[Interhemispheric relations and brain plasticity]

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Unilateral hemispheric lesions can impair cognitive functions.
• The brain exhibits functional plasticity, allowing for adaptation after injury.
• Interhemispheric communication plays a role in recovery and compensation.

Purpose of the Study:

• To investigate the compensatory role of the contralateral hemisphere in patients with unilateral brain lesions.
• To explore interhemispheric transfer and functional plasticity in neurological conditions.

Main Methods:

• A maze-learning task was used, with the index finger controlled by the intact hemisphere.
• Intracarotid amobarbital injection was employed to temporarily inactivate the nondominant hemisphere in aphasic patients.

Main Results:

• Patients with left hemisphere lesions showed improved right-hand performance after left-hand training, indicating interhemispheric transfer.
• Inactivation of the nondominant hemisphere in aphasic patients led to a decline in verbal performance, suggesting its compensatory role.

Conclusions:

• The contralateral hemisphere can play a compensatory role following unilateral brain lesions.
• These findings highlight the brain's functional plasticity and interhemispheric communication in recovery from neurological damage.