Cerebellar Transcranial Magnetic Stimulation (TMS) Impairs Visual Working Memory.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Cerebellar Function

Background:

• The cerebellum is increasingly recognized for its role in cognitive functions, including verbal working memory (WM).
• Previous research implicated distinct cerebellar regions in verbal WM, but its involvement in visual WM is less understood.
• Our prior work demonstrated that transcranial magnetic stimulation (TMS) of the right superior cerebellum disrupts verbal WM.

Purpose of the Study:

• To investigate the necessity of the left superior and inferior cerebellum in visual working memory (WM).
• To determine if the inferior cerebellum is involved in visual WM, similar to its proposed role in verbal WM.
• To explore potential differential roles of superior and inferior cerebellar regions in visual WM stages.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) to localize cerebellar regions involved in a visual WM task (Sternberg task).
• Employed fMRI-guided, double-pulse TMS to disrupt activity in identified left superior and inferior cerebellar regions.
• Assessed the impact of TMS on accuracy in the visual WM task.

Main Results:

• fMRI identified target regions in the left superior and inferior cerebellum during the visual WM task.
• TMS applied to both the left superior and inferior cerebellum significantly decreased accuracy in the visual WM task.
• Distinct patterns of visual WM deficits emerged following stimulation of the superior versus inferior cerebellar regions.

Conclusions:

• The findings support the involvement of both the left superior and inferior cerebellum in visual working memory.
• The differential effects of TMS on visual WM performance suggest that these cerebellar subregions may support distinct stages of visual WM processing.
• This study expands our understanding of the cerebellum's contribution to complex cognitive functions beyond motor control.