Impaired theory of mind in adults with traumatic brain injury: A replication and extension of findings.

OBJECTIVE: To replicate a previous study of Theory of Mind (ToM) task performance in adults with traumatic brain injury (TBI) under different working memory (WM) demands, and determine if there are sex-based differences in effects of WM load on ToM task performance.

METHOD: 58 adults with moderate-severe TBI (24 females) and 66 uninjured adults (34 females) matched group-wise for age, sex, and education viewed a series of video vignettes from the Video Social Inference Task (VSIT) (Turkstra, 2008) and answered ToM questions. Vignette presentation format required updating and maintenance of information, and WM load was manipulated by varying presence of distracters.

RESULTS: There were main effects of group and WM load, no significant effect of sex, and a marginal interaction of group by WM load, with larger between-group differences in conditions with higher WM load. VSIT scores for the condition with the highest WM load were significantly correlated with scores on the first trial of the California Verbal Learning Test.

CONCLUSIONS: We replicated findings of lower scores in adults with TBI on a video-based ToM task, and provided additional evidence of the effect of WM load on social cognition task performance. There were no significant accuracy differences between men and women, inconsistent with prior evidence - including our own data using the same test. There is strong evidence of a female advantage on other social cognition tasks, and the parameters of this advantage remain to be discovered.