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PubMed1980

[Cognitive disturbances in schizophrenia - experimental psychological examination and explanation in the frame of cognitive information processing].

The concern of the paper is, by using the example of schizophrenia, to show in a survey that it is possible and necessary to base the examination of cognitive disturbances and their exaplanation on the methodological concept of information processing. Departing from the stage reached in cognition-psychological schizophrenia research, a survey is given of such studies of cognitive disturbances in schizophrenia that are based on general psychological concepts of cognitive information processing. The approach to an identification of the defect within the frame of a model of the cognitive information processing is explained by two examples (performance of recognition, reproduction deficit).

Cognition Disorders↗
PubMed1996

[A specific disorder in Kanji writing in a learning disabled child with a visual cognition disorder--a cognitive-neuropsychological and electrophysiological analysis].

We reported a learning disabled child with a specific disorder involving Kanji writing. The patient was a 13-year-old boy. Although he manifested generally normal intellectual ability and his performance on WISC-R indicated that VIQ was 101 and PIQ 84, he could only write approximately 20% of Kanji, which he learned at age 6 to 7. On cognitive-psychological tests, he showed a visual cognition disorder that was different from that in a previously reported case during information processing. Electrophysiologically, he showed a disorder in visual task-relevant potentials. The mechanism underlying this patient appears to be a retrieval disorder for complex graphic forms in addition to a visual cognition disorder because of two reasons. One is that he could distinguish Kanji from similar graphic forms. The other is that he could read Kanji aloud.

Adolescent↗
PubMed1987

The phenomenology of acute organic psychosis. Comparison with acute schizophrenia.

The psychopathology of acute organic psychosis was investigated by interviewing 74 patients using the Present State Examination (PSE). Their delusions, perceptual disturbance, thought disorder, and emotional disorder were categorised and then compared with those seen in 74 acute schizophrenics. In acute organic psychosis there was a particular pattern to the delusions, perceptual disturbance, and thought disorder, which was quite unlike that seen in acute schizophrenia. These results have implications for theories claiming that schizophrenia is an organic psychosis. It is suggested that the psychopathology in acute organic psychosis has very different origins from that seen in schizophrenia.

Acute Disease↗
PubMed2000

Perceptual alternation in obsessive compulsive disorder--implications for a role of the cortico-striatal circuitry in mediating awareness.

Mounting evidence suggests that obsessive compulsive disorder (OCD) results from functional aberrations of the fronto-striatal circuitry. However, empirical studies of the behavioral manifestations of OCD have been relatively lacking. The present study employs a behavioral task that allows a quantitative measure of how alternative percepts are formed from one moment to another, a process mimicking the brain state in which different thoughts and imageries compete for access to awareness. Eighteen patients with OCD, 12 with generalized anxiety disorder, and 18 normal subjects participated in the experiment, in which they viewed one of the three Schröder staircases and responded by pressing a key to each perceptual reversal. The results demonstrate that the patients with OCD have a higher perceptual alternation rate than the normal controls. Moreover, the frequency of perceptual alternation is significantly correlated with the Yale-Brown obsessive compulsive and the Hamilton anxiety scores. The increase in the frequency of perceptual reversals cannot easily be accounted for by learning or by different patterns of eye fixations on the task. These results provide further evidence that an impairment of the inhibitory function of the cortico-striatal circuitry might underlie the etiology of OCD. The implications of the results for a general role of the cortico-striatal circuitry in mediating awareness are discussed.

Adult↗
PubMed2000

[Comparison between the old and new evaluation mode in the dichotic discrimination test].

The dichotic discrimination test for children could make an important contribution to the diagnosis of central auditory processing disorders. With previous test procedures and their interpretation it was not possible to get the auditory discrimination ability in only one grade. To evaluate this ability, it was necessary to measure the degree of comprehension in each ear as well as the required noise level. The evaluation cannot be used for statistical results because there are too many parameters. Moreover, results apparently similar can come from varying abilities. We are therefore working on a new method to evaluate dichotic hearing more accurately. By using a constant noise level and only evaluating positively those hearing pairs which have been repeated correctly, we arrive at one single grade. The dichotic discrimination test was administered to 46 children with auditory perception disorders and the results evaluated according to both, the previous and new evaluation system. According to the new evaluation, a maximum of 20 correct responses is possible. The average number of correct responses was significantly lower than by the previous evaluation system. The standard deviation increased from 16% on the left side and 13% in the right to 24%, or five word-pairs. The difference is even clearer when the test is subdivided into four performance ranges, each of 25%. Of all the children examined, 85% fell in the upper performance range according to the previous evaluation. No child was in the lowest performance range. According to the new evaluation, only 56.5% of the children were in the upper performance range, while three children, that is 6.5%, were in the lowest performance range. This difference, P = 0.0002, is highly significant. Our results demonstrate clearly that on the basis of the new evaluation system the measurement of dichotic ability is possible, for the first time. We consider the new evaluation method to be an improvement in determining dichotic discrimination and in comparing it with other abilities. To check the validity, further independent testing should be carried out and results compared with those obtained from children without auditory perception disorders.

Auditory Perceptual Disorders↗
PubMed2002

Auditory processing efficiency deficits in children with developmental language impairments.

The "temporal processing hypothesis" suggests that individuals with specific language impairments (SLIs) and dyslexia have severe deficits in processing rapidly presented or brief sensory information, both within the auditory and visual domains. This hypothesis has been supported through evidence that language-impaired individuals have excess auditory backward masking. This paper presents an analysis of masking results from several studies in terms of a model of temporal resolution. Results from this modeling suggest that the masking results can be better explained by an "auditory efficiency" hypothesis. If impaired or immature listeners have a normal temporal window, but require a higher signal-to-noise level (poor processing efficiency), this hypothesis predicts the observed small deficits in the simultaneous masking task, and the much larger deficits in backward and forward masking tasks amongst those listeners. The difference in performance on these masking tasks is predictable from the compressive nonlinearity of the basilar membrane. The model also correctly predicts that backward masking (i) is more prone to training effects, (ii) has greater inter- and intrasubject variability, and (iii) increases less with masker level than do other masking tasks. These findings provide a new perspective on the mechanisms underlying communication disorders and auditory masking.

Adult↗
PubMed2004

Cognitive impairments in Machado-Joseph disease.

BACKGROUND: Cognitive function of Machado-Joseph disease (MJD) patients has not been clarified. OBJECTIVES: To determine the characteristics of cognitive dysfunction in MJD patients and to assess the relationship of dysfunction to age at onset, age at examination, disease duration, education, ataxia, depression, anxiety, and CAG repeat length. DESIGN: Case-control study. SETTING: Research-oriented hospitals. PARTICIPANTS: Sixteen genetically confirmed MJD patients able to complete neuropsychological tests and 20 control subjects matched to patients by age and education. MAIN OUTCOME MEASURES: Neuropsychological tests, including general cognition, verbal and visual memory, working memory, visuospatial and constructional ability, language, executive function, depression, and anxiety. RESULTS: Machado-Joseph disease patients scored significantly lower than controls in verbal and visual memory, in visuospatial and constructional tasks, and in phonemic and semantic fluency tasks. None of these impairments correlated with CAG repeat length, age at onset, age at examination, disease duration, or education. Verbal fluency (words named in a category) correlated with the International Cooperative Ataxia Rating Scale score. CONCLUSION: Machado-Joseph disease patients have verbal and visual memory deficits, visuospatial and constructional dysfunction, and verbal fluency deficits, all unrelated to CAG repeat length.

Adult↗
PubMed1998

Cortical acetylcholine, reality distortion, schizophrenia, and Lewy Body Dementia: too much or too little cortical acetylcholine?

Aberrations in cortical cholinergic transmission have been hypothesized to mediate the development and manifestation of psychotic cognition. Based primarily on hypotheses about mesolimbic dopaminergic hyperactivity in schizophrenia, the actions of antipsychotic drugs, the trans-synaptic regulation of the excitability of basal forebrain corticopetal cholinergic neurons, and the role of cortical cholinergic inputs in attentional functions, we hypothesized that persistent disinhibition of cortical cholinergic inputs mediates the fundamental cognitive dysfunctions which form the basis for the development of positive symptoms in schizophrenia. In contrast to this hypothesis, Perry and Perry (1995), based on evidence from hallucinating patients with Lewy Body Dementia (LBD), concluded that the extensive loss of cortical acetylcholine allows irrelevant information to enter "conscious awareness" and thus hallucinations to emerge. The discussion of these contrasting hypotheses highlights the need for more dynamic and precise theories describing the cognitive variables and neuronal processes which contribute to the development and manifestation of psychotic cognition. While the hypothesis that a disinhibited cholinergic system mediates the evolution of psychotic symptoms corresponds more convincingly with current theories about the cognitive functions of cortical cholinergic inputs, both hypotheses stress the critical role of cortical acetylcholine in the highest levels of cognitive functioning.

Acetylcholine↗
PubMed1993

Study of the neurobehavioural toxicity of styrene at low levels of exposure.

Thirty workers in a dockyard exposed to concentrations of styrene lower than the TLV-TWA of 50 ppm and 30 control workers not subject to exposure but employed by the same company were subjected to three psychometric tests on one Monday morning and evening. The results were usually better in the evening than in the morning in both groups, which proves the lack of acute intoxication at the end of the day at this level of exposure. On the other hand, all of the tests conducted on the exposed subjects are significantly less good than those on the controls. The results suggest the existence of minor but significant organic mental disorders in the subjects exposed to a mean dose of 30 ppm in this study. These results are inconsistent with those of several recent studies. The advisability of lowering the TLV of 50 ppm in discussed.

Adult↗
PubMed2006

Intellectual ability, self-perceived social competence, and depressive symptomatology in children with high-functioning autistic spectrum disorders.

Although social competence deficits in children with high-functioning autistic spectrum disorders (HFASD) are well documented, there is little research investigating self-perceptions of social limitations. This study replicated research showing a negative association between self-perceived social competence and intellectual ability and investigated associations between self-perceived social competence and depressive symptomatology. Participants were 22 children with HFASD, aged 7-13 years with intelligence quotient (IQ) scores of 82-141. Parent- (N = 18) and teacher- (N = 17) rated social competence was lower for children with HFASD compared with a normative sample. Higher age and IQ predicted lower levels of self-perceived social competence, and low self-perceived social competence predicted higher levels of depressive symptomatology. Almost a third of children rated themselves for depression; parent ratings suggested even higher levels.

Adolescent↗