ScienceNOW is watching perceptual experts sketch out the first map of a strange sensory hinterland – the perceptual space that lies between what you see what you feel:
Experiments with blind subjects, for example, have found that reading Braille by touch can trigger activity in the brain’s visual cortex…. But Moore and graduate student Talia Konkle wondered if the sight-touch link might lurk in everyone and if one sense might influence the other.
So they turned to “DaVinci,” a delicate, apple-sized tactile stimulator that taps out patterns with a centimeter-square array of pins…. The researchers asked eight volunteers to watch as dark stripes fell or rose on a white screen (see first image here). Then DaVinci tapped a stationary stripe on their fingertips. Another eight subjects felt DaVinci sweep its pins upward or downward along their fingertips while they viewed a stationary stripe onscreen.
To the researchers’ surprise…[s]ubjects who watched the moving stripes rise perceived the stationary row of pins to be falling along their finger, and vice versa.
In other words, vertigo-inspiring optical illusions like this one also work on our sense of feel. We can touch what we see, even if what we’re seeing isn’t really there.