EEG correlates of cognitive strategies: Forced choice in uncertain conditions

The choice selection in a lab environment or real-life conditions remains a major problem to be tackled in the field of neuroscience.the behavioral and electrophysiological correlates of the cognitive strategies behind this issue has been studied by our group. dichotic tone listening task was given to 26 healthy subjects. the eeg was recorded during the task completion using scan 4.3 system (neuroscan,usa) from 64 ag/agcl electrodes. analysis of response patterns revealed that in such tasks effect of cognitive strategy use for response choice could prevail over ear advantage effect,expected by dichotic listening paradigm.neural correlates of strategy-use in response selection were assessed using classic eventrelated potentials (erp) and synchronization/desynchronization (ers/erd) methods. the major results are the following: 1. erp latencies in strategy-users group (su) are shorter in frontal cortex than in strategy-non-users (snu),while in parietal cortex reactions in snu are faster than in su.2.beta-erd values in frontal and parietal areas demonstrate analogous reciprocal interactions related to strategy use: beta-erd is stronger in frontal area in su,while in parietal area it is stronger in snu.3.alpha-erd was stronger in su than in snu over right frontal and left temporo-parietal areas.it could correspond to more active processes of encoding and/or verbalizing of stimuli in former group.