Theory of Mind in Patients with Temporal Lobe Epilepsy

目的：「心智推理」，意指人類具有推論他人心理狀態的能力，為社會認知功能中一項重要的層面。近年來，研究指出心智推理有其大腦的神經基礎，主要由前額葉、顳葉及鄰近幾個區域來負責該功能的運作。顳葉癲癇是一種常見的局部性癲癇類型，近年來神經病理方面的研究指出，顳葉癲癇患者腦部病變部位並非僅在內側顳葉區域，可能涉及許多腦區;這些腦部病變區域和負責心智推理運作的腦部神經機制似乎有部分重疊之處，因而提供一個利於探討顳葉癲癇患者心智推理功能的機會。然而，過去少有研究探討顳葉癲癇患者是否有心智推理功能的缺損，且結果亦有爭議。因此，本研究的目的為探討顳葉癲癇患者是否在心智推理功能方面有缺損的狀況。方法：共有31位成人顳葉癲癇患者與15位正常人（控制組）參與本研究。顳葉癲癇患者與控制組在人口學與智力等變項上配對。所有受試者接受四類心智推理作業，測量基本與進階心智推理功能。另接受其他認知功能評估，包括記憶、執行功能及語文能力。結果：顳葉癲癇患者不論在基本或進階心智推理功能的表現上，皆明顯較正常組為差，且在排除其他認知功能的影響後，其表現仍為缺損。此外，進一步分析發現，右側顳葉癲癇患者在心智推理的缺損程度上，似乎較左側患者更嚴重。結論：心智推理功能的缺損可出現於顳葉癲癇患者，特別是右側患者身上，且該功能的缺損可能對患者的心理社會適應能力方面造成影響。因此本研究建議臨床上有必要將此項功能的評估，納入顳葉癲癇患者的神經心理衡鑑中。Purpose: The ability to infer another’s mental state (theory of mind, ToM) is a crucial aspect of social cognitive function. Recently, the neural substrate underlying ToM has been proposed to mainly involve the medial prefrontal and temporal lobes, as well as the adjacent structures. Temporal lobe epilepsy (TLE) is a common type of focal epilepsy. Recent studies suggest that its neuropathological involvement includes several brain regions, rather than being circumscribed within the medial temporal structures. Some of these regions seem to overlap the neural network responsible for ToM, and thus provide us an opportunity to explore ToM function in patients with TLE. Studies on the issue of whether the patients evidence dysfunction in ToM, however, are scant and controversial. Consequently, the present study examines whether change in function is evident in patients with TLE. Methods: Thirty-one adult patients with TLE and 15 normal subjects (NCs) matched for demographic variables and IQ were recruited. All subjects received four ToM tasks measuring the basic and the advanced level of function, as well as tests measuring episodic memory, executive function, and verbal ability. Results: The patients were impaired in both the basic and the advanced level of ToM function even after minimizing the effects of other domains of cognitive function. Moreover, the deficits of ToM were more prominent in patients with right TLE than in those with left TLE. Conclusion: ToM dysfunction appears to be vulnerable to TLE, especially on the right side, and in consideration of the function might contribute to patients’ psychosocial adjustment. We thus suggest that this function measure be included in regular neuropsychological assessments of such patients