Tag Archives: maps

Maps and Infinite Homuncular Regression

Although maps provide an excellent structural representation of what is going on the brain, in themselves they have no intrinsic value (Deacon, 2012). Maps do not really tell us about how the brain is interpreting or processing the information, only how it stores and forwards the information. To be fair, even that is only based on visual interpretation not on concrete behaviour. Unfortunately, that brings up the issue of whether or not topological maps are of any value. The retinotopic map may just be a consequence of development and evolution, an attempt to minimise wiring of the brain. Deacon (2012) stresses that there is massive flaw with the current use of mapping; he summarizes it as the ‘infinite homuncular regression.’ Basically, we have come to a point where other maps are just reading maps. The actual perceptual neurology has not been determined. Deacon warns scientists of the dangerous of neuroimaging and maps when trying to prove the existence of neural activity and behaviour. All this boils down to really is the classic argument in psychology; correlation does not prove causation.

1421_sensory_homunculus

Fortunately, Graziano and his colleges (2009) suggest that perhaps a homunculus does exist that can bridge perception and behaviour: the motor cortex. To put it plainly, a motor homunculus represents the sensitivity and innervation dedicated to particular muscles in our body. This homunculus can be mapped onto our motor cortex, and stimulation of these regions leads to an immediate motor response. Hence, we can bridge the gap between map and action. In other words, the motor cortex may in fact put an end to the infinite homoncular regression. A recent study carried out by Bouchard et al. (2013) found that when participants vocalised constants and vowels, scans showed smooth trajectories in the motor cortex.