| Research Abstract |
Mismatch negativity (MMN) component of the event-related brain potentials (ERPs) reflects the memory process related to the automatic information processing. We reported the mechanism of "Temporal Window of Integration (TWI)" in auditory sensory memory as reflected by MMN (Yabe et.al., NeuroReport, 1997). On the other hand, several studies indicated that deficits of cognitive function in schizophrenia were also reflected in the impaired generation of MMN.In our previous studies, infrequently omitting one stimulus from a homogeneous sound sequence only elicited an MMN when SOA was shorter than 160-170 ms, the duration of TWI (Magnetoencephalography : MEG ; Yabe et.al., Psychophysiology, 1998, Yabe et.al., EEG journal, suppl. 40, 1999 ; 6th IEPS : Okazaki Award). Furthermore, we found that automatic detection sensitivity should decline nonlinearly toward the end of TWI (Yabe et.al., Cog.Brain Res., in press) and that the mechanism of Stream Segregation be more primary than that of TWI (Y
… More
abe et.al., Brain Res. Interactive, in press). Both results were presented in the symposium of ICON-7(1999, Budapest). We also investigated sound grouping in human brain as reflected by MMN (Shinozaki et.al., NeuroReport, 2000). We reported that Median Method should be effective in eliminating infrequent artifacts and identifying the signals blurred by latency jitter and uncertain occurrence (Yabe, Electroencephr. Clin. Neurophysiol., 1993 ; Yabe, BRMIC, 1998). We identified the equivalent of MMN in somatosensory modality (Shinozaki et.al., Cog.Brain Res., 1998). We reported that the administration of neuroleptic drugs decreased the arousal level, as reflected in a reduction of early CNV amplitude (Sato et.al., Schizo.Res., 1999). Finally, we found that the TWI mechanism might be impaired in schizophrenia (Symposium of MMN 2000, Barcerona, 2000). Additionally, we started the studies concerning the language MMN (Koyama et al., Cog. Brain Research, 2000 ; Koyama et al., NeuroReport, 2000). Less
|
