P 129. Cognitive effects induced by cerebellar transcranial DC stimulation

Abstract

Neuroanatomical, neuroimaging, neurostimulation and clinical studies have substantially extended the role of the cerebellum beyond motor control to a considerably more complex regulation of cognitive and affective functions. To assess the effect of cerebellar transcranial DC stimulation on human cognitive and affective functions. We enrolled a total of 55 healthy subjects (aged 19–49). In experiment 1 we evaluated the effect of cerebellar tDCS on working memory ( Ferrucci et al., 2008 ), in experiment 2 on emotion recognition ( Ferrucci et al., 2012 , and in experiment 3 on procedural learning. Participants did the tasks before and 35 min after receiving 20-min (2 mA) anodal/cathodal and sham cerebellar tDCS in a randomized order. Experiment 1 showed that anodal or cathodal tDCS over the cerebellum impaired the practice-dependent improvement in the reaction times in a working memory task (sham p = 0.001; tDCS p = 0.36). Experiment 2 demonstrated that anodal and cathodal cerebellar tDCS both significantly enhanced sensory processing in response to negative facial expressions (anodal tDCS p = 0.0021; cathodal tDCS p = 0.018). Finally, experiment 3 showed that anodal tDCS influenced implicit learning processes (anodal vs. sham p = 0.04). Overall cerebellar tDCS changes tests of cognitive and affective functions, possibly through cerebellum-cerebral pathways. Although whether changes induced by cerebellar tDCS in cognition, emotional recognition and learning observed in our experiments can be behaviorally relevant remains to be clarified, cerebellar DC stimulation might be a “window” for modulating complex mental process.