Extraversion, arousal, and speed of retrieval from secondary storage.

Fifty-two subjects were assigned to one of four groups on the basis of scores on the Extraversion scale of the Eysenck Personality Inventory and on the General Activation scale of the Activation-Deactivation Adjective Check List. The subjects learned two lists composed of categorically related groups of words, with the number of categories and the number of words per category varied. Memory was probed by simultaneously presenting the subject with a category name and an item-position cue, and recording the recall latency. The major finding was that activation and extraversion interactively determined the recall latency for both category and item recall. The results were considered in light of arousal theory.     

The influence of background music on learners with varying extraversion: Seductive detail or beneficial effect?

Seductive details in general affect learning and cognitive load negatively. However, especially background music as a seductive detail may also influence the learner's arousal, whose optimal level depends on the learner's extraversion. Therefore, the effects of extraversion and background music on learning outcomes, cognitive load, and arousal were investigated. We tested 167 high school students and found better transfer outcomes for the group with background music. They also reported higher germane load, but no impact of background music on extraneous cognitive load or arousal was found. In the group without background music, learners with higher extraversion reached better recall scores, which was not found in the group with background music. Results may cautiously be interpreted that there is a beneficial impact of background music that compensates for the disadvantages of low extraverted learners and which cannot be explained through arousal.     

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.     

Personality and multidimensional arousal: A study of two dimensions of extraversion

Recent research has provided conflicting accounts of the effects of extraversion on arousal, and of the role of arousal in effects of extraversion and impulsivity of performance. Data are presented from a study of the inter-relationships of various dimensions of extraversion, self-report arousal and physiological arousal. Subjects also performed a verbal intelligence test. A composite measure of skin conductance and heart rate was significantly positively correlated with a self-report general arousal measure. 16PF Extraversion, and two primary extraversion factors, F and H, were significantly negatively correlated with physiological arousal, and/or one dimension of self-report arousal. The relationship between extraversion and arousal was not affected by time of day. An interactive effect of time of day, F and general arousal on performance was found, but there were no significant effects of H on performance. Relationships between extraversion and arousal may be epiphenomenal to interactive effects of extraversion or impulsivity and arousal on performance.     

Effects of noise, activation level, and response dominance on retrieval from semantic memory.

Subjects low or high in activation, as measured by Thayer's Activation-Deactivation Adjective Check List, participated in two semantic memory tasks, one involving speed of recall and the other speed of recognition. White noise at 80 db. re 20 muN/m-2 was presented on half the trials. There was an interaction between noise and activation under the recall condition only. High activation facilitated recall performance with high dominance items, but had a detrimental effect with low dominance items. The differential effect of arousal on recall and recognition was interpreted as indicating that arousal affected the retrieval component of recall. The findings with the dominance variable were interpreted in light of D.E. Broadbent's hypothesis that high arousal enhances the probability of sampling information from dominant sources.     

Individual differences in cognition: Some relationships between personality and memory

Individual differences in cognition were studied in the form of the hypothesis that arousal, as indexed by personality measures of extraversion and neuroticism, affects the way in which verbal material is organized in memory. Subjects pretested on measures of these personality variables participated in either a paired-associates learning or a free-recall experiment. On the paired-associates task, subjects who were thought to be high on arousal made fewer errors when response terms were semantically similar than low arousal subjects. On the other hand, subjects thought low on arousal made fewer errors when response words were phonetically similar than high arousal subjects. On the free-recall task, low arousal subjects were found to cluster words together on the basis of semantic category at a higher rate than high arousal subjects. These results were taken to support the view that high arousal (as indexed by personality measures) leads to a focus on the physical aspects of verbal material, whereas low arousal leads to a memory organized around semantic aspects. The implications of these findings for other views of memory are discussed.     

The relationship of age and extraversion to arousal and performance on a sustained attention task: A cross-sectional investigation using the Mackworth clock-test

H. J. Eysenck has postulated—and received some empirical support for—an inverse relationship between extraversion and arousal level. Age and extraversion have been found to be negatively correlated. These two outcomes led to the conclusion that arousal level must be increasing with age. This conclusion, however, runs counter to evidence which indicates a lowered arousal with old age. In an attempt to resolve this apparent conundrum a sample of 134 men from 32 to 91 years of age participated in the Mackworth Clock-Test of vigilance during which their arousal level was measured by electrodermal activity. One measure of arousal was unrelated to extraversion both within and across young, middle, and old age groups. For the second measure of arousal as age increased a decrease in arousal level was observed and the relationship of extraversion and arousal was found to be a function of age: inverse for young, none for middle-aged, direct for old. In addition no relation was found between vigilance performance and extraversion.     

Positive evidence for Eysenck’s arousal hypothesis: A combined EEG and MRI study with multiple measurement occasions

Eysenck’s arousal hypothesis suggests that introverts have greater cortical activity than extraverts. This prediction was tested in several studies that used the electroencephalogram (EEG) alpha activity to index cortical arousal, but empirical findings are inconsistent. Possibly, external factors of the measurement situation or static factors such as skull thickness may act as nuisance variables on alpha activity and thus mitigate the relation between arousal and extraversion. The aim of the present study was to test the arousal hypothesis with a focus on these methodological issues. Resting EEG was acquired on several occasions of measurement, skull thickness was quantified with anatomical magnetic resonance imaging (MRI), and extraversion was assessed by questionnaire. There was a positive association between alpha activity and extraversion, which was neither affected by external factors nor by skull thickness. This finding is in line with the arousal hypothesis and suggests that external or static factors do not contribute to the inconsistency of empirical findings.     

Sensation seeking and selective attention: focused and divided attention on a dichotic listening task.

Differences in selective attention as a function of sensation seeking, extraversion, neuroticism, and psychoticism were examined in 108 undergraduates using a dichotic listening task. Dependent measures included shadowing performance, reaction times to a secondary light task, target detection, and recall. The results suggested that high sensation seekers have better focused attention than low sensation seekers, and these effects were strongest on the 1st trials of the shadowing tasks. High sensation seekers did not attend differently than low sensation seekers to words related to their interests (sexual, violent, or drug related). Extraversion was associated with greater recall of these kinds of words, although there were no overall differences in selective attention as a function of Eysenck's dimensions. The role of arousal in personality and attention is discussed, particularly in regard to the response of sensation seekers to task novelty.     

The electrophysiological correlates of dream recall and nonrecall from stage 2 sleep

This research examined the relationship between cortical activation, defined by electroencephalographic (EEG) measures, and the ability to recall dreams following awakenings from Stage 2 sleep. Period-analyzed EEG data from 40 subjects were examined for the preawakening, postawakening, and preawakening-to-postawakening time intervals. Recall differed from nonrecall at the postawakening and preawakening-to-postawakening periods on measures of muscle activity and time spent in the sigma (12-16 Hz) frequency band. There were no distinctions in recall ability on EEG hemispheric asymmetry measures. Generally, the findings do not support the hypothesis linking increased recall ability to increases in cortical activation prior to awakening. However, the recall groups depicted a different pattern of arousal in their transition from sleep to wakefulness.     

Extraversion and Arousal Procrastination: Waiting for the Kicks

Procrastination is a prevalent and complex psychological phenomenon that has been defined as the purposive delay in beginning or completing a task. Given the potential implications for a broad range of situations, including both academic performance and safety sensitive occupations, it seems reasonable and judicious to systematically examine this phenomenon. While there is growing interest in procrastination, our understanding of underlying explanatory factors remains quite limited. Eysenck’s (1967) theory of personality, and in particular his biologically-based theory of extraversion, could shed light on this phenomenon. The purpose of this paper was to examine the relationship between extraversion and arousal procrastination. In accordance with Eysenck’s theory that extraverts tend to seek external sources of arousal, it was hypothesized that they would be more likely than introverts to engage in arousal procrastination. Participants completed a series of counterbalanced questionnaires measuring extraversion and procrastination. Results indicated that extraversion significantly predicted the engagement in this type of procrastination. Limitations, implications, and future research are discussed.     

Heart rate perception in the type A personality

Heart rate (HR) estimation and actual HRs were obtained from 28 Type A and 28 Type B males before and after receiving feedback about their actual HR levels, and during performance of a moderately stressful task, digit recall. Self-reports of affective arousal during digit recall were also obtained from the Anxiety scale of the Multiple Affect Adjective Check List (MAACL) and a self-report questionnaire measuring affective reactions. Type As showed significantly higher HR increases during the digit recall than did Type Bs. Type As also reported significantly more affective reactions than Type Bs on the self-report questionnaire, but not on the MAACL Anxiety scale. Type As significantly overestimated their HRs relative to Type B at rest before receiving feedback, and during the digit-recall task. These results contradict the usual assumption that Type As underestimate their arousal levels.     

The interactive effect of personality, time of day, and caffeine: a test of the arousal model

The personality dimension of introversion/extraversion is one of the few personality dimensions that can be reliably identified from study to study and investigator to investigator. The importance of this demension within personality theory is due both to the stability of the trait and the influential theory of H. J. Eysenck. The basic assumption in Eysenck's theory of introversion/extraversion is that the personality differences between introverts and extraverts reflect some basic difference in the resting level of cortical arousal or activation. Assuming that there is a curvilinear relationship (an inverted U) between levels of stress and performance leads to a test of this arousal theory. That is, moderate increases in stress should hinder the performance of introverts who are presumably already highly aroused. However, the same moderate increase in stress might help the performance of the presumably underaroused extraverts. Revelle, Amaral, and Turriff reported that the administration of moderate doses of caffeine hindered the performance of introverts and helped the performance of extraverts on a cognitive task similar to the verbal test of the Graduate Record Examination. Assuming that caffeine increases arousal, this interaction between introversion/extraversion and drug condition supports Eysenck's theory. This interaction was explored in a series of experiments designed to replicate, extend, and test the generality of the original finding. The interaction between personality and drug condition was replicated and extended to additional cognitive performance tasks. However, these interactions were affected by time of day and stage of practice, and the subscales of introversion/extraversion, impulsivity, and sociability, were differentially affected. In the morning of the first day, low impulsives were hindered and high impulsives helped by caffeine. This pattern reversed in the evening of the first day, and it reversed again in the evening of Day 2. We concluded that the results from the first day of testing require a revision of Eysenck's theory. Instead of a stable difference in arousal between low and high impulsives, it appeared that these groups differed in the phase of their diurnal arousal rhythms. The result is that low impulsives are more aroused in the morning and less aroused in the evening than are the high impulsives. A variety of peripheral or strategic explanations (differences in caffeine consumption, guessing strategies, distraction, etc.) for the observed performance increments and decrements were proposed and tentatively rejected. It seems probable that some fundamental change in the efficiency with which information is processes is responsible for these performance changes.     

Dishabituation and spontaneous recovery of the electrodermal orienting response: Effects of extraversion,impulsivity, sociability,and caffeine

The relationship between extraversion and psychophysiological indices of arousal is not yet fully understood. The present study attempted to further clarify this relationship by using caffeine to systematically manipulate arousal. Subjects pretested on the Eysenck Personality Inventory were given caffeine or a placebo, then underwent habituation, dishabituation, and spontaneous recovery of the electrodermal OR. Separate analyses examined the main and interactive effects of extraversion, impulsivity, and sociability with caffeine. Several tonic and phasic measures showed group reversal effects, with introverts having higher tonic levels and larger phasic responses under placebo conditions and extraverts having larger phasic responses and higher tonic levels under caffeine. Although both tonic and phasic responses were differentially affected, the group reversal effects occurred at different points in time on tonic than they did on phasic measures relative to the theoretical buildup of inhibition. The findings for impulsivity were quite consistent with those for extraversion, and both sets of results were generally supportive of the Eysenck hypothesis.     

Personality and risk of cognitive impairment 25 years later

The authors examined the relationship between personality and cognitive impairment in 4,039 members of the Swedish Twin Registry. Neuroticism and extraversion scores were collected in 1973 at midlife, and cognitive impairment was assessed in the same group 25 years later. Data were analyzed with case-control and co-twin control designs. Greater neuroticism was associated with higher risk of cognitive impairment in the results from case-control, but not from co-twin, analyses. Compared with both extraversion and introversion, moderate extraversion was associated with lower risk of cognitive impairment in both case-control and co-twin designs, as was the combination of high neuroticism and low extraversion. Findings are discussed in the context of theories related to personality, psychological distress, arousal, and cognitive function.     

The relationship between extraversion and verbal-imagery learning style in twelve-year-old children

The extraversion score of 12-yr-old children was compared with a measure of their verbal-imagery learning style and their immediate recall performance on concrete and abstract prose passages. Learning style was assessed by the verbal-imagery code test which attempts to monitor the presence of verbal associations and images during information processing. The test gives a ration which when high indicates high imaginal and low verbal performance, and when low the reverse. Extraversion was found to be significantly negatively correlated with the verbal- imagery code ratio. Further, a significant interaction between extraversion and passage type in their effect on recall was observed. Extraverts were superior on the abstract passage, while introverts did best on the concrete material. The findings were consistent with the interpretation that extraverts are verbalisers and introverts are imagers.     

Electrodermal responses to movie stressors: Nicotine × extraversion interactions

Support was found for Eysenck's hypothesis that the effects of smoking sized doses of nicotine on cortical and electrodermal activity are functions of extraversion and the degree of externally-induced arousal. Responses to scenes that elicited moderate electrodermal and emotional responses followed the predicted extraversion ☆ nicotine interaction for electrodermal measures, but not for self-reported emotions, heart rate or electromyographic measures. The failure of the Ss to demonstrate an extraversion ☆ nicotine interaction when high-intensity stimuli were used (Gilbert and Hagen, 1980) is also interpreted as consistent with Eysenck's hypothesis.     

Personality differences in mental imagery and the effects on verbal memory

This study examined the effects of extraversion and neuroticism on participants’ reported vividness of visual imagery and on their memory performance for concrete and abstract nouns. Groups of extraverts (n = 15) and introverts (n = 15) were selected from a larger original sample and asked to remember a series of concrete and abstract nouns, including a set of lexically ambiguous concrete homonyms (e.g., earth = 1. planet, 2. soil). Extraverts reported more vivid imagery than introverts but this did not translate into better recall for extraverts, even for concrete stimuli. Recall was best for unambiguous concrete nouns, followed by concrete homonyms, then abstract nouns. While initial analyses suggested that there was an interaction between extraversion and the type of word presented, later analyses revealed that neuroticism was the main driver in differences in recall between different word types. While differences in recall were best explained by context availability theory (Schwanenflugel, 1991) rather than dual coding theory (Paivio, 1991), questions remain about the power of either theory to explain the role of individual differences in personality on recall, particularly given that imagery vividness effects were related to extraversion while differences in recall were related to neuroticism. The implications of these findings for future research and theoretical development are discussed.     

Motivational influence on the quality of memories: recall of general autobiographical memories related to desired attributes

This article concerns recall of general autobiographical memories in motivated self‐perception. General memories, comprising abstraction of repeated or similar behaviours, have more impact on how one defines oneself than do specific memories. In a study, participants were first induced to believe that either extraversion or introversion leads to success. In the recall task that followed, introversion‐success participants recalled more general memories related to introversion than did extraversion‐success participants. In contrast, extraversion‐success participants recalled more general extraverted memories than did introversion‐success participants. Thus, to preserve a positive self‐image as characterized by desirable attributes, recall may be directed towards generation of general memories related to the attributes. Copyright © 2004 John Wiley & Sons, Ltd.     

Not too ‘shy’ to help catch a thief: Recall memory of shy versus non-shy witnesses

Witness shyness was examined to determine its impact on recall accuracy in two experiments. It was hypothesized that shyness would facilitate witness accuracy, under some conditions. In Experiment 1, witnesses were asked to respond to directed recall questions probing crime event and culprit details. Non-shy and shy witnesses produced comparable accuracy rates when describing the culprit. In contrast, non-shy witnesses were more accurate when describing crime environment details than shy witnesses. In Experiment 2, arousal was manipulated and a free recall approach was used to assess recall accuracy. Under low arousal, shy witnesses were more accurate at describing the culprit than non-shy witnesses, whereas, non-shy witnesses were more accurate at describing crime details than shy witnesses. Under high arousal, differences in accuracy were not observed across shy and non-shy witnesses.