The perception of gaze and attention in schizophrenia

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There is long-standing evidence of visual deficits in schizophrenia; and recent visual masking studies suggest an abnormality of the fast transient (magnocellular) system, specialised for detecting fast flicker and motion and important for spatial localization and eye movement control. There is already strong evidence for magnocellular impairment in dyslexics, who show schizotypal traits of perceptual aberration and magical ideation; and we have shown that both dyslexics and normal schizotypal subjects have impaired visual motion sensitivity, a good index of magnoceUular function. Here we report an investigation of this in schizophrenic subjects. Thresholds for detecting coherent motion in random dot patterns were assessed in 9 acute schizophrenic patients (neuroleptic-naive), and two control groups, normal and dyslexic, individually matched for age, sex and handedness. Mean motion thresholds (% coherence) were: schizophrenic patients 14.79+5.26, dyslexics 12.99+4.92, and normal controls 8.32+ 1.7. The effect of group was significant (F=5.52 T M p = .0l), and on post-hoc comparisons (LSD) motion sensitivity did not differ between schizophrenic and dyslexic groups, but both were impaired relative to normal controls (p < .05). These results are consistent with magnocellular visual dysfunction in schizophrenia, which may contribute to the visual abnormalities associated with this disorder. They are also compatible with other evidence for an association between dyslexia and the schizophrenia spectrum.

XIII.D.9 EYE MOVEMENTS, SPATIAL SHORT-TERM MEMORY, AND FUNCTIONAL VISUAL FIELD IN SCHIZOPHRENIA M. Streit, W. Wrlwer, S. Kiesow a n d W. Gaebel

Department of Psychiatry, University of Dfisseldorf 40605 Dfisseldorf FRG By means of eye movement recordings during the performance of the trail-making test (TMT-B) we have recently shown that acute schizophrenics' poorer TMT performance relies mainly on longer 'planning' or search paths with more and longer search fixations. The aim of the present study was to analyse determinants of these 'planning' difficulties. Therefore the original TMT-B, an experimental variation of the task, which excludes spatial memory effects by changing remaining target positions whenever a new target has been reached, a TMT adapted version of the Corsi block test for spatial memory, and a task to assess the ability to recognise TMT targets tachistoscopically with varying visual-fieldeccentricity (1 °, 2.5 °, 4 °) and direction were applied to schizophrenics (S), major depressives (D), and normal controls (N). Preliminary results from 23 remitted S, 9 remitted D and 17 N of the ongoing study replicate our former results showing an association of a deficit in TMT performance with longer and more search fixations in acute schizophrenics, unrelated to neuroleptic medication. Whereas the spatial short-term memory capacity seems to have only a minor influence on TMT performance, our first results indicate that the size of the

functional visual field might be a potent predictor of TMT-B performance. These results point to a disturbance in visuospatial processing associated with selective attention capacities in schizophrenia.

XIII.D. 10 VISUOMOTOR INTEGRATION COGNITIVE FLEXIBILITY IN SCHIZOPHRENIA

AND

W. Wrlwer, S. Kiesow, M. Streit a n d W. Gaebel

Dep. of Psychiatry, Universityof Dfisseldorf PO 120510, 40605 Dfisseldorf Germany Using eye movement recordings during the performance of the trail-making test (TMT) we have recently shown that acute schizophrenics have difficulties in parallel processing of visuomotor search and manumotor tracking, resulting in poorer TMT performance. Since these--timestable--dysfunctions occurred especially under test conditions requiring the subjects to alternate between two response categories (TMT-B) but not under conditions using only one response category (TMT-A), the present study should clarify the contribution of (1) pure manumotor tracking abilities and of (2) the ability to shift response categories to the TMT performance deficit. Therefore, the original TMT-A/-B and experimental variations of the task (1) without the necessity of concurrent visuomotor search to manumotor tracking or (2a) with an external support of the category shift and and (2b) a task which assesses the ability to switch response categories without concurrent visuomotor search and manumotor tracking were applied to schizophrenics (S), major depressives (D) (DSM-III-R) and normal controls (N). Preliminary results from 23 remitted S, 9 remitted D, and 17 N of the ongoing study replicate our former results from acute S showing deviations in eye movement strategies associated with a TMT performance deficit, but unrelated to neuroleptic medication. Moreover, results of the TMT variations reveal that the performance in TMT-A relies mainly on manumotor tracking abilities, whereas TMT-B performance is mainly determined by the ability to shift response categories, which seem to be especially impaired in schizophrenics.

XIII.E. Facial recognition XIII.E. 1 THE PERCEPTION OF GAZE AND ATTENTION IN SCHIZOPHRENIA A.I. Jayasekera, J.S.E. Hellewell, D.I. Perrett 1 a n d J.F.W. D e a k i n

1Dept. of Psychology, University of St Andrews, U.K, University of Manchester Dept. of Psychiatry, Withington Hospital, WestDidsbury, Manchester, M20 8LR, U.K.

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Patients with schizophrenia show impairments in recognition memory for faces and in the identification of facial emotion. This may reflect pathology in the face processing regions of the temporal lobe. This region also encodes information about the direction of gaze and attention of others. We investigated these functions in patients and whether deficits related to paranoid or other symptoms or to other impairments in face processing. Patients viewed photographs of a face looking at 3 coloured pegs separated by 5, 15 or 30 degrees and had to judge at which peg a) the eyes b) the face were directed. In another task, subjects judged whether or not the face or eyes were directed at the viewer (ie to camera). In 75% of trials, the face or eyes were displaced by 5, 15 or 30 degrees. We report an examination of 24 patients with DSMIII-R schizophrenia, using normative test data. Patients were markedly impaired on both tasks. They were also impaired on other tests of face processing: affect identification, recognition memory (Warrington) and matching (Benton). Performance on the tests of face processing was strongly intercorrelated, but no association was found between measures of face processing and clinical symptoms. This suggests that deficits in face processing in schizophrenia reflect general cognitive impairment and are not causally associated with the development of symptoms.

illness 15y, mean NART IQ 111) were assessed on the Manchester scale for psychotic symptoms, which was then factor analyzed. 20 of the patients and 20 healthy volunteers, matched for age and IQ completed neuropsychological tests including naming, memory, abstraction, face recognition and face affect identification, and a new test of naming emotions in written descriptions. Patients were impaired on naming, memory, abstraction and face and emotion processing. Preliminary factor analysis generated 2 factors, accounting for 68.1% of variance; Factor 1 incoherence, incongruity, muteness, flattened affect, factor 2 - delusions, hallucinations. Factor 1 scores correlated with naming, abstraction, current IQ estimates and facial affect and written emotion naming. Factor 2 scores correlated with facial and non-facial recognition memory. Impaired verbal fluency, naming of objects and facial and written affects correlated with factor 1. This implicates impaired fronto-temporal mechanisms in affective dysregulation. Positive symptoms relate to impaired recognition memory, a temporal lobe function.

XIII.E.3 VISUALISING WHAT PATIENTS EMOTIONS IN FACES

XIII.E.2 DISSOCIATION OF FACE AFFECT IDENTIFICATION AND UNFAMILIAR FACE RECOGNITION IN SCHIZOPHRENIA J.F. W h i t t a k e r a n d J.F.W. D e a k i n

Univ. Dept. of Psychiatry, Rawnsley Building, Manchester Royal Infirmary, Manchester, U.K. Human faces convey information about identity and affect. Dysfunctional processing of this information may be a mechanism for paranoid symptom formation in schizophrenia-misreading the intentions and dispositions of others. Loss of processing of this information could account for social deficits of schizophrenia. This study investigated face processing deficits in schizophrenia and their relationship to symptoms. 26 schizophrenic patients (mean age 36 y, mean duration

SEE AS

J.F. W h i t t a k e r * , A. Lanitist, J.F.W. Deakin*, T.F. C o o t e s t a n d C.J. T a y l o r t

*Univ. Dept of Psychiatry, Rawnsley Building, Manchester Royal Infirmary, Manchester, U.K., ? Univ. Dept of Medical Biophysics, Univ. of Manchester, Manchester, U.K. A feasibility study of a computer based modelling method for recognising and analysing facial expressions has been carried out. Using statistical modelling, the variation in shape and grey level information in human faces can be reduced to less than 100 principal components, enabling the compact representation and reconstruction of human faces. We have used this model to attempt a preliminary characterisation of the location in multidimensional statistical space of six basic emotions--afraid, angry, sad, happy, disgusted and surprised~and a neutral expression. Reversing the pararnetrisation process has enabled us to generate average faces for

Correlations between factor scores and selected neuropsychological tests

Factor 1 Factor 2

Object naming

Verbal fluency

IQ estimate

Facial affect

Written emotion

Face recogn

Design recogn

-0.54** 0.16

-0.55* -0.11

-0.40(*) -0.12

-0.59** -0.27

-0.53* -0.42

-0.19 -0.45(*)

-0.06 -0.55

2 tailed significance ** = p < 0.01, * = p < 0.05, (*) = p < 0.1.