A Behavioral Manipulation Engages Right Frontal Cortex During Aphasia Therapy

Area of Science:

• Neuroscience
• Speech and Language Pathology

Background:

• Aphasia treatment aimed to shift brain activity from the left to the right frontal lobe during word production.
• Previous research suggested successful relateralization using complex left-hand movements.

Purpose of the Study:

• To determine if left-hand movements were the cause of the observed brain activity shift.
• To compare the effectiveness of a treatment with left-hand movements versus one without.

Main Methods:

• 14 aphasia patients were divided into an Intention (IT) group with left-hand movements and a Control (CT) group without.
• Both groups underwent picture naming and category-member generation tasks.
• Functional magnetic resonance imaging (fMRI) was used to assess brain activity before, after, and 3 months post-treatment.

Main Results:

• The IT group showed a significant rightward shift in lateral frontal activity post-treatment and at follow-up, unlike the CT group.
• Both groups had similar improvements in trained tasks.
• The IT group demonstrated greater gains in untrained category and picture-naming tasks.

Conclusions:

• The rightward shift in brain activity was attributed to the left-hand movements used in the IT treatment.
• The treatment involving left-hand movements (IT) led to better generalization of learned skills compared to the control treatment (CT).