Performance-related activity in medial rostral prefrontal cortex (area 10) during low-demand tasks

Gilbert, S.J., Simons, J.S., Frith, C.D., & Burgess, P.W. (2006). Journal of Experimental Psychology: Human Perception and Performance, 32, 45-58.

Neuroimaging studies frequently observe relatively high activity in medial rostral prefrontal cortex (PFC) during rest or baseline conditions. Some accounts attribute this to the occurrence of unconstrained stimulus-independent and task-unrelated thought processes during baseline conditions. Here, we investigate the alternative possibility that medial rostral PFC supports attention towards the external environment during low demand conditions. Participants performed a baseline simple RT task, along with three other tasks that differed in the requirement to attend to external stimuli versus stimulus independent thought. Medial rostral PFC activation was observed both in the baseline task and in a condition requiring strong engagement with external stimuli, relative to two conditions with greater requirement for stimulus-independent thought. Importantly, activity in this region was associated with faster RTs in the baseline task, ruling out an explanation in terms of task-unrelated thought processes during this condition. Thus, at least under certain circumstances, medial rostral PFC appears to support attention towards the external environment, facilitating performance in situations that do not require extensive processing of experimental stimuli.