B – 14 Inferences of Mental States in Hemispherectomy

Abstract Objective Hemispherectomy (HE) is a surgery in which one cerebral hemisphere is removed or functionally isolated to treat intractable seizures. This study examined social cognition in individuals with HE as revealed by intentionality and appropriateness rating of responses to two sets of 4 video animations: Theory of Mind (ToM) and Goal Directed (GD) in the Animations Test (Catelli, 2002). Method Participants viewed video clips of two triangles in motion. Four clips involved triangles interacting in a manner suggesting ToM judgements (coaxing, mocking, seducing, surprising). The other four clips suggested GD behavioral intentions (Chase, Dance, Fight, Lead). Participants were asked, “What was happening in the animation?” Responses were rated on Appropriateness and Intentionality (Castelli, 2002). Results A 2 group x 2 animation type ANOVA of appropriateness ratings indicated there was not a significant difference between the NT and HE groups, F(1,23) =.835, p=.370, η 2 p =.035. There also was not a significant effects of animation type F(3,21)=0.35, p=0.85; η2 p = 0.011, nor a significant interaction F(3,21)=1.73, p= 0.17; η2 p = 0.070. A similar ANOVA examining intentionality indicated there was a significant difference between participants, F(1,23)=5.65, p=.026, η2 p =.197, with the control group performing significantly better, and a significant difference in animation type F(3,21)=6.47, p=0.41; η2 p = 0.112. There was not significant interaction F(3,21)=2.50, p= 0.39; η2 p = 0.046. Conclusion These results suggest that NT and HE individuals are similar in their ability to accurately report the basic storyline, but the HE group had more difficulty in accurately attributing mental states.