Laterality of visuo-spatial attention in acute and chronic schizophrenia, major depression and in healthy controls

Abstract

SYNOPSISPrevious studies have suggested that schizophrenia is characterized by an asymmetry of visuo-spatial attention, in particular that acute unmedicated schizophrenics demonstrate relative inattention to right hemispace, whereas chronically medicated patients demonstrate the opposite pattern. In the present study, 30 unmedicated schizophrenic patients, 32 chronically medicated schizophrenic patients, 30 patients suffering from major depression and 60 healthy controls were assessed using two measures of hemispatial attentional neglect, namely letter and star cancellation. The results demonstrated that the chronic schizophrenic group made more total omissions for star cancellation (in both right and left hemispace), but that there was no difference between the groups in terms of omission asymmetry for either letter or star cancellation.

Asymmetries of Visuospatial Attention in Schizophrenia

“…In the right third they made greater omissions than in the left third. This observation agreed with the experimental results of Lobel et al [31], but disagreed with the results of O'Carroll et al [32]. O'Carroll et al [32] utilized a letter as well as a star cancellation task and did not find any significant hemispace asymmetry.…”

“…This observation agreed with the experimental results of Lobel et al [31], but disagreed with the results of O'Carroll et al [32]. O'Carroll et al [32] utilized a letter as well as a star cancellation task and did not find any significant hemispace asymmetry. However, there are significant methodological difference between the study by Zivotofsky et al [29] and that by O'Carroll et al [32].…”

“…O'Carroll et al [32] utilized a letter as well as a star cancellation task and did not find any significant hemispace asymmetry. However, there are significant methodological difference between the study by Zivotofsky et al [29] and that by O'Carroll et al [32]. In the O'Carroll et al's [32] study only four rows of letters were used and the sheet was divided into two hemispaces.…”

“…However, there are significant methodological difference between the study by Zivotofsky et al [29] and that by O'Carroll et al [32]. In the O'Carroll et al's [32] study only four rows of letters were used and the sheet was divided into two hemispaces. In the study by Zivotofsky et al [29] the letters were disposed in 10 rows and the sheet was divided into three spaces (left, centre, right).…”

Schizophrenia and the Neglect Syndrome: Parietal Contributions to Cognitive Dysfunction in Schizophrenia

“…In addition, Tomer and Flor-Henry [40] also demonstrated that this 'neglect like' deficit can be reversed (i.e., patients begin to omit more left visual field targets) following a period of treatment with anti-dopamanergic psychiatric medication. As is the case with much of this research, contradictory findings have also been demonstrated in which no lateralised deficit in cancellation performance is observed in medicated chronic schizophrenics [41][42][43]. In general, while drug-free schizophrenia patients may exhibit right visual neglect in cancellation tasks, this deficit seems to disappear with a period of anti-psychotic treatment.…”