Abstract Background and Hypothesis Perception integrates sensory input with prior knowledge. Alterations in how both information sources are combined may lead to the departures from consensus reality that characterize schizophrenia (SZ). One source of prior knowledge is recent experience. Visual aftereffects—perceptions of the “opposite” of previously viewed stimulus—are driven by neuronal adaptation and demonstrate how recent experience influences perception. Our recent work revealed stronger tilt (orientation) aftereffects, but not negative afterimages (luminance aftereffects) in people with SZ relating to negative symptom severity, suggesting altered adaptation is more prominent in cortical than subcortical visual systems and may be an important illness mechanism. Because different aftereffects depend differentially on adaptation at different levels of the visual hierarchy, we sought to extend findings and probe where in the cortical hierarchy neuronal adaptation is most pronounced in SZ. Study Design Two types of motion aftereffects were measured in SZ (n = 55) and healthy controls (HC; n = 43): “first-order” aftereffects caused by luminance-defined motion that elicits strong adaptation in early visual cortex, and “higher-order” aftereffects caused by non-luminance-feature-defined motion (eg, texture) that is primarily represented in extrastriate motion-sensitive areas. Study Results Relative to HC, SZ showed stronger first-order but not higher-order motion aftereffects. Differences were not explained by task sensitivity, response bias, visual acuity, blinks, or fixation deviations. Conclusions Altered neuronal adaptation in SZ is likely more pronounced at earlier (eg, V1) versus later (eg, V5/MT) stages of the visual hierarchy. Consequently, findings potentially implicate early visual cortical processing alterations in illness pathophysiology and/or clinical presentation.
Delay et al. (Fri,) studied this question.