Reach plans for grasping vs. placing objects evoke different neural dynamics within a shared cortico-cerebellar mechanism.
Many reach studies treat grasping as the endpoint of a reach, but grasping often initiates a sequence of actions, ending with placing the object. Grasping and placing both require object-specific encoding, but placing has different computational demands, introduced by the intent, sensory feedback, and tolerance for spatial error when alignment is required. Recent neuroimaging work suggests that…
Researchers have found that the neural dynamics of grasping and placing objects differ, despite both actions relying on similar cortico-cerebellar mechanisms. While many studies view grasping as the ultimate goal of a reach, grasping often sets off a chain of actions culminating in placing the object. Both grasping and placing necessitate specific encoding of the object, but placing comes with additional computational challenges due to factors like intent, sensory feedback, and spatial error tolerance.
Recent neuroimaging studies have shown that object placement shares similar cortico-cerebellar networks with grasping, albeit with slight increases in network segregation and cerebellar activity. The current study aimed to determine if grasping and placing could be differentiated by their spatiotemporal dynamics, both in behavior and scalp-recorded EEG activity.
To do this, the researchers employed high-density EEG recordings and motion tracking, enlisting 31 participants to perform alternating grasp and place movements of a 3D object towards or away from an oriented target/template.
The findings revealed that while placing movements were initiated more quickly than grasping, they were executed more slowly and with greater endpoint-orientation precision. This suggests that the control strategies for these two actions are distinct. Electroencephalography (EEG) and microstate analyses further demonstrated that both grasping and placing shared a peri-movement polarity switch, transitioning from posterior negativity/frontal positivity during preparation to posterior positivity/frontal negativity during execution.
However, this shared pattern was more pronounced during the preparation phase of placing and persisted throughout the execution phase, with stronger expression of preparatory medial frontal/cerebellar and execution-related posterior/cerebellar microstate dynamics.
Finally, support vector machine (SVM) decoding techniques indicated that task-specific information was primarily encoded in low-frequency EEG activity (below 6 Hz). Overall, these results confirm that grasping and placing utilize similar cortico-cerebellar mechanisms; yet, they employ different spatiotemporal dynamics to accommodate the unique computational demands of each behavior.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
