Human Lateral Temporal Cortical Single Neuron Activity during Language, Recent Memory, and Learning

Abstract

Findings from the author's studies utilizing intraoperative single neuron recording in lateral temporal cortex during epilepsy surgery to study changes in activity with language, recent verbal memory and verbal associative learning measures are reviewed. In an individual neuron these changes were often very specific to one function, even in only one modality. However, they were widely dispersed to either temporal lobe. Those lateralized to the language dominant hemisphere involved early and sustained changes; for language this often was inhibition of activity. Verbal memory and learning measures were characterized by increased activity in these and other neurons at memory encoding or when an association was learned, often “tonic” sustained changes. The relation of this activity to local field potentials suggests that the excitation is a local network effect, the inhibition, more distant inputs. Studies showing differential changes with implicit compared to explicit memory and recall compared to recognition memory retrieval for verbal material, and memory for spatial materials are also reviewed.