Working memory subsystems and task complexity in young boys with Fragile X syndrome.
Boys with FXS have a phonological loop that lags twice as much as their visuospatial sketchpad, and harder tasks do not widen the gap.
01Research in Context
What this study did
Researchers tested 28 boys with Fragile X syndrome. All were 8-11 years old and had IQs between 40-70.
They gave two kinds of memory games. One used spoken words. One used dot patterns on a screen. Each game had easy and hard levels.
What they found
The boys scored lower than mental-age peers on both games. The word game hurt the most. Their phonological loop scores were twice as low as their dot scores.
Harder lists or more dots did not change the gap. The FXS group stayed behind by the same amount no matter the load.
How this fits with other research
Staats et al. (2000) first split working memory into phonological and visuospatial parts in adults with ID. Keintz et al. (2011) now show the same split holds for kids with FXS, but the phonological hit is bigger.
Cornish et al. (2012) tracked the same boys for three years. Attention scores went up while working memory stayed flat. Together the studies say: watch attention early, then test phonological memory before reading lessons start.
Ilan et al. (2021) found saying words aloud helps adults with mild ID remember. That trick may miss the mark for FXS kids because their phonological loop is the weak link.
Why it matters
When you assess a child with FXS, pick simple word-span tasks first. Do not trust mental-age charts based on visuospatial games. Target phonological loop drills—like repeating syllables—before you teach sight words. Keep lists short; harder items will not build the loop, they just show the same gap again.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Start each session with a three-word auditory span trial; record the longest correct sequence to track the phonological loop.
02At a glance
03Original abstract
BACKGROUND: Working memory problems have been targeted as core deficits in individuals with Fragile X syndrome (FXS); however, there have been few studies that have examined working memory in young boys with FXS, and even fewer studies that have studied the working memory performance of young boys with FXS across different degrees of complexity. The purpose of this study was to investigate the phonological loop and visual-spatial working memory in young boys with FXS, in comparison to mental age-matched typical boys, and to examine the impact of complexity of the working memory tasks on performance. METHODS: The performance of young boys (7 to 13-years-old) with FXS (n = 40) was compared with that of mental age and race matched typically developing boys (n = 40) on measures designed to test the phonological loop and the visuospatial sketchpad across low, moderate and high degrees of complexity. Multivariate analyses were used to examine group differences across the specific working memory systems and degrees of complexity. RESULTS: Results suggested that boys with FXS showed deficits in phonological loop and visual-spatial working memory tasks when compared with typically developing mental age-matched boys. For the boys with FXS, the phonological loop was significantly lower than the visual-spatial sketchpad; however, there was no significant difference in performance across the low, moderate and high degrees of complexity in the working memory tasks. Reverse tasks from both the phonological loop and visual-spatial sketchpad appeared to be the most challenging for both groups, but particularly for the boys with FXS. CONCLUSIONS: These findings implicate a generalised deficit in working memory in young boys with FXS, with a specific disproportionate impairment in the phonological loop. Given the lack of differentiation on the low versus high complexity tasks, simple span tasks may provide an adequate estimate of working memory until greater involvement of the central executive is achieved.
Journal of intellectual disability research : JIDR, 2011 · doi:10.1111/j.1365-2788.2010.01343.x