The mapped head was associated with phrenology from its earliest publications throughout the nineteenth century. It provided a useful map of the locations on the skull discussed in phrenological tracts. One contemporary reviewer explained, “The author’s mode of treating the subject is illustrated, and rendered very intelligible, by a plate of the human head having the organs delineated” (“The Phrenological System").

Phrenological illustrations published by Fowler and Wells and others allowed untrained Americans to conduct their own phrenological readings. Similar illustrations were available to a British audience throughout the 1800s. The mapped head was essential in a non-expert examination as it allowed even the lay “reader” to “project upon the living body a whole network of anatomo-pathological mappings: to draw the dotted outline of the future autopsy” in order “to bring to the surface that which is layered in depth” (Foucault 200). Ultimately, however, phrenological guides trained the nineteenth-century reader in a gaze which privileged the exterior and the scientific—a gaze Michel Foucault identified as the "clinical gaze" (Foucault 103ff).

The image depicts a hairless head, with numbers mapped upon the exposed skin and face, indicating the location of the organs. The corresponding text identifies which characteristic or faculty is associated with each number.