Ichiro Koshida

Learn More
To reveal the spatiotemporal characteristics of the auditory automatic discrimination process, mismatch negativity (MMN) generators were assessed with a high-resolution EEG system (128ch) and scalp current density (SCD) analysis. Ten normal volunteers participated in the study. Event-related potentials were recorded during a selective attention task.(More)
OBJECTIVE Schizophrenia is associated with language-related dysfunction. At the most basic level, the dysfunction of schizophrenic patients in perceiving phoneme boundaries has been demonstrated in a behavioral task. The goal in this study was to obtain an electrophysiological index of preattentive detection of change in speech sounds by schizophrenic(More)
Differences in hemispheric predominance between across- and within-category change perception of vowels were assessed using a whole-head magnetoencephalography. The magnetic mismatch responses (MMNm) to pure-tone and vowel within-category changes were significantly predominant in the right hemisphere; on the other hand, vowel across-category MMNm did not(More)
Language processing was investigated using event-related potentials obtained using a multichannel (58-channel) EEG system, with regard to semantic dependency (i.e., selectional restriction between a verb and the arguments it takes: the SR type) and syntactic dependency between sentence-final particles and interrogative phrases (the WH-Q type) in Japanese.(More)
OBJECTIVE Many studies have demonstrated mismatch negativity (MMN) attenuation in schizophrenia. Recently, investigators have shown that GABAergic inhibitory neurons may regulate MMN generation. Considering that a substantial proportion of schizophrenic patients receive anxiolytics and hypnotics that have affinity to GABA(A) receptors to reduce their(More)
Schizophrenia is associated with dysfunction in language processing. At the earliest stage of language processing, dysfunction of categorical perception of speech sounds in schizophrenia has been demonstrated in a behavioral task. The aim of this study was to assess automatic categorical perception of speech sounds as reflected by event-related changes in(More)
OBJECTIVE Autism is a form of pervasive developmental disorder in which dysfunction in interpersonal relationships and communication is fundamental. This study evaluated neurophysiological abnormalities at the basic level of language processing, i.e. automatic change detection of speech and non-speech sounds, using magnetoencephalographic recording of(More)
We applied high resolution event-related potentials (ERPs) to assess brain activities associated with inhibition of irrelevant information processing during auditory selective attention. Ten healthy subjects performed an auditory selective attention task. ERPs in response to standard stimuli delivered to the unattended ear (irrelevant stimuli) and those(More)
The auditory mismatch negativity (MMN) of event-related potential components has been widely used to assess the ability of auditory automatic change discrimination of verbal and nonverbal stimuli in healthy individuals and patients with various illnesses. To clarify the role of gender differences in the MMN, we compared the amplitude, latency, and(More)
Brain activities were compared between semantic and syntactic processing in the Japanese language using event-related potentials with a 58-ch EEG system. We previously found that semantic violations elicited N400 and syntactic violations elicited P600 but not early left anterior negativity (ELAN) or left anterior negativity (LAN) using a relatively long(More)