Damage to either M1 or the cerebellum disables a musician’s ability to play an instrument (Holms 1922; Nudo 2013; Watson 2006). But one of the differences between damage of M1 and cerebellum is that M1 damage causes a specific body part to be affected according to the functional topography (i.e., whether the damage is to the face, the hand, or the hindlimb representation), while damage of the cerebellar cortex needs to be diffuse to interfere maximally with the way movements are initiated from M1 (Nudo 2013; Thach et al. 1992).
When stimulation is delivered to most areas of the neocortex, including the frontal eye fields, currents can be detected perceptually, i.e., currents that are subthreshold to the evocation of a motor response (Bartlet and Doty 1980; Bartlett, Doty et al. 2005; Doty 1965, 1969, 2007; Doty et al. 1980; Koivuniemiand Otto2012; Murphey and Maunsell 2007, 2008; Rutledge and Doty 1962; Tehovnik and Slocum 2013). And in humans the effect of such currents can be described verbally (Penfield 1958, 1959, 1975; Penfield and Rasmussen 1952; Murphey et al. 2009). When currents are delivered to either M1 or the cerebellar cortex and the nuclei, however, even the lowest effective currents always evoke a motor response such that the perceptual effects of stimulation cannot be evaluated independently of the movement (Donhoffer 1966; Doty 1969, 2007). Based on this, it is presumed that M1 and the cerebellum have no direct access to consciousness, unlike most regions of the neocortex (Doty 1969, 2007). It therefore follows that accomplished musicians deliver their talents using mainly unconscious networks (see Fig. 1). Perhaps the same is true of accomplished athletes and scientists. To date no one knows how Einstein came up with E = mc^2 and after dissecting his brain there was no progress on this front either, although he was known to play the violin (Kramer 2015; see Fig. 2).
Figure 1: fMRI activity of the cerebral hemispheres when an accomplished musician thinks about playing a violin and when he moves the fingers of the left hand. During the thinking process M1 is not active (C), whereas during the finger movements M1 is active (D). The dotted line in each panel indicates the (right) central sulcus and the activity profile in panel D overlaps the central sulcus, which separates S1 from M1. Data of figure 3 of Watson (2006).
Figure 2: Albert Einstein playing the violin. Image from Kramer (2015).