Becoming aware of what we usually don't perceive

This topic usually falls into the realm of ESP and parapsychology but there is no reason that it has to. For starters check out this snippet from a Wired article:

"It was slightly strange at first," Wächter says, "though on the bike, it was great." He started to become more aware of the peregrinations he had to make while trying to reach a destination. "I finally understood just how much roads actually wind," he says. He learned to deal with the stares he got in the library, his belt humming like a distant chain saw. Deep into the experiment, Wächter says, "I suddenly realized that my perception had shifted. I had some kind of internal map of the city in my head. I could always find my way home. Eventually, I felt I couldn't get lost, even in a completely new place."

The effects of the "feelSpace belt" -- as its inventor, Osnabrück cognitive scientist Peter König, dubbed the device -- became even more profound over time. König says while he wore it he was "intuitively aware of the direction of my home or my office. I'd be waiting in line in the cafeteria and spontaneously think: I live over there." On a visit to Hamburg, about 100 miles away, he noticed that he was conscious of the direction of his hometown. Wächter felt the vibration in his dreams, moving around his waist, just like when he was awake.

Direction isn't something humans can detect innately. Some birds can, of course, and for them it's no less important than taste or smell are for us. In fact, lots of animals have cool, "extra" senses. Sunfish see polarized light. Loggerhead turtles feel Earth's magnetic field. Bonnethead sharks detect subtle changes (less than a nanovolt) in small electrical fields. And other critters have heightened versions of familiar senses -- bats hear frequencies outside our auditory range, and some insects see ultraviolet light.

Pretty cool eh? I'm not sure how legitimate this type of 'belt' is and whether the results are 'real' since I haven't seen any sort of research on this. Hey If they send me the belt I'll do some research!

In any case... I wanted to highlight a slightly less exciting but more demonstrative instance of a simple change in a task that allows us to become 'aware' of something we weren't before.

My own research focuses on discovering how we successfully move around and interact with our visual world. Because the visual world is always changing there is a surprising amount of information to process in order to maintain the perception of a stable environment. Because there is such a large amount of information people often miss extraordinarily large changes in a scene. One of the worst sources of change originates from our own body. Blinks and saccadic eye movements occupy more of our day to day life than perhaps any other human behavior, yet because of the visual suppression generated by these behaviors we very rarely realize we are making these movements at all.

One of the most important roles of maintaining perceptual stability is our ability to retain the identity and location of objects, so that even if their absolute retinal position has changed due to a saccade or a body movement it can be determined whether they have moved (or not) from their original position. This has been termed 'visual direction constancy' (Bridgeman 1994) . Somewhat surprisingly people are very good at perceiving the world as stable, so skilled in fact that objects can move a remarkable distance (up to 25% of the saccade magnitude) before realizing that the object has moved (Bridgeman 1975).

Two types of information are used to construct a stable visual world (Bridgeman et. al.1994), retinal information from the structure of the external visual environment, and extra-retinal information (motor planning and execution) from the saccade itself (Bridgeman 1994). In many cases it seems that our perceptual system neglects extra-retinal information when it comes to spatially localizing target displacements (Bridgeman 1975). Surprisingly, in contrast to the perceptual system, the motor system is able to make precise spatial judgements (Prablanc & Martin, 1992). If precise spatial information is available to our motor system, is there any way for the perceptual system to access it? In fact there is.

If a target which is displaced during a saccade is not present at the end of the saccade, but reappears a short time later, after a blank interval (between 50-150ms), subjects are able to regain the ability to successfully detect whether the target has moved. The 'blanking effect' (Deubel et al., 1996) suggests that if useful retinal scene information is not available at the end of a saccade the visual system makes greater use of extra-retinal information possibly including occular motor planning info, or proprioceptive information from the actual eye movement itself. My own contribution to this research can't be posted quite yet on the blog - as it hasn't gone through the long crazy peer review process - but soon...

This is simple evidence that we are able to use different cognitive and/or motor systems to perceive what we normally don't with very simple manipulations. As far as training ourselves to do this with something like a belt I'm a little suspicious - but the potential is there so who knows!

Bridgeman, B., Van der Heijden, A.H.C., & Velichkovsky, B. M. (1994). A theory of visual
stability across saccadic eye movements. Behavioral and Brain Sciences, 17, 247-292.
Bridgeman, B., Hendry, D., & Stark, L. (1975). Failure to detect displacement of the visual
world during saccadic eye movements. Vision Research, 15, 719-722.
Deubel, H., Schneider, W.X. & Bridgeman, B. (1996). Postsaccadic target blanking
prevents saccadic suppression of image displacement. Vision Research, 36(7),
985-996.
Deubel, H., Bridgeman, B. & Schneider, W.X. (1998). Immediate post-saccadic
information mediates space constancy. Vision Research, 38, 3147-3159.
Prablanc, C. & Martin, O. (1992). Automatic control during hand reaching at undetected
two-dimensional target displacements. J. Neurophysiology, 67, 455-469.