title: Slow brain potentials in a visual-spatial memory task: topographic distribution and inter-laboratory consistency.
abstract: Slow brain electrical potentials (SPs) were investigated in a visual-spatialmemory task. Two issues were addressed: (1) the nature and topographic distribution of the potentials obtained under such conditions; and (2) the consistency of the SPs when recorded in six identically configured laboratories. Fifteen young male subjects were studied at each laboratory (total n = 90). The paradigm entailed presentations of paired-visual patterns (S1 and S2), to which subjects responded with a choice reaction time response indicating whether or not the two patterns matched. A biphasic contingent negative variation (CNV) was produced which consisted of an early symmetric component with bilateral foci at posterior temporal sites and a subsequent mid-parietal dominant wave later in the retention interval. Although the CNVs from all laboratories were similar in waveform and in topographic distribution, there were significant inter-laboratory differences in amplitude of the slow potential components. The topographic distributions of the components and the possible role of sampling effects are discussed.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Rohrbaugh
authors.forename: D N
authors.initials: DN
authors.lastname: Dunham
authors.forename: P A
authors.initials: PA
authors.lastname: Stewart
authors.forename: L O
authors.initials: LO
authors.lastname: Bauer
authors.forename: S
authors.initials: S
authors.lastname: Kuperman
authors.forename: S J
authors.initials: SJ
authors.lastname: O'Connor
authors.forename: B
authors.initials: B
authors.lastname: Porjesz
authors.forename: H
authors.initials: H
authors.lastname: Begleiter
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology*