Implicit versus explicit memory function in children with Down and Williams syndrome

Abstract

-The present study was aimed at evaluating implicit memory processes in participants with Williams syndrome and comparing them to children with Down syndrome and to mental-age matched typically developing 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 participants with Williams syndrome, 14 with Down syndrome and 32 typically developing children. Participants with Williams syndrome showed a level of repetition priming similar to that of mental-age typically developing controls. In contrast, children with Williams syndrome showed a reduced learning rate in the two procedural tasks. As regards children with Down syndrome, we document comparable implicit memory abilities. In contrast, regarding explicit memory, typically developing children performed better than individuals with Down syndrome. This fi nding is relevant for our knowledge about the qualitative aspects of the anomalous cognitive development in individuals with intellectual disabilities and the neurobiological substrate underlying this development.

Education and children with Down syndrome: Neuroscience, development, and intervention

“…Performance on these kinds of explicit memory paradigms has been linked to functions of the hippocampal system; hence, the defects suggest differential impairment in hippocampal function and thereby converge with the data from study of spatial cognition. This selective impairment of explicit, but not implicit, memory was also reported in Vicari [2001].…”

Within-session and one-week practice effects on a motor task in amnestic mild cognitive impairment

“…Although these earlier studies typically excluded participants with lower global cognitive status based on the Mini-Mental Status Exam or the Montreal Cognitive Assessment, they suggest that individuals with clinical levels of visuospatial impairment would have impaired motor skill learning. This is in fact what is seen in neurological conditions that appear to selectively impair visuospatial function, such as Huntington’s disease (Heindel, Butters, & Salmon, 1988; Heindel, Salmon, Shults, Walicke, & Butters, 1989; Knopman & Nissen, 1991; Willingham, Koroshetz, & Peterson, 1996; see also Furtado & Mazurek, 1996) and Williams syndrome (Foti et al, 2013; Vicari, 2001; Vicari, Bellucci, & Carlesimo, 2001). Although the lowest Visuospatial/Constructional Index score in our sample was 62 (<1 st percentile based on normative values), only 15 of the 54 participants were below one standard deviation from ‘normal’ on this index relative to age-matched normative data; thus, this study may not have been sufficiently powered to address whether visuospatial function independently predicted motor practice effects (pairwise correlation, r = 0.20; p = 0.15) or would reliably be included in the final regression equations.…”

Long Term Memory Profile of Disorders Associated with Dysregulation of the RAS-MAPK Signaling Cascade

“…Indeed, individuals with Williams syndrome (WS) or Down syndrome (DS) were reported by Jarrold et al (2007) to have comparable impairment on free recall and recognition for visual stimuli whereas other studies found different patterns of results depending on the etiology of ID. Preservation of free recall and recognition memory was observed in WS (Brock et al 2006;Vicari 2001) but not in DS (Vicari 2001) and preservation of free recall but impaired recognition memory was registered in individuals with Fragile-X syndrome (Ornstein et al 2008).…”