Abstract
We studied neuronal activity in medial prefrontal cortex in monkeys performing a conflict solving task in which a visual cue appeared either on the left or the right side of the panel placed in front of them. The cue's color instructed the monkeys to reach either to the left or right target, regardless of its location. The location of the cue was either compatible (congruent) or incompatible (incongruent) with the target's location. We found a focus of reaching-related neurons in the medial prefrontal cortex, rostrally to the presupplementary motor area (pre-SMA), where previous studies had not found neurons related to arm movements. The activity of some of the neurons in this region was modulated by the response conflict, but the majority of them showed task-related activity even in the absence of response conflict (i.e. congruent trials). Interestingly, neurons in this region lost task-related activity modulation when these monkeys were re-trained on congruent trials alone. In contrast, in the adjacent pre-SMA and SMA, neurons still showed task-related activity after a prolonged absence of response conflict. These results suggest that the functional map in this region is dynamically reorganized by the task demand. [J Physiol Sci. 2007;57 Suppl:S24]
