| Working memory dysfunction may be a core deficit in schizophrenia because aspects of working memory are often key components of other complex cognitive tasks. Serial order processing deficits exist in schizophrenia when delays are implemented between responses, but not when responding is unpaced. To date, however, it is unclear whether this deficit is a result of simple forgetting, a loss of the corresponding serial position information, retrieval deficits, or a vulnerability to internal processes such as updating.;The general aim of this proposed research project was to better understand the serial order processing deficit in schizophrenia, specifically in the context of updating. An additional aim was to replicate previous findings of a deficit for individuals with schizophrenia compared to healthy controls for an externally paced task.;Individuals with schizophrenia and healthy controls completed serial order processing and updating tasks as part of a broader neuropsychological battery. The primary outcomes on each of these tasks were response accuracy and latency. To examine whether patients showed deficient serial order processing task, a mixed factors ANOVA was conducted, where task type (paced vs. unpaced) and processing load (3 items vs. 4 items) were the within subjects factors and diagnosis (patient vs. control) was the between subjects factor. Mixed-effects regression modeling was used to examine updating (first response) compared to subsequent responses for patients and healthy controls.;Patient performance was significantly worse than controls for both externally paced and unpaced working memory tasks, suggesting a broader working memory deficit than found previously. When working memory demands were limited to simple updating, the present findings indicated no differences in accuracy between patients and controls. Thus, updating was intact in this sample of schizophrenia patients. Following intact updating; however, patients showed a significant drop in accuracy. After successful updating, working memory stores were vulnerable to disruption upon being accessed. Specifically, accuracy decreased for single item maintenance in both groups, but this decrease was larger in patients compared to controls. This is an important finding that adds support to the hypothesis that working memory stores seem vulnerable to disruption by other internal processes, suggesting a use it and lose it phenomenon. This pattern suggests that accessing the information may be enough to disrupt maintenance. |
