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Abstract:
The neurotransmitter dopamine (DA) has been associated with
multiple aspects of behavior within the emotional and cognitive
domains. These behaviors are likely mediated through a projection
system arising from cell bodies in the midbrain ventral tegmental
area (VTA). Mesolimbic DA projections have been associated with
reward-seeking behavior, reward-related learning processes, and the
personality trait domain of extraversion or positive emotionality.
Mesocortical DA projections to the dorsolateral prefrontal cortex
modulate delay-related cellular activity in spatial working memory
tasks. Since VTA dopamine neurons give rise to both the limbic and
cortical projections, it may be that the behaviors subserved by
each pathway covary within individuals. That is, individuals who
are high traitwise in positive emotionality might also be those
with better spatial working memory skills. The current study was
designed to test this hypothesis. Healthy young adult males and
females (n=100 to date) completed a cognitive test battery that
included tests of motor skill, attention, memory span, and working
memory for both spatial and affective stimuli. They also completed
state measures of positive and negative affect as well as a battery
of self-report personality trait inventories that included
Eysenck's Personality Inventory, Tellegen's Multidimensional
Personality Questionnaire, Zuckerman's Sensation Seeking Scale, and
others. Findings suggest that functions associated with activity in
the mesolimbic and mesocortical dopamine pathways are not highly
correlated within individuals despite common neurobiological
substrates. Implications for network theories of complex behavior
will be discussed.
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