Abstract
Objective
The present study examined the relationship between anxiety, corticomedial and basolateral amygdala volume, and cognitive flexibility among older adults (OA). We hypothesized that higher subclinical Beck Anxiety Inventory (BAI) scores would be associated with lower cognitive flexibility, assessed using the Delis-Kaplan Executive Function System (D-KEFS) verbal fluency. Additionally, we hypothesized that basolateral amygdala volume would negatively correspond to anxiety scores and exhibit a positive relationship with cognitive flexibility.
Method
Sixty-three OA (M age: 65; SD: 9; 59% female) were recruited via community advertising and cardiac clinics for a parent study on cardiovascular disease. Participants completed the D-KEFS and BAI as part of a comprehensive neuropsychological assessment prior to magnetic resonance imaging (MRI). Amygdala segmentation was completed with FreeSurfer version 6.0, using T1-weighted MPRAGE and T2-weighted FLAIR images. Data was analyzed using hierarchical multiple regression, controlling for age, sex, years of education, and intracranial volume.
Results
No significant relationship emerged between basolateral amygdala volume and BAI scores (r = .11, p = .41) or cognitive flexibility (r = .04, p = .76). However, a significant positive relationship was observed between corticomedial amygdala volume and cognitive flexibility after controls (β = 0.37, p < .01).
Conclusions
The previously reported relationship between high anxiety and basolateral amygdala volume does not appear to extend to subclinical levels. We conjecture that the significant relationship between the corticomedial amygdala and cognitive flexibility represents the upward slope between arousal and cognitive performance on the Yerkes-Dodson curve. These findings newly implicate corticomedial amygdala volume as a representative measure linking emotional arousal and cognitive performance in OA.