Inhibition of return and negative priming by persons with and without mental retardation

Persons with and without mental retardation who were matched on CA took part in three tasks: an inhibition of return task, a location negative-priming task, and an identity negative-priming task. Having participants perform all three tasks allowed us to correlate performance among the tasks and assess the various relationships among performance measures on negative priming and inhibition of return. The participants with mental retardation did not exhibit negative priming of identity. However, they did exhibit negative priming of location and inhibition of return. The participants without mental retardation exhibited all three effects. A different pattern of correlations was observed for the participants with and those without mental retardation. Possible reasons for this difference are discussed.     

Correlation between dental maturation and chronological age in patients with cerebral palsy, mental retardation, and Down syndrome

Determining a child's chronological age and stage of maturation is particularly important in fields such as paediatrics, orthopaedics, and orthodontics, as well as in forensic and anthropological studies. Some systemic conditions can cause abnormal physiological maturation, and skeletal maturation is usually more delayed than dental maturation. The aim of this study was to determine dental age in a group of patients with the most prevalent congenital or perinatally occurring physical and mental disabilities. The study group comprised 155 white Spanish children aged 3-17 years (35 with cerebral palsy, 83 with mental retardation and no associated syndromes or systemic conditions, and 37 with Down syndrome). The dental maturation indices described by Nolla and Demirjian were used to generate regression lines for the dental age of individuals in a control group (688 white Spanish children aged 3-17 years) and the formulae were then used to determine the dental age of patients in the study group. No significant differences were found between dental and chronological age in boys with cerebral palsy, mental retardation, or Down syndrome. In contrast, dental age (calculated from the linear regression model that included values for the Demirjian index) was significantly delayed compared with chronological age in girls with cerebral palsy or Down syndrome.     

Dyadic interactions between children with and without mental retardation: effects of age discrepancy

Effects of age difference in dyadic relationships where one child was severely mentally retarded and the other was nonretarded were investigated. Interactions of 53 dyads were behaviorally coded in two situations: a free-play context and a teaching context. Behavioral data, teacher's reports, and nonretarded children's self-reports suggested that relationships were most balanced, symmetrical, fun, and engaging when partners were closer in age. The behavioral results were strongest in the teaching situation. These effects were discussed with respect to the obvious asymmetry implicit in relationships between children with very different levels of competency.     

Allocation of attention and effect of practice on persons with and without mental retardation

Persons with mild and moderate mental retardation and CA-matched persons without mental retardation performed a dual-task, "pencil-and-paper task" (Baddeley, Della Sala, Gray, Papagno, & Spinnler (1997). Testing central executive functioning with a pencil-and-paper test. In Rabbit (Ed.), Methodology of Frontal and Executive Function (pp. 61-80). Hove, East Sussex, UK: Psychology Press), which includes a memory span task and a tracking task. The memory span task loads onto phonological working memory and the tracking task loads onto visuo-spatial working memory. By comparing performance between single and dual-task, we assessed the characteristics of executive function, which allocates attentional resources between two tasks. Results indicate that there was no difference in the characteristics between the two groups, and there was no improvement in the characteristics with practice. Thus, we suggest that when persons with mental retardation perform a dual-task that have no interference in the sub-storage of working memory, their function of attentional allocation can work without impairment.     

Interference and inhibition in tasks of selective attention by persons with and without mental retardation

Persons with mental retardation often exhibit greater interference in visual selective attention tasks than do persons matched with them on CA. My goal here was to evaluate whether differences in distractor interference between persons with and without mental retardation may be related to differences in negative priming. Fifteen participants with mental retardation, 15 without mental retardation matched on CA, and 15 without mental retardation matched on MA participated in three selective attention tasks, which were chosen to elicit small, medium, and large group differences in interference, respectively. The failure to engage in inhibitory processes by the participants with mental retardation in these tasks of selective attention was related to increased distractor interference.     

Effects of age, gender, and causality on perceptions of persons with mental retardation

The present study examined the effects of age, gender, and causality on the perceptions of persons with mental retardation. Participants rated individuals with mental retardation using a semantic differential scale with three factors: activity, evaluation, and potency. Target individuals in each scenario varied on the variables of age (8, 20, 45), gender (male, female), and causality of mental retardation (genetic, self-inflicted, inflicted by others). Perceptions differed significantly according to causality, with those with mental retardation due to inheritance/genetics (Down Syndrome) evaluated most positively and those whose mental retardation was self-inflicted viewed most negatively (brain damage due to drinking cleaning fluid). Female participants gave higher ratings than male participants for target subjects on evaluation and potency factors. Implications of findings for persons with mental retardation are discussed.     

Neuropsychological profiles of persons with mental retardation and dementia

This study examined the use of neuropsychological tests to assist in the differential diagnosis of dementia among persons with mental retardation. The author compared performances of persons with mental retardation and dementia (n = 10) to persons with mental retardation without dementia (n = 12). Participants were matched by IQ (mild or moderate mental retardation), age, presence of Down syndrome, and gender. In addition, all participants in the dementia group had corroborative medical tests (i.e., imaging, EEG, or high tau low AB42 protein testing) consistent with diagnosis of dementia. Test performance was compared on measures of attention and executive functions, language, memory and learning, and a dementia screening. Results from MANOVAs and nonparametric tests revealed significantly lower performance for persons with mental retardation and dementia in all areas assessed. Cut-off scores were also developed for the sample in order to maximize sensitivity and specificity for the test battery. Despite the small sample size, these findings suggest that there are significant measurable differences in several neurocognitive domains between the two groups.     

Assessment of seizures and related symptomatology in persons with mental retardation

Seizures can be debilitating across a number of physical, social, occupational, and personal variables. Given the deficits in all of these areas frequently present in persons with mental retardation, effective assessment and subsequent treatment of seizures is a primary goal for individuals with both mental retardation and epilepsy. To thoroughly address the behavioral domains related to seizures in persons with mental retardation and epilepsy, areas of assessment should include seizure behavior, triggering stimuli, reinforcing consequences, and antiepileptic medication side effects. Assessment of these areas in this population often deviates from methods typically used with persons of normal intelligence. Specifically, direct behavioral observation and third-party report with structured interviews are the most viable and accessible means of assessment, and efforts to establish reliable and valid protocols have been successful in some areas. This article reviews this assessment methodology and discusses the extant issues in establishing and proliferating such approaches.     

Spontaneous eye-blinking and stereotyped behavior in older persons with mental retardation

Previous research indicates that abnormal stereotyped movements are associated with central dopamine dysfunction and that eye-blink rate is a noninvasive, in vivo measure of dopamine function. We measured the spontaneous eye-blinking and stereotyped behavior of older adults with severe/profound mental retardation living in a state mental retardation facility. Analyses revealed that the mean eye-blink rate of the residents that engaged in stereotypy was significantly lower than the rate for residents who did not exhibit stereotypy. Moreover, the stereotypy group also demonstrated greater variability in interblink intervals. These results provide further empirical support for the involvement of dopamine in stereotyped behavior and are consistent with an emerging motor control model of stereotypy.     

Affective priming in schizophrenia with and without affective negative symptoms

Abstract. In the present study automatic perceptual sensitivity to facial affect information was examined in chronic schizophrenic patients. An affective priming task including subliminal and supraliminal presentations of sad and happy facial affect was administered to schizophrenia patients with a flat affect expression (n = 30), schizophrenia patients suffering from anhedonia (n = 30), schizophrenia patients not suffering from anhedonia or flat affect (n = 28), and a group of healthy controls (n = 30). Subjects had to judge valence of neutral Chinese ideographs. Anhedonic and flat affect patients but not patients without affect symptoms were found to be sensitive to negative facial affect on an automatic processing level. None of the schizophrenic patient groups but healthy controls showed a subliminal valence-congruent priming effect based on positive facial affect. Anhedonia as assessed by standardised psychiatric rating was related to a subliminal sensitivity to negative facial expression and a valence-inverted perception of positive facial expression. This pattern of results is largely consistent with predictions derived from Meehls model of anhedonia. The aversive automatic perception of positive facial expression primarily found in anhedonic patients but also in schizophrenic control patients could lie in structural disturbances concerning the regulation of intimacy and distance.     

Assessment and diagnosis of mental illness in persons with mental retardation. Methods and measures

The assessment and diagnosis of psychiatric disorders in individuals with mental retardation has been a neglected area of research. However, current research indicates that these individuals suffer from the same range of psychiatric disorders that is evident in those who are not mentally retarded. A model of assessment and diagnosis of mental illness in this population is presented that incorporates psychiatric as well as behavioral methods. The emphasis is on the comprehensive assessment of an individual's behavior, based on family history, self and informant clinical interviews, rating scales, direct observations, and an experimental analysis of the target behaviors. The model provides the basis for making differential diagnoses in terms of related psychiatric disorders and between psychiatric disorders and behavior problems. Depression and schizophrenia are used as illustrative disorders to describe the application of this model. Given the paucity of literature on the assessment and diagnosis of mental illness in individuals with mental retardation, a number of suggestions are made regarding future research and refinement of the model.     

Assessment of feeding and mealtime behavior problems in persons with mental retardation

Feeding and mealtime behavior problems are commonly observed among individuals with developmental disabilities. These problems include, but are not limited to, food refusal, food selectivity, mealtime aggression, rumination, pica, and insufficient feeding skills. Difficulties of this type can be associated with life-threatening consequences of other serious health-related problems. Because of the nature of these problems and the lack or accurate client self-reporting, an interdisciplinary assessment in addition to a thorough behavioral assessment is recommended to ensure the best quality of care. This article discusses the role of the various disciplines, and the types of behavioral assessments that are currently being utilized by clinicians and researchers.     

Conjunctive visual search in individuals with and without mental retardation

A comprehensive understanding of the basic visual and cognitive abilities of individuals with mental retardation is critical for understanding the basis of mental retardation and for the design of remediation programs. We assessed visual search abilities in individuals with mild mental retardation and in MA- and CA-matched comparison groups. Our goal was to determine the effect of decreasing target-distracter disparities on visual search efficiency. Results showed that search rates for the group with mental retardation and the MA-matched comparisons were more negatively affected by decreasing disparities than were those of the CA-matched group. The group with mental retardation and the MA-matched group performed similarly on all tasks. Implications for theory and application are discussed.     

Depression,anxiety, and relevant cognitions in persons with mental retardation

We assessed depression, anxiety, and relevant cognitions in persons with mental retardation by administering modified versions of the Reynolds Child Depression Scale, the Beck Anxiety Inventory, the Automatic Thoughts Questionnaire, and the Cognitions Checklist to 46 persons with borderline to moderate mental retardation. Consistent with research with other groups, self-reports of depression and anxiety were highly correlated (r = .74) in these individuals, and cognitions were strong predictors of negative affect. Subscales measuring cognitions related to depression and anxiety were also highly related, limiting the cognitive-specificity hypothesis. Hierarchical multiple regression analyses offered mixed support for cognitive-specificity. We discuss the implications of these findings for the cognitive and affective assessment of persons with intellectual limitations.     

Differences in cardiovascular disease risk between nondiabetic adults with mental retardation with and without Down syndrome

A reduced expression of the insulin resistance syndrome, a common neuroendocrine disorder underlying atherosclerosis, may play a role in reduced atherosclerosis in adults with Down syndrome. We compared selected components of the insulin resistance syndrome between 75 adults with Down syndrome and 70 with mental retardation due to other causes. After adjusting for age differences, residence, cigarette smoking, and medication use, women with Down syndrome had lower fasting plasma glucose and lower systolic blood pressure than comparison women. Men with Down syndrome had lower systolic and diastolic blood pressure than comparison men. Results suggest that women with Down syndrome may be less likely to express the insulin resistance syndrome, and men and women with Down syndrome may possess fewer atherosclerotic risk factors than the comparison groups.     

Body-rocking and other habits of college students and persons with mental retardation

Prevalence of body-rocking in college students was assessed, and the characteristics of body-rocking of college students were compared to those of individuals with mental retardation. For college students, the prevalence depended on the restrictiveness of the method used and varied between 3% and 25%. Video samples showed that when compared with college students, a greater proportion of people with mental retardation engage in body-rocking, seem less sensitive to situational factors, demonstrate atypical collateral behaviors, engage in less leg-kicking, and execute their body-rocking with larger amplitudes. There were no differences in duration or number of individual rocks or bouts of body-rocking. We conclude that body-rocking is a "normal" behavior whose form of expression may become atypical.