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Jemel, B., Achenbach, C.,
Müller, B. W., Röpcke, B., & Oades, R. D., (2002)
Mismatch negativity results from bilateral asymmetric
dipole sources in the frontal and temporal lobes. Brain
Topography, 15, 13-27.
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a pdf copy).
In accord with our understanding
of journal policy, we present the pre-publication
text (view).
The original publication (doi:10.1023/A:1019944805499) is available
at http://springerlink.metapress.com/content/la31nvtvvg6w/?p=c87874c9b69845fda1d9cd9ca76adfb6&pi=24
Introduction:
The event-related potential (ERP) reflecting auditory change detection
(mismatch negativity, MMN) registers automatic selective processing
of a deviant sound with respect to a working memory-like template (sensory
or echoic memory) that resultsg from a series of standard sounds. Controversy
remains whether MMN can be generated in the frontal as well as the
temporal cortex.
Our aim was to see if frontal as well as temporal
lobe dipoles could explain MMN recorded after pitch-deviants (Pd-MMN)
and duration deviants (Dd-MMN). [This lays an important foundation
for investigating putative temporal and frontal lobe dysfunction in
schizophrenia, where MMN amplitude is reduced in patients with non-paranoid
schizophrenia (often predominant negative symptoms) more than in the
paranoid forms of schizophrenia (ref
1).]
Methods:
EEG recordings were taken from 32 sites in 14 healthy subjects during
a passive 3-tone oddball presented during a simple visual discrimination
and an active auditory discrimination condition. Both conditions were
repeated after one month. Hypothesis-led dipole locations were calculated
and modeled by BESA and located in Talairach space (Garneron algorhythm).
Results:
First: The
Pd-MMN was larger, peaked earlier and correlated better between test
and re-test sessions than the Dd-MMN.
Second: Two
dipoles in the auditory cortex (superior
temporal gyrus) and two in the frontal
lobe (left cingulate and right inferior
frontal cortex) are described. [Residual variance for the group
= 0.87%, and for individuals 0.7-10%].
Third: These
dipole sources were similarly placed for Pd-MMN and Dd-MMN, and
were well replicated on retest.
Some of these data were reported in a preliminary
form that contrasted dipole sources with the Negative difference (Nd)
waveform found during controlled attentional processes (ref
2).
Conclusions:
This study confirms interactions between activity generated in the frontal
and auditory temporal cortices in automatic attention-like processes
that resemble initial brain imaging reports of unconscious visual change
detection (ref 3).
The lack of interference between sessions shows that the situation is
likely to be sensitive to treatment or illness effects on fronto-temporal
interactions involving repeated measures.
(1) Oades
et al.,. 1997 Biol. Psychiat., 41, 1196-1210.
(2) Jemel
et al.,. 2001 NeuroImage,
13, 323.
(3) Beck et
al., 2001 Nature Neurosci., 4, 645-650..
For some of the figures illustrating
the results , see: Oades
RD, et al., (2001). Sources
of prefrontal activity for auditory working memory (MMN): evidence for
an impaired fronto-temporal lobe dialogue in schizophrenia. Eighth
International Congress: Schizophrenia Research, [Latebreaking
data], Whistler, B.C., Canada
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