Brain activation evidence for response conflict in the exclude recognition task.

How do memory retrieval processes (i.e., familiarity and recollection processes) interact with motor and control processes to bring about an appropriate response? Our parallel task-set model predicts, and behavioral and electromyographic data support, the hypothesis that under some circumstances familiarity and recollection processes activate competing responses. Combining predictions from the parallel task-set model and the conflict monitoring hypothesis, this competition should lead to response conflict and corresponding activity in anterior cingulate cortex (ACC). However, ACC activity in response to competing familiarity and recollection retrieval processes is inconsistently reported in the literature. We tested this prediction directly by measuring brain activation with functional magnetic resonance imaging while participants performed an exclude recognition task (i.e., respond one way to one set of familiar stimuli and another way to new and to a different set of familiar stimuli). As predicted by our model, overriding a familiarity-based response led to increased activity in ACC. These data suggest that recognition, motor, and control processes interact in strategic retrieval tasks.