Memory Abilities in Children with Williams Syndrome (original) (raw)
Related papers
Neuropsychologia, 1996
Williams syndrome (WS) is a genetic syndrome of abnormal neurodevelopment, characterised by a specific linguistic pattern. Comparing performances of WS subjects with those of normal children in a word span task, we found that WS subjects revealed normal phonological similarity and length effects but a reduced frequency effect. Our results suggest comparable phonological encoding mechanisms in WS and normal controls and, at the same time, it provides evidence for an impaired access to lexicalsemantic knowledge in WS subjects. This dissociation fits well with the particular pattern of linguistic abilities of these subjects.
Neurocase, 2003
Although phonological processing is generally considered to be a proficiency in Williams syndrome (WS), there are very few studies which have extensively explored phonological processing abilities in WS. In this study, we reassessed phonological processing in WS by exploring verbal STM and phonological awareness abilities in 4 children with WS (CA: 10-12 years) and two control groups, one matched for chronological age (CA) and the other matched for verbal mental age (VA). Our results confirm and extend previous claims of preserved phonological STM in WS by showing specifically preserved STM performance for non-words, compared to both VA and CA control groups. However, we observed that this was the case only for non-words where support of phonological and lexico-semantic knowledge was minimized, with reduced phonological and lexico-semantic effects on STM performance. Furthermore, a more direct assessment of phonological processing abilities through phonological awareness tasks showed impaired performance for the 4 WS children. Our data confirm that STM for non-words represents a real strength in WS but they do not support previous assumptions of a more general preservation of phonological processing abilities in WS. Implications for impaired and preserved cognitive processes underlying verbal STM and phonological awareness abilities in WS are discussed.
Short-Term Memory Deficits Are Not Uniform in Down and Williams Syndromes
Neuropsychology Review, 2006
Neuropsychological investigation of the development of the mnesic function in mental retardation has primarily focused on evaluating short-term memory (STM). Studies have often documented a reduced verbal short-term memory span in individuals with mental retardation and with Down syndrome in particular, compared to groups of mental age-matched controls. However, recent evidence suggests that verbal short-term memory is not equally impaired in all individuals with mental retardation. Findings in children with Williams syndrome are particularly relevant in this regard. Also, data concerning STM for visual information suggest that visual-object and visual-spatial working memory may be differently compromised in people with mental retardation. In particular, individuals with Williams syndrome exhibit specific difficulties in visual-spatial but not in visual-object working memory tasks compared to typically-developing children matched for mental age. Instead, people with Down syndrome show reduced performance in both visual-spatial and visual-object tests. Taken together, these results reinforce the view that intellectual disability is not a unitary condition characterized by homogeneous slowness of cognitive development but a variety of conditions in which some cognitive functions may be more disrupted than others. The finding that the working memory deficit in individuals with S. Vicari ( ) Servizio Williams and Down syndrome may be qualitatively differentiated also supports the hypothesis that it is not simply a manifestation of general cognitive impairment but, rather, the expression of a specific deficit of a discrete cognitive ability.
Memory abilities in Williams syndrome: Dissociation or developmental delay hypothesis?
Brain and Cognition, 2008
Williams syndrome (WS) is a neurodevelopmental genetic disorder often described as being characterized by a dissociative cognitive architecture, in which profound impairments of visuo-spatial cognition contrast with relative preservation of linguistic, face recognition and auditory short-memory abilities. This asymmetric and dissociative cognition has been also proposed to characterize WS memory ability, with sparing of auditory short-term memory and impairment of spatial and long-term memory abilities. In this study, we explored the possibility of a double memory dissociation in WS (short-versus long-term memory; verbal versus visual memory). Thus, verbal memory abilities were assessed using California Verbal Learning Test and Digit Span and Rey-Osterrieth Complex Corsi Blocks was used to assess visual-spatial memory abilities. Overall, WS subjects were found to present a generalized significant impairment in verbal and visuo-spatial components either in short-or long-term memory. In sum, data from this study brings support for a developmental delay hypothesis, rather than a double dissociation within memory systems in WS.
Procedural learning deficit in children with Williams syndrome
Neuropsychologia, 2001
The present study was aimed at evaluating implicit memory processes in subjects with Williams syndrome (WS) and comparing them to mental-age (MA) matched normal children. For this purpose, tests of verbal and visuo-perceptual explicit memory, verbal and visual repetition priming as well as procedural learning tasks were administered to 12 WS and 12 MA matched subjects. WS subjects showed a level of repetition priming similar to that of MA normal controls. In contrast, WS children showed a reduced learning rate in the two procedural tasks. Although deficient explicit memory and executive dysfunction cannot be excluded from the performance of WS subjects, these results suggest a specific deficit of procedural learning in this particular group of mentally retarded children. This finding is relevant for our knowledge about the qualitative aspects of the anomalous cognitive development in mentally retarded people and the neurobiological substrate underlying this development.
Cortex, 2007
Previous studies have suggested that Williams syndrome and Down syndrome may be associated with specific shortterm memory deficits. Individuals with Williams syndrome perform relatively poorly on tests of visuo-spatial short-term memory and individuals with Down syndrome show a relative deficit on verbal short-term memory tasks. However, these patterns of impairments may reflect the impact of generally impaired visuo-spatial processing skills in Williams syndrome, and verbal abilities in Down syndrome. The current study explored this possibility by assessing long-term memory among 15 individuals with Williams syndrome and 20 individuals with Down syndrome using the Doors and People test, a battery which assesses recall and recognition of verbal and visual information. Individuals' performance was standardised for age and level of intellectual ability with reference to that shown by a sample of 110 typically developing children. The results showed that individuals with Down syndrome have no differential deficits in long-term memory for verbal information, implying that verbal short-term memory deficits in this population are relatively selective. Instead both individuals with Down syndrome and with Williams syndrome showed some evidence of relatively poor performance on tests of long-term memory for visual information. It is therefore possible that visuo-spatial short-term memory deficits that have previously been demonstrated in Williams syndrome may be secondary to more general problems in visuo-spatial processing in this population.
Phonological Short-term Memory and its Relationship to Language in Williams Syndrome
Cognitive Neuropsychiatry, 1997
P h o n o lo g ic a l S h o r t-te r m M e m o r y a n d its R e la tio n sh ip to L a n g u a g e in W illia m s S y n d r o m e J u lia G ra n t a n d A nn e tte K a rm ilo ff-S m ith M R C C o g n itive D ev elo p m en t U nit an d U niv er sity C o lle ge , L on d o n, U K a n d d ig it sp a n b u t sig n ifica n tly lo w e r th an o n B P V S . T h e re su lts len d s up p or t to th e v ie w tha t p h on o lo gy in W S is a re la tiv e s tren g th . In c o ntra s t, d es p ite re lativ e ly go o d p ro d u c tiv e a nd re c ep tiv e v o ca b ula ry , ce r ta in a sp ec ts of th e p ro c es se s o f w o rd lea r nin g in W S do n o t se em to de v elo p b ey o nd th at o f no rm al 4y ea r -o ld s. T h e go o d v o ca b ula ry sc or e s of old er ch ild re n a n d a d ults w ith W S m a y b e sim p ly d u e to th eir re la tiv e ly g o od p h on o lo g ic a l sh o r t-te rm m e m o ry .