- Email: [email protected]
Deficits in cognitive and motor functions in schizophrenia
cortical dysfunction. Previously, we reported that schizophrenic patients were impaired in remembering the relative recency of studied items. suggestive of temporal ordering deficits. In this study, we examined memory for temporal information in schizophrenic patients using the list discrimination paradigm. Twentyfour patients and 24 normal control subjects studied two lists of words in succession. At test, subjects were shown words and were asked to identify whether the word was shown in the first or second list (i.e., list discrimination). The results showed that schizophrenic patients’ ability to identify the list in which the word occurred (63% correct) did not differ significantly from that of control subjects (67% correct). Thus, these results suggest that memory for temporal order deficits may be more circumscribed in schizophrenia.
PRONOUNCED RIGHT HEMISPHERE ADVANTAGE IN SCHIZOPHRENIC PATIENTS PERFORMING A FACE MATCHING TASK
Several studies have produced evidence for a larger semantic priming effect in schizophrenic patients compared to normal controls. According to Maher’s hypothesis of heightened normal associations in schizophrenic patients, this effect represents a faster spread of activation across semantic nodes activated by the prime and probed by the target. Using data from a recent study of 70 schizophrenic patients and 84 normals, we addressed the question as to whether the semantic priming effect for 105 semantically related prime-target pairs follows the same pattern in control subjects and in patients. By subtracting the mean RT for each related word pair from the mean RT of all non-related prime-target pairs in each group, the priming effect of each semantically related prime-target pair was calculated for patients and normals. Our data indicate that itemized priming effects in schizophrenic patients and control subjects not only show a small positive correlation (t=.175), but also display striking similarities at both ends of the item by priming effect distribution. We conclude that this result provides further evidence for Maher’s hypothesis and sugest that the proposed method may be used to identify “bad” items, thereby improving the specificity of the semantic priming method as applied to schizophrenia research.
M. Spitzer*, S. Seyyedi, C. Schiementz Psychiatrische Universitiitsklinik, VowStr. 4, 6900 Heidelberg, Germany
DEFICITS IN COGNITIVE AND MOTOR FUNCTIONS IN SCHIZOPHRENIA
It has been proposed that schizophrenia involves a left hemisphere deficit. This possibly implies a relative right hemisphere information processing advantage. One of the tasks that is thought to be processed primarily by the right hemisphere is the recognition of faces: Right hemispheric lesions may produce prosopagnosia, the inability to recognize faces. The opposite phenomenon, the “tendency to physiognomize the environment” is known for a long time to be present in a significant number of acute schizophrenic patients, We used a divided visual field task to directly test the hypothesis of a relative right hemisphere advantage in the processing of faces in schizophrenic patients. After a face was shown in the centre of the screen, either the same face or a different face was represented in the right or the left visual field, and subjects had to make a speeded decision about sameness. Our data on RTs and errors show a pronounced right hemisphere advantage in schizophrenic patients (N=22) as compared to relatively small right hemisphere advantage in control subjects. We conclude that face matching is a useful task to investigate schizophrenic pathology. Further research should clarify the specificity and sensitivity of the task, its relation to clinical variables and to other neuropsychological measures.
E.V. Sullivan*, P.K. Shear, R.B. Zipursky, H.J. Sagar, A. Pfefferbaum
SEMANTIC PRIMING IN SCHIZOPHRENIC PATIENTS IS DUE TO HEIGHTENED NORMAL ASSOCIATIONS: EVIDENCE FROM AN ITEM ANALYSIS M. Spitzer*, I. Weisker Psychiatrische Universitiitsklinik, Voss-Str. 4, 6900 Heidelberg, Germany
Psychiatry Service, DVA Medical Center, 3801 Miranda Ave., Palo Alto, CA 94304, USA Recent studies characterizing neuropsychological functioning in schizophrenia (SZ) have reported deficits in executive, memory, and motor processing. This study 1) assessed functioning in SZ, using tests known to be specific to lesions in circumscribed, lateralized brain regions (dorsolateral prefrontal cortex, orbital frontal cortex, precentral gyms/basal ganglia, and medial temporal lobe), and 2) examined relationships between behavioural test scores and disease duration as well as symptom severity. The subjects were 29 male SZ on neuroleptic medication and 48 male controls (NC). The two groups did not differ in age (SZ=36.1 yr; NC=37.7 yr) or handedness; the NC had more education (SZ=12.6 yr; NC=16.2 yr) and higher WAIS-R Vocabulary age scaled scores than the SZ (SZ=9.2; NC=1 1.7). The average SZ disease duration was 11.8 yr and BPRS total score was 43.3. The scores for each cognitive test were corrected for normal aging by a regression procedure based on a sample of 76 healthy males spanning the adult age range. From these age-corrected data, we derived 8 composite scores (4 brain regions x 2 hemispheres). A group x region x hemisphere ANOVA revealed a significant group effect (p<.OOOl), with the SZ scores significantly worse than the NC scores by nearly 1 SD on average, and a significant threeway interaction (pc.02). Hemisphere composite scores were comparable in all regions except the orbital frontal, for which the SZ had worse left- than right-hemisphere scores. The three cognitive composites correlated significantly with each other but not with the motor composite. Longer illness duration was significantly related to low scores (poor performance) on the
189
dorsolateml and the orbital frontal composites, whereas high scores on the BPRS (greater symptom severity) correlated significantly with low scores on the medial temporal composite. These results present evidence for widespread deficits in multiple cognitive and motor functions subserved by distinct brain regions. They also provide a rationale for hypothesizing that 1) the frontal cognitive deficits may be related to the chronic neuropathological features of SZ, antipsychotic medication, or their interaction; 2) the memory deficit may be, in part, state-dependent; and 3) the cognitive and motor deficits of SZ may be dissociable. Supported by MH30854, MH18905, Department of Veterans Affairs.
NARSAD, Norris Foundation,
SCHIZOPHRENICS’ SPATIAL MEMORY DEFICIT IN A REPLACEMENT TASK: (I) EYE MOVEMENT BEHAVIOUR DURING THE ENCODING PERIOD W. Wijlwer*, W. Gaebel, J. Mather Department of Psychiatry, Henrich-Heine-University, Diisseldo$, Berg. Landstr. 2, D-4000 Diisseldorf 12, Germany Recent models on information processing distinguish between processess (p) of information input (“perceptual p.“), information processing (“conceptual p.“) and output processes (“behavioural Referring to the known response p.“; Burrows et al. 1986). memory deficits in schizophrenics, in the present study input as well as output processes were analysed more closely in a spatial replacement task. This part of the paper refers to scanning eye movement behaviour during the encoding period representing the input process. 20 acute schizophrenics (DSM-III-R) participated in this study. 14 depressives (DSM-III-R) and 20 normals served as controls. In patients assessment took place 4 weeks after admission. The task consisted of 3 periods: during a 60sencoding period subjects were asked to commit to memory names and positions of 10 simple geometrical shapes scattered pseudo-randomly on a video screen in front of them; after a 60s-delay period, subjects should recall by name which shapes they had seen and should then replace wooden copies of the shapes as exactly as possible regarding single item positions and overall arrangement of the shapes on a board of the same size as the video screen. Eye movements during the encoding period were recorded using infrared comeal-reflection pupil centre measurement and were analyzed offhie for the number and total time of ftxations on each of the 10 shapes as well as the temporospatial sequences of consecutive fixations (scanpath). Schizophrenics showed deficits both in the recall and replacement. The relationship of these deficits to their eye movement behaviour will be described at the conference.
SCHIZOPHRENICS’ SPATIAL MEMORY DEFICIT IN A REPLACEMENT TASK: (II) HAND MOVEMENT BEHAVIOUR DURING THE REPLACEMENT PERIOD
W. Wdlwer*, W. Gaebel, J. Mather Department of Psychiatry, Heinrich-Heine-University, Diisseldorf, Berg. Lundstr. 2. D-4000 Diisseldotf 12, Germany Recent models on information processing distinguish between processes (p) of information input (“perceptual p.“), information processing (“behavioural response p.“; BURROWS et al. 1986). Referring to the known memory deficits in schizophrenics, in the present study input as well as output processes were analyzed more closely in a spatial replacement task. This part of the paper refers to hand movements during replacement of previously memorized items representing the output process. 20 acute schizophrenics (DSM-III-R) participated in this study. 14 depressives (DSM-III-R) and 20 normals served as controls. In patients assessment took place 4 weeks after admission. The task consisted of 3 periods: during a 6Osencoding period subjects were asked to commit to memory names and positions of 10 simple geometrical shapes scattered pseudo-randomly on a video screen in front of them; after a 6Os-delay period, subjects should recall by name which shapes they had seen and should then replace wooden copies of the shapes as exactly as possible regarding single item positions and overall arrangement of the shapes on a board of the same size as the video screen. The process of replacing the shapes was coded according to predefined categories of hand movements and analyzed for total and category specific number of actions and for sequentional characteristics of the replacement behaviour. Parallel to a larger overall error in replacing the shapes, schizophrenics showed a significantly different pattern of hand movements during the replacement period.
ABNORMAL TIME PERCEPTION AND COGNITIVE ESTIMATION IN SCHIZOPHRENIA P.W.R.Woodruff* Genetics Section, Institute of Psychiatry, London, SE5 &IF, UK Previous evidence indicates that schizophrenics tend to judge prematurely when a set time period has elapsed. This study investigated the hypothesis that a) other abnormalities of judgement and b) mental state, would influence time perception in schizophrenics. DSM-III-R diagnosed male schizophrenics (n=16) were compared with normal male controls (n=ll) matched for age, race, handedness, paternal social class and total years of education. Tests included: 1) estimated duration of 1 minute, 2) Cognitive Estimates Test of Shallice and Evans to measure bizarre responses to simple questions, and 3) the Brief Psychiatric Rating Scale (BPRS). The mean results of the l-minute estimation were: controls, 61+8.7 seconds, schizophrenics, 39f24.7 seconds. Group means were significantly different (p=O.O04, 2-tailed, modified ttest with separate variance estimate); an F-test revealed a similar difference between standard deviations (F=8.03, p=O.O02. 2-tailed). In schizophrenics, inaccuracy of minute estimation was correlated with Cognitive Estimation score (cc=O.73; p=O.OOl, 2-tailed) but not with BPRS (cc=O.18; p=O.52, 2-tailed).
PRONOUNCED RIGHT HEMISPHERE ADVANTAGE IN SCHIZOPHRENIC PATIENTS PERFORMING A FACE MATCHING TASK
Several studies have produced evidence for a larger semantic priming effect in schizophrenic patients compared to normal controls. According to Maher’s hypothesis of heightened normal associations in schizophrenic patients, this effect represents a faster spread of activation across semantic nodes activated by the prime and probed by the target. Using data from a recent study of 70 schizophrenic patients and 84 normals, we addressed the question as to whether the semantic priming effect for 105 semantically related prime-target pairs follows the same pattern in control subjects and in patients. By subtracting the mean RT for each related word pair from the mean RT of all non-related prime-target pairs in each group, the priming effect of each semantically related prime-target pair was calculated for patients and normals. Our data indicate that itemized priming effects in schizophrenic patients and control subjects not only show a small positive correlation (t=.175), but also display striking similarities at both ends of the item by priming effect distribution. We conclude that this result provides further evidence for Maher’s hypothesis and sugest that the proposed method may be used to identify “bad” items, thereby improving the specificity of the semantic priming method as applied to schizophrenia research.
M. Spitzer*, S. Seyyedi, C. Schiementz Psychiatrische Universitiitsklinik, VowStr. 4, 6900 Heidelberg, Germany
DEFICITS IN COGNITIVE AND MOTOR FUNCTIONS IN SCHIZOPHRENIA
It has been proposed that schizophrenia involves a left hemisphere deficit. This possibly implies a relative right hemisphere information processing advantage. One of the tasks that is thought to be processed primarily by the right hemisphere is the recognition of faces: Right hemispheric lesions may produce prosopagnosia, the inability to recognize faces. The opposite phenomenon, the “tendency to physiognomize the environment” is known for a long time to be present in a significant number of acute schizophrenic patients, We used a divided visual field task to directly test the hypothesis of a relative right hemisphere advantage in the processing of faces in schizophrenic patients. After a face was shown in the centre of the screen, either the same face or a different face was represented in the right or the left visual field, and subjects had to make a speeded decision about sameness. Our data on RTs and errors show a pronounced right hemisphere advantage in schizophrenic patients (N=22) as compared to relatively small right hemisphere advantage in control subjects. We conclude that face matching is a useful task to investigate schizophrenic pathology. Further research should clarify the specificity and sensitivity of the task, its relation to clinical variables and to other neuropsychological measures.
E.V. Sullivan*, P.K. Shear, R.B. Zipursky, H.J. Sagar, A. Pfefferbaum
SEMANTIC PRIMING IN SCHIZOPHRENIC PATIENTS IS DUE TO HEIGHTENED NORMAL ASSOCIATIONS: EVIDENCE FROM AN ITEM ANALYSIS M. Spitzer*, I. Weisker Psychiatrische Universitiitsklinik, Voss-Str. 4, 6900 Heidelberg, Germany
Psychiatry Service, DVA Medical Center, 3801 Miranda Ave., Palo Alto, CA 94304, USA Recent studies characterizing neuropsychological functioning in schizophrenia (SZ) have reported deficits in executive, memory, and motor processing. This study 1) assessed functioning in SZ, using tests known to be specific to lesions in circumscribed, lateralized brain regions (dorsolateral prefrontal cortex, orbital frontal cortex, precentral gyms/basal ganglia, and medial temporal lobe), and 2) examined relationships between behavioural test scores and disease duration as well as symptom severity. The subjects were 29 male SZ on neuroleptic medication and 48 male controls (NC). The two groups did not differ in age (SZ=36.1 yr; NC=37.7 yr) or handedness; the NC had more education (SZ=12.6 yr; NC=16.2 yr) and higher WAIS-R Vocabulary age scaled scores than the SZ (SZ=9.2; NC=1 1.7). The average SZ disease duration was 11.8 yr and BPRS total score was 43.3. The scores for each cognitive test were corrected for normal aging by a regression procedure based on a sample of 76 healthy males spanning the adult age range. From these age-corrected data, we derived 8 composite scores (4 brain regions x 2 hemispheres). A group x region x hemisphere ANOVA revealed a significant group effect (p<.OOOl), with the SZ scores significantly worse than the NC scores by nearly 1 SD on average, and a significant threeway interaction (pc.02). Hemisphere composite scores were comparable in all regions except the orbital frontal, for which the SZ had worse left- than right-hemisphere scores. The three cognitive composites correlated significantly with each other but not with the motor composite. Longer illness duration was significantly related to low scores (poor performance) on the
189
dorsolateml and the orbital frontal composites, whereas high scores on the BPRS (greater symptom severity) correlated significantly with low scores on the medial temporal composite. These results present evidence for widespread deficits in multiple cognitive and motor functions subserved by distinct brain regions. They also provide a rationale for hypothesizing that 1) the frontal cognitive deficits may be related to the chronic neuropathological features of SZ, antipsychotic medication, or their interaction; 2) the memory deficit may be, in part, state-dependent; and 3) the cognitive and motor deficits of SZ may be dissociable. Supported by MH30854, MH18905, Department of Veterans Affairs.
NARSAD, Norris Foundation,
SCHIZOPHRENICS’ SPATIAL MEMORY DEFICIT IN A REPLACEMENT TASK: (I) EYE MOVEMENT BEHAVIOUR DURING THE ENCODING PERIOD W. Wijlwer*, W. Gaebel, J. Mather Department of Psychiatry, Henrich-Heine-University, Diisseldo$, Berg. Landstr. 2, D-4000 Diisseldorf 12, Germany Recent models on information processing distinguish between processess (p) of information input (“perceptual p.“), information processing (“conceptual p.“) and output processes (“behavioural Referring to the known response p.“; Burrows et al. 1986). memory deficits in schizophrenics, in the present study input as well as output processes were analysed more closely in a spatial replacement task. This part of the paper refers to scanning eye movement behaviour during the encoding period representing the input process. 20 acute schizophrenics (DSM-III-R) participated in this study. 14 depressives (DSM-III-R) and 20 normals served as controls. In patients assessment took place 4 weeks after admission. The task consisted of 3 periods: during a 60sencoding period subjects were asked to commit to memory names and positions of 10 simple geometrical shapes scattered pseudo-randomly on a video screen in front of them; after a 60s-delay period, subjects should recall by name which shapes they had seen and should then replace wooden copies of the shapes as exactly as possible regarding single item positions and overall arrangement of the shapes on a board of the same size as the video screen. Eye movements during the encoding period were recorded using infrared comeal-reflection pupil centre measurement and were analyzed offhie for the number and total time of ftxations on each of the 10 shapes as well as the temporospatial sequences of consecutive fixations (scanpath). Schizophrenics showed deficits both in the recall and replacement. The relationship of these deficits to their eye movement behaviour will be described at the conference.
SCHIZOPHRENICS’ SPATIAL MEMORY DEFICIT IN A REPLACEMENT TASK: (II) HAND MOVEMENT BEHAVIOUR DURING THE REPLACEMENT PERIOD
W. Wdlwer*, W. Gaebel, J. Mather Department of Psychiatry, Heinrich-Heine-University, Diisseldorf, Berg. Lundstr. 2. D-4000 Diisseldotf 12, Germany Recent models on information processing distinguish between processes (p) of information input (“perceptual p.“), information processing (“behavioural response p.“; BURROWS et al. 1986). Referring to the known memory deficits in schizophrenics, in the present study input as well as output processes were analyzed more closely in a spatial replacement task. This part of the paper refers to hand movements during replacement of previously memorized items representing the output process. 20 acute schizophrenics (DSM-III-R) participated in this study. 14 depressives (DSM-III-R) and 20 normals served as controls. In patients assessment took place 4 weeks after admission. The task consisted of 3 periods: during a 6Osencoding period subjects were asked to commit to memory names and positions of 10 simple geometrical shapes scattered pseudo-randomly on a video screen in front of them; after a 6Os-delay period, subjects should recall by name which shapes they had seen and should then replace wooden copies of the shapes as exactly as possible regarding single item positions and overall arrangement of the shapes on a board of the same size as the video screen. The process of replacing the shapes was coded according to predefined categories of hand movements and analyzed for total and category specific number of actions and for sequentional characteristics of the replacement behaviour. Parallel to a larger overall error in replacing the shapes, schizophrenics showed a significantly different pattern of hand movements during the replacement period.
ABNORMAL TIME PERCEPTION AND COGNITIVE ESTIMATION IN SCHIZOPHRENIA P.W.R.Woodruff* Genetics Section, Institute of Psychiatry, London, SE5 &IF, UK Previous evidence indicates that schizophrenics tend to judge prematurely when a set time period has elapsed. This study investigated the hypothesis that a) other abnormalities of judgement and b) mental state, would influence time perception in schizophrenics. DSM-III-R diagnosed male schizophrenics (n=16) were compared with normal male controls (n=ll) matched for age, race, handedness, paternal social class and total years of education. Tests included: 1) estimated duration of 1 minute, 2) Cognitive Estimates Test of Shallice and Evans to measure bizarre responses to simple questions, and 3) the Brief Psychiatric Rating Scale (BPRS). The mean results of the l-minute estimation were: controls, 61+8.7 seconds, schizophrenics, 39f24.7 seconds. Group means were significantly different (p=O.O04, 2-tailed, modified ttest with separate variance estimate); an F-test revealed a similar difference between standard deviations (F=8.03, p=O.O02. 2-tailed). In schizophrenics, inaccuracy of minute estimation was correlated with Cognitive Estimation score (cc=O.73; p=O.OOl, 2-tailed) but not with BPRS (cc=O.18; p=O.52, 2-tailed).