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Abstract:
It appears that different features of an object are
registered in different cortical maps and hence must later be bound
by some mechanism to form a coherent object. Multiple lines of
evidence (e.g. behavioral, neuroimaging, lesion studies) have
converged on the idea that the essential cue for feature binding is
spatial location. However, illusory conjunctions have also been
discovered using objects that occur in the same spatial location
and in close temporal proximity. We used these temporal illusory
conjunctions in order to examine the temporal dynamics of
attention. An RSVP stream consisting of letters and digits of
various colors was used. Participants were asked to respond to a
particular color and digit occurring throughout the study session.
Targets appeared at or before the expected time as defined by the
RSVP stream. The stimuli were presented for brief periods in order
to create an accuracy rate of approximately 60%. This low accuracy
rate allowed for analysis of errors and illusory conjunctions in
terms of the temporal aspects of attention. Preliminary data are
consistent with an oscillatory model of attention and are
inconsistent with either a linear process model or a stochastic
process model. Results are discussed in terms of an oscillatory
model and the possible neuronal correlates of this model.
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