The free choice whether or not to respond after stimulus presentation

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Motor Control

Background:

• Voluntary actions and free choices are linked to specific brain activations.
• Previous research often used self-paced movements or free selection between motor responses to study voluntary behavior.

Purpose of the Study:

• To determine the neural correlates of voluntary motor responses.
• To investigate the neural correlates of voluntary inhibition of motor responses.
• To examine decision-making processes underlying voluntary actions.

Main Methods:

• Simultaneous acquisition of functional MRI (fMRI) and event-related potentials (ERPs).
• Utilized a go/nogo/voluntary selection paradigm in healthy subjects.
• Subjects freely decided whether to press a button after stimulus presentation.

Main Results:

• Decision-related neural responses were enhanced in the medial frontal gyrus/supplementary motor area, lateral frontal regions, and inferior parietal gyrus.
• Activations associated with voluntary movements were observed in the frontal eye field and motor-related areas like somatosensory cortex.
• Decision processes appeared independent of the specific motor response selected.

Conclusions:

• The medial frontal gyrus/supplementary motor area, lateral frontal cortex, and inferior parietal gyrus are crucial for voluntary action decisions.
• Specific motor areas and the frontal eye field contribute to the execution of voluntary movements.
• The neural basis of decision-making in voluntary actions is largely separable from the motor execution itself.