Fig. 4.

Schizophrenia-control differences in strength of retinal cell firing as indicated by ERG.(A) Data from a light-adapted flicker stimulus ERG test, depicting cone photoreceptor response. The stimulus was white light flickering at 28.3 Hz, at an intensity of 85 troland seconds. The difference between the schizophrenia group (tan) and control group (blue) was large: t(48) = −3.58, P = .001, d = 1.01. Shaded areas depict the 25th–75th percentile interquartile range. Substantial non-overlap between groups can be observed. (B) Data from a light-adapted flash stimulus ERG test. The stimulus was light flashing at 1 Hz, at an intensity of 100 troland seconds. The differences between the schizophrenia group (tan) and control group (blue) were large: For the initial negative peak (a-wave), reflecting photoreceptor activity, t(48) = 2.86, P = .006, d = .81. For the subsequent positive peak (b-wave), reflecting bipolar cell and glial cell activity, t(48) = 2.92, P = .005, d = .83. Substantial non-overlap between groups can be observed here as well. Data in both cases from Demmin DL, Davis Q, Roché M, Silverstein SM. Electroretinographic anomalies in schizophrenia. J Abnorm Psychol. 2018;127(4):417–428. doi:10.1037/abn0000347. PMID: 29745706. ERG, electroretinography.