摘要:

The transient evoked responses of auditory cortex, reticular formation, hippocampus and cerebellar cortex to auditory stimulation have been analysed in the gamma frequency band on cats with chronically implanted electrodes. We found gamma band transient responses consisting of wave packets with 3-4 oscillations in all of the studied brain structures in the first 100 ms of the poststimulus period. The responses were strongly time-locked to the stimulation time point. The observation that the gamma band responses exist simultaneously in various brain structures supports the tentative proposal of our group on the“diffuse gamma response system”of the brain, which seems to be an important, universal operator in brain function. Furthermore, it shows that in search for generalized approaches to brain phenomena it is important to analyse the simultaneous behavior of different brain structures.

ISSN:0020-7454    

DOI:10.3109/00207459608987246

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Prepulse inhibition (PPI) is a measure of the influence of a stimulus (S1) on the response elicited by a second stimulus (S2) occurring shortly afterwards. Most S1/S2 measures of gating have used behavioural startle and the P50 event-related potential (ERP) amplitudes to detect PPI in a simple paired stimulus paradigm. We report on two behavioural (reaction time, RT, and the electromyographically recorded response of the musculus orbicularis oculi, EMG) and 5 ERP measures of PPI where S2 was the target in an auditory two-tone discrimination. Subjects were 21 healthy controls (CON), 11 obsessive-compulsive (OCD) and 9 schizophrenic patients (SCH). The prepulse 100ms before S2 induced more omission errors and longer RTs compared to a 500ms S1-S2 interval in all subjects. PPI was also evident in EMG, P50, N1, P3 but not P2 or N2 amplitudes of CON subjects. SCH patients showed attenuation of PPI on the same measures. OCD patients were characterized only by their slow RT and a marginal attenuation of PPI of the EMG response. A correlational analysis implied separate relationships of ERP indices of PPI to the cognitive and psychomotor consequences of the prepulse on behavioural and discrimination responses. However, SCH patients showed a general rather than a specific impairment of these indices.

ISSN:0020-7454    

DOI:10.3109/00207459608987247

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Brainstem auditory evoked potentials (BAEPs) were recorded in 14 artificially ventilated patients (12 males, 2 females; mean age 33.3±16.3 years, range 18-67) with respiratory insufficiency resulting from severe inflammatory encephalopathies. The results were compared with those of 17 healthy volunteers (13 males, 4 females; mean age 27.4±5.3 years, range 21-45). BAEPs in the study patients showed prolonged interpeak latencies (I-III. I-V, III-V, IV-V) and delayed absolute latencies of waves I, II, III and V at least on one side. Because the auditory pathways are in the near vicinity of the respiratory control centers in the brainstem, the electrophysiologic abnormalities of wave III and the IV/V complex may be a reflection of disturbed central control of ventilation.

ISSN:0020-7454    

DOI:10.3109/00207459608987248

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Fifty-five healthy volunteers (thirty young and twenty-five elderly), all of them right-handed, were investigated by Transcranial Doppler monitoring mean flow velocity on the right and left middle cerebral artery at rest, during a motor task performed by the hand and in the following rest condition. In all cases the motor task induced an increase in bilateral mean flow velocity, but significantly greater on the opposite side middle cerebral artery in the task. The percentage increase in mean flow velocity compared to the rest condition observed during the motor task performed by the opposite side hand to the artery investigated was significantly greater in the young than the elderly. Moreover, in the young, this increase showed a slight prevalence during the left middle cerebral artery assessment relating to right hand preference. Furthermore, elderly subjects achieved the greatest mean flow velocity percentage increase compared to rest condition later than young subjects and returned to basal values more slowly.

ISSN:0020-7454    

DOI:10.3109/00207459608987249

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The underlying factor structure of perinatal events was examined for 847 children (272 normals, 117 develop-mentally disabled, 37 speech disordered, 221 learning disordered, 91 emotionally disturbed, and 109 Head Start children). Pertinent perinatal information from the Maternal Perinatal Scale was subjected to a principle-components factor analysis. Ten factors accounting for some 58% of the total variance were isolated. In general, these factors appeared to be consistent with clinical evidence. The results were discussed in terms of their implications for the utility of perinatal information.

ISSN:0020-7454    

DOI:10.3109/00207459608987250

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

This study evaluated cerebral asymmetry for affect perception as a function of fluency classification. After being assigned to a fluency category using scores on the FAS test (Borkowski, Benton,&Spreen, 1967), forty-five right-handed subjects with normal auditory acuity listened to the Bryden and MacCrae (1989) Dichotic Emotional Words Tape. Subjects higher in fluency exhibited significantly greater right and left ear advantages than subjects lower in fluency. Conversely, REA scores for words were significantly greater than REA scores for affect, while LEA scores for affect were significantly greater than LEA scores for words.

ISSN:0020-7454    

DOI:10.3109/00207459608987251

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The present study investigated visuospatial functioning in 35 right-hand dominant patients with striatal, frontal white matter, or posterior thalamic infarction, in the right cerebral hemisphere. On tasks of visual detection and discrimination, the groups performed within normal limits and comparably to one another. On tasks of visual synthesis and spatial analysis, each group was significantly impaired, with greatest impairment following infarction of deep grey structures. Correlational analyses indicated that in the striatal and frontal white matter groups, visual synthesis and spatial analysis task performance were strongly correlated with performance on neuropsychological tests of executive control. This relationship was not observed in the posterior thalamic group. The results support the hypothesis of differential patterns of visuospatial performance depending on the anatomical locus of subcortical lesions. The findings are explained in terms of differing subcortical circuitry and suggest that multiple substrates mediate the sequelae of subcortical lesions.

ISSN:0020-7454    

DOI:10.3109/00207459608987252

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Focal brain-damaged patients (left hemisphere damage, right hemisphere damage) and hospitalized general medical patients were asked to sort test photographs into target expressions of four facial emotions, happy, sad, fear and anger. In a second task, patients were asked to match neutral photographs with these target emotion expressions in a forced-choice format. Patients were also asked to rate their mood state on a two-dimensional affect grid. Right hemisphere-damaged patients were significantly inaccurate in matching the test-target expressions of facial emotions in comparison to left hemisphere-damaged or general medical patients. Analysis of error scores indicated a bias toward negative emotions by left hemisphere-damaged patients. Congruent to their mood state, left hemisphere-damaged patients also attributed“sadness”on neutral state of expression significantly more often than right hemisphere-damaged patients.

ISSN:0020-7454    

DOI:10.3109/00207459608987253

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The purpose of this study was to validate an early childhood screening instrument concurrently with other established psychoeducational tests and predictively with a standardized measure of achievement. A battery of tests including a screener and five other established psychoeducational measures was administered to 64 children during their kindergarten year. An achievement test was administered to 33 of these children during their third grade year. The screening test scores were found to be significantly related to the results of other psychoeducational measures both concurrently and predictively. The instrument permits teachers to gather behavior samples in minutes.

ISSN:0020-7454    

DOI:10.3109/00207459608987254

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

This study investigated whether students with learning disabilities exhibited learned helpless behavior at a greater rate than their normal achieving peers when confronted with reading failure. Forty-five third grade students from a suburban elementary schools were participants in the study. Thirty of the subjects were classified as having a learning disability (LD) and the remaining 15 subjects were from regular education (RE) classrooms. Fifteen of the students with LD were placed in the treatment group and the remaining fifteen were placed in the control group. All the regular education students were placed in the treatment group. After randomly assigning the students with LD info either a treatment (stressed) group or a control (nonstressed) group, the stressed students were administered a reading instrument in order to measure how they dealt with failure. A one-way ANCOVA was conducted to determine whether significant differences existed between the groups based on their posttest scores. The results indicate that stressed students with LD have a significantly more difficult time recovering from stress than their regular education peers.

ISSN:0020-7454    

DOI:10.3109/00207459608987255

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor