Abstract
Schizophrenia is a mental illness that is associated with working memory (WM) deficits; however, a mechanistic account for these deficits has not yet been identified. Recent evidence suggests that electrophysiological abnormalities during early encoding/consolidation processes may constrain WM capacity in PSZ (Erickson et al., 2016). One hypothesis that dovetails with these observations is that PSZ do not use spontaneous configural grouping strategies to encode and consolidate items in storage the same way that healthy control subjects (HCS) do. The present study was conducted to test this hypothesis. Two HCS and one PSZ have completed the task to date, with an expanded sample size anticipated by May 2017. Participants were exposed to three variants on a change-detection task: (1) a pro-grouping task variant wherein to-be-remembered items (four sectored circles) create an illusory contour defined polygon; (2) an anti-grouping task variant wherein to-be-remembered items are rotated and surrounded by surrounding circles to inhibit illusory contour formation; and (3) a neutral task variant, wherein to-be-remembered items are rotated, but not surrounded by circles that inhibit illusory contour formation. Consistent with our hypothesis, preliminary results suggest that HCS have reduced accuracy in the anti-grouping condition compared to the neutral and pro-grouping conditions. By contrast, PSZ accuracy appears to be improved in the pro-grouping condition compared to either the anti-grouping or neutral task variants. Taken together, these observations suggest that (1) HCS can flexibly use grouping strategies to encode items regardless of whether grouping cues are weak (neutral condition) or strong (pro-grouping condition) to improve WM storage; and (2) poor WM task performance in PSZ may be due in part to decreased use of spontaneous grouping strategies to encode items. This conclusion is supported by evidence that PSZ exhibit improved WM task performance when grouping cues are made more explicit.
Meeting abstract presented at VSS 2017