Although the present study found only a trend for an association between STN activation and working memory, the findings are consistent with, and add to, an emerging literature. Experimental and clinical studies have highlighted interactions between higher-order cognitive processing and the STN. Animals with STN lesions show impaired working memory (El Massioui et al., 2007), and with disconnections between the STN and prefrontal cortex show reduced accuracy, increased perseveration and slowed response (Chudasama et al., 2003). In Parkinson’s patients, deep brain stimulation of the STN has improved motor and some executive performance, including working memory, suggesting that STN stimulation was ‘releasing the brake’ on frontal function (Jahanshahi et al., 2000) and supporting a role for the STN in higher order cognitive regulation (Marceglia et al., 2011).
