European Archives of Psychiatry and Clinical Neuroscience

Helmchen, H.

doi: 10.1007/BF01739735pmid: 2792154

The article outlines in brief why psychiatrists use disturbances of various types of eye movements as biological indicators of functional disturbances of brain systems that may be linked to psychopathology, as well as by which strategies these indicators will be applied. Basic as well as specific questions that remain to be resolved are addressed.

Marx, P.

doi: 10.1007/BF01739736pmid: 2676538

A study is presented mainly of the supratentorial structures that play an important role in saccadic eye movements and smooth pursuit. Eye-movement impairments associated with stroke in the corresponding brain region are then described.

Groner, Rudolf; Groner, Marina

doi: 10.1007/BF01739737pmid: 2676541

A review of recent experimental and theoretical findings is presented which relates the results of neurophysiological and psychological research on attention and eye movement to cognitive theorizing. With respect to the relation between shifts of attention and saccadic eye movements, several experiments have demonstrated that it is possible to dissociate the line of attention from the gaze direction. On the other hand, there is some indirect (although not yet conclusive) evidence that saccadic eye movements always produce a concomitant shift of attention. Another question is whether there is a moment-to-moment control of each consecutive saccade and latency or whether indirect control models (i.e. planning several saccades in advance) are more appropriate. The function of attentional processes which have to coordinate stimulus driven (bottom-up) and concept driven (top-down) mechanisms are discussed and related to some studies investigating local and global scanpaths.

Deubel, Heiner

doi: 10.1007/BF01739738pmid: 2676537

The oculomotor reactions have recently attracted increasing attention for diagnostic purposes. This is in line with the view that the oculomotor system is one of the simpler, machine-like sensorimotor systems. This paper presents two examples to demonstrate that the complexity of sensorimotor processing may be higher than expected from the outcome of experiments under rather restricted stimulus conditions. In the first part it is shown that complex preprocessing including the evaluation of spatial gradients of visual structure is an integral part of the programming of reflex-like saccades. The second part concerns adaptivity of saccadic eye movements. The data demonstrate that saccadic gain control is highly specific to the direction of the saccade. It is suggested that many central deficits may be hidden as a consequence of the effect of specific adaptive mechanisms.

Mather, Jennifer; Neufeld, Richard; Merskey, Harold; Russell, Nicholas

doi: 10.1007/BF01739739pmid: 2792155

This paper attempts to distinguish between inattention and inefficiency as the cause of the eye movement problems of schizophrenic subjects. It focuses on their release of fast saccadic eye movements in four different situations: interrupting smooth tracking, as double-jumps in refixation, and as inadvertent departures from steady fixation or too-early prediction moves. If an attention deficit causes saccades during tracking, they should be reduced only for schizophrenic subjects in the dark, when there is no constrasting background. Instead the reduction was present for all groups. If double-jumps in saccadic refixations were caused by inattentional instability, they should increase in schizophrenic subjects when the target is a temporary flash of light. Instead, they were reduced in all groups to almost none, suggesting a perceptual processing cause for the excess double jumps. If a global attentional problem of schizophrenia caused saccade release, saccade number should be correlated across the four situations. Instead, there were significant correlations only between departures and predictions in paranoid schizophrenic subjects (r = 0.728) and between predictions and looking in nonparanoid schizophrenic subjects (r = −0.855). This lack of over-all correlations suggests that a common inattentional problem does not produce these eye movement deficiencies. Instead, the perceptual influence on tracking and looking suggests that processing inefficiency is responsible for at least part of the deficit.

Done, D.; Frith, Christopher

doi: 10.1007/BF01739740pmid: 2792156

Drug-free schizophrenics were compared with depressive psychotics and normal controls on two saccade initiation tasks which differed with respect to the type of stimulus that initiated a saccadic response. Strategic initiation (SIS) appears to use a route different from that in automatic initiation (AIS). The SIS task revealed slowed responding in psychiatrically ill patients if their cognition was impaired, but all groups responded similarly on the AIS task. Schizophrenics could be separated from depressed psychotics by their inability to utilize temporal redundancy to speed up saccade initiation on the SIS task. Neurophysiological evidence implicates specific impairments in the frontal eye field (FEF) and/or basal ganglia.

Mackert, A.; Flechtner, M.

doi: 10.1007/BF01739741pmid: 2571502

Schizophrenics are known to have various disturbances of the visuomotor system. Whereas smooth pursuit eye movement disorders have been repeatedly confirmed, there are relatively few reports regarding possible disturbances of the saccadic system. In this study, the saccadic reaction times of 47 schizophrenic inpatients were investigated upon admission and later in the remitted state; 28 age- and sex-matched normal volunteers were tested as controls. Psychopathology and outcome were evaluated according to the Brief Psychiatric Rating Scale and the Prognostic Scale. Light stimuli were presented at random direction, location (ranging from 0° to 20°) and duration (800, 1000, and 1200 ms). The eye movements were recorded by electro-oculography. Compared with the control group, schizophrenics revealed prolonged saccadic reaction times, which correlated with pronounced negative symptoms and an unfavourable course of the illness. The saccadic reaction times remained prolonged in schizophrenic patients. These findings suggest attentional deficits in schizophrenics.

Keefe, Richard; Siever, Larry; Mohs, Richard; Peterson, Ann; Mahon, Theresa; Bergman, R.; Davis, Kenneth

doi: 10.1007/BF01739742pmid: 2792157

Schizophrenic patients and patients with schizotypal personality disorder were significantly more likely than normal controls to demonstrate impaired eye tracking performance. Fifteen of 27 schizophrenics and 15 of 27 schizotypals had impaired eye tracking, compared with 11 of 39 normal controls. In the schizophrenic group, including 10 out-patients in a stable state of relative remission, impaired eye tracking was associated with more severe formal thought disorder and more time spent in psychiatric hospitals. Among stable schizophrenic out-patients, poor eye tracking was related to more severe formal thought disorder and greater overall psychopathology. This pattern of results suggests a possible relation between eye tracking impairment and more severe enduring symptoms across the spectrum of schizophrenic and schizophrenia-related disorders.

Holzman, Philip

doi: 10.1007/BF01739743pmid: 2676539

Eye movement dysfunctions have been found in a large number of schizophrenic patients and in about half of their first-degree relatives. The distribution of these traits within the families of schizophrenic patients suggests a model of genetic transmission that fits an autosomal dominant model, which we have called the “genetic latent trait model.” The model, with seven parameters, was fitted to a U.S. population and the model was cross-validated on an independent Norwegian sample. Although the model does not invalidate other, more conventional solutions to the puzzle of schizophrenic transmission, such as multifactorial transmission, the latent trait model does more easily permit linkage studies and therefore will allow refutation or support from the use of molecular genetics techniques.

Gaebel, W.

doi: 10.1007/BF01739744pmid: 2792158

Twenty acutely admitted schizophrenic inpatients diagnosed according to RDC and 8 normal controls were instructed to search for a randomly located target letter (Z) in ten lists of 284 distractor letters of either rounded or angular shape projected on a screen (23° × 15°). Eye movements were recorded using infrared corneal reflection-pupil centre measurement. Search performance was defined as the search time in seconds from onset of the display until localization of the target. The EEG was recorded simultaneously in schizophrenics, in whom assessment took place shortly after admission and before discharge. The psychopathological status was assessed at the same time with the Brief Psychiatric Rating Scale and the Scale for the Assessment of Negative Symptoms. Search performance was not significantly different in schizophrenics and normal controls, but was heavily affected by target/distractor similarity in both groups. Moreover, search performance in schizophrenics was not significantly affected by illness severity. However, search performance was differently related to negative and positive symptoms. Schizophrenics and normal controls differed with respect to the relationship between search performance and visuomotor microbehaviour. Additionally, two relatively time-stable eye movement patterns in schizophrenics could be distinguished, which were differently related to psychopathology, performance measures and EEG.