Measuring self and informant perspectives of Restricted and Repetitive Behaviours (RRBs): psychometric evaluation of the Repetitive Behaviours Questionnaire-3 (RBQ-3) in adult clinical practice and research settgs.

BACKGROUND: Brief questionnaires that comprehensively capture key restricted and repetitive behaviours (RRBs) across different informants have potential to support autism diagnostic services. We tested the psychometric properties of the 20-item Repetitive Behaviours Questionnaire-3 (RBQ-3), a questionnaire that includes self-report and informant-report versions enabling use across the lifespan. METHOD: In Study 1, adults referred to a specialised adult autism diagnostic service (N = 110) completed the RBQ-3 self-report version, and a relative or long-term friend completed the RBQ-3 informant-report version. Clinicians completed the abbreviated version of the Diagnostic Interview for Social and Communication Disorders (DISCO-Abbreviated) with the same adults as part of the diagnostic process. For half of the assessments, clinicians were blind to the RBQ-3 ratings. We tested internal consistency, cross-informant reliability and convergent validity of the RBQ-3. In Study 2, a follow-up online study with autistic (N = 151) and non-autistic (N = 151) adults, we further tested internal consistency of the RBQ-3 self-report version. We also tested group differences and response patterns in this sample. RESULTS: Study 1 showed good to excellent internal consistency for both self- and informant-report versions of the RBQ-3 (total score, α = 0.90, ω = 0.90, subscales, α = 0.76-0.89, ω = 0.77-0.88). Study 1 also showed cross-informant reliability as the RBQ-3 self-report scores significantly correlated with RBQ-3 informant-report scores for the total score (rs = 0.71) and subscales (rs= 0.69-0.72). Convergent validity was found for both self and informant versions of the RBQ-3, which significantly correlated with DISCO-Abbreviated RRB domain scores (rs = 0.45-0.54). Moreover, the RBQ-3 scores showed significantly weaker association with DISCO -Abbreviated scores for the Social Communication domain, demonstrating divergent validity. Importantly, these patterns of validity were found even when clinicians were blind to RBQ-3 items. In Study 2, for both autistic and non-autistic groups, internal consistency was found for the total score (α = 0.82-0.89, ω = 0.81-0.81) and for subscales (α = 0.68-0.85, ω = 0.69-0.85). A group difference was found between groups. LIMITATIONS: Due to the characteristics and scope of the specialist autism diagnostic service, further testing is needed to include representative samples of age (including children) and intellectual ability, and those with a non-autistic diagnostic outcome. CONCLUSIONS: The RBQ-3 is a questionnaire of RRBs that can be used across the lifespan. The current study tested its psychometric properties with autistic adults without intellectual disability and supported its utility for both clinical diagnostic and research settings.

Maternal mortality and COVID-19: A nationwide ecological analysis from Ecuador.

BACKGROUND: During the COVID-19 pandemic, distinct population subsets, including pregnant women, have been differentially affected. While over 90% of COVID-19-infected pregnant women experience a benign course, a subset demonstrates marked clinical exacerbation. Symptomatic pregnant individuals, in particular, present a heightened risk of severe disease in comparison to their non-pregnant counterparts. OBJECTIVE: The objective of this study is to systematically evaluate the epidemiological characteristics of COVID-19 in pregnant women, assess related maternal mortalities, ascertain the case fatality rate, and delineate associated risk factors. DESIGN: This is a comprehensive population-based ecological study. METHODOLOGY: A population-based study was conducted to investigate the epidemiological patterns of COVID-19-associated morbidity and mortality in pregnant women in Ecuador from 27 February 2020 to 14 May 2021. RESULTS: A total of 3274 positive COVID-19 cases were identified among pregnant women, with 22 official fatalities, yielding a case fatality rate of 0.67%. The majority of cases were of Mestizo ethnicity (92.66%); however, the highest case fatality rate was noted among indigenous pregnant women (case fatality rate = 1.25%), those aged between 40 and 44 years (case fatality rate = 2.68%), and those with a history of comorbidities (2.08%). Pregnant women residing at lower altitudes (<2500 m) exhibited a higher incidence rate (0.20/100,000) compared to those at higher altitudes (>2500 m), which stood at 0.17/100,000. CONCLUSION: The COVID-19 pandemic has profoundly impacted pregnant women in Ecuador during the first 14 months, particularly those with comorbidities, older age, and of indigenous ethnicity. These factors have heightened their vulnerability and susceptibility to severe COVID-19 infection and subsequent mortality. This underscores the urgency for comprehensive protective measures, including prioritization for vaccination. Further studies are needed to inform tailored prevention strategies and therapeutic interventions for these high-risk groups.

A nationwide epidemiological and geodemographic analysis of lymphatic filariasis in Ecuador: a neglected and often forgotten disease in Ecuador.

Introduction: Lymphatic filariasis (LF) is a neglected parasitic disease transmitted by mosquitoes and affecting the lymphatic system. The aim of this study was to analyze the epidemiological and sociodemographic characteristics of patients with LF during the last 11 years of available data in Ecuador. Methods: A 11-year nationwide analysis of hospital admission and in-hospital mortality based on the National Institute of Statistics and Census (INEC) data was conducted in Ecuador from 2011 to 2021. The International Classification of Diseases 10th Revision (ICD-10) code for filariasis (ICD: B74) was used to retrieve information on severe LF as a proxy for incidence among 221 Ecuadorian cities. Results: A total of 26 hospital admissions and 3 deaths due to LF were registered. The highest mortality rate was found in populations over 80 years. Men accounted for 62.5% (n = 17) of total number of cases with an average incidence rate of 1.7 cases per/1,000,000, while females accounted for 34.6% (n = 9), representing 1 case per/1,000,000 woman. Cities located at lower altitude (459/1,000,000) reported higher incidence rates than those located at higher altitudes (7.4/1,000,000). Conclusion: This is the first study on LF in Ecuador. Although, Ecuador is not considered endemic for LF, we found evidence of the presence of this disease in recent years. The implementation and improvement of an adequate integrated epidemiological surveillance system will allow early identification of cases and therefore their respective treatment.

Job Satisfaction and Self-Perceptions Among Ecuadorian Medical Doctors During Their Compulsory Rural Community Social Service: A Countrywide Cross-Sectional Analysis.

INTRODUCTION: Job satisfaction has been shown to have important effects at the organizational level. In various corners of the world, physicians are obliged to perform a period of social service, generally at the first level of care in rural or remote areas. OBJECTIVE: To describe the level of job satisfaction and perceptions of Ecuadorian rural physicians regarding compulsory social service. METHODOLOGY: A descriptive, cross-sectional study was conducted based on a self-administered online questionnaire from February to March 2022, in Ecuadorian rural physicians who were performing their compulsory social service. Participants were invited through official outreach groups. A total of 247 surveys were included in this study. We assessed job satisfaction by means of the S20/23 job satisfaction questionnaire and compared these results with sociodemographic variables and job characteristics of the participants. We performed the reliability test (Cronbach's alpha) to find the validity of the S20/23 questionnaire in physicians performing compulsory social service. RESULTS: The majority of participants were women (61.0%), and overall job satisfaction was 4.1/7.0 pts. "indifferent." The only satisfaction factor in which a predominance of dissatisfaction was found related to benefits/remuneration (43.3%). Participants' perceptions of wrong academic guidance during training, insufficient induction, and negative experiences during work were related to higher levels of dissatisfaction (P < .05). CONCLUSION: The level of job satisfaction of Ecuadorian rural physicians during their compulsory social service was low and graduates indicated a neutral attitude toward job satisfaction in general. Negative perceptions with respect to training and expectation formation prior to and during the mandatory social service generated greater dissatisfaction. The Ministry of Health of Ecuador, as an organizational entity, should implement improvements to increase the job satisfaction of recently graduated physicians, given the implications that this experience may have for their professional future.

Reliability of the Commonly Used and Newly-Developed Autism Measures.

PURPOSE: The aim of the present study was to compare scale and conditional reliability derived from item response theory analyses among the most commonly used, as well as several newly developed, observation, interview, and parent-report autism instruments. METHODS: When available, data sets were combined to facilitate large sample evaluation. Scale reliability (internal consistency, average corrected item-total correlations, and model reliability) and conditional reliability estimates were computed for total scores and for measure subscales. RESULTS: Generally good to excellent scale reliability was observed for total scores for all measures, scale reliability was weaker for RRB subscales of the ADOS and ADI-R, reflecting the relatively small number of items for these measures. For diagnostic measures, conditional reliability tended to be very good (> 0.80) in the regions of the latent trait where ASD and non-ASD developmental disability cases would be differentiated. For parent-report scales, conditional reliability of total scores tended to be excellent (> 0.90) across very wide ranges of autism symptom levels, with a few notable exceptions. CONCLUSIONS: These findings support the use of all of the clinical observation, interview, and parent-report autism symptom measures examined, but also suggest specific limitations that warrant consideration when choosing measures for specific clinical or research applications.

Ethnodemographic characterization of stroke incidence and burden of disease in hospital discharge records in Ecuador.

Introduction: Stroke is the second most common cause of death and disability-adjusted life years (DALYs) globally. However, the incidence and impact of stroke by ethnicity and gender is frequently distinct. This is particularly the case in Ecuador where geographic and economic marginalization are often correlated with ethnic marginalization and the extent to which females lack the same opportunities as their male counterparts. The aim of this paper is to investigate the differential impacts in terms of stroke diagnosis and burden of disease by ethnicity and gender, using hospital discharge records over the years 2015-2020. Methods: This paper calculates stroke incidence, and fatality rates using hospital discharge and death records over the years 2015-2020. The DALY package in R was employed to calculate the Disability Adjusted Life Years lost due to stroke in Ecuador. Results: The results show that while the incidence rate of stroke in males (64.96 per 100,000 persons-year) is higher than that for females on average (57.84 per 100,000 persons-year), males accounted for 52.41% of all stroke cases and 53% of all surviving cases. Thus, hospital data suggests that females had a higher death rate when compared to males. Case fatality rates also differed significantly by ethnicity. The highest fatality rate corresponded to the Montubio ethnic group (87.65%), followed by Afrodescendants (67.21%). The estimated burden of disease of stroke calculated using Ecuadorian hospital records (2015-2020) varied from 1,468 to 2,991 DALY per 1,000 population on average. Discussion: Differences in the burden of disease by ethnic group are likely to reflect differential access to care by region and socio-economic group, both of which are frequently correlated with ethnic composition in Ecuador. Equitable access to health services remains an important challenge in the country. The gender discrepancy in fatality rates suggests that there is a need for targeted educational campaigns to identify stroke signs early, especially in the female population.

Comparative analysis of long-term self-reported COVID-19 symptoms among pregnant women.

BACKGROUND: The negative effects of COVID-19 infections during pregnancy have been amply described, however, the persistent sequels of this infection have not been explored so far. OBJECTIVE: The aim of this study was to describe persisting symptoms after COVID-19 infection in pregnant and non-pregnant women in Ecuador. METHODS: A cross-sectional analysis based on an online, self-reporting questionnaire was conducted in Ecuador from April to July 2022. Participants were invited by social media, radio, and TV to voluntarily participate in our study. A total of 457 surveys were included in this study. We compared risk factor variables and long-term persisting symptoms of pregnant and non-pregnant women in Ecuador. RESULTS: Overall, 247 (54.1 %) responders claimed to have long-term symptoms after SARS-CoV-2 infection. Most of these symptoms were reported by non-pregnant women (94.0 %). The most common Long-COVID symptoms in pregnant women were fatigue (10.6 %), hair loss (9.6 %), and difficulty concentrating (6.2 %). We found that pregnant women who smoked had a higher risk of suffering fatigue. CONCLUSIONS: The most frequent Long-COVID symptoms in pregnant women were fatigue, hair loss, and difficulty concentrating. Apparently, the patterns of presentation of long-term sequelae of SARS-CoV-2 infection in pregnant women do not differ significantly from reports available from studies in the general population.

How much do Latin American medical students know about radiology? Latin-American multicenter cross-sectional study.

BACKGROUND: Radiology is a useful tool for diagnosis and intervention in medical practice, and all the components within the teaching-learning process of this subject during undergraduate studies influence successful knowledge application. OBJECTIVE: This study aimed to describe the level of knowledge in radiology of students in the last two years of medical school and curricular characteristics of their courses in seven Latin American countries. METHODS: A multicenter cross-sectional study was carried out on medical students of 7 Latin American countries (Bolivia, Brazil, Colombia, Ecuador, Mexico, Paraguay, and Peru) in their final two years of medical school, using an online questionnaire validated by experts and adapted for each country that assessed knowledge and curricular characteristics in radiology subject. Scores were assigned according to the number of correct answers for the knowledge test. The T-test, and regression analysis with one-way ANOVA were used to search for relationships between the level of knowledge and other variables. RESULTS: A total of 1514 medical students participated in this study. All countries had similar participation (n > 200); most participants were women 57.8%. The country with the highest knowledge score was Brazil. Male, sixth year (internship) and from public universities students had higher knowledge score (n < 0.05). Participants, who considered radiology more important, and who reported higher compliance with teaching staff with the proposed syllabus, and programmed classes, obtained better scores (n < 0.05). CONCLUSIONS: Latin American medical students included in this study have a regular overall level of knowledge of Radiology, apparently influenced by curricular differences such as class and academic program compliance. Efforts to better understand and improve academic training are indispensable. LIMITATIONS: The study was subject to selection bias determined by non-probability convenience sampling. The questionnaire assessed only theoretical knowledge and the evaluation system was designed by the investigators.

A Cross-Sectional Analysis of Self-Medication Patterns during the COVID-19 Pandemic in Ecuador.

Background and Objectives: Drug consumption is a widely developed practice around the world. However, sometimes medicines are acquired with or without prescription, a practice termed self-medication, which can have negative impacts on the health of the population. It has been observed that with the arrival of the coronavirus disease 2019 (COVID-19) pandemic, self-medicated drug consumption figures increased in several countries. To describe the patterns of medication, use and the prevalence of self-medication during the COVID-19 pandemic in inhabitants of the capital province of Pichincha, Ecuador. Materials and Methods: A descriptive, cross-sectional study was conducted based on a self-administered online questionnaire from April to June 2022, among residents of the province of Pichincha, Ecuador. Participants were invited through social networks (WhatsApp and Facebook). A total of 401 surveys were included in this study. Consumption patterns (prescription of and treatment with) of medicines during the pandemic were evaluated, as well as the prevalence of self-medication and variables that characterize the way of acquiring medicines. The Chi-square test was used to look for relationships between consumption patterns, self-medication, and the characteristics of the participants. Results: Most participants were female (53.4%), and 59.4% reported having had COVID-19. A total of 244 (60.9%) consumed medications during the pandemic, mostly for the purpose of treating the infection. About half (48.4%) self-medicated. The most used medications were paracetamol (87.3%) and ibuprofen (47.5%). Drugs consumption as a treatment and informal sources of information (TV, social networks, advice) were associated with the practice of self-medication (p < 0.05). Conclusions: A significant percentage of over-the-counter (OTC) and legal drug use was found to persist after the COVID-19 pandemic. Our findings highlight the effects that alternative forms of information sources other than medical personnel can have on drug consumption and self-medication practices.

Subdomains of restricted and repetitive behaviors within autism: Exploratory structural equation modeling using the diagnostic interview for social and communication disorders.

The current study aimed to explore the factor structure of a broad range of restricted and repetitive behaviors (RRB) within the autism spectrum. Exploratory structural equation modeling was conducted using individual item-level data from the Diagnostic Interview for Social and Communication Disorders (DISCO). DISCO is a comprehensive semi-structured interview used by clinicians to elicit information from caregivers about the individual's profile of development and behavior. Data from a sample of 226 individuals with a clinical diagnosis of autism spectrum disorder (ASD) (189 males; Mage  = 11.82 years, SDage  = 7.87) were analyzed. The six-factor structure provided the most optimal and interpretable fit (comparative fit index = 0.944, Tucker-Lewis index = 0.923, root mean square error of approximation = 0.018). Derived factors were interpreted as repetitive motor behaviors (RMB), unusual sensory and object focused interests (USOI), sensory sensitivity (SS), insistence on sameness (IS), circumscribed interests (CI) and stereotyped language (SL). Age was significantly negatively associated with RMB, USOI and SL but not with SS, IS or CI factor scores. None of the factors were associated with sex. ASD individuals with intellectual disability (ID) had the highest RMB, USOI, SS and SL scores while those without ID had the highest IS and CI scores. Our findings provide preliminary evidence for the utility of the DISCO as a comprehensive measure of several distinct RRB domains in both research and clinical contexts. Importantly, the current investigation highlights crucial areas for measurement development. LAY SUMMARY: The diagnostic Interview for Social and Communication Disorders (DISCO) is a detailed caregiver report clinical interview designed to capture a wide range of key features associated with autism spectrum disorder, including restricted and repetitive behaviors (RRB). This paper provides initial evidence that the DISCO is a promising measure for assessing a wide range of RRB including repetitive motor behaviors, insistence on sameness, circumscribed interests, unusual interests in sensory stimuli, sensory sensitivity and stereotypic language.

How well are DSM-5 diagnostic criteria for ASD represented in standardized diagnostic instruments?

Five years after the publication of DSM-5 in 2013, three widely used diagnostic instruments have published algorithms designed to represent its (sub-)criteria for Autism Spectrum Disorder (ASD) in children and adolescents. This study aimed to: (1) establish the content validity of these three DSM-5-adapted algorithms, and (2) identify problems with the operationalization of DSM-5 diagnostic criteria in measurable and observable behaviors. Algorithm items of the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2), Developmental, Dimensional and Diagnostic Interview (3di) and Diagnostic Interview for Social and Communication Disorders-11th edition (DISCO-11) were mapped onto DSM-5 sub-criteria. The development and decision-making rules integrated in their algorithms were then compared with DSM-5. Results demonstrated significant variability in the number and nature of sub-criteria covered by the ADOS-2, 3di and DISCO-11. In addition to differences in the development of algorithms and cut-off scores, instruments also differed in the extent to which they follow DSM-5 decision-making rules for diagnostic classification. We conclude that such differences in interpretation of DSM-5 criteria provide a challenge for symptom operationalization which will be most effectively overcome by consensus, testing and reformulation.

Development of the Signposting Questionnaire for Autism (SQ-A): measurement comparison with the 10-item Autism Spectrum Quotient-Child and the Strengths and Difficulties Questionnaire in the UK and Latvia.

BACKGROUND: Recognising the signs of autism spectrum disorder (ASD) can be a challenge for frontline professionals. The use of brief parent-completed questionnaires for recording the signs of ASD in school-aged children may be an important and efficient contributor to professional insight. However, to date, such questionnaires have not been designed to be used in coordination with current standardised Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnostic tools. Furthermore, the measurement characteristics of such questionnaires have been unexplored across countries that differ in levels of national autism service provision and cultural interpretation of the signs of ASD. METHODS: A new 14-item questionnaire (Signposting Questionnaire for Autism (SQ-A)) was developed using published DSM-5 items from a clinical interview, the Diagnostic Interview for Social Communication Disorders (DISCO). Measurement comparison was tested with the Short Autism Spectrum Quotient-Child (AQ-10) and the Strengths and Difficulties Questionnaire (SDQ). Parents of 4-11-year-old children in the UK (N = 200) and Latvia (N = 104) completed all three questionnaires. Information on clinical diagnosis provided by parents led to classification into three groups: ASD diagnosis, other conditions and no conditions. In the UK, a subsample of teachers also provided cross-informant reliability. RESULTS: In both countries, there was evidence of acceptable to good internal consistency for the SQ-A, with significantly higher scores for the ASD group and evidence of convergent and discriminant validity. There was also good parent-teacher reliability for the three measures. Notably, the questionnaires designed specifically to measure autism (SQ-A, AQ-10) performed more similarly to one another compared to the broader SDQ, with differences found for the ASD group. The overall pattern of responding to the three questionnaires was highly similar between countries. CONCLUSIONS: These results indicate the potential of the 14-item SQ-A to guide frontline professionals in the recognition of the signs of autism in children, facilitating the provision of appropriate support.

Describing the Profile of Diagnostic Features in Autistic Adults Using an Abbreviated Version of the Diagnostic Interview for Social and Communication Disorders (DISCO-Abbreviated).

The rate of diagnosis of autism in adults has increased over recent years; however, the profile of behaviours in these individuals is less understood than the profile seen in those diagnosed in childhood. Better understanding of this profile will be essential to identify and remove potential barriers to diagnosis. Using an abbreviated form of the Diagnostic Interview for Social and Communication Disorders, comparisons were drawn between the profile of a sample of able adults diagnosed in adulthood and the profile of a sample of able children. Results revealed both similarities and differences. A relative strength in non-verbal communication highlighted a potential barrier to diagnosis according to DSM-5 criteria for the adult sample, which may also have prevented them from being diagnosed as children.

Development of restricted and repetitive behaviors from 15 to 77 months: Stability of two distinct subtypes?

A community sample of 192 parents reported on their children's restricted and repetitive behaviors (RRBs) at mean ages 15 months (N = 138), 26 months (N = 191), and 77 months (N = 125) using the Repetitive Behavior Questionnaire-2 (RBQ-2). Consistent with previous factor analytic research, 2 factors were found at each age: 1 comprising repetitive sensory and motor behaviors (RSM), and the other comprising insistence on sameness behaviors including rigidity, routines, and restricted interests (IS). Regression analyses indicated that RSM and IS subtypes develop independently. RSM at 77 months was predicted only by RSM behaviors at 26 months and not by IS behaviors at either 15 or 26 months nor by RSM behaviors at 15 months. IS at 77 months was predicted by IS behaviors at both 15 and 26 months, but not by RSM behaviors at either 15 or 26 months. Our findings provide evidence that there is stability of 2 independent subtypes of RRBs, RSM and IS, across early childhood and that these subtypes develop independently of each other. (PsycINFO Database Record

Knowledge acquisition and research evidence in autism: Researcher and practitioner perspectives and engagement.

BACKGROUND: Government policy and national practice guidelines have created an increasing need for autism services to adopt an evidence-based practice approach. However, a gap continues to exist between research evidence and its application. This study investigated the difference between autism researchers and practitioners in their methods of acquiring knowledge. METHODS: In a questionnaire study, 261 practitioners and 422 researchers reported on the methods they use and perceive to be beneficial for increasing research access and knowledge. They also reported on their level of engagement with members of the other professional community. RESULTS: Researchers and practitioners reported different methods used to access information. Each group, however, had similar overall priorities regarding access to research information. While researchers endorsed the use of academic journals significantly more often than practitioners, both groups included academic journals in their top three choices. The groups differed in the levels of engagement they reported; researchers indicated they were more engaged with practitioners than vice versa. CONCLUSIONS: Comparison of researcher and practitioner preferences led to several recommendations to improve knowledge sharing and translation, including enhancing access to original research publications, facilitating informal networking opportunities and the development of proposals for the inclusion of practitioners throughout the research process.

Diagnosing autism spectrum disorder: who will get a DSM-5 diagnosis?

BACKGROUND: Introduction of proposed criteria for DSM-5 Autism Spectrum Disorder (ASD) has raised concerns that some individuals currently meeting diagnostic criteria for Pervasive Developmental Disorder (PDD; DSM-IV-TR/ICD-10) will not qualify for a diagnosis under the proposed changes. To date, reports of sensitivity and specificity of the new criteria have been inconsistent across studies. No study has yet considered how changes at the 'sub domain' level might affect overall sensitivity and specificity, and few have included individuals of different ages and ability levels. METHODS: A set of DSM-5 ASD algorithms were developed using items from the Diagnostic Interview for Social and Communication Disorders (DISCO). The number of items required for each DSM-5 subdomain was defined either according to criteria specified by DSM-5 (Initial Algorithm), a statistical approach (Youden J Algorithm), or to minimise the number of false positives while maximising sensitivity (Modified Algorithm). The algorithms were designed, tested and compared in two independent samples (Sample 1, N = 82; Sample 2, N = 115), while sensitivity was assessed across age and ability levels in an additional dataset of individuals with an ICD-10 PDD diagnosis (Sample 3, N = 190). RESULTS: Sensitivity was highest in the Initial Algorithm, which had the poorest specificity. Although Youden J had excellent specificity, sensitivity was significantly lower than in the Modified Algorithm, which had both good sensitivity and specificity. Relaxing the domain A rules improved sensitivity of the Youden J Algorithm, but it remained less sensitive than the Modified Algorithm. Moreover, this was the only algorithm with variable sensitivity across age. All versions of the algorithm performed well across ability level. CONCLUSIONS: This study demonstrates that good levels of both sensitivity and specificity can be achieved for a diagnostic algorithm adhering to the DSM-5 criteria that is suitable across age and ability level.

Are there theory of mind regions in the brain? A review of the neuroimaging literature.

There have been many functional imaging studies of the brain basis of theory of mind (ToM) skills, but the findings are heterogeneous and implicate anatomical regions as far apart as orbitofrontal cortex and the inferior parietal lobe. The functional imaging studies are reviewed to determine whether the diverse findings are due to methodological factors. The studies are considered according to the paradigm employed (e.g., stories vs. cartoons and explicit vs. implicit ToM instructions), the mental state(s) investigated, and the language demands of the tasks. Methodological variability does not seem to account for the variation in findings, although this conclusion may partly reflect the relatively small number of studies. Alternatively, several distinct brain regions may be activated during ToM reasoning, forming an integrated functional "network." The imaging findings suggest that there are several "core" regions in the network-including parts of the prefrontal cortex and superior temporal sulcus-while several more "peripheral" regions may contribute to ToM reasoning in a manner contingent on relatively minor aspects of the ToM task.