A recent theory suggests that the agency facet of Extraversion (E) is based on brain dopamine (DA). The paucity of human data relevant to this model is probably due to the lack of widely accessible noninvasive psychophysiological indices and well-established behavioral measures sensitive to both E and manipulations of DA activity. Aiming to identify such measures, the authors assessed the electroencephalogram and n-back task performance in groups of introverts and extraverts after administration of either placebo or a selective DA D2 receptor antagonist. As predicted, the antagonist's effects on n-back reaction time measures and frontal versus parietal electroencephalogram theta activity were strongly and specifically modulated by E. New research avenues and theoretical extensions suggested by these results are discussed.

State effects on frontal alpha electroencephalograph asymmetry (ASY) are thought to reflect approach and withdrawal motivational tendencies. Although this motivational direction model has inspired a large body of research, efforts to disentangle influences of emotion (EMO) and motivational direction (MOT) on ASY are rare. The authors independently manipulated EMO (fear and anger) and MOT (approach and withdrawal) in a between-subjects design. Irrespective of MOT, anger led to greater changes toward relative left frontal activation (LFA) than did fear. Conversely, higher ratings of negative valence were associated with greater changes toward LFA in withdrawal but with greater changes toward relative right frontal activation in approach. Results are discussed within a model based on behavioral inhibition system-behavioral activation system theory.

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The convergent and discriminant validity of three models of physiological emotion specificity were compared. Forty-two female students served as subjects in a 2 (Context of emotional inductions: real-life, imagery) X 3 (Emotion: fear, anger, control) +1 (Happiness induced in real-life context) repeated measures design. The dependent measures included self-reports of emotion, Gottschalk-Gleser affect scores, back and forearm extensor EMG activity, body movements, heart period, respiration period, skin conductance, skin temperatures, pulse transit time, pulse volume amplitude, and blood volumes. Self-report data confirmed the generation of affective states in both contexts, as intended. Planned multivariate comparisons between physiological profiles established discriminant validity for fear and anger in the real-life context, whereas under imagery, emotion profiles were essentially equal. Convergent validity could not be substantiated. Implications for models of physiological specificity of emotion were discussed.

We investigated psychophysiological responses to fear and anger inductions during real-life and imagination. Female participants (N = 158) were assigned to a fear-treatment, fear-control, anger-treatment, or anger-control group. Context (real-life, imagination) was varied in two sessions of fixed order. Eleven self-report and 29 somatovisceral variables were registered. Results showed that (a) except during anger imagination, control groups were emotionless; (b) in control groups, contexts prompted diverging somatovisceral responses, but similar emotion self-reports; except during fear imagination, the emotion inductions (c) were successful and (d) produced specific emotion reports; (e) during real-life, somatovisceral fear and anger responses exhibited a marked cardiovascular defense reflex; (f) in addition, real-life fear showed an adrenaline-like specific response pattern, whereas real-life anger showed specific forehead temperature and EMG extensor increases, accompanied by an elevated DBP during imagination. A Component Model of Somatovisceral Response Organization is proposed.

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We investigated psychophysiological responses to fear and anger inductions during real-life and imagination. Female participants (N = 158) were assigned to a fear-treatment, fear-control, anger-treatment, or anger-control group. Context (real-life, imagination) was varied in two sessions of fixed order. Eleven self-report and 29 somatovisceral variables were registered. Results showed that (a) except during anger imagination, control groups were emotionless; (b) in control groups, contexts prompted diverging somatovisceral responses, but similar emotion self-reports; except during fear imagination, the emotion inductions (c) were successful and (d) produced specific emotion reports; (e) during real-life, somatovisceral fear and anger responses exhibited a marked cardiovascular defense reflex; (f) in addition, real-life fear showed an adrenaline-like specific response pattern, whereas real-life anger showed specific forehead temperature and EMG extensor increases, accompanied by an elevated DBP during imagination. A Component Model of Somatovisceral Response Organization is proposed.

This study addresses a number of unresolved issues regarding the employment of respiratory sinus arrhythmia as an index of tonic parasympathetic cardiac control in psychophysiological investigations. These questions include the following: (1) Does respiratory sinus arrhythmia reflect cardiac vagal tone under conditions in which alterations in parasympathetic control are expected to be mild to moderate? (2) Are variations in human respiratory sinus arrhythmia that occur in response to varying behavioral demands independent of beta-adrenergic effects on the heart? (3) To what extent do typical experimental tasks apparently affect tonic cardiac vagal control? Twelve healthy male subjects were administered a joint alpha- and beta-adrenoreceptor pharmacological blocker on one day and a placebo on another (balanced across subjects). On both days, respiratory sinus arrhythmia and heart period were monitored during a number of different experimental tasks while subjects continuously paced their respiration. Results indicated that respiratory sinus arrhythmia, under controlled respiratory conditions, is uninfluenced by variations in sympathetic activity, and provides a reasonably sensitive index of cardiac vagal tone, even when alterations in parasympathetic tone are not large. Furthermore, our findings suggest that cardiac vagal tone is responsive to varying behavioral demands and may interact in different ways with beta-adrenergic mechanisms.