Assessing Motivational Biases in Brain and Behavior: Event-Related
Potential and Response Time Concomitants of the Approach-Avoidance Task
Abstract
The Approach-Avoidance Task (AAT) is designed to 1) measure the implicit
motivated action biases that are instantiated by emotional stimuli, and
2) assess the changes in such biases that drive psychiatric disorder. To
establish AAT sensitivity to emotional action bias at a neural level,
some work has measured event-related potential (ERP) correlates —
however, a lack of research with unpleasant, pleasant, and neutral
stimuli together and also a common focus on psychiatric disorder-matched
(rather than generally evocative) content limits foundational
conclusions that can be drawn. In current research, then, 38 subjects
completed an AAT where normative (rather than idiosyncratic) unpleasant,
pleasant, and neutral images were shown with a color border indicating
if a joystick should be rapidly pushed or pulled to decrease or increase
image size. Using generally arousing stimuli, response times (RTs) were
found to be faster on unpleasant push compared to unpleasant pull
trials, t(37)=2.4, p=.02, and 32-sensor electroencephalography (EEG)
also revealed that amplitude of a stimulus-response conflict-related ERP
– the N200 – was reduced on unpleasant compared to neutral push trials
and un-pleasant push compared to unpleasant pull trials, t(32)=5.5,
p<.001. In addition, preliminary exploration of individual
differences suggested that relevant variables of dimensional trait
anxiety, depression, and anxiety disorder treatment seeking status did
not impact RT- or N200-indicated emotional biases. Together, then,
findings are consistent with a neurobehavioral avoidance bias for
unpleasant stimuli while also suggesting a need to further test whether
selecting images for idiosyncratic relevance is critical to revealing
individual variations in emotional bias.