The study aimed at assessing motor and sensory performance of infants with Down syndrome (DS) comparing them to typical infants at the age of six months. Eight infants - 4 with typical development, 4 with DS - were assessed as to motor performance by the Alberta infant motor scale (AIMS) at supine, prone, sitting, and standing positions. Sensory performance was assessed by using the Infant/toddler sensory profile (ITSP), which classifies sensorial behaviours as"low registration" (difficulty in detecting sensory stimuli), sensation seeking, excessive sensitivity to stimuli, and sensation avoiding behaviours. Results show that infants with DS had significantly lower scores in low registration when compared to typical infants, suggesting that their higher sensory threshold lead to longer reaction times. At the AIMS, infants with DS had lower performance when compared to typical infants at the prone subscale, which may be due to deficits in postural and antigravity control. No correlation was found between ITSP and AIMS scores. Results then suggest that infants with Down syndrome may less frequently engage in environmental interactions, probably due both to difficulty in perceiving day-to-day stimuli (like diverse sounds or people's) and difficulty to explore the environment by using their limited motor abilities.
Down syndrome; Infant; Psychomotor performance; Sensory thresholds
