Performance Monitoring by the Medial Frontal Cortex
Emeric, Erik Eduardo
Many have suggested that executive control over the perception, selection, and production systems is a central component of human cognition required for monitoring performance and compensatory adjustments in response time following errors. Evidence from human brain imaging, human event related potentials, and single units in non-human primates have implicated the medial frontal lobe as part of this monitoring system. We have used a stop signal or countermanding task to probe the ability to control action by requiring subjects to withhold a planned movement in response to an infrequent stop signal which they do with variable success depending on the delay of the stop signal. Emeric et al (2006) provided evidence that the compensatory adjustments of response time of both humans and macaque monkeys in a saccade countermanding task is influenced by stimulus and performance history. We have established a bridge between event-related potential and functional brain-imaging studies in humans and neurophysiology studies in non-human primates with event related intracranial local field potentials (LFPs) recorded in the anterior cingulate cortex and supplementary eye fields of macaque monkeys performing this task. The results provide clear evidence that error-, feedback-, and conflict-related, signals are carried by the LFP in the medial frontal lobe of macaques (Emeric et al 2008). Finally, we have examined the characteristics of extracranial field potentials from monkeys performing the saccade stop signal task and have identified putative performance monitoring potentials consistent with the human event related potential literature. Taken all together, this body of work has contributed to the groundwork for examining neural signals that are homologous to human event related potentials in the nonhuman primate.