Does cortical reorganisation explain the enduring popularity of foot-binding in medieval China?
In the past, it used to be taught that neural connections were essentially fixed and unchangeable from birth. However, in recent years it has become clear that, in fact, the brain possesses a tremendous degree of latent plasticity, and significant reorganisation can occur in response to changes in the body. This is clearly demonstrated by the phenomenon of phantom limbs--the vivid sensation of a limb still being present despite its amputation. After removal of a limb, the region of the somatosensory cortex that is deafferented is "taken over" by afferents that normally innervate the adjacent areas of cortex. This cross-activation between the different areas of the somatosensory cortex plays a large role in creating these phantom sensations. The same is also true of the motor cortex. After amputation of a limb, the deprived area of motor cortex does not remain nonfunctional but instead becomes active in the control of adjacent non-amputated muscle groups. It is notable that the genital area of the somatosensory cortex and the pelvic floor muscle area of the motor cortex are dislocated and in both cases lie adjacent to the foot area. Foot-binding of Chinese girls started around the 10th Century AD and for the next millennium was an extremely prevalent and popular custom. Mothers would tightly wrap their daughters' feet from about the age of six years, thus preventing the feet from maturing normally. The aim of the process was to create as small feet as possible, since this would greatly enhance a girl's matrimonial prospects. Historians of the period have noted that Chinese men viewed foot-binding as conducive to better sexual intercourse because they believed that women with bound feet had vaginas that were more highly muscled and sensitive. We hypothesise that since foot-binding kept a girl's feet small and atrophic, this resulted in underutilisation of the foot areas of her somatosensory and motor cortices. This resulted in cross-activation between the redundant foot cortex and the adjacent genital areas in her brain. Hence women with bound feet devoted a disproportionately large area of the sensory and motor cortices of their brains to their genitalia and pelvic floor musculature, which made them more sensitive and pleasurable lovers. This caused Chinese men to prefer their sexual partners to have bound feet, which resulted in the enduring popularity of foot-binding in China over the last millennium.
McGeoch
Paul D
PD
Center for Brain and Cognition, UCSD, La Jolla, CA 92093, USA. pmcgeoch@psy.ucsd.edu
D002681:China; D003469:Culture; D005260:Female; D005531:Foot Deformities, Acquired / Q000266:history / Q000503:physiopathology* / Q000523:psychology; D049691:History, Medieval; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology / Q000503:physiopathology; D009473:Neuronal Plasticity; D012725:Sexual Behavior; D013003:Somatosensory Cortex / Q000502:physiology* / Q000503:physiopathology