Neuroimaging study data published in Schizophrenia Research describe an association between increased thalamocortical connectivity in response to targeted cognitive training (TCT) and improved global cognition in patients with recent-onset schizophrenia.
Ian Ramsay, PhD, of the department of psychiatry, University of Minnesota, Minneapolis, and colleagues recruited patients with early-onset schizophrenia from the Early Psychosis Clinic at the University of California, San Francisco and other community sites. Eligible participants first presented with schizophrenia within the past 5 years and had no significant physical comorbidities. They were assigned to complete 40 hours of an intervention condition over 2 months: targeted cognitive training (n=24; mean age, 23.7±4.55 years; 69.6% men) or a computer game control condition (n=20; mean age, 21.3±3.87 years; 60.0% men). The TCT intervention comprised a series of computerized tasks which emphasized auditory processing and working memory, whereas the control condition used 16 commercially available games.
The patients underwent resting state function magnetic resonance imaging (fMRI) and a series of cognitive tests before and after the 2-month intervention. The fMRI data were used to examine functional connectivity between 15 thalamocortical regions of interest, assessed through repeated analyses of covariance. Covariates included baseline global cognition and baseline connectivity in each region of interest.
Between baseline and follow-up, the TCT group displayed a significant increase in global cognition (t, 2.85; P =.009), whereas the control group did not (t, 1.10; P =.29). Following a Bonferroni-correction of P <.003, only the left superior temporal gyrus (STG) showed a significant group-by-time interaction. Over the study period, STG connectivity increased nominally in the TCT group (t, 1.92; P =.07) and decreased significantly in the control condition group (t, -2.65; P =.02).
In addition, increases in thalamo-STG connectivity were significantly correlated with increases in global cognition in the TCT group (r, 0.50; P =.02), although not in the control condition group (r, −0.34; P =.14). No effect of thalamic connectivity in the left STG was observed on schizophrenia symptoms or global functioning. However, per analyses of cognitive test subdomain scores, STG connectivity was positively associated with problem solving z-score (r, 0.37; P =.04).
The investigators suggested that improvements in global cognition may correlate with increased thalamocortical connectivity in the left STG in patients with recent-onset schizophrenia. Furthermore, the results also support the ability of TCT to influence thalamotemporal connectivity networks.
As study limitations, the investigators cited the small sample size, the absence of a control group, and the higher baseline problem solving z-score observed among TCT patients vs controls (P =.04).
“Overall, the current study demonstrates that targeted cognitive training of auditory processing in young individuals with early schizophrenia drives increases in thalamocortical connectivity in the left STG, which correlated with improvements in Global Cognition,” the researchers concluded, “This may reflect a neural compensatory process.”
Disclosure: One study author declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures
Ramsay IS, Roach BJ, Fryer S, et al. Increased global cognition correlates with increased thalamo-temporal connectivity in response to targeted cognitive training for recent onset schizophrenia [published online January 29, 2020]. Schizophr Res. doi: 10.1016/j.schres.2020.01.020.