Cerebellar-parietal connections underpin phonological storage

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuroimaging

Background:

• The cerebellum's role in verbal short-term storage is supported by evidence, but its precise function in phonological storage networks remains unclear.
• Understanding cerebellar contributions to verbal memory is essential for elucidating complex cognitive processes.

Purpose of the Study:

• To investigate the human cerebellum's contribution to encoding, maintenance, and retrieval of verbal information using transcranial direct current stimulation (tDCS) and functional magnetic resonance imaging (fMRI).
• To clarify the specific role of the right cerebellum in phonological storage networks.

Main Methods:

• A randomized, crossover, sham-controlled study combining tDCS on the right cerebellum with fMRI.
• Participants underwent stimulation during tasks assessing verbal information processing.

Main Results:

• Anodal tDCS, but not cathodal, reduced item recognition capacity.
• Anodal tDCS attenuated neural signals in the right cerebellar lobule VIIb during late encoding.
• Functional connectivity between the right cerebellar lobule VIIb and the posterior parietal cortex was altered during late encoding.

Conclusions:

• The right cerebellar lobule VIIb plays a significant role in the late stages of verbal encoding.
• This cerebellar region interacts with the posterior parietal cortex during the transition of verbal information into phonological storage.