Intensive cognitive training in schizophrenia enhances working memory and associated prefrontal cortical efficiency in a manner that drives long-term functional gains

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2014-10, Vol.99, p.281-292
• Main Authors: Subramaniam, Karuna, Luks, Tracy L., Garrett, Coleman, Chung, Cleo, Fisher, Melissa, Nagarajan, Srikantan, Vinogradov, Sophia
• Format: Article
• Language: English
• Subjects: Accuracy; Adult and adolescent clinical studies; Antipsychotic Agents - therapeutic use; Behavior; Biological and medical sciences; Cognitive Therapy - methods; Cognitive training; Computer & video games; Double-Blind Method; Efficiency; Female; fMRI; Frontal Lobe - physiopathology; Fundamental and applied biological sciences. Psychology; Games, Experimental; Gender; Generalization (Psychology); Humans; Male; Medical sciences; Memory; Memory, Short-Term; Middle Aged; Prefrontal cortex; Prefrontal Cortex - physiopathology; Psychology. Psychoanalysis. Psychiatry; Psychomotor Performance; Psychopathology. Psychiatry; Psychoses; Schizophrenia; Schizophrenia - physiopathology; Schizophrenia - rehabilitation; Schizophrenic Psychology; Studies; Vertebrates: nervous system and sense organs; Working memory; Young Adult
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2014.05.057

We investigated whether intensive computerized cognitive training in schizophrenia could improve working memory performance and increase signal efficiency of associated middle frontal gyri (MFG) circuits in a functionally meaningful manner. Thirty schizophrenia participants and 13 healthy comparison participants underwent fMRI scanning during a letter N-back working memory task. Schizophrenia participants were then randomly assigned to either 80h (16weeks) of cognitive training or a computer games control condition. After this intervention, participants completed a second fMRI N-back scanning session. At baseline, during 2-back working memory trials, healthy participants showed the largest and most significant activation in bilateral MFG, which correlated with task performance. Schizophrenia participants showed impaired working memory, hypoactivation in left MFG, and no correlation between bilateral MFG signal and task performance. After training, schizophrenia participants improved their 2-back working memory performance and showed increased activation in left MFG. They also demonstrated a significant association between enhanced task performance and right MFG signal, similar to healthy participants. Both task performance and brain activity in right MFG after training predicted better generalized working memory at 6-month follow-up. Furthermore, task performance and brain activity within bilateral MFG predicted better occupational functioning at 6-month follow-up. No such findings were observed in the computer games control participants. Working memory impairments in schizophrenia and its underlying neural correlates in MFG can be improved by intensive computerized cognitive training; these improvements generalize beyond the trained task and are associated with enduring effects on cognition and functioning 6months after the intervention. •Computerized cognitive training improves working memory (WM) in schizophrenia (SZ).•Better WM is supported by enhanced prefrontal signal efficiency in SZ.•Training-induced prefrontal signal efficiency predicts better long-term functioning.•Training-induced WM improvements generalize beyond the trained tasks.•Training-induced WM improvements are sustained 6months after the intervention.