External Cues Improve Visual Working Memory Encoding in the Presence of Salient Distractors in Schizophrenia

Abstract

Objective: People with schizophrenia (PSZ) are impaired in the attentional prioritization of non-salient but relevant stimuli over salient but irrelevant distractors during visual working memory (VWM) encoding. Conversely, the guidance of top-down attention by external predictive cues is intact. Yet, it is unknown whether this preserved ability can help PSZ overcome impaired attentional prioritization in the presence of salient distractors. Methods: We employed a visuospatial change-detection task using four Gabor Patches with differing orientations in 69 PSZ and 74 healthy controls (HCS). Two patches flickered to reflect saliency and either a predictive or a non-predictive cue was displayed resulting in four conditions. Results: Across all conditions, PSZ stored significantly less information in VWM than HCS (all p < 0.001). With a non-predictive cue, PSZ stored significantly more salient than non-salient information (t140 = 5.66, p < 0.001, dt = 0.5). With a predictive cue, PSZ stored significantly more non-salient information (t140 = 5.70, p < 0.001, dt = 0.5). Conclusion: Our findings support a bottom-up bias in schizophrenia with performance significantly better for visually salient information in the absence of a predictive cue. These results indicate that bottom-up attentional prioritization is disrupted in schizophrenia, but the top-down utilization of cues is intact. We conclude that additional top-down information significantly improves performance in PSZ when non-salient visual information needs to be encoded in working memory.

Impaired Visuospatial Working Memory but Preserved Attentional Control in Bipolar Disorder

“…Importantly, our findings differ in crucial ways from our previous results in PSZ (Barnes-Scheufler et al, 2023). Both PSZ and PBD stored significantly less information across all conditions compared to HCS.…”

“…Interestingly, the analysis of catch trials revealed a significant effect of cue (p = 0.001; Table S4), which we also observed in PSZ (Barnes-Scheufler et al, 2023). This indicates that PBD's ability to use spatial cues to down-weight both salient and non-salient distractors is preserved.…”

“…Previously, we utilized the same paradigm to study people with schizophrenia (PSZ) (Barnes-Scheufler et al, 2023). We observed a significant VWM deficit in PSZ, with less information encoded by PSZ across all conditions.…”