Introduction Frontotemporal Lobar Degeneration (FTLD) commonly presents with a collapse in emotional and social awareness coupled with a failure to appreciate the consequences of the patient's own behaviour. The basis for these symptoms is not understood in detail. Here we assessed a cohort of FTLD patients on neuropsychological tasks requiring evaluation of the behaviour of self and others.

Methods 20 patients with a diagnosis of FTLD and 20 healthy age- and gender-matched controls participated. The diagnosis of FTLD was corroborated by general neuropsychological assessment and brain MRI. The Awareness of Social Inference Test (TASIT) was used to assess sensitivity to paralinguistic cues exhibited by others and the Iowa Gambling Task (IGT) was used to assess sensitivity to the consequences of one's own decision-making.

Results Compared with healthy subjects, the FTLD group showed reduced ability to detect simple emotional cues and difficulty identifying simple and paradoxical sarcasm on the TASIT; and reduced ability to identify risk and failure to modify decision making on the IGT.

Discussion Our findings provide further evidence that the capacity to evaluate one's own behaviour and the capacity to evaluate others' behaviour are both altered in FTLD. The application of tests such as the TASIT and the IGT could provide objective biomarkers of complex behavioural functions in FTLD. Further work should investigate the neuroanatomical substrates of these behavioural alterations.