What’s It like to Be a Sea Slug?

Historically, studies of light have focused on its nature as an immaterial material, perceived solely through photoreceptors in the eyes and transmitted to the brain. The sea slug Elysia Chlorotica can detect light through diffuse photosensitive cells across its body, not just through its simple eyes. Intriguingly, recent studies in photobiology have found results to, that light-activated receptors that mediate photoreception in the eye, are too expressed in epidermal skin cells of human. This link between skin and light detection has inspired research on how lighting design might support human perception. The investigation included poetic, ethnographic and sensor data retrieved from 111 people perceiving and moving in color luminated spaces. Data analyses revealed that both how people sensed their bodies and how they moved depended on the color of the lighting. These effects remained significant regardless of whether participants were blindfolded or not. This study thus points to a "blind spot" within our general understanding of the qualities and potential of light to influence our perception and behavior, by pointing to the entire human body, including skin, as a constant interface with the world. Drawing from neuroscientific perspectives on (human and non-human) brain-body-environment interconnectedness, this paper presents speculations on what non-human species like sea slugs can teach us about human perception and our being in the world. Although the question “what is it like to be a sea slug” remains unanswered, this study suggests that we may share more than expected.