Theory of mind: Independence of executive function and the role of the frontal cortex in acquired brain injury

Introduction. Theory of mind (ToM) deficits have recently been associated with executive dysfunction and frontal brain damage. This case study investigated ToM ability and its relation to executive functioning and the role of the frontal cortex, in an adult male with orbitofrontal (OF) damage and disturbance in social behaviour. It was hypothesised that both ToM ability and executive functioning would be impaired. It has also been suggested that ability to understand affective states may be mediated by OF structures. Understanding of affective state attribution was also investigated. Methods. A 59-year-old male Caucasian with social disturbance and OF damage was administered a battery of neuropsychological tests, tests of executive function, plus ToM stories and cartoons, in order to assess the ability to infer mental and affective states in others. Results. Ability to understand mental states and affective responses was found to be intact and independent of executive functioning. Conclusion. ToM ability appears to be independent of executive skills of overall strategy formation and not necessarily dependent on OF involvement. It is concluded that evidence supports the modular hypothesis of ToM and that this ability may be supported by more posterior regions.