Slow brain potentials in a visual-spatial memory task: topographic distribution and inter-laboratory consistency

Int J Psychophysiol. 1997 Feb;25(2):111-22. doi: 10.1016/s0167-8760(96)00714-3.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Brain / physiology*
  • Brain Mapping
  • Evoked Potentials / physiology*
  • Female
  • Humans
  • Male
  • Memory / physiology*
  • Photic Stimulation
  • Reaction Time / physiology*