Attention-dependent modulation of neural activity in primary sensorimotor cortex.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Motor Control

Background:

• Attention can modulate neuronal activity in motor areas, including the primary sensorimotor cortex.
• Previous studies had limitations: focusing on one hand, specific attention types, varied task complexity, and underrepresentation of left-handers.

Purpose of the Study:

• To investigate the effects of different attention levels on sensorimotor cortex activity in both right- and left-handers.
• To examine how hand dominance (dominant vs. nondominant) and task complexity influence attention's impact on motor control.

Main Methods:

• Externally paced button press task using the index finger of the dominant, nondominant, or both hands.
• Four attention conditions: no modulation, distraction (counting backward), concentration, and divided attention during bimanual movement.
• Neuroimaging techniques to assess activity in the primary sensorimotor cortex and attention networks.

Main Results:

• Distraction reduced primary sensorimotor cortex activity in both hands for both handedness groups when using the nondominant hand.
• Distraction activated the dorsal frontoparietal attention network and deactivated the ventral default network.
• Attention modulation was observed for the nondominant hand under distraction in a simple button press task.

Conclusions:

• Motor task difficulty, cognitive task demands, training status, and hand dominance critically influence attention effects on sensorimotor cortex.
• For simple tasks, attention modulation primarily occurs in the nondominant hand under distracting conditions, regardless of handedness.