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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirty families, consisting of two parents and two adolescent children, were tested on a high-processing load Continuous Performance Test, the CPT-IP, which required identification of identical stimulus pairs within a continuously presented series of stimuli. The purpose of this study was to provide normative data for research concerned with the role of attention in psychopathology, especially schizophrenia and major affective disorder. Retest data collected from 23 of the 30 families showed the CPT-IP to be a reliable measure of attention. A major developmental effect was found in capacity to sustain attention to spatial vs. verbal stimuli, which suggested that spatial skills are most developed during childhood and adolescence, while verbal attentional skills tend to peak in adulthood. Factor analysis and family transmission patterns further suggested that the two types of attention (spatial and verbal) were independent and that each was heritable to some degree. Experimental distraction did not disrupt performance in any of the subjects and, in fact, tended to improve it in the adolescents, especially for spatial stimuli. We conclude that the CPT-IP is appropriate for use with families containing members differing widely in age and processing skills.
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PMID:The Continuous Performance Test, identical pairs version (CPT-IP): I. New findings about sustained attention in normal families. 323 15

Smooth pursuit eye tracking impairment has been observed in the major psychoses, particularly schizophrenia. To understand better the relationship of smooth pursuit disruption to personality dispositions linked to psychiatric syndromes and to two other "marker variables" associated with psychosis (low platelet monoamine oxidase [MAO] activity and poor performance on the continuous performance task [CPT]), we studied the psychologic, biochemical, and psychophysiologic correlates of impaired smooth pursuit tracking in two nonpsychiatric patient populations. One sample consisted of 67 volunteers screened for extreme values in a distribution of platelet MAO activities, and the second included 29 volunteers screened for extreme scores on the CPT. An aggregate of about 5% of both samples showed clearly dysfunctional smooth pursuit. Eye tracking dysfunction did not seem to be related to either MAO or CPT performance in either study. Both studies were consistent in showing that subjects with impaired smooth pursuit eye tracking had a psychologic profile characterized particularly by social introversion.
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PMID:Smooth pursuit eye tracking impairment: relation to other 'markers' of schizophrenia and psychologic correlates. 711 10

Thirty-five schizophrenic patients in the early stages of illness, 26 of their healthy siblings, and 35 normal control subjects performed the Continuous Performance Test, Identical Pairs version (CPT-IP). Both schizophrenic patients and their siblings were significantly impaired in their attentional performance compared with normal subjects. These results support impaired attention as a vulnerability marker of schizophrenia and indicate that at-risk siblings of schizophrenic patients display attentional deficits comparable to those found for the offspring of schizophrenic parents. By contrast, a decline in performance with the onset of a distraction condition (auditory and visual stimuli) was seen only in schizophrenic patients; siblings and normal control subjects did not differ from one another in response to experimental distraction. Therefore, it was concluded that differential distractibility is likely to be a state marker of schizophrenia. In clinical assessments, healthy siblings rated themselves as experiencing significantly more physical anhedonia than did normal control subjects, but the siblings did not differ from normal control subjects in self-rated perceptual aberrations. Contrary to expectation, performance on the CPT-IP did not correlate significantly with either anhedonia or perceptual aberration in high-risk siblings. These results suggest that psychometrically measured "psychosis proneness" and neuropsychologically detected deficits may tap two nonoverlapping sources of vulnerability to schizophrenia.
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PMID:Attentional abilities and measures of schizotypy: their variation and covariation in schizophrenic patients, their siblings, and normal control subjects. 779 30

P300 (P3) is a long-latency cognitive event-related potential (ERP) elicited by relevant target stimuli. P3 was recorded from 11 schizophrenics and 13 normal controls during a cued visual continuous performance task (CPT-AX). Cue-target sequences were presented at short and long interstimulus intervals (ISIs), in order to investigate working memory in schizophrenia. There was no significant between-group difference in P3 amplitude to validly or invalidly cued targets at short ISI. In contrast, P3 amplitude to invalidly cued targets at long ISI was significantly greater in schizophrenics than in controls, suggesting decreased ability to encode or maintain inhibitory representations of stimulus context. P3 amplitude is typically reduced in schizophrenic subjects in the auditory modality, and normal or reduced in the visual modality. This study, which demonstrates a paradoxical P3 increase to targets at long ISI, suggests that P3 impairment in schizophrenia cannot be attributed solely to structural deficits within P3-generator regions.
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PMID:Premature disinhibition of P3 generation in schizophrenia. 873 59

Recent years witnessed a considerable proliferation of computer-based training programmes as instruments of cognitive rehabilitation for schizophrenic patients. A study on the effects of a 3-week computer-based attention training with schizophrenic patients is presented. The Span of Apprehension and the Continuous Performance Test (CTP) were carried out before and after the training period. Performance improvements were found only on few attention training tasks. Schizophrenics had higher post-treatment hit rates on the Span of Apprehension, but no post-treatment improvements were observed in the CPT. Performance of trained patients in the external attention measures was not superior to performance of matched schizophrenic control patients. These data suggest that brief intensive computer-based attention remediation does not lead to enhanced attentional capacity in schizophrenia. Thus, it might be more adequate to teach behavioural strategies that bypass attention deficits or to offer programmes for exercising more complex cognitive skills than to try to remedy basic cognitive impairments.
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PMID:[Effectiveness of computer-assisted attention training of schizophrenic patients]. 965 77

The existence of a genetic background is now a well admitted notion in schizophrenia, but some individuals at genetic risk for that disease could never manifest it at a clinical level. However, several vulnerability models could help us to identify such individuals. According to them, when similar perturbations at a given test are observed both in clinically stable schizophrenics and their nonschizophrenic first degree relatives, this test could be qualify as an indicator of the vulnerability to schizophrenia. In literature, that seems the case for several neuropsychological tasks, exploring attentional abilities (degraded version of the Continuous Performance Task [DS-CPT], and Span Of Apprehension task [SOA]) and executive functions (Wisconsin Card Sorting Test [WCST]). Our study was undertaken to replicate literature data and to further explore the relationship between these three neuropsychological markers. For that purpose, performances at DS-CPT, SOA and WCST were assessed among 18 clinically stable schizophrenics, 18 of their biological full siblings and 15 unrelated control subjects matched with the two others groups for several socio-demographic factors. Comparisons were performed by non parametric analysis (Kruskal-Wallis one way ANOVA, and Mann-Whitney). Compared to controls, the siblings group performances were significantly impaired on the three tasks, while they did not statistically differ from the schizophrenic ones. No relationship was observed between the markers, except for the "d'" index at DS-CPT and the number of successfully performed categories at the WCST. Results from the sibling group suggested that the observed impaired neuropsychological performances may actually represent indicators of the genetic vulnerability to schizophrenia. Moreover, the generally admitted relationship between WCST poor performances and an impairment of the prefrontal cortex, lead us to hypothesize some role of this brain area in schizophrenia vulnerability.
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PMID:[Vulnerability to schizophrenia. I: Familial nature of of neuropsychologic indicators]. 985 Aug 18

The aim of this study was to investigate whether non-psychotic relatives of schizophrenic probands have deficits in sustained attention as measured by the Continuous Performance Test, Identical Pairs version (CPT-IP) and whether such deficits are associated with negative schizotypal personality disorders. The study subjects were 23 schizophrenic probands, 45 of their first-degree relatives and 36 normal controls. For each subject, attention was assessed during five conditions (2 standard, 2 slow, 1 easy) of visual stimuli (numbers and shapes). Schizotypy status was determined with the physical anhedonia and social anhedonia scales of Chapman et al. (Chapman, L.J., Chapman, J.P., Raulin, M.L., 1976. Scales for physical and social anhedonia. Journal of Abnormal Psychology 42, 374-382). The CPT-IP sensitive index d' in the standard shape condition was significantly lower in schizophrenics and in their relatives than in controls. For all d' values, the percentage of impaired first-degree relatives was at an intermediate level between patients and control individuals. Furthermore, the schizophrenic probands made more random errors in the standard and in the slow number conditions than the other two groups. None of the schizotypy measures correlated with the CPT-IP deficits. These results suggest that spatial sustained attention deficit may be a vulnerability marker for schizophrenia; however, this deficit and the negative dimension of schizotypal personality disorders may be distinct traits.
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PMID:Attentional deficits in patients with schizophrenia and in their non-psychotic first-degree relatives. 1070 62

This study was aimed, first, at detecting neuropsychological markers that assess vulnerability to schizophrenia in siblings of patients with schizophrenia, and second, at exploring possible relationships between markers. For these purposes, performances were assessed in 18 clinically stabilized patients with schizophrenia, 18 of their unaffected full siblings, and 15 controls on attentional abilities (the Degraded Stimuli-Continuous Performance Task [DS-CPT] and the Span of Apprehension [SOA] task) and on executive functions (the Wisconsin Card Sorting Test [WCST]). Both patients and siblings were impaired on the three tasks, leading to the conclusion that these poor performances may represent markers of genetic vulnerability to schizophrenia. Furthermore, significant relationships were found between DS-CPT and WCST performance in patients only, suggesting a possible implication of prefrontal brain areas for the two tasks. In spite of the lack of similar relationships between DS-CPT and WCST in siblings, this raises the question of a putative role of prefrontal areas in vulnerability to schizophrenia.
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PMID:Neuropsychological deficit in siblings discordant for schizophrenia. 1108 21

Previous studies of executive/attentional functions have found impairments in nonpsychotic first-degree relatives of patients with schizophrenia. The aims of this study were: (1) to replicate these findings by three laboratory measures of attention/information processing - a continuous performance test (DS-CPT), a forced-choice span of apprehension task (SPAN), and a digit symbol substitution test (DSST), and by a series of neuropsychological tests sensitive to prefrontal cortical damage - Trail Making A and B, verbal fluency (VFT), Stroop Color and Word Test (Stroop), and Wisconsin Card Sorting Test (WCST); (2) to investigate whether such executive/attentional deficits are associated with schizotypal traits assessed using the social anhedonia, physical anhedonia, perceptual aberration and magical ideation scales (Chapman, L.J., Chapman, J.P., Raulin, M.L. 1976. Scales for physical and social anhedonia. J. Abnorm. Psychol. 85, 374-382; Chapman, L.J., Chapman, J.P., Raulin, M.L., 1978. Body-image aberration in schizophrenia. J. Abnorm. Psychol. 87, 399-407; Eckblad, M., Chapman, L.J., 1983. Magical ideation as an indicator of schizotypy. J. Consult. Clin. Psychol. 51, 215-225). In both patient and relative groups, performance was significantly poorer on the DSST, VFT and Trail B, and the reaction time on the SPAN was significantly longer. These neuropsychological impairments were present as much in siblings as in parents of schizophrenic patients; age did not appear to cancel differences between the relative and control groups. In the relative group, the four scores of schizotypy were at an intermediate level between those of patient and control groups, and the social anhedonia and perceptual aberration scores tended to be significantly different between the relative and the control groups. Only two significant correlations were found between the neuropsychological performance and the measures of schizotypy.
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PMID:Executive/attentional performance and measures of schizotypy in patients with schizophrenia and in their nonpsychotic first-degree relatives. 1112 Apr 38

Schizophrenia patients subjected to the A-X Continuous Performance Test (A-X CPT) show cognitive deficits that are thought to reflect impaired representation and maintenance of context information. An issue deserving attention is to what extent the acute amphetamine model of schizophrenia also models these cognitive deficits. The present experiment examined the effect of acute d-amphetamine (AMP) on the performance of rats in an animal analogue of the A-X CPT. Subjects first learned to solve an A --> X+, B --> X-, A --> Y- discrimination task, with A and B representing visual features; X and Y designating auditory target stimuli; --> signifying a serial presentation; and + and - referring to food reinforcement and non-reinforcement, respectively. Frequency of food-magazine visits was the dependent measure. After mastering the discrimination, rats received test trials under either saline or 0.5 mg/kg AMP (s.c.). At test, the interval between feature and target presentation was varied; reinforcement contingencies were maintained. AMP significantly impaired performance on the A --> X+/B --> X- discrimination by increasing the response level on B --> X- trials. AMP did not significantly affect performance on the A --> X+/A --> Y- discrimination. However, AMP also increased magazine responding in the absence of the presentation of features and targets. A parsimonious conclusion based on these preliminary results is that acute AMP does not affect processing of context information provided by the visual features in this procedure. It rather has a more non-specific response-enhancing effect, especially with respect to stimuli associated with the delivery of food.
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PMID:Effects of d-amphetamine on the performance of rats in an animal analogue of the A-X continuous performance test. 1127 4


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