Shadows are an omnipresent feature of our visual world. The appearance of shadows from objects tells us about their shape and relative location of the objects that cast them (Pavani & Galfano, 2007; see Mamassian, Knill, & Kersten, 1998 for a more detailed review). The shadow cast by our physical body within our peripersonal space has only recently come to the interest of neurological researchers.
The body-shadow is a very special visual stimulus as it reflects our movements and bears similarities to our physical selves. Shadows cue the brain to attend to the body part being reflected in the shadow. In fact, the visual stimulus of the movement of the body-shadow helps the brain refer to the location of the actual body part via interoceptive perception. Like the physical body, which is neutrally known by location and ownership, so too with the body-shadow. Even though the body-shadow plays a very small role in the formation of body image and self-identification of the body it holds a uniquely ubiquitous place: my body-shadow is never your body’s shadow and vice versa (Pavani & Galfano, 2007, 2015).
One important area of scientific interest is neurocognitive system identifies and processes shadows of one’s body and those of others to realize self-recognition and experience body ownership. Studies strongly indicate that one’s own personal shadow has a special status in the neurocognitive processing system helps to direct attention to the body in a very fast yet very specific way. This process helps aim attention at the body parts casting the shadow and binds the personal and extrapersonal space around a person (Pavani & Castiello, 2004). Consequently, observing your body shadow enhances your own feelings of embodiment (Kuylen, Balas, & Thomas, 2014).
Closing Thoughts
I remember one summer’s morning as a very little child discovering my body shadow while playing outside. I was fascinated with its movement of always “following me” and for days afterward was watching it as I assumed it watched me. I still find the body’s shadow fascinating but now for more abstract reasons. The shadow represents me, but is not me per se. The shadow, like the body, is inescapable. My shadow informs me of my body’s position, posture, and movement in space. It is not my body, but it echoes my body.
Paul Shane, Ph.D., LMT
Director, Academic Content
References
Kuylen, C., Balas, B., & Thomas, L. (2014). My shadow, myself: Cast body-shadows are embodied. Psychological Bulletin Review 21, p. 676-681.
Mamassian, P., Knill, D., & Kersten, D. (1998). The perception of cast shadows. Trends in Cognitive Sciences 2, p. 288–295.
Pavani, F. & Castiello, U. (2004). Binding personal and extrapersonal space through body shadows. Nature Neuroscience 7(1), p. 13-14.
Pavani, F. & Galfano, G. (2015). The multisensory body revealed through its cast shadows. Frontiers in Psychology 6, article 666, https://doi.org/10.3389/fpsyg.2015.00666.
Pavani, F. & Galfano, G. (2007). Self-attributed body-shadows modulate tactile attention. Cognition 104, p. 71-88.