Inefficient visual search strategies in the first-episode schizophrenia spectrum

SCHIZOPHRENIA RESEARCH

卷:224

Article

Sklar, Alfredo L.^1,2  Coffman, Brian A.^1,2  Haas, Gretchen^2,3,4,5  Ghuman, Avniel⁶  Cho, Raymond^7,8  Salisbury, Dean F.^1,2 

[1] Univ Pittsburgh, UPMC Western Psychiat Hosp, Dept Psychiat, Clin Neurophysiol Res Lab,Sch Med, Pittsburgh, PA USA

[2] Univ Pittsburgh, Sch Med, Dept Psychiat, UPMC Western Psychiat Hosp, Pittsburgh, PA USA

[3] Univ Pittsburgh, Dept Psychol, Pittsburgh, PA 15260 USA

[4] US Dept Vet Affairs, VA Pittsburgh Healthcare Syst, Pittsburgh, PA USA

[5] US Dept Vet Affairs, VISN 4 MIRECC, Pittsburgh, PA USA

[6] Univ Pittsburgh, Sch Med, Dept Neurosurg, Presbyterian Hosp,Lab Cognit Neurodynam, Pittsburgh, PA 15261 USA

[7] Baylor Coll Med, Dept Psychiat, Houston, TX 77030 USA

[8] Michael E DeBakey VA Med Ctr, Houston, TX 77030 USA

关键词: Schizophrenia spectrum;    First-episode;    Selective attention;    Visual search;    N2pc;    Magnetoencephalography;   

DOI  :  10.1016/j.schres.2020.09.015

来源: Elsevier

【 摘 要 】

Background: Knowledge is lacking regarding deficits in selective attention and their underlying biological mechanisms during early stages of schizophrenia. The present study examined the N2pc, a neurophysiological index of covert spatial attention, and its cortical sources at first psychotic episode in the schizophrenia spectrum (FESz). Methods: Neurophysiological responses measured simultaneously with magnetoencephalography (MEG) and electroencephalography (EEG) during pop-out and serial search tasks were compared between 32 FESz and 32 matched healthy controls (HC). Mean scalp-recorded N2pc was measured from a cluster of posterior-lateral EEG electrodes. Cortical source-resolved MEG activity contributing to the N2pc signal was derived for the intraparietal sulcus (IPS) and lateral occipital complex (LOC). Results: Group differences in EEG N2pc varied by task demand. FESz exhibited reduced N2pc amplitude during pop-out (p < .01), but not serial search (p = .11). Furthermore, group differences in N2pc-related MEG cortical activity varied by task demand and cortical region. Compared to HC, FESz exhibited greater IPS during serial search (p < .01). Discussion: Reductions in EEG N2pc amplitude indicate an impairment of visuo-spatial attention evident at an individual's first psychotic episode, specifically during conditions emphasizing bottom-up processing. Examination of its cortical sources with MEG revealed that, compared to HC, FESz engaged parietal structures to a greater extent during the serial search condition. This pattern suggests a less efficient, more resource intensive strategy employed by FESz in response to a minimal demand on attention. The greater reliance on this controlled attentional network may negatively impact real-world functions with much greater complexity and attentional demands. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

Free