Brain activity during interval timing depends on sensory structure
Brain Research. 2008-04-01; 1204: 112-117
DOI: 10.1016/j.brainres.2008.01.022
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1. Brain Res. 2008 Apr 14;1204:112-7. doi: 10.1016/j.brainres.2008.01.022. Epub
2008 Jan 18.
Brain activity during interval timing depends on sensory structure.
Pfeuty M(1), Ragot R, Pouthas V.
Author information:
(1)Laboratoire d’Imagerie Moléculaire et Fonctionnelle, CNRS (UMR 5231),
Université Victor Segalen Bordeaux 2, France.
Precise timing is crucial for accurate perception and action in the range of
hundreds of milliseconds. One still unresolved question concerns the influence
of sensory information content on timing mechanisms. Numerous studies have
converged to suggest that the CNV (Contingent Negative Variation), a slow
negative wave that develops between two events, notably reflects temporal
processing of the interval between these two events. The present study aimed at
investigating CNV activity in duration discrimination tasks using either filled
(continuous tones) or empty intervals (silent periods bounded by two brief
tones). Participants had to compare a test duration with a 600-ms standard. Time
perception was markedly better in the ’empty’ than in the ‘filled’ condition.
Electrophysiological analyses performed on the longest test duration (794 ms) of
the comparison phase revealed an effect of the sensory structure on both the CNV
amplitude and CNV time-course. The CNV amplitude was larger for filled than for
empty intervals, suggesting a superimposition of timing-dependent activity and
sensory sustained activity. Furthermore, the CNV time-course paralleled the
temporal structure of the memorized sensory event: for filled intervals, the CNV
amplitude stopped increasing at 600 ms, i.e. the expected end of the continuous
tone; for empty intervals, in contrast, the CNV amplitude precisely increased at
600 ms, i.e. the expected onset of the second brief tone. These results suggest
that the CNV reflects the mental rehearsal of the memorized sensory event, in
line with the idea that temporal processing in the sub-second range is based on
sensory information.
DOI: 10.1016/j.brainres.2008.01.022
PMID: 18336798 [Indexed for MEDLINE]