The Japanese journal of neuropsychology

Full Text of this Article
in Japanese PDF (674K)

ArticleTitle	Higher brain functions evaluated by event-related potentials
Language	J
AuthorList	Hirokazu Bokura
Affiliation	Department of Neurology, Shimane University, Faculty of Medicine
Publication	Japanese Journal of Neuropsychology: 23 (1), 37-43, 2007
Received
Accepted
Abstract	Event-related potentials (ERPs) can reveal the time course of information processes with high temporal resolution. We investigated inhibitory function during Go/NoGo task, and neural processing of incidental and intentional encoding of novel stimuli by measuring ERPs. LORETA analysis for Go/NoGo task revealed that Go-P3 source activity was located in the medial part of the parietal lobe, whereas the NoGo-P3 source activity was located in the left lateral orbitofrontal cortex. The sources of the NoGo-N2 component were located in the right orbitofrontal and cingulated cortex. Parkinson disease patients had selective impairments of the inhibitory mechanism involved in frontal lobe function by ERP study. Regarding progressive supranuclear palsy, there were impairments of both execute and inhibitory function. In the neural correlates for memory of novel stimuli, pictures that were successfully encoded in the intentional encoding session caused an increase in the amplitude of the frontal N2 component (260 msec) relative to the magnitude of the same component for incorrectly encoded pictures. By contrast, the difference was observed in the right posterior scalp site at the latency range after 360 msec post-stimulus in the incidental encoding session. The study demonstrates that distinct neural substrates contribute to incidental and intentional encoding of novel stimuli.
Keywords	Event-related potentials, NoGo, frontal lobe, Novelty, Memory