Visual search performance among persons with schizophrenia as a function of target eccentricity

Area of Science:

• Cognitive Neuroscience
• Psychiatry

Background:

• Schizophrenia is associated with various cognitive deficits, including impairments in visual attention.
• Visual span, the information processing range during fixation, is a potential factor influencing visual attention.

Purpose of the Study:

• To investigate whether a reduced visual span contributes to visual search impairments in schizophrenia.
• To test the hypothesis that visual search deficits in schizophrenia are mediated by a smaller visual span.

Main Methods:

• A visual search task comparing patients with schizophrenia (n=23) and healthy controls (n=22).
• Targets were presented at varying eccentricities (distances from display center) in feature and conjunctive search conditions.
• Response times were analyzed based on search type, display size, and target eccentricity.

Main Results:

• Schizophrenia patients showed greater difficulty with conjunctive search as display size increased, consistent with prior research.
• Patients' conjunctive search times were disproportionately affected by target eccentricity compared to controls.
• Impaired visual search in patients was most apparent with eccentric targets; performance approximated controls for central targets.

Conclusions:

• A narrower visual span is a likely mechanism contributing to visual search deficits in schizophrenia.
• These findings highlight the role of visual span limitations in the attentional dysfunction observed in schizophrenia.