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Müller, B. W., Achenbach,
C., Oades, R. D., Bender, S., & Schall, U., (2002). Modulation of mismatch negativity
by stimulus deviance and modality of attention.
NeuroReport, 13, 1317-1320.[request
a copy]
In accord with our understanding
of journal policy, we present the
pre-publication text (view). This is a non-final version of an article
published in final form as cited above: it is available at http://www.neuroreport.com/pt/re/neuroreport/abstract.00001756-200207190-00021.htm;jsessionid=JGhhzgbRGJy4bJKvC52qqbxCGGL2V5QhVXq2BT2YgxgXspDqHw2Q!-348297060!181195629!8091!-1
Introduction:
The effect of attention on the processing of auditory sensory input
was studied in recordings of the mismatch negativity (MMN), derived
from the event-related EEG.
Methods:
Twenty healthy normal young adults (mean 25.8y) were presented with
a series of frequent standard, and rare deviant auditory stimuli in
two sessions about 5 weeks apart. Some deviant stimuli were a little
different (80 vs. 40 ms or 0.5 vs. 1.0 KHz), others differed considerably
from the standards (complex novel sounds).
Event-related potential (ERP) recordings were made while subjects responded
first on a visual and then on an auditory discrimination task.
Results:
First: Directing
attention intramodally (to the auditory discrimination) resulted in
a larger MMN amplitude -- only in the case of low stimulus deviance,
and on the first recording session.
Second: Directing attention extramodally
(to the visual discrimination) did not differentially affect MMN amplitude
after the different auditory deviants.
Conclusions: Novel stimuli may trigger an involuntary switch of
attention, thus overwriting the effects of task-related attentional
direction seen with lower degrees of stimulus deviance. However, the
effects of task / modality involving the direction of attention on MMN
/ change detection (Oades & Dittmann-Balcar, 1995)
may diminish as task performance becomes more automatic.The potential
for differential roles for MMN sources reported in frontal and temporal
lobes (Jemel
et al., 2002) in the violations of expectation associated
with short-term auditory memory are discussed.
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