Recent findings point to an impairment in learning rate modulation in people with schizophrenia (PSZ), leading to a reduced ability to adjust task behavior in response to unexpected outcomes. Learning rate modulation deficits may be associated with decreased involvement of the dorsomedial prefrontal cortex (dmPFC) within a greater reinforcement learning network. 26 PSZ and 23 healthy volunteers completed a probabilistic reinforcement learning paradigm with occasional, sudden, shifts in contingencies. Researchers found:
- Using computational modeling, evidence was found of an impairment in trial-wise learning rate modulation (α) in PSZ before and after a reinforcement contingency shift, expressed most in PSZ with more severe motivational deficits.
- In a subsample of 22 PSZ and 22 healthy volunteers, there was little evidence for between-group differences in ventral striatum reward prediction error (VS RPE) signals and dmPFC learning rate signals, as measured with functional magnetic resonance imaging.
- However, a follow-up psychophysiological interaction analysis revealed decreased dmPFC-VS connectivity concurrent with learning rate modulation, most prominently in individuals with the most severe motivational deficits.
Hernaus D, Xu Z, Brown EC, et al. Motivational deficits in schizophrenia relate to abnormalities in cortical learning rate signals. Cogn Affect Behav Neurosci. 2018;18:1338. doi:10.3758/s13415-018-0643-z.
This Week's Must Reads
Cognition Impairment a Familial Disposition of MDD, JAMA Psychiatry; ePub 2018 Dec 26; Mackenzie, et al
Cognition in MDD and Aberrant Network Connectivity, J Psychiatr Res; 2019 Mar; Albert, Potter, Boyd, et al
Partner Criticism During Therapy for Recurrent MDD, Behav Res Ther; ePub 2018 Dec 21; Vittengl, et al
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Must Reads in Schizophrenia & Other Psychotic Disorders
Motivational Deficits in Schizophrenia Examined, Cogn Affect Behav Neurosci; 2018 Dec; Hernaus, et al
Medical Comorbidity, Mortality in Schizophrenia, Schizophr Res; ePub 2018 Dec 6; Brink, et al
Illness Awareness in Older Adults with Schizophrenia, Am J Geriatr Psychiatry; ePub 2018 Oct 21; Cohen, et al
Smartphone Program Aids Patients with Schizophrenia , Schizophr Res; ePub 2018 Dec 11; Achtyes, et al
Polygenic Risk Score Can Predict Drug Effectiveness, Am J Psychiatry; ePub 2018 Nov 5; Zhang, et al