Podcast with Vincent Hayaward on haptics and touch

Why is touch the most fundamental sense and yet the least understood? Haptics researcher Vincent Hayward argues that the field lacks the theoretical foundations that vision achieved decades ago , and that the key to unlocking touch lies in recognizing that mechanical sensing is inherently non-local, dynamic, and distributed far beyond the skin. Subscribe for more from the Convergent Science Network podcast series. Vincent Hayward joins Paul Verschure and Tony Prescott for a provocative assessment of the state of haptic science. Starting from the observation that touch may be the evolutionarily oldest modality , present in paramecia and arguably implicit in molecular shape interactions , Hayward explains why the principles governing touch cannot simply be borrowed from vision. The mechanical reality of being a viscoelastic solid means that any contact event has consequences that propagate far from the point of stimulation: a Braille dot creates a disturbance five to six millimeters wide, and frictional signals from a fingertip can be detected throughout the entire arm, even when the hand itself is anesthetized. The conversation dismantles several textbook assumptions. The separation between proprioception and tactile sensing is artificial , thousands of skin afferents, not muscle receptors, tell your brain where your fingers are during hand closure. The fingertip exhibits a remarkable mechanical invariance, maintaining the same elasticity across three orders of magnitude of applied load , a property that appears unique to primates and essential for simultaneous grasping and sensing. Hayward argues that the nervous system is tuned not to skin deformation per se but to the mechanical events that objects create, collisions, friction, compliance, and that temporal coding may be far more important than spatial mapping. Key topics include why there has been no breakthrough experiment in haptics comparable to those in vision, the evidence that synchronized afferent timing rather than spatial location signals contact with a rigid surface, why artificial touch systems remain primitive compared to computer vision, and what a proper computational theory of touch would need to explain. Part of the Convergent Science Network podcast series from the BCBT Summer School.