The hermunculus: what is known about the representation of the female body in the brain?

The representation of the body in the brain, the homunculus, was posited by Wilder Penfield based on his studies of patients with intractable epilepsy. While he mapped both male and female patients, Penfield reports little about the females. The now iconic illustration of the map is clearly male with testicles, penis, and no breasts. In order to bring attention to this omission and to stimulate studies of female somatosensory cortex (SS), we discuss what is known about the map of the female body in the brain, including Penfield's findings in his female patients and subsequent work by others exploring the human female SS. We reveal that there is much we do not know about how the entire female body is represented in the brain or how it might change with different reproductive life stages, hormones, and experiences. Understanding what is and is not currently known about the female SS is a first step toward fully understanding neurological and physiological sex differences, as well as producing better-informed treatments for pain conditions related to mastectomy, hysterectomy, vulvodynia, and fibromyalgia. We suggest that the time is ripe for a full mapping of the female brain with the production of a hermunculus.

Detailed descriptions of routes traveled, but not map-like knowledge, correlates with tests of hippocampal function in older adults.

We examined hippocampal contribution to remote spatial memory in older adults by correlating their performance on tests sensitive to hippocampal damage with their description of routes they traversed many times or only once, and with their map-like knowledge of downtown Toronto. We found that performance on table-top tests of spatial location (Smith and Milner (1981) Neuropsychologia 19:781-793) and on paired-associate learning, and the number of Internal Details on the Autobiographical Interview (Levine et al., (2002) Psychol Aging 17:677-689), all correlated significantly with the number and type of perceptual details used in describing routes one has traversed, but not with map-like knowledge of Toronto. No significant correlations were found with performance on tests of frontal function (WCST, phonemic fluency, and backward digit span). We conclude that the hippocampus is implicated in vivid re-experiencing of a familiar route, but not with map-like knowledge of a large-scale environment. These findings are interpreted as consistent with Multiple Trace Theory's prediction that it is the degree of detail of a retrieved memory that is crucially dependent on the hippocampus.