An exploratory study of gaze behaviour in young adults with developmental coordination disorder.

Developmental Coordination Disorder (DCD) is characterized by substantial difficulties with motor coordination to the extent that it has a clear impact on the daily functioning of those who suffer from the disorder. Laboratory-based research indicated impaired oculomotor control in individuals with DCD. However, it is not clear how these oculomotor problems contribute to control and coordination in daily tasks. This study explored differences and similarities in gaze behaviour during reading and cup stacking between young adults with DCD and their matched typically developing counterparts (TD; aged 20-23 years). Gaze behaviour was recorded using eye-tracking, and hand movements were registered using a digital camera. Results of the reading tasks demonstrated similar behaviour between the groups, apart from a lower number of characters recorded per fixation in the DCD group. In cup stacking, the individuals with DCD were slower than their counterparts when three cups had to be displaced to a central target using the dominant hand. The gaze strategy of individuals with DCD involved systematic fixations on the cup or target prior to the hand movement to that cup or target, whereas these alternating saccades between cup and target were less obvious in the TD group. In the bimanual stacking task, where a pyramid of six cups had to be built on a central target using both hands, both groups mainly fixated the central target for the whole duration of the task, without distinct differences in gaze behaviour and duration of performance between individuals with and those without DCD. In conclusion, gaze behaviour of young adults with DCD shows differences from that of their typically developing counterparts that may be related to underlying oculomotor deficits in some but not all daily tasks.