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Biomedical subjects

I Kadobayashi

Publications and source records attributed to I Kadobayashi.

At least 19 recordsLinked to original sources
PubMed1984

Effects of attention on auditory evoked middle latency potentials.

The effects of attention on the auditory evoked middle latency potentials (MLPs) were examined in 23 normal subjects. Early positive-negative-positive-negative waves (about 8, 11, 15 and 18 msec peak latencies) and a late positive one (about 30 msec peak latency) were recorded from the unilateral mastoid-nose tip. The amplitudes of the early portions of MLPs to binaural 50 dB SL clicks during attention decreased as compared to those obtained when the subjects were not attending to the test stimuli. No significant difference was seen in the latency of any early wave.

Adult↗
PubMed1984

A study of auditory middle latency responses in relation to electrode combinations and stimulus conditions.

Auditory middle latency responses were recorded from healthy right-handed subjects. Acoustic clicks at a rate of 10/s were presented to the subjects via headphones. Using the electrode combination unilateral mastoid-nose tip, responses characterized by two early negative waves (about 11.5 and 18 ms peak latencies), followed by a late positive one (about 30 ms peak latency), were elicited by binaural stimulation (50-dB SL clicks). The waveform of responses from the unilateral mastoid-nose tip combination was similar to that recorded from a combination of the same side mastoid and a balanced noncephalic reference electrode, although the phase was opposite to that recorded from the Cz-unilateral mastoid combination. Auditory middle latency responses were recorded simultaneously from right mastoid and left mastoid and referenced to the nose tip; interaural differences in amplitude were found in most subjects. The amplitudes of the early components for binaural stimulation were larger than those for monaural stimulation.

Acoustic Stimulation↗
PubMed1982

Slow negative potentials during problem-solving.

Electroencephalographic changes by solving mathematical problems were tested on 52 healthy young subjects. Slow negative potentials appeared in the frontal lobe (Fz) when the subject was asked to add numerals presented by a slide projector, multiply them and add them while hearing other addition problems through headphones. The mean amplitude of the potential was larger in multiplication and in addition while hearing other addition problems than in addition.

Adolescent↗
PubMed1981

Middle latency components of the auditory evoked response: lateral differences and changes by mental tasks.

Middle latency components in response to stimulation of both ears with 50 dB SL clicks at a rate of 10/sec were recorded in young healthy subjects from the left mastoid-nose tip and right mastoid-nose tip. All were right-handed. 1) Lateral differences were found in most subjects. As to the largest peak-to-peak amplitude, the amplitude on the right side was larger than that on the left in 18 subjects, but the reverse was found in 11. Only two showed little differences. 2) The amplitudes on the right side during addition were larger than those when merely looking at numerals. The amplitudes during multiplication were larger than those during addition.

Adult↗
PubMed1980

A schizophrenic subgroup: type A5.

This report concerns a group of schizophrenics whose visual evoked potential reduced in amplitude most markedly in A5 (averaged potential evoked by 1 Hz flashes which started 5 min after the addition test for 15 min). These patients in general had poor productive symptoms and progressed very slowly. Most of them were simple schizophrenics.

Adult↗
PubMed1978

Visual evoked potential characteristics and subtypes of schizophrenia.

Visual evoked potentials (VEPs) were recorded from the midoccipital area of 72 schizophrenic patients. The amplitude of wave VI (100- to 115-millisecond latency) was reduced after the addition test for 15 minutes. It recovered to the pretest level later, and four types of recovery curves were found; marked reduction in amplitude occurred in A1 (A1 type), in A3 with fast recovery (A3f type), in A3 with slow recovery (A3s type), and in A5 (A5 type) (A1, A3, A5: averaged potentials evoked by 1-Hz flashes which started 1 minute, 3 minutes, and 5 minutes after the end of the test). Each type closely corresponded to paranoid, atypical hebephrenic, typical hebephrenic, and simple schizophrenia, respectively.

Electroencephalography↗
PubMed1978

The effect of motor-response-deprivation on contingent negative variation (CNV): the morphology.

Eighty-four healthy subjects (47 males and 37 females) ranging in age between 9 and 76 years were employed in a study of the relations of the CNV morphology with the CNV amplitude, the reaction time and the MPI score. The results were as follows: 1. We classified a new type of Plateau (P) in the negative-going limb (NGL) types. 2. There was no sex difference in the NGL types, but the positive-going limb (PGL) types were influenced by age, and the type II tended to increase between the ages of 40--59 years old. 3. As a whole, the type B in the NGL and the type I in the PGL were most prominent regardless of age, session or paradigm. The type FD was very rare and appeared only in the session N. The types III and IV failed to be found in any healthy subjects. 4. Using the matched control study, the relations of the morphology with the CNV amplitude, the reaction time and the MPI score were analyzed. The conventional CNV amplitude in the sessions C and R increased in the sequences of the types B-A-P and the types I-II, and the CNV amplitudes in the session N increased in the sequences of the types A-B-P and II-I. The reaction time in the sessions C and R tended to prolong in the sequences of the types P-B-A and II-I. With the MPI, as the N-score increased with a decrease of the E-score, the NGL types changed from the type P to A through B in the conventional CNV and from the type A to B or P in the session N, while the PGL types changed from the type I to II in the conventional CNV and from the type II to I in the session N. 5. We suggest that there is a twofold arousal process, specific (task-relevant) and general, behind these types and that the dynamic balance of this process may influence psychological manifestations.

Adolescent↗
PubMed1978

The property of contingent negative variation (CNV) in psychiatric patients: schizophrenia and neurosis.

The CNV parameters (amplitude and morphology) and the relationship between CNV parameters and performances (motor response time) were studied on schizophrenics (15 subjects), neurotics (15 subjects) and normal controls (30 subjects divided into 2 groups) in order to clarify the property of CNV in psychiatric patients. Also, the relationship between CNV and personality traits was investigated in neurotics. Since it has been known that age, sex and psychoactive drugs influence the CNV genesis in normal subjects, the control group method was used for these factors in this study. The results obtained were as follows: 1) Mean amplitudes of CNV's for schizophrenics and neurotics in each session of control, nonresponse and recovery tended to be lower than those for normal controls. Significant differences were found between schizophrenics and normal controls. 2) Correlations between CNV amplitude and response time in schizophrenics tended to be positive, while normal controls showed significantly high negative correlations. These findings were discussed from the viewpoint of the arousal theory of CNV genesis. 3) For the neurotic patients, the personality variables appeared to influence CNV amplitude. 4) Type B-CNV was most frequently seen in all sessions for normal controls. Schizophrenics and neurotics tended to show the increment of type P-CNV in nonresponse sessions without a motor response. 5) "Field Dependency" type-CNV was not found in psychiatric patients. This result did not correspond with the data reported by other investigators. 6) Type III- and type IV-prolonged CNV's appeared almost especially in schizophrenics although type II-CNV was observed in all groups. The mechanism of genesis of the prolonged CNV's was discussed.

Adult↗
PubMed1977

Changes in visual evoked potentials of schizophrenics after addition test.

Visual evoked potentials were obtained for schizophrenics, neurotics and patients with affective disorders, and comparison between those before and after an addition test for 15 min was made. Reduction in amplitude and prolongation of latency of the potential were observed in schizophrenics after the test, while there was no change after that in neurotics and patients with affective psychosis. In schizophrenics, 4 types of changes in amplitude of the potential could be seen after the test. Namely, marked reduction occurred in A1 (A1 type), in A3 with fast recovery (A3f type), in A3 with slow recovery (A3s type), and in A5 (A5 type). (A1, A3, A5: Averaged potentials evoked by 1c/sec flashes which started 1 min, 3 min and 5 min after the end of the test.) Each type closely corresponded to paranoid schizophrenia, atypical hebephrenia, typical hebephrenia and simple schizophrenia, respectively.

Adolescent↗
PubMed1976

Modification of visual signals by nigral stimulation.

Responses of the lateral geniculate neurons to light were modified by stimulation of the substantia nigra. Nigral stimulation often caused enhancement of firing in neurons responding primarily to flash, but it usually had the contrary effect on units inhibited by light.

Animals↗
PubMed1976

The effect of motor-response-deprivation on contingent negative variation (CNV). III: relation with Maudsley Personality Inventory (MPI).

The contingent negative variation (CNV) was correlated with Maudsley Personality Inventory (MPI) in 43 healthy adults as follows: (1) The conventional CNV with motor-response showed a negative correlation with the scores of extroversion in the MPI (E-scores). The recovery of the conventional CNV after verbal extinction showed both a negative correlation with the E-scores and a politive correlation with the scores of neuroticism (N-scores). (2) The motor-response-deprived CNV in the stimuli and nonresponse sessions (Sa and Na) showed no correlation with the MPI, because they fluctuated according to the subject's attentiveness. On the other hand, the CNV in the discrimination session (Da) with constant attentiveness to stimuli showed a positive correlation with the N-scores. (3) The response times in the control and response sessions showed a positive correlation with the N-scores in males and a negative correlation in females. The correlation with the E-scores was nearly opposite.

Adult↗
PubMed1976

Effects of electrical stimulation of the substantia nigra on responses of lateral geniculate body neurons to light.

Effects of electrical stimulation of substantia nigra on responses of the lateral geniculate neurons to light were studied. Responses of the neurons to flash were enhanced or inhibited by conditioning stimulation of the substantia nigra. Enhancement of firing by nigral stimulation more often occurred in neurons excited primarily by flash, but inhibition was more commonly observed in those which showed a primary neuronal silence after light.

Animals↗
PubMed1976

Effects of electrical stimulation of the substantia nigra on responses of the lateral geniculate body neurons to light.

Effects of electrical stimulation of the substantia nigra on responses of the lateral geniculate neurons to light were studied. Responses of the neurons to flash were enhanced or inhibited by conditioning stimulation of the substantia nigra. Enhancement of firing by nigral stimulation more often occurred in neurons excited primarily by flash, but inhibition was more commonly observed in those which showed a primary neuronal silence after light.

Animals↗
PubMed1975

Effect of motor-response-deprivation on contingent negative variation (CNV). I: Normal adult data.

CNV's were obtained in S1-S2-MR paradigm from 22 normal subjects between the ages of 19 and 67 years (the mean age, 33.5+/-12.5). And then the effect of the presence or absence of a motor response on the CNV was studied. Results were as follows; (1) In the control session (S1-S2-MR), the mean CNV amplitude was 14+/-5 muV, and the mean response time was 291+/-76 msec. There was no significant difference with age, but the mean CNV amplitude for female was significantly higher than that for male. (2) Under the nonresponse condition (S1-S2) where the subject was instructed to attend to S1-S2 without a motor response, CNV amplitude significantly reduced for all subjects (7+/-5 muV). The mean voltage of the attentive-to-stimuli group was significantly higher than that of the inattentive group, and sex difference was not significant for the attentive group. However, CNV of the inattentive male disappeared completely, while the CNV of the inattentive female was significantly higher (8+/-5 muV). (3) Under the response condition (S1-S2-MR), CNV recovered almost to the magnitude level of the control condition (14+/-3 muV), in spite of the fact that the mean response time was significantly shortened between the control and response sessions. (4) We speculate that CNV changes may be dependent upon the dynamic balance of the excitatory-inhibitory activity.

Adult↗