Multiple representations of the body schema for the same body part

Area of Science:

• Neuroscience
• Motor Control
• Body Representation

Background:

• The body schema, or the brain's internal representation of the body, is crucial for motor actions.
• Previous research assumed a single, common body schema for all movements.
• The operation of the body schema during multiple simultaneous actions remains unexplored.

Purpose of the Study:

• To investigate how the body schema functions during multiple simultaneous motor actions.
• To develop and utilize a novel technique for measuring the body schema during concurrent movements.
• To determine if the body schema is a unified representation or effector-specific.

Main Methods:

• Developed a technique to measure the body schema during simultaneous eye and reach movements.
• Participants performed coordinated movements to 10 hand landmarks.
• Analyzed the internal configuration of landmark locations for each movement type to create hand shape maps.

Main Results:

• Hand maps derived from eye and reach movements showed significant differences in distortion, with reach movements yielding more distorted representations.
• The integration of visual and proprioceptive cues varied between eye and reach movements.
• These findings indicate effector-specific body representations within the broader body schema.

Conclusions:

• The body schema is not a single entity but comprises multiple effector-specific representations.
• The motor effector used influences which body representation is accessed.
• This approach offers a new method for studying body schema disorders in patients.