Voluntary control of a phantom limb

Area of Science:

• Neuroscience
• Cognitive Science
• Psychology

Background:

• The neural basis of conscious intention and voluntary action is debated.
• One perspective suggests intentions are retrospective explanations for actions.
• Investigating brain activity during voluntary movement preparation is crucial.

Observation:

• Electroencephalography (EEG) frequency analysis examined sensorimotor rhythms.
• A participant with congenital absence of a limb performed actions with their real and phantom limb.
• Brain activity was recorded during preparation, execution, and cancellation of voluntary movements.

Findings:

• Typical beta-band spectral power changes were observed for real hand movements.
• A distinct EEG pattern, including left frontal power increase, accompanied perceived intention and movement cancellation.
• These neural signatures of volition were present for both real and phantom limb movements, mirroring findings in able-bodied individuals.

Implications:

• Conscious intention appears to depend on preparatory brain activity, independent of physical movement.
• Findings challenge theories reducing volition to retrospective confabulation.
• Specific pre-movement neural events may underlie conscious experiences of volition, supporting a forward-looking model of intention.