PERCEIVING TOUCH: Artificial whiskers placed on the index fingers of blindfolded and earplugged adults tease out the involvement of movement in tactile sensation.COURTESY OF EHUD AHISSAR
While it’s generally easy for humans to describe the color of an object or the feel of a fabric, neurobiologists have struggled to articulate the psychophysical mechanics of perception. Movement is nearly always part of sensing the world around us—we scan a room with our eyes or step back from a painting to get a different perspective; we tilt our heads to sniff; we lean in for a better listen; we stroke our babies’ heads to learn their contours. A central question, however, has been whether these physical movements are influenced by what they perceive. In other words, does perception shape our information-seeking activity or do we rely on predetermined data-gathering motions?
In vision, at least on a superficial level, it appears obvious that the ...
