Ken-Ichi Hiramatsu

Mismatch negativity and N2b attenuation as an indicator for dysfunction of the preattentive and controlled processing for deviance detection in schizophrenia: a topographic event-related potential study

The present study compares the amplitudes and topographic patterns of mismatch negativity (MMN) and N2b in schizophrenic patients and normal controls. Twenty-one schizophrenic outpatients and 19 normal volunteers participated in the study. Event-related potentials (ERPs) were recorded in a selective attention task. During the task, subjects were required to focus on one ear, counting deviant stimuli, those deviating in duration from a sequence of standard stimuli. MMN was significantly attenuated in the schizophrenics as compared with the normals in the frontocentral regions. In addition to MMN, the N2b amplitude was also reduced, which showed a significant correlation with the MMN amplitude in the schizophrenics. The late negativity elicited by the deviant stimuli in the unattended condition showed different topographical features between the groups. Whereas the normals showed a lateralized distribution with an ear-related asymmetry, similar to that of the N2b, the schizophrenics showed a frontal dominance, coinciding with the sustained negativity reported by Näätänen et al. (1982), which reflects the automatic preparation for detecting possible subsequent stimulus changes. The amplitude of the sustained negativity was significantly correlated with the performance level in the schizophrenics. The results indicated that although both preattentive and controlled processings are impaired, schizophrenic patients, presumably due to the deficient controlled processing, owe much to automatic processing in the deviant stimulus detection process.

Event-related potential correlates of functional hearing loss: Reduced P3 amplitude with preserved Nl and N2 components in a unilateral case

Abstract A female patient exhibiting functional hearing loss in her left ear demonstrated reduced amplitude of P3 component in event‐related potentials (ERP) to left monaural stimulation, with preserved N1 and N2 components to stimulation of either ear. This result suggested that stimuli in the affected ear were conducted successfully up to the auditory cortex but that further processing in higher brain regions was ‘repressed’. Event‐related potential examination for such hysterical disorders could be useful in clarifying their brain mechanism and offer a useful diagnostic clue to its nature.

Plasma vanillylmandelic acid level as an index of psychological stress response in normal subjects

The relationships between psychological stress responses and plasma levels of vanillylmandelic acid (VMA), 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindolacetic acid (5-HIAA) were investigated in normal volunteers. Two questionnaires were used to measure stress: the Psychological Stress Response Scale (PSRS) and the State-Trait Anxiety Inventory (STAI). Plasma levels of VMA--but not MHPG, HVA, and 5-HIAA--showed significant positive correlations with PSRS emotional and cognitive-behavioral stress and STAI state anxiety. Significant positive correlations were also found between plasma levels of VMA and MHPG and psychological stress responses measured repeatedly in a longitudinal study of an Olympic swimmer. Plasma VMA measurements, which reflect the level of activity of the peripheral sympathetic nervous system, may provide a useful biochemical index of psychological stress responses in normal subjects.

Frontolimbic Dysfunction as a Pathogenetic Mechanism of Autism: Localization of Paroxysmal Abnormality in the Magnetoencephalogram.

Frontolimbic Dysfunction as a Pathogenetic Mechanism of Autism: Localization of Paroxysmal Abnormality in the Magnetoencephalogram. Yoko Kawasaki, “Keiji Yokota, TMieko Shinomiya,

Correlations of event-related potentials with schizophrenic deficits in information processing and hemispheric dysfunction

Kenichi Hiramatsu,

Behavioral and P3 amplitude enhancement in schizophrenia following feedback training

Masat0 Yumoto, OYasuo Shimizu, and \)Shin-ichi Niwa (Tokyo Metropolitan Tama Habilitation Clinic, *Tokyo Metropolitan Fuchu Hospital, ?-Tokyo Metropolitan Hospital of Neurology, and

Effectiveness of comprehensive supports for schizophrenic women during pregnancy and puerperium: Preliminary study

Tokyo University, Tokyo; §Yokohama Rehabilitation Center, Yokohama; and IlFukushima Medical College, Fukushima, Japan).

Distributions of the Nd and P300 in a normal sample

In order to obtain further insight into hemispheric dysfunction in schizophrenics, two experiments were conducted employing event-related potential (ERP) recording during dichotic detection tasks as well as syllable discrimination tasks. Results concerning ERPs derived from the T3 and T4 regions are reported. Based on results in the two experiments, it is concluded that schizophrenics display a dysfunction of the left hemisphere, as well as a dysfunction in the ingration mechanism of both hemispheres. It is also speculated that the left-hemisphere dysfunction in schizophrenics is particularly correlated with positive psychotic symptoms.

Decreased plasma cortisol level during alprazolam treatment of panic disorder: a case report.

In order to clarify the remediability of behavioral and electrophysiological abnormalities in schizophrenia, hit rate, reaction time, and P3 amplitude from auditory event-related potentials were evaluated before and after feedback training of a task in 14 schizophrenics and 12 age-matched normal controls. Although mean changes in the three indices due to the training were nonsignificant in both schizophrenic and normal control groups as a whole, the changes in hit rate and reaction time correlated significantly with the P3 amplitude change in the schizophrenic (r = 0.60 and -0.58, respectively) but not in the normal control group. The P3 amplitude change also correlated with the P3 amplitude before the training only in the schizophrenic group (r = -0.68), suggesting that the training was more effective for the schizophrenic patients with marked P3 amplitude reduction. The observed P3 amplitude increase due to training may represent an electrophysiological correlate of a remediable aspect of behavioral deficits in schizophrenics, which may underlie the effectiveness of nonpharmacological treatments.

Shortening of N1 and P3 Latencies in Event‐Related Potentials Observed Coincidentally with Clinical Improvement during Nootropic Medication in a Demented Patient: Specific Effect of Nicergoline

Abstract  The risks of deteriorated psychiatric symptoms/daily life functioning should be warned of in schizophrenic women during pregnancy and puerperium. The purpose of the present paper was to prospectively monitor mental status and functioning of pregnant women with schizophrenia, and investigate the effects of various supports. Subjects were 20 schizophrenic women who visited a clinic providing care and support for pregnant women with psychiatric diseases, consisting of 12 patients with psychotic deterioration (deterioration group) and eight remitted stable patients (stable group). Psychiatric assessments were performed using Positive and Negative Syndrome Scale (PANSS) and Global Assessment of Functioning (GAF) at three time‐points: at the first examination, after fixed prescription during pregnancy, and after delivery. The types/doses of drugs and other non‐drug‐related supports (13 items) were recorded during the study period. Although a higher total PANSS score at the first examination (P = 0.004) and lower GAF scores at the first examination and even after fixed prescription (P = 0.0003) were observed in the deterioration group, those after delivery finally caught up with the levels in the stable group. Doses of antipsychotic drugs were gradually increased in the deterioration group although no significant differences in chlorpromazine equivalent doses were found between the two groups after fixed prescription. There was a positive correlation between the number of non‐drug‐related supports and amelioration score in PANSS (rs = 0.553, P = 0.012). These findings suggest that comprehensive intervention is a requisite in pregnant schizophrenic women, especially with psychotic deterioration, and that non‐drug‐related supports may also contribute to maintenance of good and stable mental status in these patients.