Observation of the point-light animation of a grasping hand activates sensorimotor cortex in nine-month-old infants

Area of Science:

• Neuroscience
• Developmental Psychology
• Motor Control

Background:

• The sensorimotor cortex is crucial for planning and executing movements.
• Understanding how infants process visual information related to action is important for developmental research.
• Previous studies have explored visual processing in infants, but the role of the sensorimotor cortex in response to degraded biological motion is less understood.

Purpose of the Study:

• To investigate the involvement of the sensorimotor cortex in nine-month-old infants during the observation of Point-Light (PL) animations of a grasping hand.
• To determine if infants' sensorimotor alpha band activity changes in response to visual stimuli depicting hand movements and object interaction.
• To explore the potential predictive or perceptual roles of the sensorimotor system in response to visual cues.

Main Methods:

• Measured changes in sensorimotor alpha band activity using electroencephalography (EEG) in nine-month-old infants.
• Presented infants with Point-Light (PL) animations of a grasping hand, with and without the target object.
• Analyzed alpha activity during different phases of movement observation, including object presence/absence and movement initiation.

Main Results:

• Alpha activity attenuation was observed when the PL display moved towards the object and when the object was removed.
• Before movement onset, alpha activity attenuation occurred only when the object was present, suggesting potential movement prediction or object perception.
• The infants' sensorimotor system activated during observation of degraded moving stimuli, irrespective of the object's presence, indicating processing of biological kinematics.

Conclusions:

• The sensorimotor system in infants is activated by biological motion, even when visual information is minimal or absent.
• This activation appears independent of the goal-directed object, highlighting the system's role in processing movement kinematics.
• The findings suggest a potential compensatory function of the sensorimotor system in interpreting highly degraded visual motion stimuli during development.