Saturday, August 27, 2005

Why Hats Should Be Iron, Not Tinfoil

A new study done at the University College, London, shows that it is possible to use a magnetic field to turn of that part of the brain that notices when the visible environment has changed.  The background is this: When something critical changes in the environment, for example, a traffic light changes from green to red, the right parietal lobe is supposed to notice the change and alert the rest of the brain.  

This was a bit of a surprise, since most processing of visual information occurs in the occipital lobes.  Be that as it may, it is the right parietal lobe that serves to alert us to such changes.  And, as it turns out, repetitive transcranial magnetic stimulation (rTMS) can be used to turn off that part of the brain, temporarily.  The subject does not have any way of knowing that his or her brain has been tampered with.  
In previous experiments using brain scanning (functional magnetic resonance imaging or fMRI), the team led by Professor Nilli Lavie at the UCL Department of Psychology, discovered that detection of visual changes was not only correlated with activity in conventional visual areas of the brain but also with activity in the parietal cortex.

But, until this experiment, when the team actually switched off the parietal cortex using TMS, they didn't know that noticing change critically depends on activity in the parietal cortex. When that region of the brain was effectively switched off, 'change blindness' (a failure to notice large changes in a visual scene) occurred.
The people in black helicopters can use this technique to render us unaware of their presence.

For years, bloggers have been urging others to wear hats made of tinfoil (which is actually aluminum) to prevent this kind of thing.  However, a thin piece of aluminum is not able to block the effects of rTMS.  Therefore, we need to put away our tinfoil hats, and use iron instead.