Renzo Vianello

Executive function in adolescents with Down Syndrome.

BACKGROUND The present work is aimed at analysing executive function (EF) in adolescents with Down Syndrome (DS). So far, EF has been analysed mainly in adults with DS, showing a pattern of impairment. However, less is known about children and adolescents with this syndrome. Studying adolescents with DS might help us better understand whether performances on EF tasks of individuals with DS are determined by age or by Alzheimer disease, as some studies suggest, or whether their performances are directly related to DS cognitive profile. METHOD A battery of EF tasks assessing set shifting, planning/problem-solving, working memory, inhibition/perseveration and fluency, as well as a tasks assessing sustained attention has been administered to a group of 15 adolescents with DS and 15 typically developing children matched for mental age. All EF tasks were selected from previous studies with individuals with intellectual disabilities or from developmental literature and are thought to be useful for the samples considered. RESULTS The present results revealed that the group of individuals with DS performed at a significantly lower level on tasks assessing set shifting, planning/problem-solving, working memory and inhibition/perseveration, but not on the tasks assessing fluency. In addition, individuals with DS demonstrated a greater number of errors and less strategy use for the sustained attention task. CONCLUSIONS The results suggest a broad impairment in EF in adolescents with DS, and are consistent with several similar studies conducted with adults with DS. We assume that EF deficit is a characteristic of DS.

Verbal and Visuospatial Working Memory Deficits in Children With Down Syndrome

The hypothesis that deficits of children with Down syndrome on working memory tasks are more evident the higher the control required and for verbal than visuospatial tasks was tested. Two groups of children, one with Down syndrome, who ranged in age from 7 to 18, and a control group were assessed with batteries of verbal and visuospatial working memory tests requiring different levels of control. On tasks requiring low control, children with Down syndrome showed impairment of verbal but not visuospatial working memory tasks. As the requirement for control increased, they showed greater impairment on both tasks. Children with Down syndrome were comparatively better in visuospatial than verbal tasks. Implications of these results for working memory models and the role of working memory in intelligence were discussed.

Working memory in individuals with fragile X syndrome

The present research tests the hypothesis that fragile X syndrome (FXS) is associated with a deficit in working memory (WM) and the deficit is more pronounced the higher the control requirements of the task. To this purpose, 15 boys with FXS and 15 typically developing children, matched for mental age, assessed with Logical Operation Test, were tested with batteries of 4 verbal and 4 visuospatial WM tasks requiring different levels of control. Children with FXS showed a performance equal to controls, in WM tasks requiring low and medium-low control but significant impairment in correspondence with greater control requirements. Results show that boys with FXS present a WM deficit only when high control is required by the task, supporting the hypothesis that control can be a critical variable distinguishing WM functions and explaining intellectual differences. On the contrary the hypothesis that the FXS is associated with a visuospatial deficit was not supported.

Working Memory and Cognitive Skills in Individuals with Down Syndrome

This work is aimed at analyzing working memory (WM) components and their relationships with other cognitive processes in individuals with Down syndrome (DS). Particular attention is given to examine whether a verbal WM deficit is due to difficulties in verbal abilities often showed by individuals with DS, or whether it is a deficit per se. A group of 20 individuals with DS was compared to a group of 20 typically developing (TD) children matched on vocabulary comprehension and to a group of 20 TD children matched on general verbal intelligence. The groups received a battery of 3 verbal and 3 visuospatial WM tasks requiring different degrees of control, and tests assessing verbal abilities (WPPSI verbal scale, PPVT), nonverbal skills (WPPSI performance scale), and logical thinking (LO). The results revealed that individuals with DS have deficits in both central executive (control) and verbal components of the WM system, and the latter one is independent of the general verbal abilities deficit. The data suggest that the development of central executive proceeds at a slower rate in individuals with DS and differently from TD children with comparable verbal abilities. The performance of individuals with DS on high-control WM tasks requires additional general resources that are strictly linked to intelligence.

Working memory in Down syndrome: is there a dual task deficit?

BACKGROUND Recent studies have shown that individuals with Down syndrome (DS) are poorer than controls in performing verbal and visuospatial dual tasks. The present study aims at better investigating the dual task deficit in working memory in individuals with DS. METHOD Forty-five individuals with DS and 45 typically developing children matched for verbal mental age completed a series of verbal and visuospatial working memory tasks, involving conditions that either required the combination of two tasks in the same modality (verbal or visual) or of cross-modality pairs of tasks. RESULTS AND CONCLUSIONS Two distinct deficits were found in individuals with DS: impairment in verbal tasks and further impairment in all dual task conditions. The results confirm the hypothesis of a central executive impairment in individuals with DS.

Children's understanding of death

According to most researchers (Anthony, Nagy, Childers & Wimmer, Melear, Weininger, White, Elsom & Prawat, etc.) children understand that death is irreversible and universal only after the age of 7‐8. In contrast with these opinions, for some years now we have been carrying out investigations demonstrating that, even from the age of 4‐5, children have a highly evolved understanding of death. Our investigations were carried out using the Piagetian interview (on 348 children aged between 4 and 10) and longitudinal research (by means of hundreds of hours of almost pure observation in kindergarten and junior schools and daily record kept at home over periods of several months, on more than 30 children between 2 and 5). Results confirm our hypothesis: at the age of 4‐5, most children reveal a particularly well‐structured understanding of death, implying the substantial comprehension that they do not consider death as something which may happen only to others, but also to their parents and to themselves and tha...

Paraprofessionals in Italy: Perspectives from an Inclusive Country

Since 1977, Italy has largely eliminated special schools and special classes in favor of neighborhood school placements where students with disabilities are served primarily in general education classes. Overall class sizes are small and caseloads of special education teachers are very favorable (about two students with disabilities for each special education teacher). Because of these factors, it was thought that attitudes toward the role of paraprofessionals in Italian schools would differ from those toward paraprofessionals in the United States, where many paraprofessionals take on a more independent role in inclusive classrooms. In this discussion article, we suggest that the role of paraprofessionals might be viewed differently in Italy than in the United States, and that these differences may reflect differing levels of available support for inclusive classrooms.

Spatial-sequential and spatial-simultaneous working memory in individuals with Williams syndrome.

The aim of the present study was to compare visuospatial working memory performance in 18 individuals with Williams syndrome (WS) and 18 typically developing (TD) children matched for nonverbal mental age. Two aspects were considered: task presentation format (i.e., spatial-sequential or spatial-simultaneous), and level of attentional control (i.e., passive or active tasks). Our results showed that individuals with WS performed less well than TD children in passive spatial-simultaneous tasks, but not in passive spatial-sequential tasks. The formers performance was also worse in both active tasks. These findings suggest an impairment in the spatial-simultaneous working memory of individuals with WS, together with a more generalized difficulty in tasks requiring information storage and concurrent processing, as seen in other etiologies of intellectual disability.

Memory coding in individuals with Down syndrome

Previous research has identified a deficit in phonological short-term memory in individuals with Down syndrome. The present work aimed to analyze how a group of 30 individuals with Down syndrome performed in a picture span task compared with 30 typically developing children of the same mental age. The task involved four conditions (i.e., dissimilar, phonologically similar, visually similar, and long-name items) chosen to analyze the strategy used by individuals with Down syndrome to code visually presented nameable items. Individuals with Down syndrome performed less well than typically developing children. Both groups showed the visual similarity effect. Taken together, our results confirm that individuals with Down syndrome have a verbal working memory deficit, even when nameable items are presented visually. Mental age appears to be an important determinant of memory coding stage in individuals with Down syndrome.

Working Memory Deficits in individuals With and Without Mental Retardation

The authors critically examine the issue of working memory in mental retardation. Different outcomes reported in the literature could be due to the different aspects of working memory tested. It was hypothesized that working memory functions can be distinguished according to a control continuum: a deficit of an individual with mental retardation in working memory tasks should be more evident to the extent to which they require higher control. 30 individuals with mental retardation, aged between 7 and 17, with a mean mental age of 5 years 6 months, and 30 children without mental retardation, matched for mental age, were given a battery of four working memory tests requiring different levels of control: low (forward word span), medium-low (backwards word span), medium-high (listening word span), and high (dual task span). Results confirmed the hypothesis that an increase in the gap between the two groups corresponds to an increase in the control required by the task. Results are discussed for their implications on working memory models and the role of working memory in intelligence.