| |
Abstract:
Abstract: The attentional blink (AB) refers to an impairment
in detecting the second (T2) of 2 targets embedded in a rapid
serial visual presentation (RSVP) of distractor stimuli. We used
event-related fMRI to isolate the neural substrates associated with
the occurrence of the AB. In the first two studies, we manipulated
the interference produced by the distractors during identification
of the first target (T1) to create two conditions which differ in
their magnitude of the attentional blink. For both studies, when
comparing the condition that generated a large AB (HIGH
interference condition) with the condition that yielded little AB
(LOW interference), three brain regions were more activated: the
(right) intra-parietal sulcus (IPS), the lateral mid./inf. frontal
gyrus and to a lesser extent the anterior cingulate gyrus. In
another study we found that, in addition to temporal interference,
spatial interference with T1 processing also generates an
attentional blink. Furthermore, when comparing two conditions which
differed in their level of spatial interference (and hence of AB
magnitude), we found the same neural network (especially IPS)
activated by the classical attentional blink paradigm. Finally, the
relative contributions of T1 processing difficulty and distractor
interference in generating the attentional blink will be presented.
Overall, our results indicate that the parieto-frontal network of
visuo-spatial attention may underlie our attentional limitations to
visual perception.
|
