Eye Movement Patterns and Approximate Number Sense Task Performance in Williams Syndrome and Down Syndrome: A Developmental Perspective

Exploring relative strengths in people with Down syndrome: Spatial thinking and its role in mathematics

There is convincing evidence that training spatial abilities leads to improved mathematics performance in typically developing (TD) children. However, a lack of information on mathematical development and spatial-mathematical associations in people with Down syndrome (DS) hinders the translation of these interventions. Here, we established developmental trajectories of mathematics and explored whether spatial ability predicts attainment on different mathematics measures in individuals with DS. Participants with DS (n = 36; ages 9-35 years) and TD children (n = 132; ages 4-11 years) completed three groups of tasks: spatial tasks assessing different subdomains of spatial thinking; mathematics tasks assessing early mathematics skills, mathematical reasoning, arithmetic, and geometry; and IQ tasks. The developmental trajectories of mathematics performance against mental age revealed similar starting points of the trajectories and similar rates of development for DS and TD groups. Furthermore, after controlling for verbal skills, spatial skills explained 5.8% to 18.1% of the variation in mathematical performance across different mathematics tasks, and the pattern of spatial-mathematical relations was similar for DS and mental age-matched TD groups. This shows that mathematical development in DS groups appears to mirror that in TD children, indicative of delay only. Strong spatial-mathematical relations were observed for individuals with DS, like those seen for TD participants. This is the vital preliminary knowledge needed to support the design and use of spatial intervention for improving mathematics in individuals with DS.

Block Design Performance in Williams Syndrome: Visuospatial Abilities or Task Approach Skills?

The block design task (BDT) is a visuospatial measure that individuals with Williams syndrome (WS) perform poorly on. However, it is unclear what underlies their impaired performance. This study investigated whether poorer performance is a result of visuospatial difficulties, executive function (EF) difficulties, atypical looking strategies, or a combination of these. Eleven individuals with WS participated alongside mental age (MA)- and chronological age (CA)-matched control groups. Eye movements were recorded while they took the BDT. Dwell times and visits to areas of interest in WS differed from CA, but not MA, groups. Findings suggest that BDT abilities of individuals with WS are delayed, but not atypical. Delays result from visuospatial and attention-switching difficulties rather than atypical looking strategies.

Eye-trackers, digital-libraries, and print-referencing: A single case study in CDKL5

BACKGROUND

Providing emergent literacy intervention and assessing outcomes for children with low-incidence, complex disabilities with concomitant physical, cognitive, sensory, and communication impairments presents a significant challenge to researchers, educators, clinicians, and families alike.

AIMS

This study aimed to leverage advancements in commercially available eyetracking technologies to measure visual attention to print before and after a parentmediated print referencing intervention with a child with a severe, low incidence, congenital disability. Print referencing means drawing attention to the print on the page while reading.

METHODS AND PROCEDURES

The single case study investigated a mother-daughter dyad who completed the protocol using eye-gaze technology, digital children's books, and a computer configured with software for observing and recording interactions that were shipped to the family's home and set up by the mother with remote support from a researcher.

OUTCOMES AND RESULTS

Results demonstrate that the eye-tracker successfully captured the participant's eye-gaze. Furthermore, mean-level shifts in frequency of fixations demonstrates changes in visual attention to print after the parent introduced the print referencing strategy during reading.

CONCLUSIONS AND IMPLICATIONS

Commercially available eye-trackers and digital libraries were successfully used by the parent-child dyad to record visual attention. Furthermore, remote support from a trained researcher was sufficient to support the parent through set-up, calibration, intervention, and implementation.

Training basic numerical skills in children with Down syndrome using the computerized game "The Number Race"

Individuals with Down syndrome (DS) present reduced basic numerical skills, which have a negative impact on everyday numeracy and mathematical learning. Here, we evaluated the efficacy of the adaptive (non-commercial) computerized game “The Number Race” in improving basic numerical skills in children with DS. The experimental group (EG; N = 30, M_{age-in-months} 118, range 70–149) completed a training playing with “The Number Race”, whereas children in the control group (CG; N = 31, M_{age-in-months} 138, range 76–207) worked with software aiming at improving their reading skills. The training lasted 10 weeks with two weekly sessions of 20–30 min each. We assessed both groups’ numerical and reading skills before and immediately after the end of the training, as well as at a 3-months follow-up. We found weak evidence for post-training groups differences in terms of overall numeracy score. However, the EG displayed substantial improvements in specific numerical skills and in mental calculation, which were maintained over time, and no improvement in reading. Conversely, the CG showed improvements in their reading skills as well as in number skills but to a lesser extent compared to the EG. Overall, “The Number Race” appears as a suitable tool to improve some aspects of numeracy in DS.

Perceptual subitizing and conceptual subitizing in Williams syndrome and Down syndrome: Insights from eye movements

BACKGROUND AND AIMS

Mathematical difficulties in individuals with Williams Syndrome (WS) and in individuals with Down Syndrome (DS) are well-established. Perceptual subitizing and conceptual subitizing are domain-specific precursors of mathematical achievement in typically developing (TD) population. This study employed, for the first time, eye-tracking methodology to investigate subitizing abilities in WS and DS.

METHODS AND PROCEDURES

Twenty-five participants with WS and 24 participants with DS were compared to a younger group of TD children (n = 25) matched for mental age. Participants were asked to enumerate one to six dots arranged either in a dice or a random pattern.

OUTCOMES AND RESULTS

Accuracy rates and analyses of reaction time showed no significant differences between the clinical groups (WS and DS) and the control group, suggesting that all participants used the same processes to perform the enumeration task in the different experimental conditions. Analyses of the eye movements showed that both individuals with WS and individuals with DS were using inefficient scanning strategies when counting. Moreover, analyses of the eye movements showed significantly shorter fixation duration in participants with DS compared to the control group in all the experimental conditions.

CONCLUSIONS AND IMPLICATIONS

The current study provides evidence that individuals with WS and individuals with DS perform both perceptual subitizing and conceptual subitizing. Moreover, our results suggest a fixation instability in DS group that does not affect their performance when subitizing but might explain their low accuracy rates when counting. Findings are discussed in relation to previous studies and the impact for intervention programmes to improve counting and symbolic mathematical abilities in these populations.