Attention to Television: Alpha Power and Its Relationship to Image Motion and Emotional Content

A laboratory experiment investigated the impact of image motion and emotional content in brief television clips on attention. Using an electroencephalogram (EEG) as a measure of attention, cortical activity in 25 participants was measured while they viewed either still or moving emotion-provoking images. Spectral analysis of the EEG was done to gauge changes in alpha-wave (8-13 Hz) power because reductions in alpha power are thought to indicate greater attention. The analysis revealed that subjective reports of emotional arousal were directly related to cortical activation (i.e., reduced alpha power), and this was particularly true at the parietal recording site. The relationship between alpha power and ratings of valence was curvilinear; cortical activation was associated with both positive and negative images relative to neutral images. Alpha power was also reduced during the viewing of moving compared with still images, and this effect occurred independent of stimulus valence. The association of greater cortical activation with moving than with still images is consistent with previous research using autonomic measures and suggests that image motion modulates emotional responding-and sustains attention-primarily through increasing "gain" in the arousal dimension.     

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.     

Investigating models of affect: relationships among EEG alpha asymmetry, depression, and anxiety

The approach-withdrawal and valence-arousal models both predict that depressive and anxious profiles will be associated with relatively reduced left frontal and increased right frontal activity respectively, while the valence-arousal model also proposes a dissociation by lower and higher right parietotemporal activity, respectively. Recent work further suggests that subtypes of anxiety disorders may be characterized by distinctive patterns of activity depending on their type of arousal (anxious arousal/apprehension). The aim of this study was to investigate the relationships among nonclinical depression/anxiety and lateralized frontal/parietotemporal activity by categorizing participants (N=428) on the basis of both negative mood and alpha EEG. Key findings include: (i) greater right frontal lateralization in anxious participants, symmetrical frontal activity in depressed/comorbid, and left frontal lateralization in healthy controls; (ii) right frontal lateralization in anxious arousal participants, left frontal and right parietotemporal lateralization in anxious apprehension; (iii) bilateral increase in frontal and increased right parietotemporal activity in depressed/comorbid participants. Findings support predictions for frontal but not posterior regions. Grouping on the basis of EEG may not be reciprocally predictive of negative mood groupings, suggesting involvement of additional factors.     

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 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.     

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.     

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.     

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.     

QEEG markers of superior shooting performance in skilled marksmen: An investigation of cortical activity on psychomotor efficiency hypothesis

For elite performers, psychomotor behavior's success or failure can be traced to differences in brain dynamics. The psychomotor efficiency hypothesis suggests refined cortical activity through 1) selective activation of task-relevant processes and 2) inhibition of non-essential processes. The use of electroencephalography (EEG) has been applied to investigate psychomotor performance's neural processes. The EEG markers that reflect an elevation of psychomotor efficiency include left temporal alpha (T3 alpha), frontal midline theta (Fm theta), sensorimotor rhythm (SMR), and the coherence between frontal and left temporal regions. However, the relationship between elite performers' task-relevant and non-essential neural processes is still not well understood. Therefore, this study aimed to explore how each task-relevant and inhibition of non-essential processes contribute to superior psychomotor behavior. Thirty-five highly skilled marksmen were recruited to perform 30 shots in the shooting task while the EEG was recorded. The marksmen were divided into two groups (superior & inferior) based on a median split of shooting performance. The superior group exhibited higher accuracy and precision, with a reduction in movement jerk. EEG measures revealed that the superior group exhibited higher SMR before the trigger pull than the inferior group. In addition, the superior group demonstrated reduced Fz-T3 coherence in their bull's eye shots than the missed shots. These results suggest that the superior group exhibited less effortful engagement of task-relevant processes and lower interference from non-essential cortical regions than the inferior group. The study's overall findings support the psychomotor efficiency hypothesis. When comparing highly skilled performers, the slight differences in brain dynamics ultimately contribute to the success or failure of psychomotor performance.     

Cortical arousal and mentation in sleeping and waking subjects

Cognitive variables and cortical arousal levels were examined in order to determine whether differences in cortical arousal levels within REM and waking could account for different aspects of mentation derived from the two states. Cognitive variables were derived from mentation reports collected from 30 subjects in both the waking state and after being awakened from REM sleep. Mentation reports were independently scored on seven content rating scales, by two judges blind to the conditions. These scales include among others, Total Recall Count (TRC), a count of all words in which the subject described his/her experience during the previous interval. The EEG activity, obtained from left and right midtemporoparietal and central sites, was recorded for 5-min periods before obtaining mentation reports. The absolute power of the EEG activity was calculated for each of six bandwidths. EEG power data from both waking and REM were entered into multiple linear regression equations to predict TRC. No relationships were found between TRC and general cortical activation, as measured by the EEG. Other statistical analyses, including relationships between EEG and scales of visual imagery, are discussed.     

EEG correlates of posthypnotically controlled degrees of cognitive arousal

Experimental control over five degrees of cognitive (as opposed to organismic) arousal has been developed by hypnotic programming techniques. Previously, these posthypnotic manipulations have been applied to the investigation of diverse topics such as visual discrimination, performance on the Stroop test, selective concentration on color vs. form of consonants, and cognitive “reverberation.” The present study explored electroencephalographic (EEG) correlates of the five degrees of cognitive arousal in a task requiring participants to visualize objects for l-rain periods while lying on a couch with their eyes closed. Analysis of data from the occipital area in left and right hemispheres revealed that the highest degree of arousal was accompanied by larger amplitudes of alpha and beta power and smaller amplitudes of theta. This pattern of results was similar in both hemispheres, although more marked in the left. The findings, which provide an independent source of support for validity of the hypnotic programming, are discussed in relation to EEG literature on cognitive activity.     

The Effects of Textured Insoles on Cortical Activity and Quiet Bipedal Standing With and Without Vision: An EEG Study

Abstract

Wearing textured insoles (TIs) can reduce static postural sway, but the neurophysiological mechanisms by which these changes occur are not well understood. To address this issue, cortical activity was investigated in this study using electroencephalography (EEG) recordings from 19 scalp locations, in 15 healthy young adults (5 females; mean age = 27?±?4.09 years) during quiet bipedal standing, under different insole conditions (textured versus smooth), with and without vision. Compared to smooth insoles (SIs), TIs significantly reduced postural sway in two measures; anterior–posterior range and standard deviation. In the EEG data, whole-head analyses showed cortical activity in the upper alpha power band was significantly reduced for textured compared to SIs. Exploratory analyses revealed this effect was significant both with and without vision, and was more pronounced over the parietal, compared to central regions, and over central compared to frontal regions. This trend was observed in low alpha and theta bands, but the effect of insole type was not significant. Textured insoles thus appear to affect not only balance outcomes but also cortical activity. The cortical activity adaptation may represent greater information becoming readily available at the cortical level, enhancing the representation of the body in space.     

Emotional Television Scenes and Hemispheric Specialization

This study examined hemispheric differences¹ in cortical arousal as a function of positive and negative emotional television scenes. A three-factor within-subjects design was used: hemispheres (right and left), location of cortical arousal (frontal and occipital), and emotional content of messages (positive and negative). Based on findings that the frontal cortex responds differently to emotional stimuli, it was predicted that negative television content would produce greater right hemisphere activity, and that positive content would produce greater left hemisphere activity, but that differences would be apparent only in the frontal region. The results confirmed these predictions. There was a significant interaction between hemisphere and emotional content for frontal alpha, but no interaction for occipital alpha.² There were two other main effects: (1) greater cortical arousal for negative than positive scenes, and (2) greater occipital than frontal arousal. The results are discussed in relation to a definition of emotional scenes that emphasizes approach (positive emotion) versus withdrawal (negative emotion), and in relation to hemispheric specialization and the ability of television to prime overt behavior.     

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.     

Oscillatory brain responses evoked by video game events: the case of super monkey ball 2.

Electroencephalography (EEG) was recorded while the subjects played a video game where the player had to steer a monkey into a goal while collecting bananas for extra points and had to avoid falling off the edge of the game board. Each of these three studied events evoked differential EEG oscillatory changes. Picking up bananas evoked decreased theta activation on central electrodes, decreased high alpha activation on frontal electrodes, and increased beta activation on frontal electrodes. Falling off the game board evoked decreased central theta activation and increased fronto-central beta activation. Reaching the goal evoked increased theta activation on parietal electrodes, increased low alpha activation on frontal electrodes, increased high alpha activation on frontal, central, and parietal electrodes, and increased beta activation on frontal and central electrodes. It is suggested that the EEG oscillations evoked by picking up bananas reflect increased cortical activation and arousal; the oscillations evoked by falling off the edge of the game board reflect motor functions; and the oscillations evoked by reaching the goal reflect a relaxed state. Thus, EEG may turn out to be a valuable tool when examining psychological responses to video game events.     

Intelligence and spatiotemporal patterns of event-related desynchronization (ERD)

Recently, several studies have reported negative associations between brain activity under cognitive load and psychometric intelligence. The position emission tomography (PET) used in these studies allows a high spatial resolution, but it does not permit an assessment of the temporal course of cerebral activation. Therefore, this study examined the relationship between psychometric intelligence (determined by Raven's Advanced Progressive Matrices) and spatiotemporal patterns of cortical activation. Seventeen university students performed an elementary cognitive task, the Sentence Verification Test (SVT), during which the electroencephalogram (EEG) was recorded. In the EEG, the event-related desynchronization (ERD) was quantified, which can be interpreted as a correlate of cortical activation. Lower IQ participants displayed a comparatively unspecific cortical activation increasing with time, whereas higher IQ participants were characterized by a temporal development of activation in those cortical regions that are required for task performance, resulting in less overall activation as compared to the lower IQ participants. These findings support the hypothesis of a more efficient use of the brain in higher IQ individuals.     

EEG characteristics prior to and following the evoked K-Complex.

This study was designed to determine if the K-Complex reflects an arousal from sleep or a sleep protection mechanism. Ten participants were presented auditory stimuli every 20 s while asleep. Trials were sorted according to the presence or absence of a K-Complex. A fast Fourier Transformation of the data was computed on EEG segments prior to and following stimulus onset. The log power of activity in delta, theta, alpha, sigma, and beta bandwidths was computed. When a K-Complex was elicited, there were no differences in EEG activity prior to and following the stimulus. However, during slow wave sleep, when a K-Complex was not elicited, there was a significant overall increase in theta, alpha, sigma, and beta activity following stimulus. These results tend to support the notion that the K-Complex appears to prevent arousal.     

Rostral anterior cingulate activity generates posterior versus anterior theta activity linked to agentic extraversion

Recent research using the resting electroencephalogram (EEG) showed that posterior versus anterior theta activity (around 4–8 Hz) is consistently associated with agency, reflecting the dopaminergic core of extraversion (i.e., incentive motivation, positive emotion). Neuroimaging studies using various methodologies and experimental paradigms have converged on the anterior cingulate cortex (ACC) as a neurophysiological correlate of extraversion. The aim of the present study is integrate these lines of research by testing the hypothesis that posterior versus anterior EEG theta is at least partly based on ACC theta activity. Resting EEG data were analyzed in N = 78 healthy, male participants extremely high or low in agentic extraversion (aE). Using the low-resolution electromagnetic tomography algorithm, we localized the sources of aE-dependent intracerebral theta activity within rostral subdivisions of the ACC. The posterior versus anterior index and theta current density within the rostral ACC were significantly correlated (r = -.52), and both displayed high retest stability across 5 hr and were associated with traits from the aE spectrum. These neurophysiological correlates of aE and their possible functional significance are discussed.     

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.     

Electroencephalographic and autonomic alterations in subjects with frequent nightmares during pre-and post-REM periods

Abnormal arousal processes, sympathetic influences, as well as wake-like alpha activity during sleep were reported as pathophysiological features of Nightmare Disorder. We hypothesized that in Nightmare Disorder, wake-like cortical activity and peripheral measures linked to arousals would be triggered by physiological processes related to the initiation of REM periods. Therefore, we examined electroencephalographic (EEG), motor and autonomous (cardiac) activity in a group of nightmare (NM) and healthy control (CTL) subjects during sleep-state-transitions while controlling for the confounding effects of trait anxiety. Based on the second-nights’ polysomnographic recordings of 19 Nightmare Disordered (NM) and 21 control (CTL) subjects, we examined the absolute power spectra focusing on the alpha range, measures of heart rate variability (HRV) and motor (muscle tone) activity during pre-REM and post-REM periods, separately. According to our results, the NM group exhibited increased alpha power during pre-REM, but not in post-REM, or stable, non-transitory periods. While CTL subjects showed increased HRV during pre-REM periods in contrast to post-REM ones, NM subjects did not exhibit such sleep state-specific differences in HRV, but showed more stable values across the examined sleep stages and less overall variability reflecting generally attenuated parasympathetic activity during sleep-state-transitions and during stable, non-transitory NREM states. These differences were not mediated by waking levels of trait anxiety. Moreover, in both groups, significant differences emerged regarding cortical and motor (muscle tone) activity between pre-REM and post-REM conditions, reflecting the heterogeneity of NREM sleep. Our findings indicate that NM subjects’ sleep is compromised during NREM–REM transitions, but relatively stabilized after REM periods. The coexistence of sleep-like and wake-like cortical activity in NM subjects seems to be triggered by REM/WAKE promoting neural activity. We propose that increased arousal-related phenomena in NREM–REM transitions might reflect altered emotional processing in NM subjects.