Representational Neural Mapping of Dexterous Grasping Before Lifting in Humans

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• Human object interaction relies on integrating grasp and lift forces.
• Previous research often studied reaching and grasping in isolation.
• The neural basis for coordinating grasp and lift remains unclear.

Purpose of the Study:

• To investigate how the brain represents grasp configuration and lift force during object manipulation.
• To determine if neural representations for grasp and lift are spatially or temporally distinct.
• To identify brain regions involved in coordinating grasp and lift actions.

Main Methods:

• fMRI was used to measure BOLD activity in human subjects performing a precision grasp and lift task.
• Object's center of mass was manipulated (left/right) to vary required grasp and lift forces.
• Bayesian variational representational similarity analysis was applied to fMRI data.

Main Results:

• Grasp configuration and lift force are not represented in spatially separate brain regions.
• The same cortical and cerebellar regions show sensitivity to grasp and lift at different time points.
• Neural sensitivity to grasp emerged sequentially before sensitivity to lift.

Conclusions:

• The brain uses shared neural resources, but with temporal dynamics, to represent grasp and lift.
• Coordinated grasp-to-lift actions are controlled by specific dorsolateral, parietal, somatosensory, and cerebellar regions.
• This temporal coding strategy allows for efficient integration of grasp and lift for dexterous object interaction.