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Abstract:
In this paper it is proposed that during the performance of a
task demanding attention to internal processing, other stimuli,
unrelated to the task, should be affected. Auditory ERPs were
recorded in 10 subjects during 2 different conditions: 1) the
subject had to solve a verbal task reordering the 5 letters that
were visually presented to form a word and give a verbal answer; 2)
the presentation of a control stimulus with the same physical
characteristics as in 1) to make the subject say ëAí .
In each trial, before, during and 8 sec after the presentation of
the visual stimuli, standard and deviant tones were presented in an
oddball paradigm. Auditory ERPs to tones delivered after the
presentation of the visual stimuli for the 2 conditions were
averaged. ERPs to standard tones were very similar in both
conditions. However, important condition effects were observed for
the segments 250-300 and 300-350 ms for the deviant tones, with
higher amplitudes during control than during task condition in Fz
and Cz . These results suggest that the most sensitive component to
the differences between conditions was P3a, which has been related
with the orienting response to deviant stimuli. This project was
partially supported by Grant IN 214295 from DGAPA and 1028P-H from
CONACyT.
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