Steady state visually evoked potential (SSVEP) topography in a graded working memory task.

Full Abstract

The steady state visually evoked potential (SSVEP) elicited by a diffuse 13-Hz visual flicker was recorded from 64 scalp sites in 30 subjects performing a low and high demand version of an object working memory task. During the perceptual component of the task, the SSVEP amplitude was reduced at left and right parieto-occipital sites. During the hold or memory component of the task, the SSVEP amplitude exhibited a load-dependent increase at frontal and occipito-parietal sites, while the SSVEP latency exhibited a load-dependent reduction at central and left frontal sites. We suggest that SSVEP amplitude changes index cortical information processing modes in that perceptual processes are associated with an SSVEP amplitude reduction, while holding information in active short-term or working memory is associated with an SSVEP amplitude increase. We also discuss changes in SSVEP amplitude and latency in terms of changes in the behavior of cortico-cortico and thalamo-cortico loops that utilize cortical layer I. Such cortico-cortico and thalamo-cortical loops are also proposed to constitute a neurophysiological mechanism for holding information in working memory.

Author information

Author/s: Silberstein, R B (RB); Nunez, P L (PL); Pipingas, A (A); Harris, P (P); Danieli, F (F);

Affiliation: Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia. rsilberstein(-atsign-)bsi.swin.edu.au

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: International journal of psychophysiology : official journal of the International Organization of Psychophysiology (Int J Psychophysiol), published in Netherlands. (Language: eng)

Reference: 2001-Oct; vol 42 (issue 2) : pp 219-32

Dates: Created 2001/10/05; Completed 2001/12/05; Revised 2006/11/15;

PMID: 11587778, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

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