Sign Language: How the Brain Represents Phonology without Sound

Area of Science:

• Neuroscience
• Linguistics
• Neurosurgery

Background:

• The functional organization of the sensorimotor cortex is crucial for motor control and sensory processing.
• Understanding how the brain processes sign language is vital for comprehending non-auditory communication modalities.

Purpose of the Study:

• To investigate the functional organization of the sensorimotor cortex in a deaf sign language user.
• To explore neural activity related to sign language production during awake craniotomy.

Main Methods:

• Electrocorticography (ECoG) recordings were obtained from a deaf signer during an awake craniotomy.
• Neural activity was analyzed in relation to specific handshapes, body locations, and movement types (linguistic vs. transitional).

Main Results:

• The sensorimotor cortex demonstrated functional organization tailored for sign language.
• Electrocorticography revealed neural tuning to linguistically relevant handshapes and body locations.
• Distinct neural activity patterns were observed for linguistic movements compared to transitional movements.

Conclusions:

• The sensorimotor cortex is functionally adapted for processing sign language in deaf individuals.
• This case highlights the brain's plasticity and its capacity to support complex linguistic functions through sensorimotor pathways.