An Opponent Process Cerebellar Asymmetry for Regulating Word Association Priming

Area of Science:

• Neuroscience
• Cognitive Science
• Linguistics

Background:

• The cerebellum's role in language is increasingly recognized but not fully understood.
• The connection between the language-dominant left cerebral hemisphere and the right cerebellum presents a puzzle regarding cerebellar contributions to language.

Purpose of the Study:

• To investigate the distinct roles of the left and right cerebellar hemispheres in associative word priming.
• To explore the psychobiology of cerebellar contributions to linguistic processes.

Main Methods:

• Used a lexical decision task measuring reaction time to word/non-word targets.
• Applied continuous theta-burst transcranial magnetic stimulation (TMS) to selectively disrupt left and right cerebellar hemispheres.
• Calculated associative word priming as the reduction in reaction time with related word primes.

Main Results:

• Left cerebellar hemisphere TMS decreased associative word priming.
• Right cerebellar hemisphere TMS increased associative word priming.
• Neurodisruption of the two cerebellar hemispheres had opposing effects on associative word priming.

Conclusions:

• The cerebellum contributes to predictive sequential processing in language.
• Cerebellar hemispheres coordinate language functions through an opponent process mechanism.
• These findings shed light on the enigmatic psychobiology of cerebellar language contributions.