The Journal of General Psychology, 119(3), 217-228
Sustained Attention and the Type A Behavior Pattern: The Effect of Daydreaming on Performance ANTHONY R. PERRY Department of Psychology and Center for Complex Systems Brandeis University CYNTHIA A. LAURIE Department of Psychology Westminster College
ABSTRACT. The present study examined the ability of Qpe A and ?Lpe B subjects to sustain attention during a 40-min visual vigilance task. It was predicted that A subjects would perform better than Qpe B subjects and that the performance of both groups would be related to the frequency of daydreams during the vigil. lLpe A subjects outperformed Qpe B subjects with regard to perceptual sensitivity (A‘) and number of signal detections. Although both groups reported an increase in the number of their daydreams as the vigil progressed, Qpe A subjects reported fewer daydreams during each period of watch than did Qp e B subjects. In addition, an inverse relationship was found between the number of signal detections and the frequency of daydreams.
OVER 3 DECADES AGO, Friedman and Rosenman (1959) observed that their coronary heart disease patients shared a characteristic pattern of behaviors and emotional reactions. Friedman and Rosenman labeled this pattern ’ISlpe A behavior. Since then, the concept of the Type A behavior pattern has evolved to include a number of heterogeneous behavioral, emotional, and physical components (Matthews, 1982; Rosenman, Swan, & Carmelli, 1988). One behavioral characteristic of the m e A behavior pattern has been described as “hyperalertness or hypervigilance” (Price, 1982). It has been suggested that the 5 p e A individual’s hyperalertness is specific only to stimuli that are relevant to the task (Jennings, 1983). That is, when 5 p e A individuals are focused on a task, they seem to ignore peripheral stimuli that could adversely affect their successful performance. In a study by Matthews 217
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and Brunson (1979). Type A and Type B subjects performed the Stroop task while distracting noise was being presented. The Type A subjects outperformed the Type B subjects, suggesting that the Type A subjects actively ignored the task-irrelevant noise. Similarly, Moch (1984) exposed Type A and Type B subjects to steadily increasing noise while they were engaged in a complex memory task. Again, the Type A subjects consistently maintained their level of tolerance for the distracting noise, whereas the Type B subjects reported increased sensitivity to the noise as the experiment progressed. A series of related studies has demonstrated that Type A individuals not only ignore external peripheral stimuli but also appear to suppress internal cues that may interfere with their performance. For example, Carver, Coleman, and Glass (1976) reported that Type A subjects demonstrated greater suppression of fatigue than did Type B subjects on a treadmill test, even though the Type A subjects exerted greater effort. Similarly, Type A subjects do not report a variety of other physical symptoms during task performance, compared with Type B subjects (Weidner & Matthews, 1978). The Type A’s focused attentional style is not always advantageous, however. In Strube, Turner, Patrick, and Perrillo’s (1983) study, the peripheral stimuli (soothing music) was designed to reduce negative affect and enhance performance on a frustrating cognitive task, but only the Type B subjects benefited from the peripheral stimuli. These studies suggest that Type A and Type B individuals process information differently. Specifically, the data indicate that Type A individuals tend to filter out extraneous peripheral stimuli and distracting internal cues while remaining centrally focused on the task at hand. Bearing this in mind, we designed the present study to examine the ability of Type A and Type B subjects to sustain attention on a task for a prolonged period of time. Sustained attention, or vigilance, is usually studied experimentally, using tasks that require subjects to remain alert and to monitor displays for transient signals during continuous vigils that last from 30 min to an hour, or longer (Davies & Parasuraman, 1982; Davies & Tune, 1969). To date, the performance of Type A and Type B subjects during sustained attention has been examined in only one study that used this method (Lundberg, Warm, Seeman, & Porter, 1980). Lundberg et al. compared the performance of Type A and Type B subjects in a 1-hr visual vigilance task. Both groups of subjects demWe would like to thank Kevin M . Kane for his assistance in testing subjects und scoring data and also to acknowledge the support of T32-AGO0204from the National Institute on Aging. Address correspondence either to Anthony R . Perry. Department of Psychology and Center for Complex Systems, Brandeis University, Waltham. MA 02254, bitnet address Perry@Brandeis, or to Cynthia A. Laurie, Department of Psychology, Westminster College, New Wilmington. PA 16172.
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onstrated a typical vigilance decrement-a deterioration in signal detection over time that typifies performance in sustained attention or vigilance tasksduring the 1-hr session, and the rate of decline in signal detections was similar between ?Lpe A and Type B subjects. However, the Qpe A subjects’ performance was superior (they detected more signals) to the w e B subjects, performance throughout the session. Lundberg et al. (1980)suggested several hypotheses that might explain the Qpe A individual’s superior vigilance performance. Of particular relevance to the present study was the notion that ’Ifipe A individuals may be more able to resist internal distractions (i.e., daydreaming). The possibility of a relationship between daydreaming and sustained attention has been explored in previous experiments. In a classic study by Antrobus, Coleman, and Singer (1967)subjects were divided into high- and low-daydreaming groups, based on a self-report scale of daydreaming frequency, and were then given an auditory detection task. Antrobus et al. reported that a vigilance decrement was accompanied by an increase in the frequency of daydreams. Specifically, the high-daydreaming group exhibited a significant decrement in vigilance over time, whereas the low-daydreaming group showed little change in this area. The high-daydreaming group also reported the occurrence of significantly more thoughts that were unrelated to the auditory detection task. Perry et al. (1989)found a similar relationship between vigilance decrement and frequency of daydreams. Moreover, this effect was not limited to a select group, as it was in the Antrobus et al. study, but was observed in a broader sample of subjects who had not been selected for a predisposition to daydreaming. Thus, another aspect of the present study was to explore the possibility that the expected superior performance of Qpe A subjects in the vigilance task might be related to l &.A subjects having fewer daydreams during the experimental session.
Method Subjects We identified Qpe A and Qpe B subjects by administering the 21-item student version (Form T) of the Jenkins Activity Survey (JAS; Krantz,Glass, & Snyder, 1974)to students in a large introductory psychology class at the University of Cincinnati. Glass (1977)reported that, when the JAS is administered to large groups of undergraduates, the median score usually falls between 7 and 8. Our sample’s median score on the JAS was 8.5.Using the criteria established by Glass, we classified all individuals who scored 1 1 or above as Qpe A, and those who scored 4 or below as Type B. We selected at random 40 individuals from each classification from the pool of l&.A and m e B students and recruited them to participate in our experiment. The 40
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Q p e A students (14 women and 26 men) had JAS scores that ranged from 1 I to 21, with a mean of 14.48 (SD = 2.61). The 40 Type B students (19 women and 21 men) had JAS scores that ranged from 0 to 4, with a mean of 2.0 (SD = 1.06). The mean ages for the Type A and Type B groups were 18.7 and 19.3 years, respectively. All the subjects participated in the experiment to partially fulfill a course requirement in introductory psychology. Design and Procedure
Twenty subjects from each behavior pattern classification were randomly assigned to a vigilance alone condition, and 20 were assigned to a vigilance and daydream reporting condition. The vigilance alone condition was included as a control because the requirement to handle information from the vigilance display and to report the occurrence of daydreams might have affected performance. All four groups participated in a 40-min vigil, which was divided into four uninterrupted periods of 10-min each. The subjects’ task was to monitor the repetitive presentation of a pair of green vertically oriented 1 x 20 mm lines that were separated laterally by 15 mm. The line pairs appeared against a grey background in the center of the computer screen. Critical signals for detection were occasional 2-mm increments in the height of the pair of lines. Ten critical signals were presented per period of watch. The interval between signals varied from 20 to 100 s, with a mean of 60 s. Line pairs were presented at a rate of 30 per min, and the stimuli remained on the screen for 200 ms. In addition, stimulus events were displayed on the screen once every 2 s. The Type A and Type B subjects in the daydream reporting condition were instructed to be aware of the times during the experiment session when thoughts occurred that were not related to the task at hand (i.e., daydreams). Throughout the experimental session, the subjects heard a tone (1000 Hz at 53 dB), which prompted them to report daydreams by pressing a button. The experimental session began with the tone. Thereafter, the subjects were instructed to press a button whenever they heard the tone if daydreams or thoughts that were not related to the task had occurred since the last prompt. The prompts were presented 20 times per period of watch. Interprompt intervals ranged from 18 to 36 s, with a mean of 30 s. The Type A and Q p e B subjects in the vigilance alone condition (controls) also heard the tone and were told that it was not part of the experimental task. We used an Apple IIe microcomputer to orchestrate the presentation of all stimuli, deliver tone prompts, and record the subjects’ responses. The subjects indicated that they detected signals in the vigilance task by pressing a red button on the right side of the keyboard. Responses that occurred within 1,000 ms of the onset of a critical signal were recorded as correct detections, or hits, and all other responses were logged as errors of commission or false
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alarms. The button the subjects used to report daydreams or thoughts that were not related to the task was color-coded in black and located on the left side of the computer keyboard. The subjects were tested individually in a 1.01 x 1.23 x 1.98m Industrial Acoustics sound chamber. The computer screen was mounted at eyelevel on a table in front of the seated subjects. Ambient illumination was provided by a 40-watt bulb mounted in an aluminum cone-shaped fixture. The fixture was positioned to diffuse light evenly, minimizing glare on the screen. Ambient illumination in the chamber was 68 cd/m2. All the subjects surrendered their watches upon reporting to the laboratory. Thus they had no knowledge about the length of the session other than it would not exceed 1 hr. Prior to the initiation of the main session, the subjects participated in a 10-min practice session that duplicated the conditions they would be exposed to during the main task. After the practice period, the subjects left the sound chamber for approximately 5 min' while the experimenter prepared the computer for the main session. The experimenterwas unaware of the subjects' behavior pattern classification during the experimental session.
ReSUltS
PerjfonnanceMeasures Unlike the Lundberg et al. (1980) study, which only reported percentages of hits and false alarms for Type A and Qpe B subjects, the present study used nonparametric indices of perceptual sensitivity (A') and response criterion (B", Grier, 1971) calculated from the percentages of hits and false alarms for each subject in all experimental conditions. We used distribution-free measures in response to arguments that the assumptions of normality and equal variance in the noise and signal plus noise distributions necessary for their parametric analogues, d' and p, are not likely to be met in vigilance experiments (Craig, 1979; Warm & Jerison, 1984). Mean A' values for the ?Lpe A and Qpe B subjects in the daydream reporting and control conditions are plotted as a function of time in Figure 1. The figure shows that as a group, '&pe A subjects demonstrated superior perceptual sensitivity relative to that of Type B subjects, throughout the 40-min session. In addition, reporting daydreams had no apparent effect on percep tual sensitivity for either Type A or ?Lpe B subjects. A 2 x 2 x 4 (Behavior Pattern: Qpe A, Type B x Daydream Reporting: Yes, No x Periods of Watch) mixed analysis of variance (ANOVA), with periods of watch the only within-group factor, confirmed our impressions of the data shown in Figure 1. The ANOVA indicated that perceptual sensitivity was significantly greater for Qpe A subjects than for Type B subjects, F(1, 76) = 15.74, p c .001, w2 = .08. In addition, there was a significant main effect for periods of
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-z 3
0.85
.
0.80
-
0.75
-
0.70
-
0.65
'
>"
---@--.
Type
1
B - Control
2
3
4
Periods of Watch (10 Min) FIGURE 1. A' scores as a function of behavior pattern type and periods of watch for the control and daydream reporting conditions.
watch, F(3, 228) = 19.01, p < .00001, w2 = .09.There was also a significant Behavior Pattern x Periods of Watch interaction, F(3, 228) = 4.53, p < .01, w2 = .01. Newman-Keuls tests (with an alpha of .05 for all comparisons) indicated that perceptual sensitivity for Type A subjects dropped significantly only from Period 1 to Period 2, whereas perceptual sensitivity for Type B subjects dropped significantly from Period 1 to Period 2 and from Period 3 to Period 4. There was no main effect for daydream reporting, and all the other interactions in the analysis were nonsignificant ( p > .05). The results for perceptual sensitivity, A', were similar to those for detection probability. The results of an ANOVA based on an arcsin transformation of the percentages of correct signal detections indicated that signal detection probability was significantly greater for Type A subjects (59.63%) than for Type B subjects (45.50%), F(1, 76) = 11.28, p < .001, w2 = .07. The ANOVA also indicated that signal detection probability declined significantly over time (Period 1 = 66.50%, Period 2 = 52.50%, Period 3 = 49.63%, Period 4 = 41.63%), F(3, 228) = 30.50, p < .0001, w2 = .lo. The absence of a Behavior Pattern X Periods of Watch interaction ( p > .05) indicated that the rate of decline in signal detections over time was similar for the Q p e A and Type B groups. Mean B" scores for all experimental conditions are shown in Table 1. A 2 x 2 x 4 (Behavior Pattern: Type A, Type B x Daydream Reporting: Yes,
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TABLE 1
Mean B" Scores in all Experimental Conditions'
Behavior pattedCondition S P A
Control
Daydream reporting TypeB
Control
Daydream reporting
M
Period of watch 3 4
M
1
2
.30 .25
.44 .47
.47
.55
SO
.56
.44 .45
.21 .46 .31
.37 .58 .47
.39 .60 .49
.36
.33
.55
.55
.5 1
'Higher B" scores correspond to more conservative responses.
No x Periods of Watch) mixed ANOVA, with periods of watch the only within-group factor, indicated that both ?Lpe A and Qpe B subjects became significantly more cautious as the session progressed, F(3, 228) = 19.70, p < .0001, 02 = .04.In addition, there was a significant Behavior Pattern x Periods of Watch interaction, F(3, 228) = 2.77, p < .05, w2 = .001. Subsequent Newman-Keuls tests (with an alpha level of .05 for all comparisons) indicated that 'Qpe A and ?Lpe B subjects were equally conservative in their responses in Periods 1-3, but that ?Lpe A subjects became significantly more conservative than Qpe B subjects in Period 4. All other sources of variance in this analysis were nonsignificant (p > .05).
Daydreaming and Performance The average number of daydreams for ?Lpe A and ?Lpe B subjects is plotted as a function of periods of watch in Figure 2. Overall frequency of daydreams was greater for Qpe B subjects than for Qpe A subjects, and there was a general increase in the frequency of daydreams as the session wore on. This was conlirmed by the results of a 2 X 4 (Behavior Pattern: ?Lpe A, 'Qpe B x Periods of Watch) mixed ANOVA, which indicated significant main effects for behavior pattern, F( 1,38) = 5.91, p < .05, w2 = .08, and for periods of watch, F(3, 114) = 5.03, p < .01, w2 = .02. The interaction between these factors was not significant, F(3, 114) < 1 . A comparison of the perceptual sensitivity and detection data with the daydream report data indicates that the time course of signal detections and daydreaming varied in opposite directions (see Figure 3). The figure, based on group data, clearly shows that temporal declines in the frequency of signal detections were accompanied by increments in the frequency of daydreams.
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1
2
3
4
Periods of Watch (10 Min) FIGURE 2. Mean number of daydreams reported by Qpe A and Qpe B subjects as a function of periods of watch.
We also wanted to determine if this covariation could also be observed on an individual, as well as a group basis. Using a similar procedure reported by Perry et al. (1989). we calculated a correlation between the magnitude of the vigilance decrement and the temporal increment in daydreams by using difference scores between the first and last half of the vigil for the signal detection data and by subtracting second half scores of daydream data from first half scores. The difference scores for signal detections were positive in sign, whereas those for daydreams were negative. The correlation between the difference scores was significantly less than zero ( r = - .43, ’d = 38, p < .05, one-tailed test). Thus, the inverse relationship between the time course of signal detections and that of daydreams was present on an individual as well as on a group level.
Discussion The results of the present study confirm the report by Lundberg et al. (1980) that, compared with Type B individuals, Type A individuals demonstrate a superior ability to sustain attention to a task for a prolonged period of time. Specifically, the results of this study demonstrated that 5 p e A subjects had significantly higher scores of perceptual sensitivity (A’) and detected significantly more signals than did Type B subjects. These results are also consistent
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Periods of Watch (10 Min)
FIGURE 3. Mean number of signal detections (hits) and daydreams as a function of periods of watch.
with a previous report that ?Lpe A individuals are hyperalert in relation to 'I)rpe B individuals (Price, 1982). As we noted previously, performance in sustained attention tasks has been shown to be affected by daydreaming (Antrobus et al., 1967; Perry et al., 1989). A variety of other studies have demonstrated that ?Lpe A individuals are better able than Type B individuals to focus on a central task and to ignore distractions from external and internal sources that are not related to the task at hand (Jennings, 1983). A reasonable hypothesis drawn from these lines of research was that 'I).pe A subjects would outperform m e B subjects during a sustained attention task,benefiting from their ability to resist a prominent s o m e of distraction in such tasks-namely, daydreams. In fact, the results indicated that although the frequency of daydreaming for both groups increased as the session progressed, q p e A subjects reported having fewer daydreams during each period of watch than did 5 p e B subjects. The results of the present study indicate an apparent relationship between the vigilance performance of m e A and Qpe B subjects and the frequency of daydreaming, but there might be other contributing factors. One such factor, suggested by Lundberg et al. (1980), may be that 'Ifipe A individuals chronically respond to various situations with greater physiological arousal than do Type B individuals. Such differences have been reported. For example, 'Qpe A subjects tend to react to challenges with greater increases in
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indices of sympathetic nervous system activity, compared with Type B subjects (Houston, 1983; Jennings & Choi, 1981). Because there is evidence that performance during sustained attention is related to various indices of sympathetic arousal (Loeb & Alluisi, 1977; Parasuraman, 1984), it is conceivable that a heightened state of sympathetic arousal could enhance the vigilance performance of Type A subjects. The results of this study are important with respect to the findings of Antrobus and his coworkers (1967). Consistent with their report, the vigilance decrement was accompanied by an increase in the frequency of daydreams. Furthermore, as Perry et al. (1989) have found, this effect is not limited to individuals who have a predisposition to daydream, but can also be observed in a broader sample of subjects. In addition, the negative correlation between the magnitude of the vigilance decrement and the temporal increment in daydreams found in the present study indicated that this effect was observed on an individual basis within each group of Type A and Type B subjects. The present study may support a theoretical position put forth by Jerison ( 1970), regarding the nature of vigilance performance. Jerison’s elicited observing response rate hypothesis suggests that subjects in vigilance tasks constantly make sequential decisions about whether or not to emit observing responses about the display being monitored. Jerison treats these responses very broadly as “unitary attentive acts,” which may involve some form of message selection by the central nervous system. The theory asserts that detection failures occur when the subject does not emit these observing responses or does so in an imperfect manner. It also proposes that there is an energy cost in the effort to observe and that decisions to observe or not to observe are appropriately based on utility, that is, the overall cost of observing relative to the reward involved in detecting critical signals. Jerison’s hypothesis is a tempting theoretical position because it views the observer in sustained attention experiments as a dynamic information processor. However, as some researchers have noted (e.g., Dember & Warm, 1979), there have been no definitive tests of Jerison’s position because of the difficulty in examining the “internal observing response” independently of the observer’s performance. The combination of the results from this study and those of previous work (Antrobus et al., 1967; Perry et a]., 1989) suggest that a possible independent measure of Jerison’s observing response is the occurrence of daydreams, or thoughts that are not related to the task. REFERENCES
Antrobus, J. S., Coleman, R., & Singer, J. L. (1967). Signal-detection performance by subjects differing in predisposition to daydream. Journal of Consulting Psychology, 31. 487-49 1.
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Carver, C. S.,Coleman, A. E., & Glass, D. C. (1976). The coronary-prone behavior pattern and the suppression of fatigue on a treadmill test. Journal of Personality and Social Psychology,33, 460-466. Craig, A. (1979). Nonparametric measures of sensory efficiency for sustained monitoring tasks. Human Facrors, 21, 69-78. Davies, D. R., & Parasuraman, R. (1982). The psychology of vigilance. London: Academic Press. Davies, D. R., & n n e , G. S. (1969). Human vigilance performance. New York: Holt, Rinehart, & Winston. Dember, W. N., & Warm, J. S. (1979). Psychology of perception. New York. Holt. Rinehart, &Winston. Friedman, M., & Rosenman, R. H. (1959). Association of specific overt behavior pattern with blood and cardiovascular findings. Journal of rhe Americun Medical Association, 169, 1286-1296. Glass, D. C. (1977). Behawiorparrerns. stress, and coronary disease. Hillsdale, NJ: Erlbaum . Grier, J. B. (1971). Non-parametric indexes for sensitivity and bias: Computing formulas. Psychological Bulletin. 75, 424-429. Houston, B. K. (1983). Physiological responsitivity and the Qpe A behavior pattern. Journal of Research in Personality, 17, 22-39. Jennings, J. R. (1983). Attention and coronary heart disease. In D. S. Krantz, A. Baum, & J. E. Singer (Eds.), Handbook of psychology and healrh (Vol. 3, pp. 85-124). Hillsdale. NJ: Erlbaum. Jennings, J. R., & Choi, S. (1981). Qpe A components and the psychophysiological responses to an attention-demanding performance task. Psychosomatic Medicine, 43, 475-487. Jerison, H.J. (1970). Vigilance, discrimination and attention. In D. I. Mostofsky (Ed.), Arrenrion: Contemporary rheory and analysis (pp. 127-147). New York: Appleton Century-Crofts. Krantz. D. S.,Glass, D. C., & Snyder, M. L. (1974). Helplessness, stress level, and the coronary-prone behavior pattern. Journal of Experimental Social Psychology, 10, 284-300. Loeb, M., & Alluisi, E. A. (1977). An update of findings regarding vigilance and a reconsideration of underlying mechanisms. In R. R. Mackie (Ed.), Vigilance: Theory, operational performance and physiological correlates (pp. 7 19-749). New York Plenum Press. Lundberg, P. K.,Warm, J. S., Seeman, W., & Porter, P. K. (1980). Vigilance and rhe Type-A individual: Atrenrive, aroused and able. Paper presented at the meeting of the Midwestern Psychological Association, Chicago, It. Matthews, K. A. (1982). Psychological perspectives on the Qpe A behavior pattern. Psychological Bulletin, 91, 293-323. Matthews, K. A., & Brunson, B. (1979). Allocation of attention and Qpe A coronary-prone behavior. Journal of Personality and Social Psychology, 37,208 12090.
Mach, A. (1984). Qpe A and Qpe B behaviour patterns, task type and sensitivity to noise. Psychological Medicine, 14, 643-646. Parasuraman, R. (1984). The psychobiology of sustained attention. In J. S . Warm (Ed.), Sustained atrention in human performance (pp. 61-101). New Y o k Wdey. Perry, A. R., Warm, J. S.. Dember, W. N., Kane, K. M., Giambra, L. M., Scerbo, M. W., & McDaniel, C. (1989). Daydreaming and vigilance performance.Paper
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presented at the meeting of the Southern Society for Philosophy and Psychology, New Orleans, LA. Price, V. A. (1982). Type A behavior pattern: A model for research and practice. New York: Academic Press. Rosenman, R. H., Swan, G. E., & Carmelli. D. (1988). Definition, assessment, and the evolution of the Type A behavior pattern. In B. K. Houston & C. R. Snyder (Eds.), Type A behavior pattern: Research, theory, and intervention (pp. 8-3 1). New York: Wiley. Strube, M., Turner, C., Patrick, S., & Perrillo, R. (1983). Type A and Type B attentional responses to aesthetic stimuli: Effects on mood and performance. Journal of Personality and Social Psychology, 45, 1369-1379. Warm, J. S., & Jerison, H. J. (1984). The psychophysics of vigilance. In J. S . Warm (Ed.), Sustained attention in human performance (pp. 15-59). New York: Wiley. Weidner, G.. & Matthews, K. A. (1978). Reported physical symptoms elicited by unpredictable events and the Type A coronary prone behavior pattern. Journal of Personaliry and Social Psychology, 36. 1213-1 220.
Received January 21, 1992
Sustained Attention and the Type A Behavior Pattern: The Effect of Daydreaming on Performance ANTHONY R. PERRY Department of Psychology and Center for Complex Systems Brandeis University CYNTHIA A. LAURIE Department of Psychology Westminster College
ABSTRACT. The present study examined the ability of Qpe A and ?Lpe B subjects to sustain attention during a 40-min visual vigilance task. It was predicted that A subjects would perform better than Qpe B subjects and that the performance of both groups would be related to the frequency of daydreams during the vigil. lLpe A subjects outperformed Qpe B subjects with regard to perceptual sensitivity (A‘) and number of signal detections. Although both groups reported an increase in the number of their daydreams as the vigil progressed, Qpe A subjects reported fewer daydreams during each period of watch than did Qp e B subjects. In addition, an inverse relationship was found between the number of signal detections and the frequency of daydreams.
OVER 3 DECADES AGO, Friedman and Rosenman (1959) observed that their coronary heart disease patients shared a characteristic pattern of behaviors and emotional reactions. Friedman and Rosenman labeled this pattern ’ISlpe A behavior. Since then, the concept of the Type A behavior pattern has evolved to include a number of heterogeneous behavioral, emotional, and physical components (Matthews, 1982; Rosenman, Swan, & Carmelli, 1988). One behavioral characteristic of the m e A behavior pattern has been described as “hyperalertness or hypervigilance” (Price, 1982). It has been suggested that the 5 p e A individual’s hyperalertness is specific only to stimuli that are relevant to the task (Jennings, 1983). That is, when 5 p e A individuals are focused on a task, they seem to ignore peripheral stimuli that could adversely affect their successful performance. In a study by Matthews 217
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and Brunson (1979). Type A and Type B subjects performed the Stroop task while distracting noise was being presented. The Type A subjects outperformed the Type B subjects, suggesting that the Type A subjects actively ignored the task-irrelevant noise. Similarly, Moch (1984) exposed Type A and Type B subjects to steadily increasing noise while they were engaged in a complex memory task. Again, the Type A subjects consistently maintained their level of tolerance for the distracting noise, whereas the Type B subjects reported increased sensitivity to the noise as the experiment progressed. A series of related studies has demonstrated that Type A individuals not only ignore external peripheral stimuli but also appear to suppress internal cues that may interfere with their performance. For example, Carver, Coleman, and Glass (1976) reported that Type A subjects demonstrated greater suppression of fatigue than did Type B subjects on a treadmill test, even though the Type A subjects exerted greater effort. Similarly, Type A subjects do not report a variety of other physical symptoms during task performance, compared with Type B subjects (Weidner & Matthews, 1978). The Type A’s focused attentional style is not always advantageous, however. In Strube, Turner, Patrick, and Perrillo’s (1983) study, the peripheral stimuli (soothing music) was designed to reduce negative affect and enhance performance on a frustrating cognitive task, but only the Type B subjects benefited from the peripheral stimuli. These studies suggest that Type A and Type B individuals process information differently. Specifically, the data indicate that Type A individuals tend to filter out extraneous peripheral stimuli and distracting internal cues while remaining centrally focused on the task at hand. Bearing this in mind, we designed the present study to examine the ability of Type A and Type B subjects to sustain attention on a task for a prolonged period of time. Sustained attention, or vigilance, is usually studied experimentally, using tasks that require subjects to remain alert and to monitor displays for transient signals during continuous vigils that last from 30 min to an hour, or longer (Davies & Parasuraman, 1982; Davies & Tune, 1969). To date, the performance of Type A and Type B subjects during sustained attention has been examined in only one study that used this method (Lundberg, Warm, Seeman, & Porter, 1980). Lundberg et al. compared the performance of Type A and Type B subjects in a 1-hr visual vigilance task. Both groups of subjects demWe would like to thank Kevin M . Kane for his assistance in testing subjects und scoring data and also to acknowledge the support of T32-AGO0204from the National Institute on Aging. Address correspondence either to Anthony R . Perry. Department of Psychology and Center for Complex Systems, Brandeis University, Waltham. MA 02254, bitnet address Perry@Brandeis, or to Cynthia A. Laurie, Department of Psychology, Westminster College, New Wilmington. PA 16172.
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onstrated a typical vigilance decrement-a deterioration in signal detection over time that typifies performance in sustained attention or vigilance tasksduring the 1-hr session, and the rate of decline in signal detections was similar between ?Lpe A and Type B subjects. However, the Qpe A subjects’ performance was superior (they detected more signals) to the w e B subjects, performance throughout the session. Lundberg et al. (1980)suggested several hypotheses that might explain the Qpe A individual’s superior vigilance performance. Of particular relevance to the present study was the notion that ’Ifipe A individuals may be more able to resist internal distractions (i.e., daydreaming). The possibility of a relationship between daydreaming and sustained attention has been explored in previous experiments. In a classic study by Antrobus, Coleman, and Singer (1967)subjects were divided into high- and low-daydreaming groups, based on a self-report scale of daydreaming frequency, and were then given an auditory detection task. Antrobus et al. reported that a vigilance decrement was accompanied by an increase in the frequency of daydreams. Specifically, the high-daydreaming group exhibited a significant decrement in vigilance over time, whereas the low-daydreaming group showed little change in this area. The high-daydreaming group also reported the occurrence of significantly more thoughts that were unrelated to the auditory detection task. Perry et al. (1989)found a similar relationship between vigilance decrement and frequency of daydreams. Moreover, this effect was not limited to a select group, as it was in the Antrobus et al. study, but was observed in a broader sample of subjects who had not been selected for a predisposition to daydreaming. Thus, another aspect of the present study was to explore the possibility that the expected superior performance of Qpe A subjects in the vigilance task might be related to l &.A subjects having fewer daydreams during the experimental session.
Method Subjects We identified Qpe A and Qpe B subjects by administering the 21-item student version (Form T) of the Jenkins Activity Survey (JAS; Krantz,Glass, & Snyder, 1974)to students in a large introductory psychology class at the University of Cincinnati. Glass (1977)reported that, when the JAS is administered to large groups of undergraduates, the median score usually falls between 7 and 8. Our sample’s median score on the JAS was 8.5.Using the criteria established by Glass, we classified all individuals who scored 1 1 or above as Qpe A, and those who scored 4 or below as Type B. We selected at random 40 individuals from each classification from the pool of l&.A and m e B students and recruited them to participate in our experiment. The 40
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Q p e A students (14 women and 26 men) had JAS scores that ranged from 1 I to 21, with a mean of 14.48 (SD = 2.61). The 40 Type B students (19 women and 21 men) had JAS scores that ranged from 0 to 4, with a mean of 2.0 (SD = 1.06). The mean ages for the Type A and Type B groups were 18.7 and 19.3 years, respectively. All the subjects participated in the experiment to partially fulfill a course requirement in introductory psychology. Design and Procedure
Twenty subjects from each behavior pattern classification were randomly assigned to a vigilance alone condition, and 20 were assigned to a vigilance and daydream reporting condition. The vigilance alone condition was included as a control because the requirement to handle information from the vigilance display and to report the occurrence of daydreams might have affected performance. All four groups participated in a 40-min vigil, which was divided into four uninterrupted periods of 10-min each. The subjects’ task was to monitor the repetitive presentation of a pair of green vertically oriented 1 x 20 mm lines that were separated laterally by 15 mm. The line pairs appeared against a grey background in the center of the computer screen. Critical signals for detection were occasional 2-mm increments in the height of the pair of lines. Ten critical signals were presented per period of watch. The interval between signals varied from 20 to 100 s, with a mean of 60 s. Line pairs were presented at a rate of 30 per min, and the stimuli remained on the screen for 200 ms. In addition, stimulus events were displayed on the screen once every 2 s. The Type A and Type B subjects in the daydream reporting condition were instructed to be aware of the times during the experiment session when thoughts occurred that were not related to the task at hand (i.e., daydreams). Throughout the experimental session, the subjects heard a tone (1000 Hz at 53 dB), which prompted them to report daydreams by pressing a button. The experimental session began with the tone. Thereafter, the subjects were instructed to press a button whenever they heard the tone if daydreams or thoughts that were not related to the task had occurred since the last prompt. The prompts were presented 20 times per period of watch. Interprompt intervals ranged from 18 to 36 s, with a mean of 30 s. The Type A and Q p e B subjects in the vigilance alone condition (controls) also heard the tone and were told that it was not part of the experimental task. We used an Apple IIe microcomputer to orchestrate the presentation of all stimuli, deliver tone prompts, and record the subjects’ responses. The subjects indicated that they detected signals in the vigilance task by pressing a red button on the right side of the keyboard. Responses that occurred within 1,000 ms of the onset of a critical signal were recorded as correct detections, or hits, and all other responses were logged as errors of commission or false
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alarms. The button the subjects used to report daydreams or thoughts that were not related to the task was color-coded in black and located on the left side of the computer keyboard. The subjects were tested individually in a 1.01 x 1.23 x 1.98m Industrial Acoustics sound chamber. The computer screen was mounted at eyelevel on a table in front of the seated subjects. Ambient illumination was provided by a 40-watt bulb mounted in an aluminum cone-shaped fixture. The fixture was positioned to diffuse light evenly, minimizing glare on the screen. Ambient illumination in the chamber was 68 cd/m2. All the subjects surrendered their watches upon reporting to the laboratory. Thus they had no knowledge about the length of the session other than it would not exceed 1 hr. Prior to the initiation of the main session, the subjects participated in a 10-min practice session that duplicated the conditions they would be exposed to during the main task. After the practice period, the subjects left the sound chamber for approximately 5 min' while the experimenter prepared the computer for the main session. The experimenterwas unaware of the subjects' behavior pattern classification during the experimental session.
ReSUltS
PerjfonnanceMeasures Unlike the Lundberg et al. (1980) study, which only reported percentages of hits and false alarms for Type A and Qpe B subjects, the present study used nonparametric indices of perceptual sensitivity (A') and response criterion (B", Grier, 1971) calculated from the percentages of hits and false alarms for each subject in all experimental conditions. We used distribution-free measures in response to arguments that the assumptions of normality and equal variance in the noise and signal plus noise distributions necessary for their parametric analogues, d' and p, are not likely to be met in vigilance experiments (Craig, 1979; Warm & Jerison, 1984). Mean A' values for the ?Lpe A and Qpe B subjects in the daydream reporting and control conditions are plotted as a function of time in Figure 1. The figure shows that as a group, '&pe A subjects demonstrated superior perceptual sensitivity relative to that of Type B subjects, throughout the 40-min session. In addition, reporting daydreams had no apparent effect on percep tual sensitivity for either Type A or ?Lpe B subjects. A 2 x 2 x 4 (Behavior Pattern: Qpe A, Type B x Daydream Reporting: Yes, No x Periods of Watch) mixed analysis of variance (ANOVA), with periods of watch the only within-group factor, confirmed our impressions of the data shown in Figure 1. The ANOVA indicated that perceptual sensitivity was significantly greater for Qpe A subjects than for Type B subjects, F(1, 76) = 15.74, p c .001, w2 = .08. In addition, there was a significant main effect for periods of
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-z 3
0.85
.
0.80
-
0.75
-
0.70
-
0.65
'
>"
---@--.
Type
1
B - Control
2
3
4
Periods of Watch (10 Min) FIGURE 1. A' scores as a function of behavior pattern type and periods of watch for the control and daydream reporting conditions.
watch, F(3, 228) = 19.01, p < .00001, w2 = .09.There was also a significant Behavior Pattern x Periods of Watch interaction, F(3, 228) = 4.53, p < .01, w2 = .01. Newman-Keuls tests (with an alpha of .05 for all comparisons) indicated that perceptual sensitivity for Type A subjects dropped significantly only from Period 1 to Period 2, whereas perceptual sensitivity for Type B subjects dropped significantly from Period 1 to Period 2 and from Period 3 to Period 4. There was no main effect for daydream reporting, and all the other interactions in the analysis were nonsignificant ( p > .05). The results for perceptual sensitivity, A', were similar to those for detection probability. The results of an ANOVA based on an arcsin transformation of the percentages of correct signal detections indicated that signal detection probability was significantly greater for Type A subjects (59.63%) than for Type B subjects (45.50%), F(1, 76) = 11.28, p < .001, w2 = .07. The ANOVA also indicated that signal detection probability declined significantly over time (Period 1 = 66.50%, Period 2 = 52.50%, Period 3 = 49.63%, Period 4 = 41.63%), F(3, 228) = 30.50, p < .0001, w2 = .lo. The absence of a Behavior Pattern X Periods of Watch interaction ( p > .05) indicated that the rate of decline in signal detections over time was similar for the Q p e A and Type B groups. Mean B" scores for all experimental conditions are shown in Table 1. A 2 x 2 x 4 (Behavior Pattern: Type A, Type B x Daydream Reporting: Yes,
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TABLE 1
Mean B" Scores in all Experimental Conditions'
Behavior pattedCondition S P A
Control
Daydream reporting TypeB
Control
Daydream reporting
M
Period of watch 3 4
M
1
2
.30 .25
.44 .47
.47
.55
SO
.56
.44 .45
.21 .46 .31
.37 .58 .47
.39 .60 .49
.36
.33
.55
.55
.5 1
'Higher B" scores correspond to more conservative responses.
No x Periods of Watch) mixed ANOVA, with periods of watch the only within-group factor, indicated that both ?Lpe A and Qpe B subjects became significantly more cautious as the session progressed, F(3, 228) = 19.70, p < .0001, 02 = .04.In addition, there was a significant Behavior Pattern x Periods of Watch interaction, F(3, 228) = 2.77, p < .05, w2 = .001. Subsequent Newman-Keuls tests (with an alpha level of .05 for all comparisons) indicated that 'Qpe A and ?Lpe B subjects were equally conservative in their responses in Periods 1-3, but that ?Lpe A subjects became significantly more conservative than Qpe B subjects in Period 4. All other sources of variance in this analysis were nonsignificant (p > .05).
Daydreaming and Performance The average number of daydreams for ?Lpe A and ?Lpe B subjects is plotted as a function of periods of watch in Figure 2. Overall frequency of daydreams was greater for Qpe B subjects than for Qpe A subjects, and there was a general increase in the frequency of daydreams as the session wore on. This was conlirmed by the results of a 2 X 4 (Behavior Pattern: ?Lpe A, 'Qpe B x Periods of Watch) mixed ANOVA, which indicated significant main effects for behavior pattern, F( 1,38) = 5.91, p < .05, w2 = .08, and for periods of watch, F(3, 114) = 5.03, p < .01, w2 = .02. The interaction between these factors was not significant, F(3, 114) < 1 . A comparison of the perceptual sensitivity and detection data with the daydream report data indicates that the time course of signal detections and daydreaming varied in opposite directions (see Figure 3). The figure, based on group data, clearly shows that temporal declines in the frequency of signal detections were accompanied by increments in the frequency of daydreams.
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1
2
3
4
Periods of Watch (10 Min) FIGURE 2. Mean number of daydreams reported by Qpe A and Qpe B subjects as a function of periods of watch.
We also wanted to determine if this covariation could also be observed on an individual, as well as a group basis. Using a similar procedure reported by Perry et al. (1989). we calculated a correlation between the magnitude of the vigilance decrement and the temporal increment in daydreams by using difference scores between the first and last half of the vigil for the signal detection data and by subtracting second half scores of daydream data from first half scores. The difference scores for signal detections were positive in sign, whereas those for daydreams were negative. The correlation between the difference scores was significantly less than zero ( r = - .43, ’d = 38, p < .05, one-tailed test). Thus, the inverse relationship between the time course of signal detections and that of daydreams was present on an individual as well as on a group level.
Discussion The results of the present study confirm the report by Lundberg et al. (1980) that, compared with Type B individuals, Type A individuals demonstrate a superior ability to sustain attention to a task for a prolonged period of time. Specifically, the results of this study demonstrated that 5 p e A subjects had significantly higher scores of perceptual sensitivity (A’) and detected significantly more signals than did Type B subjects. These results are also consistent
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Periods of Watch (10 Min)
FIGURE 3. Mean number of signal detections (hits) and daydreams as a function of periods of watch.
with a previous report that ?Lpe A individuals are hyperalert in relation to 'I)rpe B individuals (Price, 1982). As we noted previously, performance in sustained attention tasks has been shown to be affected by daydreaming (Antrobus et al., 1967; Perry et al., 1989). A variety of other studies have demonstrated that ?Lpe A individuals are better able than Type B individuals to focus on a central task and to ignore distractions from external and internal sources that are not related to the task at hand (Jennings, 1983). A reasonable hypothesis drawn from these lines of research was that 'I).pe A subjects would outperform m e B subjects during a sustained attention task,benefiting from their ability to resist a prominent s o m e of distraction in such tasks-namely, daydreams. In fact, the results indicated that although the frequency of daydreaming for both groups increased as the session progressed, q p e A subjects reported having fewer daydreams during each period of watch than did 5 p e B subjects. The results of the present study indicate an apparent relationship between the vigilance performance of m e A and Qpe B subjects and the frequency of daydreaming, but there might be other contributing factors. One such factor, suggested by Lundberg et al. (1980), may be that 'Ifipe A individuals chronically respond to various situations with greater physiological arousal than do Type B individuals. Such differences have been reported. For example, 'Qpe A subjects tend to react to challenges with greater increases in
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indices of sympathetic nervous system activity, compared with Type B subjects (Houston, 1983; Jennings & Choi, 1981). Because there is evidence that performance during sustained attention is related to various indices of sympathetic arousal (Loeb & Alluisi, 1977; Parasuraman, 1984), it is conceivable that a heightened state of sympathetic arousal could enhance the vigilance performance of Type A subjects. The results of this study are important with respect to the findings of Antrobus and his coworkers (1967). Consistent with their report, the vigilance decrement was accompanied by an increase in the frequency of daydreams. Furthermore, as Perry et al. (1989) have found, this effect is not limited to individuals who have a predisposition to daydream, but can also be observed in a broader sample of subjects. In addition, the negative correlation between the magnitude of the vigilance decrement and the temporal increment in daydreams found in the present study indicated that this effect was observed on an individual basis within each group of Type A and Type B subjects. The present study may support a theoretical position put forth by Jerison ( 1970), regarding the nature of vigilance performance. Jerison’s elicited observing response rate hypothesis suggests that subjects in vigilance tasks constantly make sequential decisions about whether or not to emit observing responses about the display being monitored. Jerison treats these responses very broadly as “unitary attentive acts,” which may involve some form of message selection by the central nervous system. The theory asserts that detection failures occur when the subject does not emit these observing responses or does so in an imperfect manner. It also proposes that there is an energy cost in the effort to observe and that decisions to observe or not to observe are appropriately based on utility, that is, the overall cost of observing relative to the reward involved in detecting critical signals. Jerison’s hypothesis is a tempting theoretical position because it views the observer in sustained attention experiments as a dynamic information processor. However, as some researchers have noted (e.g., Dember & Warm, 1979), there have been no definitive tests of Jerison’s position because of the difficulty in examining the “internal observing response” independently of the observer’s performance. The combination of the results from this study and those of previous work (Antrobus et al., 1967; Perry et a]., 1989) suggest that a possible independent measure of Jerison’s observing response is the occurrence of daydreams, or thoughts that are not related to the task. REFERENCES
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Carver, C. S.,Coleman, A. E., & Glass, D. C. (1976). The coronary-prone behavior pattern and the suppression of fatigue on a treadmill test. Journal of Personality and Social Psychology,33, 460-466. Craig, A. (1979). Nonparametric measures of sensory efficiency for sustained monitoring tasks. Human Facrors, 21, 69-78. Davies, D. R., & Parasuraman, R. (1982). The psychology of vigilance. London: Academic Press. Davies, D. R., & n n e , G. S. (1969). Human vigilance performance. New York: Holt, Rinehart, & Winston. Dember, W. N., & Warm, J. S. (1979). Psychology of perception. New York. Holt. Rinehart, &Winston. Friedman, M., & Rosenman, R. H. (1959). Association of specific overt behavior pattern with blood and cardiovascular findings. Journal of rhe Americun Medical Association, 169, 1286-1296. Glass, D. C. (1977). Behawiorparrerns. stress, and coronary disease. Hillsdale, NJ: Erlbaum . Grier, J. B. (1971). Non-parametric indexes for sensitivity and bias: Computing formulas. Psychological Bulletin. 75, 424-429. Houston, B. K. (1983). Physiological responsitivity and the Qpe A behavior pattern. Journal of Research in Personality, 17, 22-39. Jennings, J. R. (1983). Attention and coronary heart disease. In D. S. Krantz, A. Baum, & J. E. Singer (Eds.), Handbook of psychology and healrh (Vol. 3, pp. 85-124). Hillsdale. NJ: Erlbaum. Jennings, J. R., & Choi, S. (1981). Qpe A components and the psychophysiological responses to an attention-demanding performance task. Psychosomatic Medicine, 43, 475-487. Jerison, H.J. (1970). Vigilance, discrimination and attention. In D. I. Mostofsky (Ed.), Arrenrion: Contemporary rheory and analysis (pp. 127-147). New York: Appleton Century-Crofts. Krantz. D. S.,Glass, D. C., & Snyder, M. L. (1974). Helplessness, stress level, and the coronary-prone behavior pattern. Journal of Experimental Social Psychology, 10, 284-300. Loeb, M., & Alluisi, E. A. (1977). An update of findings regarding vigilance and a reconsideration of underlying mechanisms. In R. R. Mackie (Ed.), Vigilance: Theory, operational performance and physiological correlates (pp. 7 19-749). New York Plenum Press. Lundberg, P. K.,Warm, J. S., Seeman, W., & Porter, P. K. (1980). Vigilance and rhe Type-A individual: Atrenrive, aroused and able. Paper presented at the meeting of the Midwestern Psychological Association, Chicago, It. Matthews, K. A. (1982). Psychological perspectives on the Qpe A behavior pattern. Psychological Bulletin, 91, 293-323. Matthews, K. A., & Brunson, B. (1979). Allocation of attention and Qpe A coronary-prone behavior. Journal of Personality and Social Psychology, 37,208 12090.
Mach, A. (1984). Qpe A and Qpe B behaviour patterns, task type and sensitivity to noise. Psychological Medicine, 14, 643-646. Parasuraman, R. (1984). The psychobiology of sustained attention. In J. S . Warm (Ed.), Sustained atrention in human performance (pp. 61-101). New Y o k Wdey. Perry, A. R., Warm, J. S.. Dember, W. N., Kane, K. M., Giambra, L. M., Scerbo, M. W., & McDaniel, C. (1989). Daydreaming and vigilance performance.Paper
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presented at the meeting of the Southern Society for Philosophy and Psychology, New Orleans, LA. Price, V. A. (1982). Type A behavior pattern: A model for research and practice. New York: Academic Press. Rosenman, R. H., Swan, G. E., & Carmelli. D. (1988). Definition, assessment, and the evolution of the Type A behavior pattern. In B. K. Houston & C. R. Snyder (Eds.), Type A behavior pattern: Research, theory, and intervention (pp. 8-3 1). New York: Wiley. Strube, M., Turner, C., Patrick, S., & Perrillo, R. (1983). Type A and Type B attentional responses to aesthetic stimuli: Effects on mood and performance. Journal of Personality and Social Psychology, 45, 1369-1379. Warm, J. S., & Jerison, H. J. (1984). The psychophysics of vigilance. In J. S . Warm (Ed.), Sustained attention in human performance (pp. 15-59). New York: Wiley. Weidner, G.. & Matthews, K. A. (1978). Reported physical symptoms elicited by unpredictable events and the Type A coronary prone behavior pattern. Journal of Personaliry and Social Psychology, 36. 1213-1 220.
Received January 21, 1992
