Related Experiment Videos
Mechanically evoked perioral reflexes in infants
S M Barlow1, D S Finan, S G Rowland
1Department of Speech and Hearing Sciences, Indiana University, Bloomington 47405.
Insights
Infant lip reflexes were studied using EMG. Mechanical stimulation caused quick, widespread muscle activation, important for developing motor skills like speech and smiling.
Area of Science:
- Neuroscience
- Developmental Biology
- Motor Control
Background:
- The orbicularis oris muscle is crucial for facial expressions and oral motor functions.
- Understanding early facial reflex development is key to comprehending motor skill acquisition.
Purpose of the Study:
- To investigate mechanically evoked muscle activity in the orbicularis oris muscle of young infants.
- To analyze the developmental trajectory of facial reflex sensitivity.
Main Methods:
- Utilized a custom position-servo linear motor and an EMG-instrumented pacifier.
- Recorded electromyography (EMG) signals from superior and inferior orbicularis oris segments.
- Applied unilateral mechanical stimulation to the lip vermilion.
Main Results:
- Short-latency, bilateral activation of upper and lower lip muscles was observed following unilateral stimulation.
- Demonstrated a clear reflex response to mechanical input in infant facial muscles.
Conclusions:
- Infant facial reflexes show rapid, bilateral responses to mechanical stimuli.
- These findings provide insights into the ontogenesis of facial reflex sensitivity and its role in motor skill development, including speech and smiling.
Abstract:
Mechanically evoked activity in the superior and inferior segments of the orbicularis oris muscle was sampled in several young infants using a specially designed position-servo linear motor and a pacifier instrumented with eight miniature EMG electrodes. Unilateral stimulation of lip vermilion resulted in short latency, bilateral activation of the upper and lower lip recording sites. The ontogenesis of facial reflex sensitivity to mechanical inputs is discussed in relation to the acquisition of motor skills, including speech and smiling.