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Abstract:
Abstract: Humans respond more quickly and accurately to
sounds that are presented at an attended frequency than to sounds
presented at an unattended frequency. When listeners expect to hear
a target sounds at a particular frequency region over a long series
of trials, all sounds presented at that frequency elicit an
enhanced negativity, called the negative difference (Nd), in the
auditory evoked potential. An Nd effect has also been found in a
trial-by-trial cueing experiment using informative frequency cues
(Prime, McDonald, & Ward, CNS, 1999). We investigated
stimulus-driven auditory frequency orienting in a cue-target
experiment with uninformative frequency cues. Reaction time was
measured for a Go-NOGO frequency discrimination task. Subjects
responded more quickly to targets appearing at the validly cued
frequency than to targets appearing at the invalidly cued
frequency. Moreover, a Nd effect was observed over central scalp
regions. These results indicate that similar brain mechanisms are
involved in goal-driven and stimulus-driven orienting of auditory
frequency attention.
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