Exogenous Cues Aid Salient Distractor Suppression and Enhance Attentional Prioritization during Visual Working Memory Encoding in Schizophrenia

BackgroundPeople with schizophrenia (PSZ) are impaired in attentional prioritization of non-salient but relevant stimuli over salient distractors during visual working memory (VWM) encoding. Conversely, guidance of top-down attention by exogenous 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.MethodsWe employed a visuospatial change-detection task using four Gabor Patches with differing orientations in 66 PSZ and 74 healthy controls (HCS). Two patches flickered which were either the targets or non-targets and either a predictive or a non-predictive cue was displayed to manipulate top-down attention, resulting in four conditions.ResultsAcross all conditions, PSZ stored significantly less information in VWM than HCS (all p < 0.001). PSZ stored significantly more flickering and non-flickering information in the predictive cue conditions compared to the non-predictive cue conditions (p = 0.049, d = 0.5; p < 0.001, d = 1.0). Additionally, PSZ stored significantly more flickering than non-flickering information in the non-predictive cue conditions (p < 0.001, d = 0.9). These effects were not observed in HCS.ConclusionsOur findings indicate that attentional prioritization is disrupted in schizophrenia, but the top-down utilization of cues is intact. We conclude that additional top-down information significantly improves the amount of information encoded in PSZ. We report a specific deficit in attentional control, which is possibly mediated by GABAergic inhibition in early visual areas. This finding proposes a mechanism that enhances attentional prioritization and could be utilized in future therapies.