Effects of punishment on response latency in extraverts

Previous findings indicate that in comparison to introverts, extraverts are prone to form responses that are resistant to interruption by punishment. Because the tendency to stop and reflect following punishment may be crucial for subsequent learning, the present study was designed to examine differences between introverts' and extraverts' reactions to punishment using response latency on the trial following punishment as the dependent variable. Sixty-six extraverted and 66 introverted male undergraduates performed a pattern-matching task in which they received noncontingent 50% success and 50% failure feedback under three incentive conditions including reward only, punishment only, or both. As predicted, a significant interaction was found in the both condition, reflecting the tendency of extraverts to respond more quickly and introverts more slowly following punishment feedback than following reward feedback. No significant effects were found in the other two conditions; however, a tendency was noted for extraverts to respond more quickly overall when only reward was given. A second experiment using reward-only and punishment-only feedback replicated this finding and yielded a significant interaction of Group X Condition. The results indicate that in contrast to introverts, extraverts are activated by the availability of reward and, paradoxically, that punishment may facilitate rather than interrupt extraverts' reward seeking behavior.     

Electrodermal activity and extraversion: Caffeine,preparatory signal and stimulus intensity effects

The Eysenck hypothesis that introverts are more and extraverts less cortically aroused has been supported by the results of most electrodermal studies, though there is some inconsistency in the literature. Further tests of the hypothesis can be carried out using arousal-manipulation paradigms. Some studies have used caffeine or stimulus intensity to increase arousal, as was also the case in the present study. The latter, however, also introduced a preparatory signal, which may be expected under certain conditions, to reduce responses to the stimulus which follows it. Extraverts and introverts were randomly assigned to receive low, medium or high doses of caffeine or a placebo. Each S then heard two sets of tones with the tones in one set preceded by a preparatory signal. Results showed that the preparatory signal reduced phasic amplitudes only at the highest levels of stimulus intensity. Introverts had higher overall SCLs and response magnitudes. In addition, the preparatory signal had little effect on extraverts, but reversed dosage-related response patterns in introverts. Results were supportive of the basic Eysenck arousal hypothesis and also showed that the arousal difference leads to attentional variability between the two groups.     

Biological Bases of Extraversion Psychophysiological Evidence

There is a good deal of evidence, particularly from electrodermal and electrocortical recording procedures, that introverts exhibit greater reactivity to sensory stimulation than extraverts. There is little evidence that introverts and extraverts differ in base level of arousal in neutral conditions, and there is no clear evidence that their differences in sensitivity to stimulation are determined by differences in attentional state. Faster auditory brainstem evoked response latencies observed for introverts implicate differences in peripheral sensory processes that are not determined by mechanisms in the reticular system as proposed in the arousal hypothesis. There is also evidence that individual differences in the expression of motor activity between introverts and extraverts involve differences in motoneuronal excitability.     

Emotional influences on evaluative judgments: Roles of arousal,attention, and spreading activation

A conceptual framework and experimental technique for investigating the influence of phasic emotional states on information processing are described. The theoretical framework utilizes the constructs of arousal, attention, and spreading activation to characterize the potential nature of emotional effects. The experimental technique employs a game format within which simple emotional states are elicited by incentive warning signals and feedback signals occurring within each trial. Subjects judged the emotional tone of a target word presented following the warning signal, and reaction times and error rates were measured. Two experiments demonstrated an effect related to general arousal; responses were faster and less accurate following valuable as compared to neutral warnings. In addition, both studies found several more selective effects. A congruent incentive influence was evident in the more efficient processing of positive words following positive incentives and negative words following negative incentives. An incongruent outcome influence was evident in the more efficient processing of positive words following trials involving negative feedback. Analyses of processing benefits and costs indicated that these selective influences arose from attentional rather than spreading activation mechanisms. Control conditions demonstrated that neither effect was influenced by cognitive variables involving the symbolic form of the warning, the location of the warning, or the location of positive responses. Instead, the two effects depended primarily on the presence of a valuable as compared to neutral incentive signal. These results are discussed in light of contemporary model of interactions between emotion and cognition.These studies were conducted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the University of Oregon. I would like to thank my committee members S. W. Keele, M. I. Posner, and M. K. Rothbart, and also Marjorie A. Reed, for their many helpful suggestions.     

Extraversion and sleep: A psychophysiological study of the arousal hypothesis

In order to examine Eysenck's (1967) hypothesis concerning the relationship between extraversion and arousal, autonomic measures were taken from introverts and extraverts immediately before sleep and during 6 hr of sleep. Introverts and extraverts did not differ in heart rate (HR) or skin-potential response rate (SPR) during the pre-sleep period. A variety of sleep-related measures of arousal provided no strong support for the hypothesis that introverts are more aroused than extraverts. The only consistent autonomic difference between introverts and extraverts during sleep was a tendency for introverts to have higher SPRs in the second 3 hr of the night. The results are discussed in terms of the level of environmental stimulation present in the experimental conditions, and suggestions are made for future sleep studies of the relationship between extraversion and arousal.     

Effects of noise on sensitivity of introverts and extraverts to signals in a vigilance task

Forty Ss, previously classified as introverts or extraverts on the basis of scores on the Eysenck Personality Inventory, performed a visual vigilance task while being stimulated with noise at an intensity level of either 65 or 85 dB. Introverts given noise of 65 dB intensity showed an improvement in detection rate across trials, whereas introverts given noise of 85 dB intensity showed a decline in detection rate. Extraverts responded to noise of 65 dB intensity with a slight decrease in detection rate, but showed an improvement in detection over trials when noise of 85 dB intensity was given. When noise of the lower intensity was given, introverts showed greater sensitivity to signals than extraverts. When noise of the higher intensity was given, introverts and extraverts were equal in sensitivity. The results are discussed in terms of a hypothesized relationship between stimulation and arousal, with E-I as a moderator variable.     

Reaction to punishment, reflectivity, and passive avoidance learning in extraverts

Passive avoidance learning occupies a central role in accounts of disinhibited behavior, ranging from psychopaths' persistent criminality (Hare 1970) to extraverts' gregariousness (Gray, 1972). To explore the mechanism underlying passive avoidance deficits, we assessed the relation of extraversion, neuroticism, and response latency after punishment to passive avoidance learning by using two successive go/no go discrimination tasks. The tasks were designed to examine two aspects of subjects' reactions to punishment: response speed on trials immediately following punishment (Experiment 1) and time to terminate punishment feedback between successive trials (i.e., reflectivity; Experiment 2). Consistent with previous findings, the results of Experiment 1 showed that extraverts commit more passive avoidance errors than introverts do (Newman, Widom, & Nathan, 1985) and fail to pause following punished errors (Nichols & Newman, 1986). In Experiment 2, only neurotic extraverts displayed this pattern of performance differences. In both experiments, longer pausing following punishment predicted better learning from punishment for both introverts and extraverts. These results suggest that, in the presence of salient cues for reward, extraverts' characteristic reaction to punishment interferes with processing punished errors and may contribute to their more general propensity for impulsive, nonreflective action.     

The influence of introversion/extraversion on the skin conductance response to stress and stimulus intensity

A series of studies compared skin conductance level (SCL) for introverts and extraverts during a series of tones varying in both stimulus intensity (SI) and the amount of stress preceding the tones. When a difficult paired-associate task preceded the tones, both groups were about the same for 83 dB tones but extraverts were much higher at 103 dB, introverts failing to show an increase as a function of SI. There were no differences between the two groups following a simple paired-associate task, both groups showing a similar increase with increased SI. Finally, SCL was higher for introverts than extraverts during tones preceded by a rest period, and this was especially true for the early trials and for lower SI (75 and 83 dB compared with 100 and 103 dB). Taken together, these results suggest that SCL is higher for extraverts at higher levels of arousal but that the reverse is true for lower levels of arousal. This relationship is consistent with the theory that introverts have a “weak nervous system” which develops transmarginal or protective inhibition under stress.     

Effects of goal-related motivational states on the orienting of spatial attention

Three experiments are presented indicating that motivational processes arising from incentive and feedback signals exert specific effects on the orienting of visual spatial attention. Subjects played a video game in which targets were presented in one of two peripheral locations. Pre-target cues were employed to orient attention to a location where points could be gained (positive incentive cue), to a location where points could be lost (negative incentive cue) or to neither location (neutral cue). Cost-benefit analyses were used to assess the consequences of such orienting. Although there was no evidence of general attentional biases favoring positive over negative incentives, all three experiments demonstrated an interaction between the incentive value of the current trial and the outcome of the previous trial. Following unsuccessful outcomes, attentional costs were greater for positive than negative incentives, whereas following successful outcomes, costs were larger for negative than positive cues. This pattern was evident for tasks involving detection, perceptual discrimination and memory scanning. These findings are discussed in light of contemporary models of motivation and the control of attention.     

Individual differences in components of slow cortical potentials: implications for models of information processing

Individual differences in the effects of pharmacological and behavioural manipulations on slow cortical potentials (SCP), may reflect personality differences in type of informational control under attentional stress. Two experiments were conducted to examine SCP component differences in extraverts and introverts under different attentional tasks and with and without nicotine smoking ‘stressor’ conditions. In an initial experiment a decrease in late negativity for introverts and an increase in late negativity for extraverts suggested that smoking enhanced introverts' stimulus set and extraverts' motor set. In a second experiment, personality differences in SCP were examined again, but within a signal-detection paradigm, which allows separate assessment of the contribution of sensory sensitivity and response bias factors to performance. Smoking increased sensitivity in both personality groups, but response bias (caution) increased in introverts only. Extraverts showed an increase in central negativity during smoking whilst introverts showed a decrease in negativity and a decrease in positive wave components. The results are explained in terms of a motor model of attentional control whereby smoking regulates inhibitory controlled actions in introverts, but activates general motor processes for extraverts.     

Attention and personality in augmenting/reducing of visual evoked potentials

Earlier research has shown that extraverts tend to increase their visual evoked potential amplitudes with increasing light intensity (augmenting), while introverts reach their maximum amplitude at lower intensities (reducing). The evoked response has normally been measured from association areas of the brain (at the vertex). The present study measured VEP amplitudes over visual cortex and at the vertex, using four light intensities in two conditions, where attention was either directed towards the light stimuli, or away from them by a concurrent auditory task. Forty subjects were classified as extraverts or introverts based on the Eysenck Personality Inventory. The results show that attention interacted significantly with extraversion. Introverts exhibited a narrower focus of attention, while higher amplitudes and amplitude-intensity functions when attending to the light flashes and lower when distracted. Extraverts showed smaller differences between conditions, indicating a more evenly distributed attention. Higher arousal in introverts is the probable cause of their narrower focus of attention. There were marked differences in the distribution of activity between vertex and occipital cortex. Introverts showed relatively stronger occipital responses and extraverts stronger vertex responses across all intensities and in both conditions. The predisposition for mainly perceptual responses to aversive stimuli in introverts, and for general alerting and motor preparatory responses in extraverts, are interpreted as supportive of Brebner and Cooper's hypothesis that introverts are ‘geared to inspect’ and extraverts are ‘geared to respond’.     

Stimulus- or response-induced excitation. A comparison of the behavior of introverts and extraverts

The tendency to inspect visual material (slides) rather than to respond by pressing a key in an attempt to move on to the next slide, was compared among introverts and extraverts. As predicted from Brebner and Cooper (1974): (1) extraverts inspected the stimuli for a shorter time before making their first response, (2) extraverts made more responses at a faster rate than introverts did, and (3) extraverts produced a significantly higher proportion of runs of accelerating responses.     

Memory scanning,introversion-extraversion,and levels of processing

Individual differences in information processing were studied in the form of the hypothesis that arousal, as indexed by a personality measure of introversion-extraversion, affects the speed with which certain kinds of processing are completed. The Sternberg paradigm was used, and the results suggested that introverts and extraverts scanned for physical features equally rapidly, but that introverts were slower than extraverts at scanning for the semantic features of category membership. There was limited support for the hypothesis that introverts, thought to be more aroused than extraverts, are less able to engage in shared or parallel processing. It was concluded that information processing in introverts and extraverts may differ qualitatively as well as quantitatively.     

Simple visual reaction time,personality and strength of the nervous system: A signal-detection theory approach

Eysenck (1967) has reviewed evidence which suggests that introverts have a higher level of arousal than extraverts. Moreover, Gray (1967) has proposed that introverts have weak nervous systems, in the Russian terminology. Studies of simple reaction time such as that of Mangan and Farmer (1967) have posed problems for these views, but it is suggested that this may have been due to criterion differences between introverts and extraverts. In the present study a simple visual reaction-time task and a signal-detection task were conducted side by side. No significant differences between introverts and extraverts were found in measures of strength derived from the former, or measures of criterion derived from the latter. However, high N Ss were found to have a significantly lower value for Nebylitsyn's index of the slope of the reaction time/stimulus intensity function, thus supporting the view that high N Ss have relatively weak nervous systems.     

Extraversion and task properties as determinants of incidental recall

The present research investigated in a dual task design the effects of extraversion level and structural task properties on the recall of an incidentally learned text. First, the hypothetical relation between arousal level and attentional selectivity was tested. Second, the relation between structural levels in the text and recall of text elements was studied. It was found that (a) extraverts performed significantly better on incidental recall compared to introverts; (b) the nuclear sentences at the top of the hierarchical structure were the best recalled sentences, independently of arousal level; (c) the effect of differences in arousal on recall was only significant in case of the top sentences. The effect was absent in case of specificúsecondary sentences.     

Effects of smoking and nicotine on EEG lateralization as a function of personality

The effects of nicotine/smoking on lateralization of the EEG were evaluated in 40 smokers while they responded to a low-stress, visual vigilance task. Smoking a high-nicotine cigarette was associated with a relatively larger increase in right hemisphere EEG arousal in extraverts and Type-A individuals, but with a relatively larger increase in left hemisphere EEG arousal in introverts and Type Bs. These findings suggest that nicotine/smoking may differentially influence the left and right hemispheres and that this interaction may be a function of personality.     

Do extraverts get more bang for the buck? Refining the affective-reactivity hypothesis of extraversion

One of the most robust observations in personality and emotion research is the finding that extraverts are happier than introverts. Some theorists have attributed this to differential reactivity of the brain reward system, which is central to many biologically inspired models of extraversion. This affective-reactivity hypothesis, which suggests that extraverts should be more susceptible to the induction of positive affect, has so far received very mixed empirical support. In this article, we consider a more biologically plausible account of extraverts' affective-reactivity. Over 5 experiments, we demonstrate that extraverts show greater affective-reactivity only in response to clearly appetitive stimuli and situations (e.g., where rewards are being pursued). Conversely, after merely pleasant stimuli and situations (without any reward-approach element), extraverts and introverts respond similarly. We also show that it is specifically activated affect (e.g., feelings of alertness), rather than pleasantly valenced affect (e.g., feelings of contentment), that characterizes the affective-reactivity of extraverts. Such reactions may potentially facilitate the reward-seeking behavior associated with extraversion, but they seem unlikely to explain the broadly happy disposition of extraverts.     

Extraversion and electrodermal activity: arousability and the inverted-U

The Eysenck hypothesis that extraverts are less aroused or more inhibited than introverts has been subjected to a number of tests in the psychophysiological literature. Research to date suggests the need to clearly differentiate between tests of overall group differences in arousal or inhibition and studies of the differential reactions of the two groups to arousal manipulations. Psychophysiological studies of overall arousal differences in our laboratories and elsewhere have yielded somewhat inconsistent results for SCL, nonspecific response frequency, trials-to-criterion habituation and initial response amplitude, though dishabituation results are consistent with the expectation of higher amplitudes in introverts. Far more consistent are findings testing the inverted-U hypothesis, which suggests that introverts reach a point of optimal arousal at lower levels of stimulus input than do extraverts and hence should show earlier asymptotes and decrements in arousal measures. Using stimulus intensity and caffeine to manipulate arousal, we have found supportive results for SCL and several phasic measures, including the initial, test, and dishabituation responses. Overall, findings suggest that the two personality groups differ more clearly in arousability than in overall arousal level and that this difference is most consistent when conditions induce a rapid breakdown of inhibition and increase in arousal. Further research is needed to better understand the conditional relationship of extraversion to arousability, and arousal-manipulation paradigms would appear to be a fruitful initial approach to carrying out the needed research.     

奖惩线索条件下内外倾个体的自主唤醒和行为反应

将停止信号任务和金钱激励延迟任务相结合,使用16导生理记录仪记录被试的生理指标,探讨内外倾者在动机凸显情景下的生理唤醒特点以及反应调节能力。结果发现,隐含奖励和惩罚线索呈现之后,内外倾者的心率增快,内倾者的皮肤电活动显著增强。在停止信号任务中的优势反应阶段,内外倾者表现为对奖励凸显线索刺激的反应时缩短;而在非优势反应阶段,和外倾者相比较,内倾者的抑制反应错误率增高。表明内外倾者在奖惩线索条件下表现出不同的生理唤醒特点和行为反应。     

Extraversion and reward-related processing: probing incentive motivation in affective priming tasks

Based on an incentive motivation theory of extraversion (Depue & Collins, 1999), it was hypothesized that extraverts (relative to introverts) would exhibit stronger positive priming effects in affective priming tasks, whether involving words or pictures. This hypothesis was systematically supported in four studies involving 229 undergraduates. In each of the four studies, and in a subsequent combined analysis, extraversion was positively predictive of positive affective priming effects, but was not predictive of negative affective priming effects. The results bridge an important gap in the literature between biological and trait models of incentive motivation and do so in a way that should be informative to subsequent efforts to understand the processing basis of extraversion as well as incentive motivation.