Cerebellar Contribution to Rapid Cross‐Modal Attentional Shift in Visual‐Tactile Processing

ABSTRACT Clinical and behavioral studies suggest the right lateral cerebellar hemisphere plays a critical role in cognition, particularly attention. Contralateral connections between the cerebellum and cerebrum via the thalamus support this involvement. When rapid attentional shifts occur between two target stimuli (T1 and T2) in close succession, a phenomenon known as attentional blink (AB) results in decreased accuracy in reporting T2. Continuous theta burst stimulation (cTBS) studies indicate that inhibiting the right cerebellar hemisphere enhances visual AB. However, it is uncertain whether the cerebellum impacts sensory processing when presented with two relevant targets in different sensory modalities, and if lateralization of function is conserved. This study investigated cerebellar involvement in cross‐modal AB, particularly the influence of right cerebellar stimulation on rapid attentional shifts between visual and tactile stimuli. In two experiments, participants completed a cross‐modal attentional blink task pre‐ and post‐cTBS stimulation applied to the left or right cerebellar hemisphere. Stimuli included a visual or tactile T1, followed by a cross‐modal T2 and a mask. In Experiment 1, stimuli were presented to the second and fifth digits of the left hand and left visual space, whereas in Experiment 2, they were presented to the second and fifth digits of the right hand and right visual space. Results revealed that right cerebellar inhibition led to reduced accuracy in reporting tactile T2 targets irrespective of stimulus location. No significant changes following left cerebellar stimulation were observed. These findings suggest hemisphere‐specific cerebellar modulation of cross‐modal AB performance, where the right cerebellum plays a role in managing relevant T2 targets from distractors (mask).