The Effect of Cognitive Limb Embodiment on Vascular Physiological Response
The rubber hand illusion (RHI) is a visual tactile perceptual illusion commonly used to study body ownership. In this paradigm, a rubber hand is positioned in front of a participant, and the person's real hand is hidden from sight behind a barrier. When the real hand and the rubber hand are stroked synchronously, individuals perceive the rubber hand as if it were their own; it becomes "embodied." This illusory experience of body ownership is associated with multimodal integration of touch and vision. From these visual tactile cognitive mechanisms, we establish that our hands belong to us when what we see matches what we feel. Recently, studies have established a correlation between the induction of the RHI and temperature changes at the skin surface. Interestingly, when the brain perceives its real limb to be "disembodied" during the cognitive illusion, the temperature of that real limb drops. The central hypothesis for the proposed study is that cognitive limb embodiment directly affects blood flow patterns; blood flow in a specific limb can be disrupted by altering the sense of the limb's embodiment. Our rationale is that understanding the mechanisms underlying thermal vascular regulation in healthy and diseased populations is clinically significant because blood flow can be used as a physiological marker of cognitive limb embodiment and may also be particularly important in identifying and understanding disease states.