No apparent influence of psychometrically-defined schizotypy on orientation-dependent contextual modulation of visual contrast detection

PeerJ. 2017 Jan 24;5:e2921. doi: 10.7717/peerj.2921. eCollection 2017.

Abstract

We investigated the relationship between psychometrically-defined schizotypy and the ability to detect a visual target pattern. Target detection is typically impaired by a surrounding pattern (context) with an orientation that is parallel to the target, relative to a surrounding pattern with an orientation that is orthogonal to the target (orientation-dependent contextual modulation). Based on reports that this effect is reduced in those with schizophrenia, we hypothesised that there would be a negative relationship between the relative score on psychometrically-defined schizotypy and the relative effect of orientation-dependent contextual modulation. We measured visual contrast detection thresholds and scores on the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) from a non-clinical sample (N = 100). Contrary to our hypothesis, we find an absence of a monotonic relationship between the relative magnitude of orientation-dependent contextual modulation of visual contrast detection and the relative score on any of the subscales of the O-LIFE. The apparent difference of this result with previous reports on those with schizophrenia suggests that orientation-dependent contextual modulation may be an informative condition in which schizophrenia and psychometrically-defined schizotypy are dissociated. However, further research is also required to clarify the strength of orientation-dependent contextual modulation in those with schizophrenia.

Keywords: Contextual modulation; Contrast detection; Psychophysics; Schizophrenia; Schizotypy; Surround suppression; Vision.

Grant support

This research was supported in part by grants from the National Health and Medical Research Council of Australia (APP1090507 to TW) and the Australian Research Council (DP140104394 to TW and DE130100129 to CD). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.