The relationship between theory of mind and the executive functions: Evidence from patients with frontal lobe damage.

"Theory of mind" (ToM) refers to the ability to predict others' thoughts, intentions, beliefs, and feelings. Evidence from neuropsychology and functional imaging indicates that ToM is a domain-specific or modular architecture; however, research in development psychology has suggested that ToM is the full development of the executive functions in individuals. Therefore, the relationship between ToM and the executive functions needs to be clarified. Since the frontal lobe plays a critical role in the abilities of ToM and the executive functions, patients with frontal lobe damage were recruited for the present study. Assessments of ToM and the executive functions were performed on 23 patients with frontal lobe damage and 20 healthy controls. When controlling for the executive functions, significant differences between the patient and normal groups were found in the affective component of ToM, but not in the cognitive component. The present study suggests that in various social situations, executing ToM abilities requires logical reasoning processes provided by the executive functions. However, the reasoning processes of affective ToM are independent of executive functions.

Mentalizing ability in patients with prefrontal cortex damage.

INTRODUCTION: Mentalizing ability is the issue in the social cognition of patients with brain injury that has received the most attention. The present study investigated mentalization ability in patients with prefrontal cortex damage. The aims of this study were to investigate: (a) whether patients with prefrontal cortex damage are impaired in mentalizing ability, including theory of mind (ToM) and empathy; (b) whether patients with ventromedial prefrontal cortex damage are impaired in different aspects of ToM; (c) whether patients with ventromedial prefrontal cortex damage are impaired in different aspects of empathy; and (d) whether impairment of mentalizing ability in patients with prefrontal cortex damage can be explained by executive dysfunction. METHOD: Mini-Mental State Examination (MMSE), Matrix Reasoning subtest, working memory, executive function, theory of mind, and empathy assessments were conducted on eight patients with ventromedial prefrontal cortex damage, 15 patients with dorsolateral prefrontal cortex damage, and 19 normal comparisons matched for level of education and intelligence. RESULTS: The results showed that performance on affective and nonverbal theory of mind was significantly lower in patients with dorsolateral prefrontal cortex damage than in the comparison group. Performance on personal distress items of empathy was significantly lower in the ventromedial prefrontal cortex damage group than in the dorsolateral prefrontal cortex damage group. In addition, further multiple regression analysis showed that affective theory of mind could be explained by the Wisconsin Card Sorting Test-Modified (WCST-M), with an explained variance of up to 44%. CONCLUSION: The present study suggests that the impairment of mentalizing ability in patients with prefrontal cortex damage is partially the result of executive dysfunction.

Neuropsychological performance in patients with carbon monoxide poisoning.

This study investigated changes in cognitive function in acute and delayed carbon monoxide (CO) poisoning groups with comprehensive neuropsychological tests at 1 month and 6 months after therapy. For this study, 11 patients with acute and 14 with delayed CO poisoning were recruited. The neuropsychological tests included psychomotor speed, visual-spatial ability, language, logical memory, working memory, and executive function. The results showed that patients with delayed neuropsychiatric syndrome (DNS) had poorer performance on neuropsychological tasks than did those with acute CO poisoning at the 1st month and reached almost the same level as the acute group on the neuropsychological tasks at the 6-month follow-up assessment. The DNS group had more significant progress on general cognitive function, psychomotor speed, and visual-spatial ability than did the acute group after continuous hyperbaric-oxygen therapy.