Risky economic choices and frontal EEG asymmetry in the context of Reinforcer-Sensitivity-Theory-5.

This study investigated individual risky choice behavior in a gambling task and its relation with traits proposed by the Reinforcer-Sensitivity-Theory-5 (RST-5; Corr & McNaughton in Neuroscience and Biobehavioral Reviews, 36(10), 2339-2354, 2012) as well as with frontal EEG asymmetry. As assumed by the RST-5, the results showed independent influences of approach/avoidance and gain/loss sensitivities on participants' behavior in risky choices. Individual approach/avoidance sensitivity was predicted by trait measures of the behavioral approach system (BAS) and the behavioral inhibition system (BIS), while no such correlation was present for gain/loss sensitivity. EEG recordings revealed relatively stronger left-frontal cortical activity for trials with approach motivation compared to conflict and avoidance motivation. On the individual level, relatively stronger left-frontal cortical activity was associated with trait BAS. In addition, activity changes in frontal EEG asymmetry were associated relatively higher behavioral approach sensitivity. We conclude that frontal EEG asymmetry is an especially useful neuronal marker of BAS sensitivity and that the traits proposed by the RST-5 (measured by frontal EEG asymmetry and self-report) can be used to explain individual differences in risky choice behavior.

Single-trial electroencephalogram predicts cardiac acceleration: a time-lagged P-correlation approach for studying neurovisceral connectivity.

Cortical efferences to the heart are important for cardiovascular health, psychopathology, emotion regulation and other dimensions of human functioning. Although researchers have already begun to outline the underlying neuroanatomy, the timing of neurovisceral communication in humans is difficult to study non-invasively. A possible coupling between the brain and the heart can be observed following feedback stimuli, which have been shown to evoke both, early (i.e. <500 ms) signatures in the electroencephalogram (EEG) and changes in the chronotropy of subsequent heart beats. Because standard approaches may be insufficient to study how these responses are related, we suggest a method termed "Cardio-Electroencephalographic Covariance Tracing" (CECT), which is based on time-lagged P-correlations (i.e., correlations within individuals) between single-trial EEG magnitudes and heart period changes. When CECT was applied to data from n=31 individuals who performed a gambling task, central midline EEG magnitudes from 280 to 340 ms after feedback reliably P-correlated with cardiac acceleration 2 to 5 s thereafter. In addition positive vs. negative feedback lead to enhanced event related potential amplitudes from 200 to 280 ms and to relative cardiac acceleration from 1 to 3.5 s after feedback presentation. The results imply that neurogenic cardiac modulations begin to be affected 200 to 400 ms after stimulus presentation and demonstrate the utility of CECTs for future investigations.

Constraints for emotion specificity in fear and anger: the context counts.

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.

On the status of individual response specificity.

The concept of physiological individual response specificity (IRS) was critically discussed. A review of empirical studies focused on IRS magnitude, stability, and personality correlates. Using difference scores, an average of 33% of the participants showed a significant IRS. IRS stability was found in only 15% of the participants. In some studies, IRS incidence was associated with neuroticism or stress coping styles. We suggest that the IRS concept should include not only purely constitutional but also situational and psychological determinants. Predictions from this revised biopsychological model were tested with a data set comprising 48 healthy male participants who completed six tasks, which were replicated three times in 1-week intervals. At Session 1, 21% of the participants displayed a significant IRS. IRS stability was found in only 8% of the participants. Participants with a significant IRS at Session 1 reported higher levels of fear (anger and happiness as covariates) and of pounding heart. Between-session IRS (trait-IRS) but not within-session IRS (state-IRS) was associated with trait anxiety.

Receptor antagonists as tools for structural measurement in psychophysiology.

This paper proposes the structural measurement of autonomic cardiovascular activation components. In a double-blind cross-over design 48 male subjects received either placebo or a combination of 2 out of 3 partial autonomic blockers (p.o.); an alpha-1-adrenergic (indoramin), an unselective beta-adrenergic (propranolol), or a cholinergic antagonist (atropine). During each of the four sessions, the same seven tasks were presented (speech, mental arithmetic, handgrip, signal detection, loud noise, cold pressor, and an anticipation period). Based on a formal model of cardiovascular activation, estimates of the parameters of the model were obtained. The resulting regulatory patterns quantitatively revealed the effects of an alpha-adrenergic, three beta-adrenergic and a cholinergic activation component on 22 cardiovascular variables.

A model of cardiovascular activation components for studies using autonomic receptor antagonists.

Alpha-adrenergic, beta-adrenergic, and cholinergic responses are often considered important activation components when conceptual and empirical analyses are made of single physiological variables and of patterns of cardiovascular reactivity; these autonomic distinctions are also of particular significance in autonomic blockade studies. A Model of Cardiovascular Activation Components is introduced that relates these components to both the measured cardiovascular variables and the protocol of autonomic blockade studies. It is pointed out that a restricted form of the complete model is often implicitly used in cardiovascular psychophysiology. The differential consequences of an erroneous employment of the restricted model are discussed for single and dual blockade protocols. Critical evaluations of autonomic blockade as a tool in cardiovascular psychophysiology are examined and are proposed to be often the consequence of the restricted model assumptions. Lastly, the utility of the Activation Components Model for a componential description of tasks and for componential intertask relationships is illustrated with data from the literature.

Paced respiratory sinus arrhythmia as an index of cardiac parasympathetic tone during varying behavioral tasks.

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.

The autonomic differentiation of emotions revisited: convergent and discriminant validation.

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.

Postalcoholic diseases: diagnostic relevance of computerized EEG.

In 48 patients with sequels of chronic alcoholism automatically analysed EEGs were taken twice: (1) some 2 days after cessation of acute delirious or predelirious states; (2) some 18 days later, after clinical recovery. EEG results were supplemented by neuropsychological, biochemical and clinical data. Complementary analyses in the time (Hjorth's descriptors) and frequency (spectral analysis) domains at the first time operationally identified EEG correlates of a hallucinatory syndrome vs. personality deterioration ("depravation'), together with specific effects of drinking habits and withdrawal. The second examination disclosed prognostically different types of EEG reactions to chronic alcoholism.

AMP-rated psychopathology in chronic alcoholics.

In a group of 39 alcoholics within a withdrawal process, the psychical situation was rated using AMP scales (Angst et al. 1969). Cluster analysis of the items rendered the following five-cluster solution: (1) "aggressive-depressive" patients, (2) "less impaired" persons, (3) "slowed persons with diminished contact", (4) "emotionally inadequate" persons, (5) "appealing depressive" persons. These results are discussed with respect to other data from clinical history and diagnostic findings.

Determinants of chlormethiazole-induced EEG effects in chronic alcoholics.

At beginning and end of hospital treatment with chlormethiazole (Distraneurin), the EEGs of 41 male alcoholics were analyzed, employing spectral analysis and Hjorth's parameters. Hierarchical regression analysis of selected data showed significant influence of hallucinations and/or personality deterioration on chlormethiazole-induced EEG effects, especially at the beginning of treatment.

Methodological Conditions of Congruent Factors: A Comparison of EEG Frequency Structure Between Hemispheres.

A study was conducted to examine congruence relations of EEG frequency factors between hemispheres. The central questions were aimed at procedural details of the factoring process which have the greatest "destructive" influence on congruence of factor patterns. On the basis of serially-rotated oblique solutions and evaluative simple structure criteria, two methodological results are reported: (a) the original principal components of two lead placements show a marked departure from an ideal congruence pattern, but can be forced into high congruence beyond 0.90 for the first twelve components by orthogonal procrustes rotation; (b) after this matching of principal components the expected optimum of congruence is only achieved in rotated solutions showing an optimal simple structure in terms of the Index of Factorial Simplicity (Kaiser, 1974). Additionally, the study leads to two substantive electroencephalographic results; (c) the factorial frequency structure of spontaneous EEG from two homologous positions (C3, C4) of the hemispheres is highly congruent. Thus, an identical measurement rationale for EEG frequency bands can be justified in asymmetry research; (d) the spectral dimensions of the alpha region show good correspondence to a recently published synoptic model of factor analytically defined EEG bands (Andresen, Thom, Irrgang, & Stemmler, 1982). The weight system of the three alpha components in this model can be recommended for psychophysiologically oriented EEG research.