Individual differences in emotional reactivity or affective style can be decomposed into more elementary constituents. Several separable of affective style are identified such as the threshold for reactivity, peak amplitude of response, the rise time to peak and the recovery time. latter two characteristics constitute components of affective chronometry The circuitry that underlies two fundamental forms of motivation and and withdrawal-related processes-is described. Data on differences in functional activity in certain components of these are next reviewed, with an emphasis on (...) the nomological network of surrounding individual differences in asymmetric prefrontal The relevance of such differences for understanding the nature affective dysfunction in affective disorders is then considered. The ends by considering what the prefrontal cortex “does” in certain of affective style and highlights some of the important questions for future research. (shrink)

Extraversion has two central characteristics: (1) interpersonalengagement, which consists of affiliation (enjoying and valuing close interpersonal bonds, being warm and affectionate) and agency (being socially dominant, enjoying leadership roles, being assertive, being exhibitionistic, and having a sense of potency in accomplishing goals) and (2) impulsivity, which emerges from the interaction of extraversion and a second, independent trait (constraint). Agency is a more general motivational disposition that includes dominance, ambition, mastery, efficacy, and achievement. Positive affect (a combination of positive feelings and (...) motivation) is closely associated with extraversion. Extraversion is accordingly based on positiveincentivemotivation. (shrink)

Because little is known about the human trait of affiliation, we provide a novel neurobehavioral model of affiliative bonding. Discussion is organized around processes of reward and memory formation that occur during approach and consummatory phases of affiliation. Appetitive and consummatory reward processes are mediated independently by the activity of the ventral tegmental area (VTA) dopamine (DA)–nucleus accumbens shell (NAS) pathway and the central corticolimbic projections of the u-opiate system of the medial basal arcuate nucleus, respectively, although these two projection (...) systems functionally interact across time. We next explicate the manner in which DA and glutamate interact in both the VTA and NAS to form incentive-encoded contextual memory ensembles that are predictive of reward derived from affiliative objects. Affiliative stimuli, in particular, are incorporated within contextual ensembles predictive of affiliative reward via: (a) the binding of affiliative stimuli in the rostral circuit of the medial extended amygdala and subsequent transmission to the NAS shell; (b) affiliative stimulus-induced opiate potentiation of DA processes in the VTA and NAS; and (c) permissive or facilitatory effects of gonadal steroids, oxytocin (in interaction with DA), and vasopressin on (i) sensory, perceptual, and attentional processing of affiliative stimuli and (ii) formation of social memories. Among these various processes, we propose that the capacity to experience affiliative reward via opiate functioning has a disproportionate weight in determining individual differences in affiliation. We delineate sources of these individual differences, and provide the first human data that support an association between opiate functioning and variation in trait affiliation. Key Words: affiliation corticolimbic-striatal networks; appetitive and consummatory reward; dopamine; oxytocin; personality; social bonds; social memory; u-opiates. (shrink)

For most of this past century, scholarship on the topics of personal- ity and emotion has emerged from the humanities and social sciences. In the past decade, a remarkable change has occurred in the influence of neuro- science on the conceptualization and study of these phenomena. This article ar- gues that the categories that have emerged from psychiatric nosology and descriptive personality theory may be inadequate, and that new categories and dimensions derived from neuroscience research may produce a more tractable (...) parsing of this complex domain. The article concludes by noting that the dis- covery of these biological differences among individuals does not imply that the origins of these differences lie in heritable influences. Experiential shaping of the brain circuitry underlying emotion is powerful. The neural architecture provides the final common pathway through which culture, social factors, and genetics all operate together. (shrink)

Computer modelling of personality and behaviour is becoming increasingly important in many fields of computer science and psychology. Personality and emotion-driven Believable Agents are needed in areas like human–machine interfaces, electronic advertising and, most notably, electronic entertainment. Computer models of personality can help explain personality by illustrating its underlying structure and dynamics. This work presents a neural network model of personality and personality change. The goals are to help understand personality and create more realistic and believable characters for interactive video (...) games. The model is based largely on trait theories of personality. Behaviour in the model results from the interaction of three components: personality-based predispositions for behaviour, moods/emotions and environmental situations. Personality develops gradually over time depending on the situations encountered. Modelling personality change produces interesting and believable virtual characters whose behaviours change in psychologically plausible ways. (shrink)