Bistable Perception Discriminates Between Depressive Patients, Controls, Schizophrenia Patients, and Their Siblings.

Summary

People with schizophrenia rely less on prior experiences when interpreting visual stimuli, leading to faster perceptual switches in a bistable perception task called Structure-from-Motion (SfM). In the intermittent version of this task, patients with schizophrenia and their unaffected siblings showed significantly higher alternation rates than healthy controls, while patients with depression had the lowest alternation rates. In the continuous version, only patients with schizophrenia had shorter percept durations. The intermittent SfM paradigm may serve as an endophenotype for schizophrenia, reflecting altered adaptation or cross-inhibition mechanisms that affect prior processing.

Study at a glance

Abstract

Individuals with schizophrenia have less priors than controls, meaning they rely less upon their prior experiences to interpret the current stimuli. These differences in priors are expected to show as higher alternation rates in bistable perception tasks like the Structure-from-Motion (SfM) paradigm. In this paradigm, continuously moving dots in two dimensions are perceived subjectively as traveling along a three-dimensional sphere, which results in a direction of motion (left or right) that shifts approximately every few seconds. Here, we tested healthy controls, patients with schizophrenia, siblings of patients with schizophrenia, and patients with depression with both the intermittent and continuous variants of the SfM paradigm. In the intermittent variant of the SfM paradigm, depressive patients exhibited the lowest alternation rate, followed by unaffected controls. In contrast, patients with schizophrenia and their unaffected siblings displayed significantly higher alternation rates. In the continuous variant of the SfM paradigm, patients with schizophrenia showed the lowest mean percept durations, while there were no differences between the other three groups. The intermittent SfM paradigm is a candidate endophenotype for schizophrenia. The aberrant processing in the patients may stem from alterations in adaptation and/or cross-inhibition mechanisms leading to changes in priors, as suggested by current models in the field. The intermittent SfM paradigm is, hence, a trait marker that offers the great opportunity to investigate perceptual abnormalities across the psychiatry spectrum, ranging from depression to psychosis.