TY  - JOUR
A1  - Leeuwen, Tessa M. van
A1  - Sauer, Andreas
A1  - Jurjut, Anna-Maria
A1  - Wibral, Michael
A1  - Uhlhaas, Peter J.
A1  - Singer, Wolf
A1  - Melloni, Lucia
T1  - Perceptual gains and losses in synesthesia and schizophrenia
T2  - Schizophrenia Bulletin
N2  - Individual differences in perception are widespread. Considering inter-individual variability, synesthetes experience stable additional sensations; schizophrenia patients suffer perceptual deficits in, eg, perceptual organization (alongside hallucinations and delusions). Is there a unifying principle explaining inter-individual variability in perception? There is good reason to believe perceptual experience results from inferential processes whereby sensory evidence is weighted by prior knowledge about the world. Perceptual variability may result from different precision weighting of sensory evidence and prior knowledge. We tested this hypothesis by comparing visibility thresholds in a perceptual hysteresis task across medicated schizophrenia patients (N = 20), synesthetes (N = 20), and controls (N = 26). Participants rated the subjective visibility of stimuli embedded in noise while we parametrically manipulated the availability of sensory evidence. Additionally, precise long-term priors in synesthetes were leveraged by presenting either synesthesia-inducing or neutral stimuli. Schizophrenia patients showed increased visibility thresholds, consistent with overreliance on sensory evidence. In contrast, synesthetes exhibited lowered thresholds exclusively for synesthesia-inducing stimuli suggesting high-precision long-term priors. Additionally, in both synesthetes and schizophrenia patients explicit, short-term priors—introduced during the hysteresis experiment—lowered thresholds but did not normalize perception. Our results imply that perceptual variability might result from differences in the precision afforded to prior beliefs and sensory evidence, respectively.
Y1  - 2020
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/74802
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-748026
SN  - 0586-7614
VL  - 47
IS  - 3
SP  - 722
EP  - 730
PB  - Oxford Univ. Press
CY  - Oxford
ER  -