Lectures and seminars Cognitive Neuroscience Club with Mikael Lundqvist: "Neural Mechanisms of Cognitive Control"

"Neural Mechanisms of Cognitive Control"

Speaker

Mikael Lundqvist, Karolinska Institutet, Department of Clinical Neuroscience

Abstract

Working memory (WM) is the fundamental function by which we break free from reflexive input-output reactions to gain control over our own thoughts. It has two types of mechanisms: online maintenance of information and its volitional or executive control. Control aspects include selective input gating, output gating and deletion of obsolete information from WM. The neural mechanisms underlying the maintenance and control of WM is a topic of vigorous research. In the presented work, analysis of neural data from prefrontal cortex of non-human primates demonstrated oscillations in gamma (30-100 Hz) and beta (10-30 Hz) frequencies as correlates of maintenance and control, respectively. This further suggested a division of labor between superficial and deep layers of cortex. Moreover, the gamma oscillations occurred in brief bursts, suggesting that maintenance was manifested in brief reactivations rather than sustained activity, as classically thought. The bursts patterns also helped explain classical findings regarding reduced spike pattern variability as primates engage in cognitive tasks. Finally, working memory control seemed to utilize the spatial dimensions of cortex. We propose such scheme aids the generalization of cognitive control to novel situations. Taken together, the findings support a new model of working memory.