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.

The impacts of acute carbon monoxide poisoning on the brain: Longitudinal clinical and 99mTc ethyl cysteinate brain SPECT characterization of patients with persistent and delayed neurological sequelae.

OBJECTIVE: Acute carbon monoxide (CO) poisoning poses a significant threat to the central nervous system. It can cause brain injury and diverse neurological deficits including persistent neurological sequelae (PNS) and delayed neurological sequelae (DNS). The study aimed to investigate the long-term impacts of acute CO poisoning on brain perfusion and neurological function, and to explore potential differences between PNS and DNS patients. METHODS: We evaluated brain perfusion using (99m)Tc ethyl cysteinate (ECD) brain single photon emission computed tomography (SPECT) and assessed clinical neurological symptoms and signs one month following acute poisoning. For DNS patients, ECD SPECT and clinical evaluation were performed when their delayed symptoms appeared. All patients had follow-up SPECT imaging, along with clinical assessments six months following poisoning. RESULTS: 12 PNS and 12 DNS patients were recruited between 2007 and 2010. Clinically, the main characteristic presentations were cognitive decline, emotional instability, and gait disturbance. SPECT imaging demonstrated consistent frontal hypoperfusion of varying severities in all patients, which decreased in severity at follow-up imaging. DNS patients usually had more severe symptoms and perfusion defects, along with worse clinical outcomes than the PNS group. CONCLUSION: These results suggest that acute CO poisoning might lead to long term brain injuries and neurological sequelae, particularly in DNS patients.

Impairment on theory of mind and empathy in patients with stroke.

AIMS: Impaired social function has been described in patients following stroke. The present study was designed to explore the degree of impairment in the ability to infer mental states in others, or cognitive and affective theory of mind, and empathy, in patients with stroke. METHOD: A total of 34 patients with stroke were compared to 40 control subjects on tasks testing verbal and non-verbal theory of mind and empathy. RESULTS: Results indicated that patients with stroke were significantly impaired in both cognitive and affective theory of mind, even controlling for basic cognitive function and emotional processing. The patients with right stroke had poorer performance than those with left stroke on the cognitive component of non-verbal theory of mind. On the subscale of cognitive empathy, the right stroke group had poorer performance on perspective-taking than the control group. CONCLUSION: The right hemisphere may play an important role in decoding non-verbal cues to infer others' minds as well as the processing of empathy, especially the ability of perspective-taking.

Theory of mind in patients with temporal lobe epilepsy.

Theory of mind (ToM) is a crucial aspect of social cognition and is mediated by a complex neural network. Studies on temporal lobe epilepsy (TLE) suggest that its neuropathological involvement includes several brain regions. Some regions seem to overlap the neural network responsible for ToM, and this overlap provides an opportunity to explore ToM in TLE patients. Another concern is psychosocial problems in TLE, and the study of ToM in TLE could serve as a basis for further understanding the nature of such psychosocial disturbances. Studies on whether TLE patients evidence ToM deficit, however, are scant and controversial. Consequently, we examine whether ToM deficit is evident in TLE. Thirty-one TLE patients and 24 matched controls were recruited and completed four tasks measuring different levels of ToM: false belief, faux pas recognition, processing of implied meanings, and cartoon ToM. The patients were impaired in both basic and advanced ToM. Right TLE had a more wide-ranging picture of deficit than left TLE. ToM appears to be vulnerable to TLE, especially on the right side. Since ToM might contribute to patients' psychosocial adjustment, we thus suggest that a ToM measure be included in regular neuropsychological assessments of such patients.

Role of theory of mind and executive function in explaining social intelligence: a structural equation modeling approach.

OBJECTIVES: Social intelligence is the ability to understand others and the social context effectively and thus to interact with people successfully. Research has suggested that the theory of mind (ToM) and executive function may play important roles in explaining social intelligence. The specific aim of the present study was to test with structural equation modeling (SEM) the hypothesis that performance on ToM tasks is more associated with social intelligence in the elderly than is performance on executive functions. METHODS: One hundred and seventy-seven participants (age 56-96) completed ToM, executive function, and other basic cognition tasks, and were rated with social intelligence scales. RESULTS: The SEM results showed that ToM and executive function were strongly correlated (0.54); however, only the path coefficient from ToM to social intelligence, and not from executive function, was significant (0.37). CONCLUSIONS: ToM performance, but not executive function, was strongly correlated with social intelligence among elderly individuals. ToM and executive function might play different roles in social behavior during normal aging; however, based on the present results, it is possible that ToM might play an important role in social intelligence.

Development of the Insomnia Screening Scale based on ICSD-II.

OBJECTIVE: Although various instruments have been developed to evaluate insomniac symptoms in individuals, none of them are based on the International Classification of Sleep Disorder, 2nd (ICSD-II). The purpose of this study is to develop a new scaling system, the Insomnia Screening Scale (ISS) to fit the new diagnostic criteria. METHODS: Study 1 was conducted to formulate the new items of the insomnia screening scale (ISS), which were divided into four major subscales, and establish the reliability and validity of the ISS in clinical insomniac subjects. Study 2 tested the external validity of the ISS, which was used in a community survey, and investigated the relationship between ISS and daytime function, especially working memory. RESULTS: The final version of the ISS has good internal consistency (α = 0.87-0.98), and explains 64% of the variance. The insomnia group had poor working memory performance on the cognitive tasks. CONCLUSIONS: The ICSD-II based ISS is a reliable and valid instrument for evaluating an individual's insomniac symptoms. The major difference between the ISS and the previous instruments is that the ISS not only assess the subjective insomniac and daytime symptoms but also examines the sleep environment and sleep opportunities of the participants.

Validation of Patient Health Questionnaire for depression screening among primary care patients in Taiwan.

PURPOSE: The aim of this study was to determine the reliability and validity of a Chinese version of the Patient Health Questionnaire (PHQ-9) for the purpose of screening major depressive disorder (MDD) among primary care patients in Taiwan. METHOD: A total of 1954 primary care patients completed the PHQ-9. Patients (n = 1532) were interviewed using the Schedule for Clinical Assessments in Neuropsychiatry and 17-item of Hamilton Rating Scale. Subsample cases were retested within 2 weeks. RESULTS: The PHQ-9 had a good internal consistency (α = .80) and test-retest reliability (intraclass correlation coefficient = 0.87). A principal component factor analysis yielded 1-factor structure, which accounted for a total of 42.0% of the variance. The PHQ-9 was significantly correlated with the external validators such as the 17-item of Hamilton Rating Scale and the Short Form of the Quality of Life Enjoyment and Satisfaction Questionnaire (P < .001). Using the Schedule for Clinical Assessments in Neuropsychiatry interview as the criterion standard, a PHQ-9 score of 10 or higher had a sensitivity of 0.86 and a specificity of 0.94 for recognizing MDD. The screening accuracy of the 2 items version, PHQ-2, was also satisfactory (scores ≥ 2: sensitivity 0.88; specificity 0.82). The single-question screen, PHQ-1 (depressed mood), was 78% sensitive and 93% specific for detecting MDD (score ≥ 2). CONCLUSION: The PHQ-9 and its 2 subscales, PHQ-2 and PHQ-1, seem reliable and valid for detecting MDD among Chinese primary care patients.

Effects of depressive disorder on false memory for emotional information.

BACKGROUND: This study explored with a false memory paradigm whether (1) depressed patients revealed more false memories and (2) whether more negative false than positive false recognition existed in subjects with depressive disorders. METHODS: Thirty-two patients suffering from a major depressive episode (DSM-IV criteria), and 30 age- and education-matched normal control subjects participated in this study. After the presentation of a list of positive, negative, and neutral association items in the learning phase, subjects were asked to give a yes/no response in the recognition phase. They were also asked to rate 81 recognition items with emotional valence scores. RESULTS: The results revealed more negative false memories in the clinical depression group than in the normal control group; however, we did not find more negative false memories than positive ones in patients. When compared with the normal group, a more conservative response criterion for positive items was evident in patient groups. It was also found that when compared with the normal group, the subjects in the depression group perceived the positive items as less positive. CONCLUSIONS: On the basis of present results, it is suggested that depressed subjects judged the emotional information with criteria different from normal individuals, and patients' emotional memory intensity is attenuated by their mood.

Controlled trial of problem-solving therapy and consultation-liaison for common mental disorders in general medical settings in Taiwan.

OBJECTIVE: Common mental disorders (CMD) are prevalent high-impact illnesses seen in general medical settings worldwide. There has been no investigation on the efficacy of enhanced care in Chinese societies. The aim of this study was to compare the outcome of three interventions for treating CMD: usual care (UC), problem-solving therapy plus UC (PST-UC), and psychiatric consultation plus UC (PC-UC). METHOD: The sample for this randomized controlled trial consisted of 254 patients with CMD being managed in general medical care settings. Clinical and functional assessments were done at baseline and at 16 weeks. RESULTS: Two hundred six patients had complete data at 16 weeks (66 in the UC group, 63 in the PST-UC group, 77 in the PC-UC group). All patients had significant improvement on all scales over time, with no significant differences among the three treatment groups. CONCLUSION: This trial failed to demonstrate the efficacy of enhanced care with consultation-liaison by mental health professionals for patients with CMD in general medical settings in Taiwan. Improved outcomes may require more integrated interventions.

Depressive realism: evidence from false interpersonal perception.

The present study examined the depressive realism hypothesis, which posits that depressed people are often more accurate in their perceptions and judgments than non-depressed people are. Each subject initially generated descriptions of others important to them, both positive and negative important others, in the pretest section, and 3 or 4 weeks later, some subjects were invited into the formal experiment to measure the accuracy of their perceptions in a pseudo-social interaction situation. A total of 52 patients diagnosed with clinical depression and 62 normal matched subjects participated in the experimental procedure. The results indicate that clinically depressed patients provided more accurate, less distorted descriptions of their positive important others than did those in the normal group. However, when information involved the negative important others, the results exhibited a trend, but these results did not provide significant support for the depressive realism hypothesis. The results support the depressive realism hypothesis when tasks involve subjects' own positive important others.