Mirror Box

The mirror box is a box with two mirrors in the centre (one facing each way), invented by Vilayanur S. Ramachandran to help alleviate phantom limb pain, in which patients feel they still have a limb after having it amputated.

English: A diagrammatic explanation of the mir...

The patient places the good limb into one side of the box (in this case the right hand) and the amputated limb into the other side. Due to the mirror, the patient sees a reflection of the good hand where the missing limb would be. The patient thus receives artificial visual feedback that the “resurrected” limb is now moving when they move the good hand.

Their hypothesis was that every time the patient attempted to move the paralysed limb, they received sensory feedback (through vision and proprioception) that the limb did not move.

This feedback stamped itself into the brain circuitry so that, even when the limb was no longer present, the brain had learned that the limb (and subsequent phantom) was paralysed.

To retrain the brain, and thereby eliminate the learned paralysis, Ramachandran created the mirror box. The patient places the good limb into one side, and the stump into the other.

The patient then looks into the mirror on the side with good limb and makes mirror symmetric movements, as a symphony conductor might, or as we do when we clap our hands.

Because the subject is seeing the reflected image of the good hand moving, it appears as if the phantom limb is also moving. Through the use of this artificial visual feedback it becomes possible for the patient to “move” the phantom limb, and to unclench it from potentially painful positions.

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