Second-order motor planning in children: insights from a cup-manipulation-task

Area of Science:

• Developmental Psychology
• Cognitive Neuroscience
• Comparative Psychology

Background:

• Anticipatory motor planning is crucial for object manipulation.
• Previous studies demonstrated motor planning in non-human primates using a cup-manipulation task.
• Understanding the developmental trajectory of this skill in humans is important.

Purpose of the Study:

• To investigate the development of anticipatory motor planning in children and adults.
• To compare human motor planning abilities with those of non-human primates.
• To explore age-related differences in grip strategies during object manipulation.

Main Methods:

• A cup-manipulation task was administered to 75 participants across four age groups: preschool children (5.1 years), primary school children (7.7 and 9.8 years), and adults.
• Participants reached for a suspended cup in either upright or inverted orientations, removed it by its stem, and retrieved a toy.
• Grip postures (upright vs. inverted) were analyzed to assess anticipatory motor planning.

Main Results:

• All participants used an upright grip for an upright cup.
• For an inverted cup, only adults consistently adopted an inverted grip posture.
• The use of inverted grips increased with age, indicating a protracted development of anticipatory motor planning.

Conclusions:

• Anticipatory motor planning abilities develop gradually throughout childhood.
• Adults' performance on this task aligns more closely with non-human primates than with children, even older children.
• Morphological constraints may influence motor planning flexibility and development.