Brain reserve theory: Are adults with intellectual disability more vulnerable to age than peers with typical development?

BACKGROUND: Life expectancy is on rise and the intriguing question is: When does cognitive decline occur among adults with intellectual disability, compared to adults with typical development? This cross-sectional study examined cognitive performance of crystallised/fluid intelligence, working and long-term memory of adults with intellectual disability of etiologies other than Down syndrome (IQ 50-68) and adults with typical development (IQ 85-114) in four age cohorts (30-39; 40-49; 50-59; 60-69). METHOD: The WAIS IIIHEB and the Rey-AVLT were administered to both groups. RESULTS: Four patterns of cognitive performance were found: (a) Vocabulary (crystallised intelligence), Spatial Span Forward and Retention yielded similar scores across all four age cohorts in participants with typical development and with intellectual disability. (b) Similarities, Raven and Digit Span Backward exhibit lower scores only in 50-59 or 60-69 compared to the 30-39 age cohort in both groups, (c) Digit Span Forward, Spatial Span Backward and Total Leaning (LTM) yielded lower scores in the 50-59 or 60-69 age cohorts in the typical group, but similar scores in participants with intellectual disability along the age cohorts, (d) Block Design (fluid intelligence) yielded a lower score in the 50-59 cohort versus lower scores only at ages 60-69 in participants with typical development. CONCLUSIONS: Our findings suggest a possible parallel trajectory in age-related cognitive performance for individuals with and without intellectual disability in six measures, and a possible more preserved trajectory in fluid intelligence and some memory measures in adults with intellectual disability compared to their peers. Caution should be exercised regarding Digit and Spatial Span Backwards, which yielded a floor effect in participants with intellectual disability. The Cognitive Reserve Theory, the Safeguard Hypothesis and late maturation might serve as explanations for these findings.

How do students with intellectual disabilities tell stories? An investigation of narrative macrostructure and microstructure.

Individuals with intellectual disability may have limited narrative skills. The novelty of this study lies in the examination of strengths and weaknesses which may enable a more facilitative approach to narrative and other storytelling-based methodologies among adults with intellectual disability who study in an academic enrichment program in comparison to typical students with the same chronological age. Seventeen adult students with intellectual disability and 16 typically developing students, produced narratives which were examined for microstructure (e.g., length, lexis, grammaticality, and complexity) macrostructure (e.g., goals, attempts, and outcomes) and Internal state terms (ISTs). The findings indicate that in spite of weakness of adults with intellectual disability in terms of coherence, syntactic complexity, and grammatical sentences, they exhibit strengths in narrative macrostructure story scheme and use IST. With increasing age, narratives performance of adults with intellectual disability continues to advance possibly due to maturity, life experience and indirect exposure to the environment.

The contribution of distress factors and Coping Resources to the motivation to use ICT among adults with intellectual disability during COVID-19.

The current study focused on people with intellectual disability (ID), who have unique disadvantages that place them at greater risk for negative outcomes due to COVID-19. The study goals are three-fold: (a) To examine whether differences in distress factors (loneliness and stress) would be found between adults with ID who used the Zoom application, and those who did not use Zoom during the pandemic; (b) To examine whether differences in psychological and coping resources (psychological capital), and practical-technological resources (attitudes and motivation to use information communication technology) would be found between the groups; (c) To examine the contribution of background variables (gender, type of residence, Zoom use), distress factors and psychological and practical technological coping resources on the motivation to use technology. The sample included 35 adults with ID (MCA = 40.06, SD = 11.02). Of these, 57% learned to use the Zoom application during the COVID-19 pandemic (N = 20), and 47% did not (N = 15). Participants answered seven questionnaires examining distress factors and psychological and technological resources. Both groups exhibited distress factors. However, the Zoom users demonstrated higher scores in hope and motivation to use technology. Regression analysis indicated that the resilience and attitudes toward technology among the Zoom users contributed to the explained variance of motivation to use technology. In light of the higher coping resources among Zoom users, we may carefully say that using Zoom might increase the independence of individuals with ID in learning, develop their communications possibilities, and help them to cope better in distress situations.

Lexical decision performance using the divided visual field technique following training in adults with intellectual disabilities with and without Down syndrome.

Studies of brain lateralization in individuals with non-specific intellectual disability and Down syndrome suggest atypical brain lateralization to speech perception. According to the biological dissociation model, the right hemisphere (RH) mediates speech perception and the left hemisphere (LH) mediates motor control in Down syndrome. The current study aimed to test, for the first time, brain lateralization in both non-specific intellectual disability and Down syndrome, compared to individuals with typical development. Furthermore, bilateral word presentation was utilized to assess interhemispheric communication. Twenty adults with non-specific intellectual disability, 14 adults with Down syndrome, and 30 adults with typical development participated in the study. Participants in the non-specific intellectual disability and Down syndrome groups were trained to perform the task prior to the experiment. The results showed that whereas hemispheric lateralization did not differ between individuals with non-specific intellectual disability and typical development, individuals with DS showed reduced brain lateralization in comparison to adults with typical development. All three groups showed no significant difference between words presented to the LH and bilaterally. Our results also show that individuals with intellectual disabilities can benefit from training programmes and that they may perform equally as fast as their typically developing peers.

Specific Susceptibility to COVID-19 in Adults with Down Syndrome.

The current SARS-CoV-2 outbreak, which causes COVID-19, is particularly devastating for individuals with chronic medical conditions, in particular those with Down Syndrome (DS) who often exhibit a higher prevalence of respiratory tract infections, immune dysregulation and potential complications. The incidence of Alzheimer's disease (AD) is much higher in DS than in the general population, possibly increasing further the risk of COVID-19 infection and its complications. Here we provide a biological overview with regard to specific susceptibility of individuals with DS to SARS-CoV-2 infection as well as data from a recent survey on the prevalence of COVID-19 among them. We see an urgent need to protect people with DS, especially those with AD, from COVID-19 and future pandemics and focus on developing protective measures, which also include interventions by health systems worldwide for reducing the negative social effects of long-term isolation and increased periods of hospitalization.

Health status and ADL functioning of older persons with intellectual disability: community residence versus residential care centers.

The objective of the study was to study differences in aging phenomena among adults with intellectual disability (ID), who live in community residence versus their peers in residential care centers and to determine the contribution of health status, age, gender, etiology and level of ID to the decline in ADL function with age. Our study was based on matched pairs between persons with ID in community residence (N=101) and their peers living in residential centers (N=101) by age, gender, etiology and level of ID. Fifty-three percent were aged 40-49 years, 23% were aged 50-59 years and 14% were aged 60-71 years. Ten percent had Down syndrome (DS), 16% had cerebral palsy (CP) and the rest had ID with no specific etiology (NSID). Caregivers were interviewed to ascertain health problems, sensory impairments and activity of daily living (ADL). The type of residence alone could not explain the morbidity and health problems of adults with ID, which were affected by age and etiology. Participants with NSID functioned better than those with Down syndrome or cerebral palsy in all ADL areas. MANOVA and regression analysis indicated that age and health status did not contribute to the explained variance of the ADL function of the participants without specific etiology. The CP group had the most vulnerable etiology exposed to medical problems and decline in ADL function with age. Action should be taken to increase the awareness of the staff to health deterioration that can occur among adult persons with ID, especially among various types of etiologies, such as DS and CP.

Enhancing the comprehension of visual metaphors in individuals with intellectual disability with or without down syndrome.

This study is the first to investigate the effectiveness of deep and shallow intervention programs in the acquisition of visual metaphor comprehension in individuals with non-specific intellectual disability (NSID; aged 15-59, N = 53) or Down syndrome (DS; aged 15-52, N = 50). The deep intervention program was based on dynamic assessment model for enhancing analogical thinking. The shallow intervention program involves memorizing a metaphorical relationship between pairs of pictures. Visual metaphor comprehension was measured by the construction of a metaphorical connection between pairs of pictures. The results indicated that both etiology groups exhibited poor understanding of visual metaphors before the intervention. A significant improvement was observed in both interventions and both etiology groups, with greater improvement among individuals who underwent the deep processing. Moreover, the latter procedure led to greater generalization ability. The results also indicated that vocabulary contributed significantly to understanding unstudied metaphors and that participants with poorer linguistic abilities exhibited greater improvement in their metaphorical thinking. Thus, individuals with ID with or without DS are able to recruit the higher-order cognitive abilities required for visual metaphor comprehension.

Crystallized and fluid intelligence of university students with intellectual disability who are fully integrated versus those who studied in adapted enrichment courses.

BACKGROUND: Inclusion of people with intellectual disability (ID) in higher postsecondary academic education is on the rise. However, there are no scientific criteria for determining the eligibility for full inclusion of students with ID in university courses. This study focuses on two models of academic inclusion for students with ID: (a) separate adapted enrichment model: students with ID study in separate enrichment courses adapted to their level; (b) full inclusion model: students with ID are included in undergraduate courses, receive academic credits and are expected to accumulate the amount of credits for a B.A. AIM: (a) To examine whether crystallized and fluid intelligence and cognitive tests can serve as screening tests for determining the appropriate placement of students with ID for the adapted enrichment model versus the full inclusion model. (b) To examine the attitudes towards the program of students with ID in the inclusion model. METHOD/PROCEDURE: The sample included 31 adults with ID: students with ID who were fully included (N = 10) and students with ID who participated in the adapted enrichment model (N = 21). Crystallized and fluid intelligence were examined (WAIS-III, Wechsler, 1997) and Hebrew abstract verbal tests (Glanz, 1989). Semi-structured interviews were conducted in order to examine the attitudes of students in the inclusion model towards the program. OUTCOMES AND RESULTS: The ANOVAs indicate that the most prominent difference between the groups was in vocabulary, knowledge and working memory. ROC analysis, a fundamental tool for diagnostic test evaluation, was used to determine the students' eligibility for appropriate placement in the two models. Seven tests distinguished between the groups in terms of sensitivity and specificity. The interviews were analyzed according to three phases. CONCLUSIONS/IMPLICATIONS: The results indicate that students with ID are able to participate in undergraduate courses and achieve academic goals. The general IQ and idioms test seem to be best determiners for appropriate placement of students with ID to one of the two models. The included students with ID are motivated and self-determined in continuing in the program.

Working memory studies among individuals with intellectual disability: An integrative research review.

BACKGROUND: Integrative research review infers generalizations about a substantive subject, summarizes the accumulated knowledge that research has left unresolved and generates a new framework on these issues. Due to methodological issues emerging from working memory (WM) studies in the population with non-specific intellectual disability (NSID) (N=64) between 1990-2014, it is difficult to conclude on WM performance in this population. AIM: This integrative research review aimed to resolve literature conflicts on WM performance among individuals with NSID and to identify the conditions/moderators that govern their WM performance compared to controls with Typical development. METHOD/PROCEDURE: We used the six stages of integrative research review: problem formulation, data collection, evaluation, data analysis, results, interpretation and discussion. OUTCOMES AND RESULTS: The findings indicate two types of moderators that determine WM performance in the population with NSID: Participants' moderators (criteria for matching the ID and TD groups, CA and MA), and task moderators [the three WM components of Baddeley and Hitch's (1974) model and task load]. Only an interaction between the two moderators determines WM performance in this population. The findings indicate a hierarchy (from more to less preserved) in WM performance of individuals with NSID: The visuospatial tasks, then some of the executive functions tasks, and the phonological loop tasks being less preserved. Furthermore, at a low level of control, the performance of participants with NSID was preserved beyond the modality and vice versa. CONCLUSIONS AND IMPLICATIONS: Modality and MA/intelligence determine WM performance of individuals with ID. Educators should prepare intervention programs take the impact of the two moderators into account.

Ageing and intellectual disability in Israel: a study to compare community residence with living at home.

The present study was conducted to compare ageing phenomena in people with intellectual disabilities aged 40 years and above living in community residences (n = 29) with those living with their families (n = 31). The goals were to compare the health status between the two types of settings, to compare the health status between the study sample and the general Israeli population of the same age group, and to investigate whether deterioration occurs among the participants in activities of daily living (ADLs), cognitive ability and leisure activity. Health problems had already appeared by 40 years of age among the participants. The most frequent problems were visual impairment (33%), hearing impairments (20%) and heart problems (20%). Dental problems were found in 30%. The community-based residence group displayed more medical problems than people living at home, whereas individuals living at home had more dental problems. The functioning of the participants in the ADL areas was high, with no evident decline reported during the previous 5 years. Concerning leisure time, a decline in functioning in both residential groups was observed, and interestingly, the scores for social life and leisure activities were better for the community-based residential group. There is a need for better dental service provision for people with intellectual disabilities living at home. The data provided in the current study can serve as a preliminary base for the development of geriatric services for older adults with intellectual disabilities in the community and also provide a basis for further comparison with peers in the general population.

Aging among persons with intellectual disability in Israel in relation to type of residence, age, and etiology.

This study was conducted to compare aging phenomena of persons with intellectual and developmental disability (ID) aged 40 years and older living in community residence (N = 65) with those living with their families (N = 43) in Jerusalem, Israel. All 108 persons and care givers were interviewed to ascertain health problems, sensory impairment, activity of daily living (ADL), cognitive skills, and leisure activities. Health problem had already developed by age 40 years. The most frequent were visual (33%), hearing impairments (20%) and dental problems (30%). The community residence group displayed more medical problems, whereas individuals living at home had more dental problems. Health problems in persons with Down syndrome were significantly higher. ADL functioning for all participants was high, but persons with Down syndrome and cerebral palsy had more dependence. A decline in functioning in both residential groups was observed concerning leisure time, but scores for social life leisure activities were better for the community residential group. The data provided in this study can serve as information to develop geriatric services for persons with ID and provide a basis for comparison with peers in the general population in Israel. Dental service to persons with ID living at home should be improved.

New model of mapping difficulties in solving analogical problems among adolescents and adults with intellectual disability.

The main goal of the study was to map the difficulties and cognitive processes among adolescents (aged 13-21, N = 30) and adults (aged 25-66, N = 30) with mild and moderate intellectual disability (ID) when solving analogical problems. The participants were administered the Conceptual and Perceptual Analogical Modifiability test. A three-fold tailored dynamic assessment (DA) model for mapping difficulties was constructed based on Sternberg's analogical components model (encoding, inference, mapping, application): (a) mapping pre-teaching difficulties; (b) assessing the level of mediation; and (c) analyzing post-teaching responses. Another goal was to find out whether participants receiving "tailored" mediation would receive higher scores than participants receiving the standard DA procedure (adolescents aged 14-20; N = 30) and adults (25-55, N = 31). Repeated measures MANOVA of time × age × ID level indicated significant pre to post-teaching improvement across all age groups and ID levels. The adults gained more from mediation than the adolescents. The tailored DA model was more effective in producing change than the standard DA model. The greatest difficulties in the pre-teaching stage were in inference and mapping of perceptual analogies, where the participants received the highest level of mediation. Stepwise regression analysis indicated that inference, ID level and age predicted modifiability in the application of conceptual analogies, whereas encoding, ID level and mediation for inference predicted modifiability in the application of perceptual analogies.

Analogies solving by individuals with and without intellectual disability: Different cognitive patterns as indicated by eye movements.

Eighteen adults with intellectual disability (ID) and 20 children with typical development (TD) matched for cognitive level, participated in this study. Participants solved perceptual and conceptual analogies (from the Conceptual and Perceptual Analogical Modifiability Test-CPAM) while having their eye movements monitored. As predicted, the overall percent of correct answers was significantly higher for the TD group compared to that of the ID group. Comparison of the eye movement pattern of each group while solving the analogies revealed that in addition to the quantitative difference between the groups, there is a qualitative difference in the process of solving the analogies. The difference in the scanning pattern between the TD and the ID groups is interpreted as a reflection of two different types of strategies, Constructive matching and Response elimination, respectively.

Effects of MISC intervention on cognition, autonomy, and behavioral functioning of adult consumers with severe intellectual disability.

This study examined the effects of a yearlong Mediational Intervention for Sensitizing Caregivers (MISC; Klein, 1992) on: (a) the quality of interactions between rehabilitation day center paraprofessional staff (n=10) and their adult consumers (n=19) with severe intellectual disability (ID) and (b) the consumers' cognition, autonomy, and behavioral functioning, versus a consumers' control group (n=13). Regarding the staff-consumer interactions, more mediation of meaning (choice-making), expansion, and competence with explanation and less mediation of physical assistance were observed in the intervention group than in the control group following intervention. On a battery of cognitive measures (n=17), consumers in the MISC group improved their arithmetic skills, temporal concepts, and sequential memory of two digits. Behavioral observations indicated that the MISC group revealed increased positive behaviors, autonomy, and duration of work and decreased verbal and maladaptive behaviors.