RT Journal Article SR Electronic T1 F41 Comparison of affective and cognitive components of theory of mind in Huntington‘s and Parkinson‘s diseases JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP A50 OP A50 DO 10.1136/jnnp-2022-ehdn.132 VO 93 IS Suppl 1 A1 Sonia Di Tella A1 Paola Zinzi A1 Maria Rita Lo Monaco A1 Alice Tondinelli A1 Martina Petracca A1 Marcella Solito A1 Paolo Calabresi A1 Anna Rita Bentivoglio A1 Maria Caterina Silveri YR 2022 UL http://jnnp.bmj.com/content/93/Suppl_1/A50.3.abstract AB Theory of Mind (ToM) is the ability to predict others’ behavior by inference of their mental states. The affective component (Aff-ToM) is responsible for understanding others’ emotions, while the cognitive component (Cogn-ToM) refers to the knowledge of others’ beliefs and intentions. We examined ToM abilities in patients with Huntington’s disease (HD) and Parkinson’s disease (PD) compared to healthy controls (HC). All 63 participants (HD (n=20) 55.65±12.86; PD (n=21) 72.00±5.98; HC (n=22) 61.82±12.25 years) were evaluated using the computerized Yoni task which assesses affective and cognitive ToM abilities. This task also contains control items balanced for the level of difficulty (1st and 2nd order). Only patients with mild-moderate cognitive impairment were included (MoCA: HD 17.58±5.90; PD 20.19±4.00). Compared to HC, HD patients performed worse on both Aff-ToM and Cog-ToM (1st and 2nd order), whereas PD scored lower than HC only on 2nd order Cog-ToM. No between-group differences were observed on control items. Within groups comparisons showed differences only on 2nd order items: for HC the accuracy in both Aff-ToM and Cog-ToM items was poorer than in the control items; for HD the accuracy on Cog-ToM was lower than Aff-ToM, which resulted both lower than control items; and for PD only Cog-ToM was lower than the control items. The good performance in control items confirms a specific ToM deficit in clinical groups. In both groups, the affective component is more preserved than the cognitive component suggesting that the affective dimension might be less sensitive to damage of the striatum and corticostriatal circuits.