Dopamine: Go/No-Go motivation versus switching. Commentary on “Neurobiology of the structure of personality: dopamine, facilitation of incentive motivation, and extraversion”

In: Behavioral and Brain Sciences, Jg. 22 (1999) ; Nr. 3, S. 532 - 533
ISSN: 0140-525X
Zeitschriftenaufsatz / Fach: Medizin
Abstract:
Extraversion has two central characteristics: (1) interpersonal engagement, 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 positive incentive motivation.
Parallels between extraversion (particularly its agency component) and a mammalian behavioral approach system based on positive
incentive motivation implicate a neuroanatomical network and modulatory neurotransmitters in the processing of incentive motivation.
A corticolimbic-striatal-thalamic network (1) integrates the salient incentive context in the medial orbital cortex, amygdala, and hippocampus;
(2) encodes the intensity of incentive stimuli in a motive circuit composed of the nucleus accumbens, ventral pallidum, and
ventral tegmental area dopamine projection system; and (3) creates an incentive motivational state that can be transmitted to the motor
system.
Individual differences in the functioning of this network arise from functional variation in the ventral tegmental area dopamine projections,
which are directly involved in coding the intensity of incentive motivation. The animal evidence suggests that there are three
neurodevelopmental sources of individual differences in dopamine: genetic, “experience-expectant,” and “experience-dependent.” Individual
differences in dopamine promote variation in the heterosynaptic plasticity that enhances the connection between incentive context
and incentive motivation and behavior.
Our psychobiological threshold model explains the effects of individual differences in dopamine transmission on behavior, and their
relation to personality traits is discussed.