects and general design Sixteen male employees of a Swedish metal industry volunteered for the study. The subjects ranged in age between 22 and 35 yr (mean = 28.7 yr) and their body weights ranged between 59 and 78 kg (mean = 69.7 kg). They were white- and bluecollar workers in the research department of the plant and they were all nonsmokers or light to moderate smokers in good health. Before the experiment proper all subjects came to a 1 h introductory session. The experiments included four morning sessions, starting at 7:30 a.m. when the subjects arrived at work and lasting till noon, the start of the regular lunch hour. Two of the four sessions, a control and an experimental session, took place in June, 2 to 4 weeks before a period of summer vacation, and the procedure was repeated in September, 2 to 6 weeks after the vacation. Each subject had 3 to 4 weeks of vacation. The intervals between experimental periods and the beginning and end of the vacation were introduced to avoid interfering anticipatory and readjustment effects. The introductory session as well as control and experimental sessions were conducted at the subjects' place of work. Each subject was paid 25 Swedish kronas (about U.S. $6.00) for participating in the introductory session which took place off working hours. 2.2. Procedure In the introductory session the subjects were informed about the general procedure and about different conditions that might affect the variables to be investigated and therefore had to be avoided before and during the experiments, e.g. intake of coffee, drugs, alcohol and nicotine. They were instructed to standardize, as far as possible, their breakfast on the days of investigation. Instructions were given regarding the procedure for urine collection during the different sessions, and detailed information was given concerning the forthcoming sessions. Two psychological tests and a self-rating technique (see below), which were to be used in the experiments, were introduced. In the first part of the investigation the subjects participated in one control session and one experimental session on consecutive days. The conditions were rotated so that eight subjects started with the experimental session and eight subjects with the control session. When the procedure was repeated after the vacation each subject had the same order of conditions as on the first occasion. Data were collected
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on Tuesdays, Wednesdays, and Thursdays, and each subject was studied on the same weekdays on both occasions. Both the experimental (E) and control (C) sessions consisted of four 1 h periods (El- E4 and C1-C4) separated by 10 min intervals (fig. 1). Before the first period started each subject micturated in order to empty his bladder. All control periods, C1-C4, as well as experimental periods El, E3, and E4, were spent by the subjects in their regular work routine, except for the 10 min breaks during which urine samples were collected and self-ratings of mood and wakefulness were made. Control and experimental sessions diiYered only with respect to the second period. In the E2 periods the subjects performed two psychological tests (see below). 2.3. Experimental stress periods During the E2 periods, the subjects performed two types of tests. One of them, an audiovisual-conflict test, was chosen as being an effective stressor in group settings (P~itkai et al., 1967). The other test, a mental-arithmetic task, was interspersed in a pause between two periods of the audiovisual-conflict test. The E2 periods started with 5 min of instructions followed by 15 min of the audiovisual-conflict test. Another 5 min of instructions preceded the arithmetic test which was then performed for 20 min, and, finally, the audiovisual-conflict test was repeated during the remaining 15 min. 2.3.1. Audiovisual-conflict test The test was a modified form of the color-word test introduced by Stroop (1935) and used by several investigators in various forms (Bj6rkvall, 1966; Rissler, 1967; Thurstone and Mellinger, 1953). In essence the test consists of color words which are printed in different colors, the combination of words and colors being incongruent; for example, the word 'green' may be colored red, etc. The subject's task is to ignore the word and name the color of the print. In the present version of the test (Bj6rkvall, 1966), modified to suit a group
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situation, additional complications were introduced by simultaneous auditory presentation of conflicting color words, which also had to be ignored. The words were 'orange', 'cobalt', 'turquoise', and 'carmine'. The visual stimuli were projected on a screen and the auditory stimuli were presented via a loudspeaker; the two types of signals were synchronized. The combination of color words presented through the two senses was raadom. The duration of the visually presented words varied randomly between 0.4 and 1.0 sec and the interval between successive words varied between 0.8 and 1.7 sec. The test consisted of 12 blocks of 21 stimuli. Each block lasted for about 1 min and the intervals between blocks from 8 to 17 sec. The subjects responded to the stimuli by marking the correct word on a response sheet which contained successively numbered rows, each listing the four color words in random order. Tile performance score was equal to the percentage of correct responses out of the total number of possible responses. 2.3.2. Mental arithmetic test The arithmetic test (Norinder, unpublished) consists of a series of one-digit items arranged in pairs. The task is to add and subtract numbers according to certain rules. All operations have to be performed without the aid of pencil and paper, and only the final answer to each item is noted on the test sheet. Two scores were recorded: the number of items solved and the percentage of items correctly solved. 2.4. Catecholamine excretion
On arrival at work in the morning each subject emptied his bladder by voluntary voiding. Urine samples were then collected after each period, i.e. at 6 0 - 7 0 min intervals. The exact time of each micturation was noted. The pH of the urine was adjusted to about 3.0 with 2 N HCI and the volume was measured. The samples were stored at -18°C until analyzed by the fluorimetric method of Euler and Lishajko (1961). 2.4.1. Rate o f adrenaline decrease The temporal pattern of adrenaline secretion in response to the mental load introduced in period E2 was examined by the same procedure as in our previous study (Johansson and Frankenhaeuser, 1973), the diurnal variation in adrenomedullary function being taken into account. The design makes it possible to relate adrenaline values during successive periods in the experimental sessions to corresponding values in the control sessions. On the basis of this comparison it is possible to divide the subjects into two groups differing with regard to the temporal pattern of their secretion: (1) a group of 'rapid decreasers', defined as those who show a decrease of adrenaline output after the E2 period so that their excretion during E3 and/or E4 is equal to or below the C3 and/or C4 levels, (2) a group of 'slow decreasers' defined as subjects whose adrenaline output remains at an elevated level throughout th~ experimental session. That is, the excretion rate of these subjects is higher during the E3 and E4 than during the C3 and C4 periods.
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2.5. Self-ratings In each 10 min interval between successive periods the subject estimated his state during the preceding period in terms of different variables referring to mood and wakefulness. The following eight variables were rated: 'tired', 'apprehensive', 'happy', 'irritated', 'concentrated', 'stressed', 'relaxed', and 'alert'. In order to make each subject use, as far as possible, a constant frame of reference the following technique was used. Graphic scales of 120 mm were used and the subjects were told to let the endpoints of each scale represent the recollections of their maximum and minimum experience of that particular variable. The minimum was represented by the left and the maximum by the right endpoint. For each rating the subjects were instructed first to indicate by a vertical line the position of their 'ordinary' state of mind, and then to indicate, by a vertical arrow, their state of mind during the preceding period. The score used was the distance from the left endpoint to the arrow subtracted by the distance from the same endpoint to the vertical line. 2.6. Persona6ty hlventory The Eysenck Personality Inventory (Eysenck and Eysenck, 1964; translated into Swedish and modified by Bederoff-Peterson, J/igtoft and Astr6m, 1971) was administered to each subject individually a few days after he had participated in the last session of the investigation.
3. Results 3.1. Subjects' mental state and wellbeing on the two occasions o f investigation In response to the first, pre-vacation questionnaire all subjects rated their mental condition as generally being better in September than in June. The responses to the post-vacation questionnaire showed that all except two subjects felt in a better mental condition after the vacation than before. The two subjects who stated that their mental condition was better before they went on holiday explained that they had been unable to arrange their holiday in the way they had planned to. When asked about their physical condition six subjects said it was better after vacation than before and ten subjects claimed it was equally good on both occasions. Subjective estimates of mood and alertness, averaged over the four periods of each control session, were also used to appraise the subjects' general mental state on the two occasions of investigation. The results are shown in table 1. These average estimates for control days did not differ significantly between occasions for any of the variables. Thus, a difference between the two occasions of investigation in terms
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Table 1 Self-ratings (deviation from 'ordinary' state of mind) of mood and alertness averaged over control sessions on the In'st (column 1) and the second (column 2) occasion of investigation (arbitrary unit of measurement). Variable
Occasion
Tired Apprehensive Irritated Happy Concentrated Stressed Relaxed Alert
-0.9 -4.6 - 1.7 -0.1 - 1.6 -2.0 -2.6 -0.1
-0.1 -6.7 -4.6 + 1.0 -2.2 -4.7 -4.2 -0.5
of subjects' mood and wellbeing was generally expressed in the questionnaires, whereas data collected in the actual situations did not differ significantly between occasions. It is possible that the differences were not large or distinct enough to affect the data that were collected in the actual situation.
3.2. General temporal patterns Catecholamine data and subjective estimates of mood and alertness for the entire group were submitted to a four-way analysis of variance and errorterms chosen according to a repeated measurement model presented by Winer (1962) 1. The results are presented in table 2. The pattern of adrenaline output (fig. 2) showed a high resemblance to the results o f the earlier study by Johansson and Frankenhaeuser (1973). During experimental days a peak level was reached during period E2. During control days the output rose slowly from period CI to C4. The analysis of variance showed that the effect o f time o f day (Periods 1--4) as well as the effect o f treatment × time of day was significant. Further information was gained by subsequent t-tests showing that in both experimental sessions the E2 levels of adrenaline output were significantly higher than the El levels (t = 4.006, p < 0.01, and t = 3.479, p < 0.01, respectively) but not significantly higher than the E3 and E4 levels. In both the control and the experimental sessions the first and the last periods differed significantly with regard to adrenaline output. Fig. 2 also shows that the average adrenaline-excretion levels were generally higher on the second occasion, although not significantly so (table 2), and that the general time pattern was almost identical for both conditions on 1 The complexity of the design, with each subject measured under all conditions, calls for an analysis for which appropriate data programs were lacking. The consequence of the method chosen is a conservative test of significance with increased risk for 'type II' error, i.e. false acceptance of the null hypothesis.
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the two occasions. For noradrenaline a markedly decreasing trend was observed within each occasion as well as between the two occasions. However, as shown in table 2, no significant effects were obtained for this variable. The average subjective estimates showed only minor variations, all falling within -+10 units of the total scale range of 120. Their temporal patterns were similar to those obtained in the previous study (Johansson and Frankenhaeuser, 1973). Thus, the subjects felt more 'tired' and 'stressed' and less 'relaxed' during E2 periods than during other periods. In opposition to results of the previous study they felt less 'concentrated' during the E2 periods than during other periods. The analyses of variance (table 2) showed that differences between occasions were non-significant for all subjective variables. Estimates of apprehension were significantly higher in experimental than in other sessions, and subjective stress varied significantly between
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the four periods. Significant interactions between treatment and time of day were observed for the variables 'tired', 'concentrated', and 'stressed' (fig. 3).
3.3. Rate of adrenaline decrease The temporal pattern of adrenaline output, averaged over subjects, is shown in fig. 2. The figure further shows that the average adrenaline decrease tended to be less complete before the vacation than after. On the former occasion the average adrenaline excretion did not reach control-day levels before the end of the fourth period, whereas after vacation baseline levels were reached during the E4 period. Furthermore, the E3-C3 difference was significantly larger before than after vacation (t = 2.311, p < 0.05). Individual rates of adrenaline decrease on both occasions of investigation are shown in tables 3 and 4. Table 3 shows that, just as in the previous study (Johansson and Frankenhaeuser, 1973), some subjects showed 'paradoxical' adrenaline reactions, i.e. their adrenaline excretion was lower in the E2 than in the C2 period.
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Table 3 The distribution of subjects on 'normal' and 'paradoxical' adrenaline reaction patterns on two occasions of investigation. Adrenaline reaction
I st occasion
2nd occasion
Normal Paradoxical
14 (85%) 2 (15%)
11 (69%) 5 (31%)
Total
16 (100%)
16 (100%)
On the first occasion two subjects and on the second occasion five subjects exhibited this pattern. This increase from 15 to 31% was statistically significant (t = 2.747, p < 0.01). Table 4 shows that on the first occasion o f investigation 65% o f the subjects showing an adrenaline increase under stress were 'rapid decreasers' and 35% were 'slow decreasers'. The corresponding percentages on the second occasion were 55% 'rapid' and 45% 'slow decreasers'. The change in the relative frequencies was not significant. That is, the increase o f rapid decreasers, that had been expected, was not obtained. This means that as far as average adrenaline levels are concerned, the entire group o f subjects, in agreement with the hypothesis, recovered more rapidly on the second occasion o f investigation than on the first. However, when attention is focussed on individual data no change in the proportion o f rapid decreasers was obtained. A closer inspection o f the data showed that six subjects belonged to the same category o f reaction pattern on both occasions. Four of them were rapid decreasers, one was a slow decreaser, and one showed paradoxical adrenaline responses. The remaining ten subjects represented all possible combinations of reaction patterns. Thus, it is clear that intraindividual as well as interindividual variation may be found in the temporal pattern o f adrenaline release.
3.4. Variability versus constancy in the temporal pattern o f adrenaline release Since the subjects' general mental condition on the two occasions did not differ as markedly as expected, a complementary analysis was made in order to test the Table 4 The distribution of 'normally' reacting subjects on rapid and adrenaline decrease. Adrenaline decrease
1st occasion
2nd occasion
Rapid Slow
9 (65%) 5 (35%)
6 (55%) 5 (45%)
Total
14 (100%)
11 (100%)
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hypothesis. Therefore, a subgroup comprising five subjects showing rapid decrease on one occasion and slow decrease on the other, was studied separately. (This group comprised all subjects who never showed paradoxical reactions and whose adrenaline-decrease pattern was differently classified on the two occasions.) In the following, intraindividual comparisons between occasions will be presented
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for these subjects and, for control purposes, for a group of four consistently rapid decreasers. On the basis of the initial hypothesis the latter group, i.e. those showing a consistent adrenaline-decrease pattern would be expected to show less variation of mood and wellbeing between the two occasions of investigation than the former group consisting of subjects with a variable decrease rate. Fig. 4 presents self-ratings of mood and alertness averaged over control days for subjects whose rate of adrenaline decrease varied between the two occasions. The graph shows that, on the whole, rapid adrenaline decrease after stress in these subjects was associated with a higher level of wellbeing than slow adrenaline decrease. The difference was statistically significant in several aspects. Thus, these subjects felt less tired (t = 3.934, p < 0.05), more relaxed (t = 3.031, p < 0.05), more alert (t = 7.795, p < 0.05), and happier (t -- 2.753, p < 0.05) on the occasion of rapid decrease than when their adrenaline decrease was slow. The consistently rapiddecrease group rated their mood very similarly on both occasions and no significant differences were observed. When corresponding comparisons were made for performance data it was found that the consistently rapid-decrease group showed significant differences between occasions with regard to mental arithmetic performance. Thus, they covered significantly more items in the arithmetic test (t = 6.529, p < 0.01) and solved a significantly larger proportion of these items correctly (t = 4.173, p < 0.05) on the second occasion than on the first one. For the variable decrease-rate group no differences in performance were found between the occasion of rapid adrenaline decrease and the occasion of slow decrease. It should be pointed out that the effect of training which was clearly borne out in the former group, and the difference in tiredness and alertness may have cancelled out a performance difference in the latter group. 3.5. lnterindividual differences in adrenaline decrease
Interindividual differences in adrenaline decrease were studied in the previous investigation (Johansson and Frankenhaeuser, 1973) under conditions which may be compared with those of the first occasion of the present investigation. The rapid and slow decreasers, as established on the first occasion, differed only slightly and non-significantly in other variables. The differences were, however, of the same direction as in the previous study, i.e. the rapid decreasers had slightly lower neuroticism scores on the EPI (Eysenck personality inventory), they performed slightly better, and they excreted more adrenaline during the entire control day than the slow decreasers.
4. Discussion
The aim of this study was to explore intraindividual variations in the rate at which adrenomedullary activity returns to baseline levels after a short period of
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strenuous mental activity. It was postulated that the adrenaline decrease would be more rapid when subjects were in a relaxed and emotionally balanced condition. On designing the study two occasions of examination were chosen which were expected to differ in respect of the subjects' general mental condition. Although this expectation turned out to be only partly true, support was obtained for the hypothesis posed. Thus, the subjects tended to return more rapidly to baseline levels of adrenomedullary activity under conditions of mental relaxation, alertness and general satisfaction than under conditions of tension and tiredness. The study also provides further data on interindividual variations in rate of adrenaline decrease. Such data were reported in a previous study (Johansson and Frankenhaeuser, 1973), the findings of which are in general agreement with the present data. In both studies a majority of the subjects returned to baseline level within 1 - 2 h after the end of a psychological test session, whereas a smaller group of subjects remained on an elevated level of excretion throughout the experimental sessions. The distribution of subjects on these two categories was identical in the two studies. In the previous study rapid adrenaline decrease was positively related to high baseline levels of adrenaline output, good performance, and low scores of neuroticism. Similar trends, although non-significant, were obtained in the present data. The failure to confirm a relationship between rate of adrenaline decrease and neuroticism may be due to insufficient sensitivity of the inventory or to a general difference in neuroticism levels between the two groups of subjects. The average neuroticism scores of the students in the first study were higher and their variability larger than the corresponding parameters of the present group. A distinct trend of this study was the increase from the first to the second occasion of the number of subjects showing a 'paradoxical' adrenaline reaction, i.e. subjects with a stress level of adrenaline output that was lower than the corresponding control level. When comparing the results of the two studies it should be kept in mind that the control condition in the present case was spent by the subjects in their regular work routine, whereas the subjects of the previous study spent the control periods under relaxing conditions, reading and listening to the radio. This difference is reflected in slightly lower adrenaline excretion under control conditions in the latter group. Thus, in this study a slightly higher general arousal level, in combination, perhaps, with a certain amount of habituation to the stressor may have contributed to the increased proportion of subjects on the second occasion who were less aroused during the test session than during their regular work. It may, in fact, be argued that this type of reaction is not really 'paradoxical' in the present context, but rather a 'lack of response'. The difference in control-period activities may explain yet another difference in results between the two studies. In this study the subjects felt significantly less able to concentrate during the stress periods than during the corresponding control periods, whereas the subjects of the previous study felt most able to concentrate during the stress period. However, the former group compared a situation in which they performed an extremely difficult task presenting confusing stimulation with
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their ordinary work routine, the tasks of which are familiar and well mastered by the subjects. The subjects of the previous study, oh the other hand, compared a well-structured, although speed- and concentration-demanding situation with a totally unstructured situation in which they could read or listen to music or even to just let their mind wander. The results of this study also render some information on the question of seasonal variations of catecholamine output. This problem was discussed in a study by Johansson and Post (1974), who did not find any significant variations over one year. The present results support their finding as regards June and September. Only non-significant changes in adrenaline and noradrenaline excretion were found within this period. The rate at which adrenomedullary activity returns to baseline levels is supposedly determined by a number of factors, psychological as well as physiological. This study and the previous study by Johansson and Frankenhaeuser (1973) show that the individual's basic emotional balance, as well as his current state of mind and subjective wellbeing, are involved. Factors like physical health and the duration, intensity, and type of stressor were kept constant in these studies, but may deserve further investigation.
Acknowledgements The investigation was supported by grants from the Swedish Council for Social Science Research and the University of Stockholm. It was facilitated by a grant to Dr. Marianne Frankenhaeuser from the Swedish Medical Research Council (Project No. 997). Dr. Ulf Lundberg gave valuable advice concerning the scaling technique. The author is grateful to Anita Elgerot who participated in the data collection and to Lars Holmberg who carried out the catecholamine analyses.
References Bederoff-Peterson, A., J~'gtoft, K. and Astr6m, J. (1971). Eysenck Personality Inventory. Synpunkter och n~gra svenska unders6kningsdata. [Comments and some Swedish empirical findings.] Scandinavian Test Corporation: Stockholm. Bj6rkvaU, C. (1966). A note on inducing stress by an audio-visual-conflict test. Reports from the Psychological Laboratories, University of Stockholm, No. 210. Cannon, W.B. (1932). The Wisdom of the Body. Norton: New York. Euler, U.S.v. and Lishajko, F. (1961). Improved technique for the fluorimetric estimation of catecholamines. Acta Physiologica Scandinavica, 51,348-355. Eysenck, H.J. and Eysenck, S.B.G. (1964). Manual of the Eysenck Personality Inventory. University of London Press: London. Ferguson, G.A. (1966). Statistical Analysis in Psychology and Education. McGraw-Hill: New York. Frankenhaeuser, M. (1975). Sympathetic-adrenomedullary activity, behaviour and the psycho-
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social environment. In: Venables, P.H. and Christie, M.J. (Eds.) Research in Psychophysiology. Wiley: New York, 71-94. Frankenhaeuser, M., Mellis, I., Rissler, A., Bj6rkvali, C. and Pfitkai, P. (1968). Catecholamine excretion as related to cognitive and emotional reaction patterns. Psychosomatic Medicine, 30, 109-120. Frankenhaeuser, M. and Rissler, A. (1970). Effects of punishment on catecholamine release and efficiency of performance. Psychopharmacologia, 17,378-390. Johansson, G. (1973). Activation, adjustment and sympathetic-adrenal medullary activity. Field and laboratory studies of adults and children. Reports from the Psychological Laboratories, University of Stockholm, Suppl. 21. Johansson, G. and Frankenhaeuser, M. (1973). Temporal factors in sympatho-adrenomedullary activity following acute behavioral activation. Biological Psychology, 1,67-77. Johansson, G., Frankenhaeuser, M. and Magnusson, D. (1973). Catecholamine excretion of school children as related to performance and adjustment. Scandinavian Journal of Psychology, 14, 20-28. Johansson, G. and Post, B. (1974). Catecholamine output of males and females over a one-year period. Acta Physiologica Scandinavica, 92,557-565. Levi, L. (Ed.) (1972). Stress and Distress in Response to Psychosocial Stimuli. Acta Medica Scandinavica, 191, Suppl. 528. P.-itkai, P. (1970). Relations between catecholamine release and psychological functions. Reports from the Psychological Laboratories, The University of Stockholm, Suppl. 2. P:itkai, P., Frankenhaeuser, M., Rissler, A. and Bj~irkvall, C. (1967). Catecholamine excretion, performance, and subjective stress. Scandinavian Journal of Psychology, 8, 113-122. Rissler, A. (1967). Performance in a task involving conflict. In: Levi, L. (Ed.) Emotional Stress. F6rsvarsmedicin, 3, Suppl. 2. Stroop, J.R. (1935). Interference in serial verbal reactions. Journal of Experimental Psychology, 18,643-661. Thurstone, L.L. and MeUingcr, J.J. (1953). The Stroop test. Reports from the Psychometric Laboratories, University of North Carolina, No. 3. Winer, B.J. (1962). Statistical Principles in Experimental Design. McGraw-Hill: New York.
SUBJECTIVE WELLBEING AND TEMPORAL PATTERNS OF SYMPATHETICA D R E N A L MEDULLARY A C T I V I T Y GUNN JOHANSSON Department o f Psychology, University o f Stockholm, P.O. Box 6706, S-113 85 Stockholm, Sweden Accepted for publication 13 April 1976
Sixteen male subjects performed an audiovisual-conflict test during 1 h of an ordinary day of work. Adrenaline and noradrenaline excretion and subjective reactions were measured before, during, and after the test period as well as at corresponding points in time in a control day of ordinary work without interruption. This program was carried out on two occasions, which were expected to differ with respect to the subjects' general mental condition and wellbeing. There were large intraindividual as well as interindividual variations in the rate at which adrenaline output decreased after the stress period. The results support the hypothesis that rapid recovery to baseline levels is positively related to a relaxed, alert and subjectively pleasant state of mind.
1. Introduction The activity o f the sympathetic-adrenal medullary system is enhanced by a variety of physical as well as psychosocial stimuli (for reviews see Frankenhaeuser, 1975; Johansson, 1973; Levi, 1972). In this investigation urinary excretion of adrenaline and noradrenaline were used as indices o f peripheral catecholamine secretion. It has long been known (Cannon, 1932) that the adrenaline secreted from the adrenal medulla is o f vital importance for mobilization of physical energy in emergency situations. By stimulating glycogenolysis, the activity of the heart and the dilation o f arterioles in the skeletal muscles, etc., adrenaline facilitates adjustment to demands for the physical environment. Noradrenaline, which is also released from the adrenal medulla but mainly at the sympathetic nerve endings, plays an important role in maintaining blood pressure homeostasis. The mobilization of catecholamines in response to psychosocial stressors has also been shown to have beneficial effects on adjustment to demands in the psychosocial environment. Several studies have demonstrated positive relations between mental performance and concurrent rate o f adrenaline output (Frankenhaeuser and Rissler, 1970; P~itkai, Frankenhaeuser, Rissler and Bjfrkvall, 1967). In a few investigations a positive correlation between mental performance and noradrenaline 157
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output has been found (Frankenhaeuser, Mellis, Rissler, Bj6rkvall and P~itkai, 1968). A similar, positive relationship between adrenaline output in a school situation and performance in standardized tests of school achievement has also been found (Johansson, Frankenhaeuser and Magnusson, 1973). These relationships have commonly been explained in terms of increased general arousal (P~itkai, 1970). Although the release of catecholamines, in some respects, appears to have beneficial effects in a short perspective, it is evident that frequent or prolonged adrenal medullary activity may insert an extra load on several physiological functions in a way that may be harmful to the individual. However, so far, only little empirical evidence is available to test the validity of this assumption. Even less is known about possible mechanisms by which disease might develop (cf. Levi, 1972). When both the harmful and tile beneficial effects of adrenal medullary activity are taken into consideration it seems natural that the temporal pattern of adrenaline response should be one important part of the adjustment to external demands. A pattern of rapid mobilization in response to stressful experiences and, likewise, a rapid demobilization after elimination of the stressor would be the most 'economic' reaction and, thus, could be expected to promote optimal adjustment. Until recently, little attention has been focussed on the process of adrenaline 'recovery', i.e. return to baseline levels after exposure to a stressor. In a previous investigation in our laboratory (Johansson and Frankenhaeuser, 1973) considerable interindividual variation was found in the rate of adrenaline decrease. It was also demonstrated that subjects who performed well and who had low neuroticism scores showed the most 'economic' adrenaline response, i.e. their adrenaline excretion decreased rapidly. The noradrenaline excretion was not significantly affected by the stressor. The classification of subjects into slow and rapid 'decreasers' is of interest under the assumption that slow demobilization of adrenaline is, in some respect, undesirable. Equally important, from a prophylactic point of view, would be to explore intraindividual variations in rate of adrenaline decrease, since this may provide a possibility to specify the conditions under which individual subjects exhibit a rapid versus slow decrease. The aim of the present study was to explore intraindividual variation in the rate of adrenaline decrease after stress. By analogy with earlier findings concerning differences between rapid and slow decreasers, it was postulated that the time pattern of adrenaline release indicating optimal adjustment, i.e. the most rapid adrenaline decrease, would occur when the individual is in a relaxed, emotionally balanced and subjectively satisfactory mental condition. Therefore two situations, assumed to differ clearly in these respects, were chosen: a job setting before and after a period of vacation. It was known that the industry where the study was to be carried out reported less absence from work and less complaints about health problems during the period following summer vacations than during the rest of the year. On the basis of the above considerations, it was predicted that adrenaline excre-
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tion would return to baseline level after a period of_stress more rapidly after than before vacation.
2. Methods 2.1. Subjects and general design Sixteen male employees of a Swedish metal industry volunteered for the study. The subjects ranged in age between 22 and 35 yr (mean = 28.7 yr) and their body weights ranged between 59 and 78 kg (mean = 69.7 kg). They were white- and bluecollar workers in the research department of the plant and they were all nonsmokers or light to moderate smokers in good health. Before the experiment proper all subjects came to a 1 h introductory session. The experiments included four morning sessions, starting at 7:30 a.m. when the subjects arrived at work and lasting till noon, the start of the regular lunch hour. Two of the four sessions, a control and an experimental session, took place in June, 2 to 4 weeks before a period of summer vacation, and the procedure was repeated in September, 2 to 6 weeks after the vacation. Each subject had 3 to 4 weeks of vacation. The intervals between experimental periods and the beginning and end of the vacation were introduced to avoid interfering anticipatory and readjustment effects. The introductory session as well as control and experimental sessions were conducted at the subjects' place of work. Each subject was paid 25 Swedish kronas (about U.S. $6.00) for participating in the introductory session which took place off working hours. 2.2. Procedure In the introductory session the subjects were informed about the general procedure and about different conditions that might affect the variables to be investigated and therefore had to be avoided before and during the experiments, e.g. intake of coffee, drugs, alcohol and nicotine. They were instructed to standardize, as far as possible, their breakfast on the days of investigation. Instructions were given regarding the procedure for urine collection during the different sessions, and detailed information was given concerning the forthcoming sessions. Two psychological tests and a self-rating technique (see below), which were to be used in the experiments, were introduced. In the first part of the investigation the subjects participated in one control session and one experimental session on consecutive days. The conditions were rotated so that eight subjects started with the experimental session and eight subjects with the control session. When the procedure was repeated after the vacation each subject had the same order of conditions as on the first occasion. Data were collected
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on Tuesdays, Wednesdays, and Thursdays, and each subject was studied on the same weekdays on both occasions. Both the experimental (E) and control (C) sessions consisted of four 1 h periods (El- E4 and C1-C4) separated by 10 min intervals (fig. 1). Before the first period started each subject micturated in order to empty his bladder. All control periods, C1-C4, as well as experimental periods El, E3, and E4, were spent by the subjects in their regular work routine, except for the 10 min breaks during which urine samples were collected and self-ratings of mood and wakefulness were made. Control and experimental sessions diiYered only with respect to the second period. In the E2 periods the subjects performed two psychological tests (see below). 2.3. Experimental stress periods During the E2 periods, the subjects performed two types of tests. One of them, an audiovisual-conflict test, was chosen as being an effective stressor in group settings (P~itkai et al., 1967). The other test, a mental-arithmetic task, was interspersed in a pause between two periods of the audiovisual-conflict test. The E2 periods started with 5 min of instructions followed by 15 min of the audiovisual-conflict test. Another 5 min of instructions preceded the arithmetic test which was then performed for 20 min, and, finally, the audiovisual-conflict test was repeated during the remaining 15 min. 2.3.1. Audiovisual-conflict test The test was a modified form of the color-word test introduced by Stroop (1935) and used by several investigators in various forms (Bj6rkvall, 1966; Rissler, 1967; Thurstone and Mellinger, 1953). In essence the test consists of color words which are printed in different colors, the combination of words and colors being incongruent; for example, the word 'green' may be colored red, etc. The subject's task is to ignore the word and name the color of the print. In the present version of the test (Bj6rkvall, 1966), modified to suit a group
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situation, additional complications were introduced by simultaneous auditory presentation of conflicting color words, which also had to be ignored. The words were 'orange', 'cobalt', 'turquoise', and 'carmine'. The visual stimuli were projected on a screen and the auditory stimuli were presented via a loudspeaker; the two types of signals were synchronized. The combination of color words presented through the two senses was raadom. The duration of the visually presented words varied randomly between 0.4 and 1.0 sec and the interval between successive words varied between 0.8 and 1.7 sec. The test consisted of 12 blocks of 21 stimuli. Each block lasted for about 1 min and the intervals between blocks from 8 to 17 sec. The subjects responded to the stimuli by marking the correct word on a response sheet which contained successively numbered rows, each listing the four color words in random order. Tile performance score was equal to the percentage of correct responses out of the total number of possible responses. 2.3.2. Mental arithmetic test The arithmetic test (Norinder, unpublished) consists of a series of one-digit items arranged in pairs. The task is to add and subtract numbers according to certain rules. All operations have to be performed without the aid of pencil and paper, and only the final answer to each item is noted on the test sheet. Two scores were recorded: the number of items solved and the percentage of items correctly solved. 2.4. Catecholamine excretion
On arrival at work in the morning each subject emptied his bladder by voluntary voiding. Urine samples were then collected after each period, i.e. at 6 0 - 7 0 min intervals. The exact time of each micturation was noted. The pH of the urine was adjusted to about 3.0 with 2 N HCI and the volume was measured. The samples were stored at -18°C until analyzed by the fluorimetric method of Euler and Lishajko (1961). 2.4.1. Rate o f adrenaline decrease The temporal pattern of adrenaline secretion in response to the mental load introduced in period E2 was examined by the same procedure as in our previous study (Johansson and Frankenhaeuser, 1973), the diurnal variation in adrenomedullary function being taken into account. The design makes it possible to relate adrenaline values during successive periods in the experimental sessions to corresponding values in the control sessions. On the basis of this comparison it is possible to divide the subjects into two groups differing with regard to the temporal pattern of their secretion: (1) a group of 'rapid decreasers', defined as those who show a decrease of adrenaline output after the E2 period so that their excretion during E3 and/or E4 is equal to or below the C3 and/or C4 levels, (2) a group of 'slow decreasers' defined as subjects whose adrenaline output remains at an elevated level throughout th~ experimental session. That is, the excretion rate of these subjects is higher during the E3 and E4 than during the C3 and C4 periods.
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2.5. Self-ratings In each 10 min interval between successive periods the subject estimated his state during the preceding period in terms of different variables referring to mood and wakefulness. The following eight variables were rated: 'tired', 'apprehensive', 'happy', 'irritated', 'concentrated', 'stressed', 'relaxed', and 'alert'. In order to make each subject use, as far as possible, a constant frame of reference the following technique was used. Graphic scales of 120 mm were used and the subjects were told to let the endpoints of each scale represent the recollections of their maximum and minimum experience of that particular variable. The minimum was represented by the left and the maximum by the right endpoint. For each rating the subjects were instructed first to indicate by a vertical line the position of their 'ordinary' state of mind, and then to indicate, by a vertical arrow, their state of mind during the preceding period. The score used was the distance from the left endpoint to the arrow subtracted by the distance from the same endpoint to the vertical line. 2.6. Persona6ty hlventory The Eysenck Personality Inventory (Eysenck and Eysenck, 1964; translated into Swedish and modified by Bederoff-Peterson, J/igtoft and Astr6m, 1971) was administered to each subject individually a few days after he had participated in the last session of the investigation.
3. Results 3.1. Subjects' mental state and wellbeing on the two occasions o f investigation In response to the first, pre-vacation questionnaire all subjects rated their mental condition as generally being better in September than in June. The responses to the post-vacation questionnaire showed that all except two subjects felt in a better mental condition after the vacation than before. The two subjects who stated that their mental condition was better before they went on holiday explained that they had been unable to arrange their holiday in the way they had planned to. When asked about their physical condition six subjects said it was better after vacation than before and ten subjects claimed it was equally good on both occasions. Subjective estimates of mood and alertness, averaged over the four periods of each control session, were also used to appraise the subjects' general mental state on the two occasions of investigation. The results are shown in table 1. These average estimates for control days did not differ significantly between occasions for any of the variables. Thus, a difference between the two occasions of investigation in terms
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Table 1 Self-ratings (deviation from 'ordinary' state of mind) of mood and alertness averaged over control sessions on the In'st (column 1) and the second (column 2) occasion of investigation (arbitrary unit of measurement). Variable
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of subjects' mood and wellbeing was generally expressed in the questionnaires, whereas data collected in the actual situations did not differ significantly between occasions. It is possible that the differences were not large or distinct enough to affect the data that were collected in the actual situation.
3.2. General temporal patterns Catecholamine data and subjective estimates of mood and alertness for the entire group were submitted to a four-way analysis of variance and errorterms chosen according to a repeated measurement model presented by Winer (1962) 1. The results are presented in table 2. The pattern of adrenaline output (fig. 2) showed a high resemblance to the results o f the earlier study by Johansson and Frankenhaeuser (1973). During experimental days a peak level was reached during period E2. During control days the output rose slowly from period CI to C4. The analysis of variance showed that the effect o f time o f day (Periods 1--4) as well as the effect o f treatment × time of day was significant. Further information was gained by subsequent t-tests showing that in both experimental sessions the E2 levels of adrenaline output were significantly higher than the El levels (t = 4.006, p < 0.01, and t = 3.479, p < 0.01, respectively) but not significantly higher than the E3 and E4 levels. In both the control and the experimental sessions the first and the last periods differed significantly with regard to adrenaline output. Fig. 2 also shows that the average adrenaline-excretion levels were generally higher on the second occasion, although not significantly so (table 2), and that the general time pattern was almost identical for both conditions on 1 The complexity of the design, with each subject measured under all conditions, calls for an analysis for which appropriate data programs were lacking. The consequence of the method chosen is a conservative test of significance with increased risk for 'type II' error, i.e. false acceptance of the null hypothesis.
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the two occasions. For noradrenaline a markedly decreasing trend was observed within each occasion as well as between the two occasions. However, as shown in table 2, no significant effects were obtained for this variable. The average subjective estimates showed only minor variations, all falling within -+10 units of the total scale range of 120. Their temporal patterns were similar to those obtained in the previous study (Johansson and Frankenhaeuser, 1973). Thus, the subjects felt more 'tired' and 'stressed' and less 'relaxed' during E2 periods than during other periods. In opposition to results of the previous study they felt less 'concentrated' during the E2 periods than during other periods. The analyses of variance (table 2) showed that differences between occasions were non-significant for all subjective variables. Estimates of apprehension were significantly higher in experimental than in other sessions, and subjective stress varied significantly between
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the four periods. Significant interactions between treatment and time of day were observed for the variables 'tired', 'concentrated', and 'stressed' (fig. 3).
3.3. Rate of adrenaline decrease The temporal pattern of adrenaline output, averaged over subjects, is shown in fig. 2. The figure further shows that the average adrenaline decrease tended to be less complete before the vacation than after. On the former occasion the average adrenaline excretion did not reach control-day levels before the end of the fourth period, whereas after vacation baseline levels were reached during the E4 period. Furthermore, the E3-C3 difference was significantly larger before than after vacation (t = 2.311, p < 0.05). Individual rates of adrenaline decrease on both occasions of investigation are shown in tables 3 and 4. Table 3 shows that, just as in the previous study (Johansson and Frankenhaeuser, 1973), some subjects showed 'paradoxical' adrenaline reactions, i.e. their adrenaline excretion was lower in the E2 than in the C2 period.
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Table 3 The distribution of subjects on 'normal' and 'paradoxical' adrenaline reaction patterns on two occasions of investigation. Adrenaline reaction
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On the first occasion two subjects and on the second occasion five subjects exhibited this pattern. This increase from 15 to 31% was statistically significant (t = 2.747, p < 0.01). Table 4 shows that on the first occasion o f investigation 65% o f the subjects showing an adrenaline increase under stress were 'rapid decreasers' and 35% were 'slow decreasers'. The corresponding percentages on the second occasion were 55% 'rapid' and 45% 'slow decreasers'. The change in the relative frequencies was not significant. That is, the increase o f rapid decreasers, that had been expected, was not obtained. This means that as far as average adrenaline levels are concerned, the entire group o f subjects, in agreement with the hypothesis, recovered more rapidly on the second occasion o f investigation than on the first. However, when attention is focussed on individual data no change in the proportion o f rapid decreasers was obtained. A closer inspection o f the data showed that six subjects belonged to the same category o f reaction pattern on both occasions. Four of them were rapid decreasers, one was a slow decreaser, and one showed paradoxical adrenaline responses. The remaining ten subjects represented all possible combinations of reaction patterns. Thus, it is clear that intraindividual as well as interindividual variation may be found in the temporal pattern o f adrenaline release.
3.4. Variability versus constancy in the temporal pattern o f adrenaline release Since the subjects' general mental condition on the two occasions did not differ as markedly as expected, a complementary analysis was made in order to test the Table 4 The distribution of 'normally' reacting subjects on rapid and adrenaline decrease. Adrenaline decrease
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9 (65%) 5 (35%)
6 (55%) 5 (45%)
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11 (100%)
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hypothesis. Therefore, a subgroup comprising five subjects showing rapid decrease on one occasion and slow decrease on the other, was studied separately. (This group comprised all subjects who never showed paradoxical reactions and whose adrenaline-decrease pattern was differently classified on the two occasions.) In the following, intraindividual comparisons between occasions will be presented
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for these subjects and, for control purposes, for a group of four consistently rapid decreasers. On the basis of the initial hypothesis the latter group, i.e. those showing a consistent adrenaline-decrease pattern would be expected to show less variation of mood and wellbeing between the two occasions of investigation than the former group consisting of subjects with a variable decrease rate. Fig. 4 presents self-ratings of mood and alertness averaged over control days for subjects whose rate of adrenaline decrease varied between the two occasions. The graph shows that, on the whole, rapid adrenaline decrease after stress in these subjects was associated with a higher level of wellbeing than slow adrenaline decrease. The difference was statistically significant in several aspects. Thus, these subjects felt less tired (t = 3.934, p < 0.05), more relaxed (t = 3.031, p < 0.05), more alert (t = 7.795, p < 0.05), and happier (t -- 2.753, p < 0.05) on the occasion of rapid decrease than when their adrenaline decrease was slow. The consistently rapiddecrease group rated their mood very similarly on both occasions and no significant differences were observed. When corresponding comparisons were made for performance data it was found that the consistently rapid-decrease group showed significant differences between occasions with regard to mental arithmetic performance. Thus, they covered significantly more items in the arithmetic test (t = 6.529, p < 0.01) and solved a significantly larger proportion of these items correctly (t = 4.173, p < 0.05) on the second occasion than on the first one. For the variable decrease-rate group no differences in performance were found between the occasion of rapid adrenaline decrease and the occasion of slow decrease. It should be pointed out that the effect of training which was clearly borne out in the former group, and the difference in tiredness and alertness may have cancelled out a performance difference in the latter group. 3.5. lnterindividual differences in adrenaline decrease
Interindividual differences in adrenaline decrease were studied in the previous investigation (Johansson and Frankenhaeuser, 1973) under conditions which may be compared with those of the first occasion of the present investigation. The rapid and slow decreasers, as established on the first occasion, differed only slightly and non-significantly in other variables. The differences were, however, of the same direction as in the previous study, i.e. the rapid decreasers had slightly lower neuroticism scores on the EPI (Eysenck personality inventory), they performed slightly better, and they excreted more adrenaline during the entire control day than the slow decreasers.
4. Discussion
The aim of this study was to explore intraindividual variations in the rate at which adrenomedullary activity returns to baseline levels after a short period of
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strenuous mental activity. It was postulated that the adrenaline decrease would be more rapid when subjects were in a relaxed and emotionally balanced condition. On designing the study two occasions of examination were chosen which were expected to differ in respect of the subjects' general mental condition. Although this expectation turned out to be only partly true, support was obtained for the hypothesis posed. Thus, the subjects tended to return more rapidly to baseline levels of adrenomedullary activity under conditions of mental relaxation, alertness and general satisfaction than under conditions of tension and tiredness. The study also provides further data on interindividual variations in rate of adrenaline decrease. Such data were reported in a previous study (Johansson and Frankenhaeuser, 1973), the findings of which are in general agreement with the present data. In both studies a majority of the subjects returned to baseline level within 1 - 2 h after the end of a psychological test session, whereas a smaller group of subjects remained on an elevated level of excretion throughout the experimental sessions. The distribution of subjects on these two categories was identical in the two studies. In the previous study rapid adrenaline decrease was positively related to high baseline levels of adrenaline output, good performance, and low scores of neuroticism. Similar trends, although non-significant, were obtained in the present data. The failure to confirm a relationship between rate of adrenaline decrease and neuroticism may be due to insufficient sensitivity of the inventory or to a general difference in neuroticism levels between the two groups of subjects. The average neuroticism scores of the students in the first study were higher and their variability larger than the corresponding parameters of the present group. A distinct trend of this study was the increase from the first to the second occasion of the number of subjects showing a 'paradoxical' adrenaline reaction, i.e. subjects with a stress level of adrenaline output that was lower than the corresponding control level. When comparing the results of the two studies it should be kept in mind that the control condition in the present case was spent by the subjects in their regular work routine, whereas the subjects of the previous study spent the control periods under relaxing conditions, reading and listening to the radio. This difference is reflected in slightly lower adrenaline excretion under control conditions in the latter group. Thus, in this study a slightly higher general arousal level, in combination, perhaps, with a certain amount of habituation to the stressor may have contributed to the increased proportion of subjects on the second occasion who were less aroused during the test session than during their regular work. It may, in fact, be argued that this type of reaction is not really 'paradoxical' in the present context, but rather a 'lack of response'. The difference in control-period activities may explain yet another difference in results between the two studies. In this study the subjects felt significantly less able to concentrate during the stress periods than during the corresponding control periods, whereas the subjects of the previous study felt most able to concentrate during the stress period. However, the former group compared a situation in which they performed an extremely difficult task presenting confusing stimulation with
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their ordinary work routine, the tasks of which are familiar and well mastered by the subjects. The subjects of the previous study, oh the other hand, compared a well-structured, although speed- and concentration-demanding situation with a totally unstructured situation in which they could read or listen to music or even to just let their mind wander. The results of this study also render some information on the question of seasonal variations of catecholamine output. This problem was discussed in a study by Johansson and Post (1974), who did not find any significant variations over one year. The present results support their finding as regards June and September. Only non-significant changes in adrenaline and noradrenaline excretion were found within this period. The rate at which adrenomedullary activity returns to baseline levels is supposedly determined by a number of factors, psychological as well as physiological. This study and the previous study by Johansson and Frankenhaeuser (1973) show that the individual's basic emotional balance, as well as his current state of mind and subjective wellbeing, are involved. Factors like physical health and the duration, intensity, and type of stressor were kept constant in these studies, but may deserve further investigation.
Acknowledgements The investigation was supported by grants from the Swedish Council for Social Science Research and the University of Stockholm. It was facilitated by a grant to Dr. Marianne Frankenhaeuser from the Swedish Medical Research Council (Project No. 997). Dr. Ulf Lundberg gave valuable advice concerning the scaling technique. The author is grateful to Anita Elgerot who participated in the data collection and to Lars Holmberg who carried out the catecholamine analyses.
References Bederoff-Peterson, A., J~'gtoft, K. and Astr6m, J. (1971). Eysenck Personality Inventory. Synpunkter och n~gra svenska unders6kningsdata. [Comments and some Swedish empirical findings.] Scandinavian Test Corporation: Stockholm. Bj6rkvaU, C. (1966). A note on inducing stress by an audio-visual-conflict test. Reports from the Psychological Laboratories, University of Stockholm, No. 210. Cannon, W.B. (1932). The Wisdom of the Body. Norton: New York. Euler, U.S.v. and Lishajko, F. (1961). Improved technique for the fluorimetric estimation of catecholamines. Acta Physiologica Scandinavica, 51,348-355. Eysenck, H.J. and Eysenck, S.B.G. (1964). Manual of the Eysenck Personality Inventory. University of London Press: London. Ferguson, G.A. (1966). Statistical Analysis in Psychology and Education. McGraw-Hill: New York. Frankenhaeuser, M. (1975). Sympathetic-adrenomedullary activity, behaviour and the psycho-
172
G. Johansson / Wellbeing and temporal patterns of catecholamine output
social environment. In: Venables, P.H. and Christie, M.J. (Eds.) Research in Psychophysiology. Wiley: New York, 71-94. Frankenhaeuser, M., Mellis, I., Rissler, A., Bj6rkvali, C. and Pfitkai, P. (1968). Catecholamine excretion as related to cognitive and emotional reaction patterns. Psychosomatic Medicine, 30, 109-120. Frankenhaeuser, M. and Rissler, A. (1970). Effects of punishment on catecholamine release and efficiency of performance. Psychopharmacologia, 17,378-390. Johansson, G. (1973). Activation, adjustment and sympathetic-adrenal medullary activity. Field and laboratory studies of adults and children. Reports from the Psychological Laboratories, University of Stockholm, Suppl. 21. Johansson, G. and Frankenhaeuser, M. (1973). Temporal factors in sympatho-adrenomedullary activity following acute behavioral activation. Biological Psychology, 1,67-77. Johansson, G., Frankenhaeuser, M. and Magnusson, D. (1973). Catecholamine excretion of school children as related to performance and adjustment. Scandinavian Journal of Psychology, 14, 20-28. Johansson, G. and Post, B. (1974). Catecholamine output of males and females over a one-year period. Acta Physiologica Scandinavica, 92,557-565. Levi, L. (Ed.) (1972). Stress and Distress in Response to Psychosocial Stimuli. Acta Medica Scandinavica, 191, Suppl. 528. P.-itkai, P. (1970). Relations between catecholamine release and psychological functions. Reports from the Psychological Laboratories, The University of Stockholm, Suppl. 2. P:itkai, P., Frankenhaeuser, M., Rissler, A. and Bj~irkvall, C. (1967). Catecholamine excretion, performance, and subjective stress. Scandinavian Journal of Psychology, 8, 113-122. Rissler, A. (1967). Performance in a task involving conflict. In: Levi, L. (Ed.) Emotional Stress. F6rsvarsmedicin, 3, Suppl. 2. Stroop, J.R. (1935). Interference in serial verbal reactions. Journal of Experimental Psychology, 18,643-661. Thurstone, L.L. and MeUingcr, J.J. (1953). The Stroop test. Reports from the Psychometric Laboratories, University of North Carolina, No. 3. Winer, B.J. (1962). Statistical Principles in Experimental Design. McGraw-Hill: New York.