Habituation of the Flexion and Glabella Reflexes in Normal One- and Two-Month-Old Infacnts

Abstract

Habituation, dishabituation, and retention of habituation of the flexion reflex and the glabella reflex by normal one- and two-month-old infants were studied using 2 groups of 10 subjets each. The habituation paradigm for both reflexes included 2 sets of stimuli each of which was divided into 3 segments. The 2 sets of stimuli were separated by a proposed dishabituator. A 2 x 2 x 2 analysis of variance was used to test for habituation (main effect for segment), retention (main effect for set), age (main effect for group,) and interaction effects. Results indicate that both age groups demonstrated habituation, retention, and dishabituation of both reflexes. Also, the older infants responded significantly less to the repetitive testing of the flexion reflex than the younger infants. Clinical implications of this study include that testing for habituation of motor reflexes may be a useful assessment tool and that a relationship may exist between retention of habituation and the waning of early motor reflexes.