Cerebellar volume in humans related to magnitude of classical conditioning

Neural circuits in the cerebellum are essential for eyeblink classical cond itioning, and hippocampal activation is also present during acquisition. An atomical (volumetric) brain MRI, delay eyeblink conditioning and 'neuropsyc hological tests were administered to eight healthy older subjects. The corr elation between cerebellar volume (corrected for total cerebral volume) and conditioned response percentage was 0.81 (p < 0.02), but neither hippocamp al nor total cerebral volume correlated with conditioning or any neuropsych ological test scores. There was no relationship between age and cerebellar volume, but the correlation between hippocampal volume and age was -0.80 (p < 0.02). These volumetric results add to the increasing evidence in humans demonstrating a relationship between the integrity of the cerebellum and e yeblink classical conditioning. NeuroReport 11:609-615 (C) 2000 Lippincott Williams & Wilkins.