Regional cerebral blood flow in sign language users

Area of Science:

• Neuroscience
• Linguistics
• Cognitive Science

Background:

• Investigating the neural underpinnings of language processing is crucial for understanding human cognition.
• Previous research has primarily focused on spoken language, leaving the cerebral activation patterns for sign language less understood.
• The study addresses the unique linguistic environment of hearing children with deaf parents, who are often bilingual in spoken and signed languages.

Purpose of the Study:

• To compare cerebral activation patterns during the comprehension of sign language versus spoken language.
• To determine if sign language comprehension recruits similar or different neural areas compared to spoken language.
• To explore the role of typically spatial processing areas during sign language perception.

Main Methods:

• Regional cerebral blood flow (rCBF) was measured in nine hearing children of deaf parents.
• Participants underwent neuroimaging while comprehending complex materials presented in both sign language and spoken language.
• Analysis focused on identifying differences and similarities in cortical activation between the two language modalities.

Main Results:

• Both sign language and spoken language comprehension elicited bilateral activation in posterior temporal regions.
• The observed activation patterns were remarkably similar across both spoken and signed language comprehension.
• Cortical areas typically associated with spatial abilities did not show increased activation during sign language perception.

Conclusions:

• Sign language comprehension engages neural mechanisms comparable to those used for spoken language.
• The findings suggest that the brain processes signed and spoken languages through largely overlapping cortical networks.
• This study provides evidence against the hypothesis that sign language relies heavily on spatial processing cortical areas.