Conflicted between Goal-Directed and Habitual Control – an fMRI Investigation

Abstract

“Slips of action” occur in everyday life when we momentarily lose sight of a goal (for example when in a rush or distracted). Associative models propose that these habitual responses can be activated via a direct stimulus-response mechanism, regardless of the current hedonic value of the outcome. The slips-of-action task (SOAT) has been extensively used in both healthy and pathological populations to measure habit tendencies – the likelihood of making erroneous responses for devalued outcomes. Inspection of behavioral performance does not reveal, however, whether the impairments were due to impaired goal-directed control or aberrantly strong habit formation. In the current study we used functional MRI while human participants performed both the instrumental training and SOAT test phases, to elucidate the relative contributions of these mechanisms to performance on the SOAT. On trials in which conflict arises between competing goal-directed and habitual responses we observed increased activation across areas including the anterior cingulate cortex, paracingulate gyrus, lateral OFC, insula and inferior frontal gyrus. Responding for devalued outcomes was related to increased activation in the premotor cortex and cerebellum – implicating these regions in habitual responding. Increased activation in the caudate, dorsolateral prefrontal cortex and frontal pole during training was associated with better performance during the test phase, indicative of goal-directed action control. These results endorse interpretation of the SOAT in terms of competing goal-directed and habitual mechanisms and highlight that cognitive control processes present an additional bottleneck for successful performance on this task.

Significance Statement Imagine that you step in the car intending to drive to your new office but distracted, end up driving the route to your old office instead. We are all familiar with the feeling that results from inadvertently carrying out a previously valid behavior, even if we no longer desire the consequence. In the current study we examined how the brain reacts to cues that signal a previously rewarded response whose outcome value has now changed. We were also able to identify the brain regions that were activated when participants made an erroneous (habitual) response under time-pressure. These results give us a richer sense of how the brain acts to control behavior when goal-directed processes are otherwise engaged.