Article

Many theories have been advanced to explain how the brain incorporates time into
its computations, in particular for the purpose of estimating the duration of an
event. In the present study we examine with a new paradigm the ability to compare
the duration of two visual stimuli in the parafoveal visual field, presented
either sequentially or overlapping in time. We found that judging the duration of
a pair of objects is more difficult when they overlap in time. Furthermore, all
healthy participants presented a bias to over-estimate the duration of the second
event (a negative time-order-error). We then presented the same task to eight
left neglect patients with extinction (N-patients). Relative to the healthy
participants, the patients displayed similar loss of sensitivity and increased
bias in the time overlap condition. However, N-patients were particularly
impaired when the first object was presented in their right visual field and the
second one appeared on their left before the first one vanished. Rather than a
simple engage/disengage disorder, these results highlight a specific problem with
shifting attention to the impaired visual field. We discuss these findings in the
light of contemporary models of time estimation.
CI - Copyright A(c) 2012 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS