INHIBITION AND SET -SHIFTING TASKS IN CENTRAL EXECUTIVE FUNCTION OF WORKING MEMORY : AN EVENT -RELATED POTENTIAL (ERP) STUDY

Abstract

Understanding of neuro-dynamics of a complex higher cognitive process, Working Memory (WM) is challenging. In WM, information processing occurs through four subsystems: phonological loop, visual sketch pad, memory buffer and central executive function (CEF). CEF plays a principal role in WM. In this study, our objective was to understand the neurospatial correlates of CEF during inhibition and set-shifting processes. Thirty healthy educated subjects were selected. Event-Related Potential (ERP) related to visual inhibition and set-shifting task was collected using 32 channel EEG system. Activation of those ERPs components was analyzed using amplitudes of positive and negative peaks. Experiment was controlled using certain parametric constraints to judge behavior, based on average responses in order to establish relationship between ERP and local area of brain activation and represented using standardized low resolution brain electromagnetic tomography. The average score of correct responses was higher for inhibition task (87.5%) as compared to set-shifting task (59.5%). The peak amplitude of neuronal activity for inhibition task was lower compared to set-shifting task in fronto-parieto-central regions. Hence this proposed paradigm and technique can be used to measure inhibition and set-shifting neuronal processes in understanding pathological central executive functioning in patients with neuro-psychiatric disorders.