Following Instructions in Patients With Schizophrenia: The Benefits of Actions at Encoding and Recall

Abstract

The ability to follow spoken instructions is important to everyday functioning but has seldom been studied in patients with schizophrenia (SZ). Recent evidence suggests that action-based processing may facilitate the ability to follow instructions, which relies largely on working memory. In this study, we tested the hypothesis that SZ patients may also benefit from action-based advantages in following instructions. Forty-eight clinically stable SZ patients and 48 demographic- and IQ-matched controls completed a following spoken instruction span task involving varied encoding and recall conditions. While SZ patients were impaired in the overall performance of following spoken instructions, this deficit could be attributed to working memory impairment. More importantly, SZ patients showed action-based advantages both at the encoding and retrieval stage to the same extent as healthy controls. Specifically, both healthy controls and SZ patients showed improved memory performance when they additionally performed the actions, or watched the experimenter carrying out the actions compared with simply listening to spoken instructions during the encoding stage. During the retrieval stage, memory was improved when they recalled the instructions by physical enactment compared with oral repetition. The present study provides the first empirical evidence for the impairment in the ability to follow instructions in SZ. We have shown that involving action-based processing in the encoding and retrieval stage facilitated memory of instructions, indicating that the enactment advantage in working memory also applies to SZ patients. These findings provide useful insights for clinical interventions and cognitive remediation for SZ patients.

Keywords: enacted-recall advantage; experimenter-performed task effect; schizophrenia; subject-performed task effect; working memory.