Size distortions are intrinsic to self-face representation, characterised for a tendency to overestimate its width: The metric map for self-face representation shows larger distortion for the nose, followed by the mouth and the eyes

My true face: Unmasking one's own face representation. Laura Mora et al. Acta Psychologica, Volume 191, November 2018, Pages 63-68. https://doi.org/10.1016/j.actpsy.2018.08.014

Highlights
•    Size distortions are intrinsic to self-face representation, characterised for a tendency to overestimate its width.
•    Self-face length perception is compartmentalised into upper and bottom regions.
•    The metric map for self-face representation shows larger distortion for the nose, followed by the mouth and the eyes.
•    There is an asymmetrical representation of the face, with over representation of the right hemispace.
•    Face representation relies on influences from visual experience, typical body posture, frequency of use and functionality.

Abstract: Face recognition has been the focus of multiple studies, but little is still known on how we represent the structure of one's own face. Most of the studies have focused on the topic of visual and haptic face recognition, but the metric representation of different features of one's own face is relatively unknown. We investigated the metric representation of the face in young adults by developing a proprioceptive pointing task to locate face landmarks in the first-person perspective. Our data revealed a large overestimation of width for all face features which resembles, in part, the size in somatosensory cortical representation. In contrast, face length was compartmentalised in two different regions: upper (underestimated) and bottom (overestimated); indicating size differences possibly due to functionality. We also identified shifts of the location judgments, with all face areas perceived closer to the body than they really were, due to a potential influence of the self-frame of reference. More importantly, the representation of the face appeared asymmetrical, with an overrepresentation of right side of the face, due to the influence of lateralization biases for strong right-handers. We suggest that these effects may be due to functionality influences and experience that affect the construction of face structural representation, going beyond the parallel of the somatosensory homunculus.