Motoring along

The workings of motor cortex have been on my mind since they pop up from neuroimaging studies on meditation every now and then. In Fox et al. meta-analysis on functional neuroimaging studies (Fox et al., 2016) that dealt with modalities of mindfulness meditation (plus mantra recitation, which isn’t part of mindfulness), premotor cortex and supplementary motor area exhibited activation (meta-analytic clusters). The activation was noted both in focused attention meditation modality (concentrating on body parts or following of breath) and open monitoring modality (observing thoughts and sensation without trying to interfere with them). The explanation for the activation originated from the idea that mental manipulation of objects activates the same areas that are involved in actual manipulation. I wonder if this has workable analogies in the mirror cell mechanism? On the other hand, activation has been observed in these region during a variety of mental task recruiting higher order cognitive functions and attention regulation, such as working memory, attentional control, mental imagery and conceptual reasoning. Therefore, meditation, an activity especially coupled with attention control, fits well into the image.

We learned that not only motor cortex, but also other areas of the brain send in some cases commands to the outside world. The tasks of higher and lower motor neurons and interneurons was discussed, as well as activation and the simultaneous inhibition of the antagonist muscles, in eg. biceps (flexion) and triceps (the antagonist, extension). A very interesting thing: the artificially induced crossed innervation of muscles, i.e. innervating slow muscle cells with fast motor neurons or vice versa, changes the action of the thus innervated cell to resemble the type of innervation. This led me to think, would it be possible to alter the muscle type distribution by tampering with the muscle innervation somehow? I assume I have mostly slow muscle cells and gaining strength and high speed has always been a challenge, but if one were to take a very fast runner to start with, would it be possible to increase the sunning speed beyond the inborn gifts of nature?

Ref

Fox, K. C. R., Dixon, M. L., Nijeboer, S., Girn, M., Floman, J. L., Lifshitz, M., Ellamil, M., Sedlmeier, P. and Christoff, K. (2016) ‘Functional neuroanatomy of meditation: A review and meta-analysis of 78 functional neuroimaging investigations’, Neuroscience & Biobehavioral Reviews. Elsevier Ltd, 65, pp. 208–228. doi: 10.1016/j.neubiorev.2016.03.021.

 

Posted by Tapio Saarinen

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