Development of language in six hemispherectomized patients

Area of Science:

• Neuroscience
• Developmental Psychology
• Linguistics

Background:

• The brain's hemispheres specialize in different functions, with the left typically dominant for language.
• Understanding how brain injury affects language development is crucial for intervention strategies.
• Hemispherectomy, the removal of one hemisphere, provides a unique model to study brain plasticity and functional recovery.

Purpose of the Study:

• To investigate the impact of isolated right hemisphere function on language development.
• To compare language skills in patients with left or right hemispherectomy across different childhood injury timings.
• To assess the production and judgment of morphological markers in hemispherectomy patients.

Main Methods:

• Compared language performance in 3 left hemispherectomy patients and 3 right hemispherectomy patients against control groups.
• Assessed baseline clinical language measures, and production/judgment of morphological markers.
• Analyzed data based on the timing of the initial brain insult (early, middle, or late childhood).

Main Results:

• Left hemispherectomy patients exhibited severe language processing impairments irrespective of injury timing.
• Right hemispherectomy patients showed more restricted language deficits.
• Deleterious effects on language development from right hemisphere injury were primarily observed when the insult occurred during early childhood.

Conclusions:

• The left hemisphere plays a critical role in language processing throughout development.
• The right hemisphere has a more limited, but still significant, role in language, particularly in early development.
• Early childhood brain insults to the right hemisphere can have lasting negative consequences on language acquisition.