In addition to cognitive deficits in executive functions, decision-making in a transaction can vary with neuropsychiatric features such as the absence of feelings of unfairness among bvFTD patients and its presence among those with AD.  One method to assess these feelings of fairness in decision-making is the Ultimatum Game (UG). 

Using a novel variant of the UG, this study investigated rejection responses to unfair offers among 10 patients who met International Consensus Criteria for early bvFTD, 11 comparably-demented patients with AD, and 9 healthy controls (HC).  Participants were presented with choices previously determined to have an acceptance rate of 100% by Level 2 and 75% at Level 1.  During the UG, participants underwent continuous skin conductance (SC) monitoring to gauge sympathetic reactivity.  The results were further compared with differences on the caregiver Neuropsychiatric Inventory (NPI). 

Overall, the bvFTD patients rejected significantly fewer offers than did the AD patients (p<0.01).  In contrast, the bvFTD patients did not differ from HC. Also correspondingly, they had a higher level of sympathetic activation (as measured by SC levels) when making a second level response as compared to AD patients.

On the NPI, logistic regression did not reveal significant differences for predicting acceptance rates across groups based on NPI domains.  However, among the 8 AD patients who persisted in rejected the offer, all scored 2 or more on the NPI dysphoria/depression domain (2X2 Fisher’s test, p<0.01).

Early bvFTD patients could be distinguished from early AD patients on the UG; the bvFTD patients accepted more offers than the AD patients, despite a mismatch with their sympathetic responsivity.  In contrast, AD patients rejected more offers, which correlated with their  dysphoria/depression.