PT  - JOURNAL ARTICLE
AU  - Daniel Linares
AU  - Silvia Amoretti
AU  - Rafael Marin-Campos
AU  - André Sousa
AU  - Laia Prades
AU  - Josep Dalmau
AU  - Miquel Bernardo
AU  - Albert Compte
TI  - Perceptual spatial suppression and sensitivity for motion are weakened in schizophrenia
AID  - 10.1101/799395
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 799395
4099  - http://biorxiv.org/content/early/2019/10/09/799395.short
4100  - http://biorxiv.org/content/early/2019/10/09/799395.full
AB  - Perceptual spatial suppression is a phenomenon in which the perceived strength of a stimulus in some region of the space is reduced when the stimulus is surrounded by other stimuli. For contrast perception, several studies suggest that spatial suppression is reduced in patients with schizophrenia. For motion perception, only one study has been conducted in a cohort of 16 patients, suggesting that spatial suppression is reduced. It is unknown, however, whether this reduction is related to the lower intelligence quotient (IQ) that schizophrenic patients usually show; as there is evidence that spatial suppression for motion increases with IQ in healthy individuals. Here, we sought to determine the spatial suppression for motion in a larger cohort of 32 patients with schizophrenia and controlling the results for the IQ of patients. We found a weakened spatial suppression in patients with schizophrenia, consistent with the previous study (effect size g = 0.47 with CI = [0.055, 0.88], combining the previous and our study). For comparison, we performed a meta-analysis on spatial suppression for contrast (7 studies) and found a similar effect size, but with higher evidence (g = 0.56 with CI = [0.40, 0.72]). We found that patients had a lower IQ than controls, but this difference did not explain their weaker spatial suppression. Further, we found that spatial suppression of patients, but not controls increased with their IQ and decreased with age in both groups. Finally, as we estimated lapses of attention, we could estimate motion sensitivity and found that it was decreased in patients. We discuss how this reduced spatial suppression and sensitivity might be related to glutamatergic hypofunction in schizophrenia.