Williams syndrome (WS) is a neurodevelopmental disorder characterized by a distinctive behavioral and cognitive profile, including widespread problems with attention. However, the specific nature of their attentional difficulties, such as inappropriate attentional allocation and/or poor attentional disengagement abilities, has yet to be…

Recent evidence suggests that there are age-related neurocognitive implications for fragile X premutation carriers, including deficits in executive function, and that such deficits are more common in male than female premutation carriers. The purpose of the current study is to examine one aspect of executive function, language dysfluencies, in a…

This study examined whether "melodic contour deafness" (insensitivity to the direction of pitch movement) in congenital amusia is associated with specific types of pitch patterns (discrete versus gliding pitches) or stimulus types (speech syllables versus complex tones). Thresholds for identification of pitch direction were obtained using discrete…

The aims of the present study are twofold: (1) to examine cortical morphology (CM) associated with alterations in cognition in fragile X syndrome (FXS); (2) to characterize the CM profile of FXS versus FXS with an autism diagnosis (FXS+Aut) as a preliminary attempt to further elucidate the behavioral distinctions between the two sub-groups. We…

Source recognition memory deficits have repeatedly been observed in people with schizophrenia (SZ), and have also recently been observed in their first-degree relatives. These deficits have been hypothesized to result, at least in part, from impairments in the conscious recollection process. Although other processes are clearly also affected in…

The high frequency of the fragile X premutation in the general population and its emerging neurocognitive implications highlight the need to investigate the effects of the premutation on lifespan cognitive development. Until recently, cognitive function in fragile X premutation carriers (fXPCs) was presumed to be unaffected by the mutation. Here…

Williams syndrome (WS) is a neurodevelopmental disorder characterized by severe impairment of visuospatial abilities. Figure-drawing abilities, which are thought to reflect visuospatial abilities, have yet to be fully investigated in WS. The purpose of the present study was to clarify whether drawing abilities differ between WS individuals and…

The present study investigated verbal and spatial working memory (WM) functioning in individuals with the neuro-developmental disorder Williams syndrome (WS) using WM component tasks. While there is strong evidence of WM impairments in WS, previous research has focused on short-term memory and has neglected assessment of executive components of…

Fragile X Syndrome is a neurodevelopmental disorder that is caused by the silencing of a single gene on the X chromosome, the Fragile X Mental Retardation 1 ("FMR1") gene. In recent years, the premutation ("carrier") status has received considerable attention and there is now an emerging consensus that despite intellectual functioning being within…

Huntington's disease (HD), an autosomal-dominant genetic disorder, has historically been viewed as a degenerative movement disorder but it also includes psychiatric symptoms and progressive cognitive decline. There has been a lack of consensus in the literature about whether or not cognitive signs can be detected in carriers before clinical…

Fragile X syndrome is the world's most common hereditary cause of developmental delay in males and is now well characterized at the biological, brain and cognitive levels. The disorder is caused by the silencing of a single gene on the X chromosome, the "FMR1" gene. The premutation (carrier) status, however, is less well documented but has an…

Perceptual grouping is a pre-attentive process which serves to group local elements into global wholes, based on shared properties. One effect of perceptual grouping is to distort the ability to estimate the distance between two elements. In this study, biases in distance estimates, caused by four types of perceptual grouping, were measured across…

Williams syndrome (WS) is a neurodevelopmental disorder associated with impaired visuospatial representations subserved by the dorsal stream and relatively strong object recognition abilities subserved by the ventral stream. There is conflicting evidence on whether this uneven pattern in WS extends to working memory (WM). The present studies…