Handedness change after dominant side amputation: Evaluation from a hand laterality judgment task.

Area of Science:

• Neuroscience
• Psychology
• Rehabilitation Medicine

Background:

• Dominant hand amputation necessitates exclusive use of the non-dominant hand.
• The impact of this forced adaptation on established handedness preference is not well understood.

Purpose of the Study:

• To investigate changes in handedness preference following dominant hand amputation.
• To determine if chronic non-dominant hand use influences handedness.

Main Methods:

• A hand laterality judgment task was employed to assess handedness in amputees and healthy controls.
• Response times to images of the lost and remaining hands were compared.
• A handedness index was calculated based on response time lateralization.

Main Results:

• Healthy controls exhibited a dominant hand advantage, responding faster to their dominant hand images.
• Amputees did not display this typical handedness advantage.
• The handedness index correlated with response time, accuracy, age at amputation, and time post-amputation.

Conclusions:

• Dominant side amputation leads to changes in handedness preference.
• These observed handedness changes may not be solely driven by the chronic use of the intact hand.