The right hemisphere involvement in the processing of morphologically derived words

Area of Science:

• Neuroscience
• Linguistics
• Cognitive Science

Background:

• The left hemisphere is traditionally considered dominant for complex linguistic tasks, including morphology.
• Selective deficits in derivational morphology are rare and typically not associated with specific brain lesions.

Observation:

• Two patients with right-hemisphere lesions presented with selective impairments in producing derivational morphology.
• These patients exhibited no general aphasic disorders or difficulties with verb infinitives.

Findings:

• A specific deficit was observed in deriving nouns from verbs, but not from other word classes like adjectives.
• Patients often substituted derived nouns with the past participle of the source verb.

Implications:

• This case study provides the first evidence for a right-hemisphere contribution to derivational morphology.
• It suggests a more complex and potentially lateralized neural architecture for word formation than previously understood.