Andrew J. Tomarken - US grants

Resting anterior electroencephalographic (EEG) asymmetry is a marker of temperament that predicts affective reactivity and affective traits. However, the predispositions indexed by resting anterior asymmetry (RAA) are unclear, as is its relation to the broader functions of the prefrontal cortex. Based on evidence concerning the prefrontal cortex and concerning a robust correlate of RAA (depression), it is proposed that RAA promotes differential access to cognitive processes that serve to regulate emotional responsivity. To test this overriding hypothesis, five experiments are proposed that use college-student subjects. In each experiment, resting EEG will be assessed on three occasions, after which affective reactions to emotion elicitors and cognitive processes that serve to modulate such reactions will be assessed. These experiments will assess whether RAA predicts: expectancies, goal-setting, and attributions in response to success and failure; responses to failure characterized by a ruminative "state" orientation vs. a task-focused "action" orientation; self-focused attentional responses to success and failure; selective attention to positive and negative information about the self; and selective memory for positive and negative affectively toned events. In addition, the proposed experiments address whether individual differences in stability as well as degree of asymmetry can be identified, and whether stability of asymmetry serves as a moderator variable. By linking RAA to the wider body of evidence concerning functions mediated by the prefrontal cortex, the present studies will promote greater understanding of the biological substrates of emotion- cognition interaction. The present studies also have implications for identifying patterns of brain activity that may be markers of risk for affective disorders.

ABSTRACT For a number of years, there has been a wide-ranging interest in the biological basis of personality and temperament. However, few reliable biological markers of temperament have been identified. Recent research has shown that resting electroencephalographic (EEG) asymmetry recorded from frontal regions of the brain is a biological marker that predicts individual differences in emotional reactivity and in emotional traits. This research has shown that individuals characterized by relative activation of right hemisphere frontal regions have an increased predisposition for negative affect and a decreased predisposition for positive affect. The opposite pattern appears characteristic of individuals with relative left frontal activation. However, the research has left unclear precisely what predisposition are linked to frontal asymmetry. In addition, prior work has not linked anterior asymmetry to known functions mediated by the frontal lobes. On the basis of evidence concerning functions mediated by the frontal lobes and evidence concerning affective traits that are linked to anterior asymmetry, it is proposed that the critical predispositions linked to frontal asymmetry are individual differences in cognitive and related processes that serve to regulate or modulate emotional reactions or goal-directed performance on tasks that elicit significant emotion. It is hypothesized that relative left anterior activation promotes access to cognitive processes that serve to amplify or sustain positive affect and to inhibit or dampen negative affect. It is hypothesized that relative right anterior activation is linked to the opposite pattern. To test these hypotheses, four experiments will be conducted to assess the relation between resting frontal asymmetry and: 1. various components of a "state" vs "action" orientation in response to experimentally induced failure; 2. self-focused attentional responses to success and failure; 3. selective memory for affectively toned events; and 4. selective attention to affective stimuli. These studies will help elucidate the critical predispositions linked to resting frontal asymmetry and will have more general implications for models of the contribution of the cerebral cortex to individual differences in emotion-related personality traits. In addition, because few studies have assessed the relation between the prefrontal cortex and the regulation of emotion, the present studies will contribute to knowledge concerning the functions served by this clearly important, yet largely uncharted, region of the brain.