Principle Investigator: Dr Jo Van Herwegen

Co-investigators: Dr Victoria Simms (Ulster University) and Prof Annette Karmiloff-Smith (Birkbeck, University of London)


This study is funded by the British Academy/ Leverhulme Small Research Grants: September 2015- 2016

Aim of the study:

Studies have shown that mathematical abilities relate to the approximate number

system (ANS) in typically developing children. ANS abilities are impaired and

develop atypically in Williams syndrome (WS) in contrast to matched individuals

with Down syndrome (DS). Thus far studies have not investigated why ANS

abilities develop atypically in WS in contrast to DS, nor evaluated the importance

of basic skills such as eye-movement planning and attention for the development

of ANS in general. By using developmental trajectories analyses of eye-tracking

data, we will identify precisely how participants scan visual arrays during the ANS

task, how such looking patterns relate to the development of ANS as well as to

subsequent mathematical development. Most intervention studies target the

domain of deficit directly. Our approach will allow us to establish whether training

programmes for young children with neurodevelopmental disorders should directly

target mathematical abilities, e.g., ANS precision, or focus more indirectly on

training attention and saccadic eye-movement planning.


Thirty participants with WS and Thirty with DS aged 8 to 53 years old took part in this study and results were compared to a group of typically developing controls.

This study has now been concluded we will publish the results of this study here soon.