Overlapping Areas of Neuronal Activation After Motor and Mental Imagery Training

The question whether mental imagery of perceptual and/or motor acts produces activation in the same or overlapping brain areas has fascinated neuroscientists and cognitive psychologists for several decades. For example , in a series of pioneering studies on visual imagery, Kosslyn and colleagues showed that visual imagery is associated with activity in striate and extrastriate cortex (Kosslyn and Thompson, 2003; Kosslyn et al., 2001), with the same areas being activated in visual object perception. Similarly, Ersland et al. (1996) reported in a functional magnetic resonance imaging (fMRI) study that mental imagery of a motor act, finger-tapping in a patient with an amputated right arm produced activation in contralateral motor cortex, in the same areas similar to tapping with the intact left arm fingers. In a follow-up study, Hugdahl et al. (2001; see also Rosen et al., 2001) revealed that imagining finger-tapping with imagined pain shifted the activation to sensory cortex areas and in sub-cortical pain pathways, such as the thalamus and insula. Hence, it is clear that visual imagery of both object perception and motor acts has neuronal correlates that overlap with areas activated during canonical visual perception and motor execution (see also Setiz et al., 1990; Tootell et al., 1998). However, while the practice of motor skills produce activations in cerebellum, imagery learning produces activation in occipital areas such as primary and secondary visual areas (Nyberg et al., 2006). An interesting question, addressed by Olsson et al. (2008), is therefore whether combining physical and mental motor learning and practice would result in both facilitated performance and whether such a combination would produce activations in the same or different brain areas. An applied perspective of such an approach is that mental training is often used in athletics, which is combined with actual practice of the behavior in question. In a previous study by the research group (Nyberg et al., 2006) it was however suggested that combining physical and imagery training may result in interference effects, actually decreasing performance efficiency. Olsson et al. (2008) used a novel approach of combining mental and physical motor training and evaluated the effects with fMRI, also using a novel and untrained motor act as a test for transfer effects of the training exercises. The task was a finger-tapping task in which the subjects had to practice over a 6-week period, using canonical motor training , visual imagery, or combined motor and imagery training. The transfer-of-learning …