Stimulating learning: A functional MRI and behavioral investigation of the effects of transcranial direct current stimulation on stochastic learning in schizophrenia. (November 2022)

• Record Type: Journal Article
• Authors: Orlov, Natasza D.; Muqtadir, Syed Ali; Oroojeni, Hooman; Averbeck, Bruno; Rothwell, John; Shergill, Sukhi S.
• Is Part Of: Psychiatry research. Volume 317(2022)
• Publication Date: 2022-11
• Subjects: Imaging -- Schizophrenia -- tDCS -- Stochastic learning -- Neuromodulation -- Cognition -- Cognitive deficits; Psychiatry -- Periodicals; Psychiatry -- periodicals; Psychiatrie -- Périodiques; 616.89
• DOI: 10.1016/j.psychres.2022.114908
• Languages: English
• ISSNs: 0165-1781

Abstract

Highlights: Stochastic learning is impaired in schizophrenia. Cognitive training and tDCS improved stochastic learning outcomes. Long-term effect of tDCS on stochastic learning task observed. fMRI showed increased insular activity and reduced amygdala activity during task. Abstract: Transcranial direct current stimulation (tDCS) of the medial prefrontal cortex (mPFC) is under clinical investigation as a treatment for cognitive deficits. We investigate the effects of tDCS over the mPFC on performance SSLT in individuals with schizophrenia, and the underlying neurophysiological effect in regions associated with learning values and stimulus-outcome relationships. In this parallel-design double-blind pilot study, 49 individuals with schizophrenia, of whom 28 completed a fMRI, were randomized into active or sham tDCS stimulation groups. Subjects participated in 4 days of SSLT training (days 1, 2, 14, 56) with tDCS applied at day-1, and during a concurrent MRI scan at day-14. The SSLT demonstrated a significant mean difference in performance in the tDCS treatment group: at day-2 and at day-56. Active tDCS was associated with increased insular activity, and reduced amygdala activation. tDCS may offer an important novel approach to modulating brain networks to ameliorate cognitive deficits in schizophrenia, with this study being the first to show a longer-term effect on SSLT.