You didn't read this, but....

...though I haven't gotten to anyone's blog, one might remember (or not) ones of the nature science news stories I couldn't access. Well, I found a way! ...Thanks to faithful internet companion, Galtron.

Anyway, it was called Hidden memories guide choices by Heidi Ledford. Hidden memories? Huh? No, seriously, I learned about this even before college... there are memories you can talk about and are aware of, called 'explicit memory', as well as ones you can be shown to have, but can't seem to remember, in which case they are called 'implicit memories'.

For example, amnesiacs who can't form new memories can learn skills - like writing backwards in a mirror - and yet claim they don't know how. They can also solve specific puzzles more quickly even when they claim they have never seen them.

Here's the meat of the article....

In a study published in Nature Neuroscience, Joel Voss from the Beckman Institute for Advanced Science and Technology at the University of Illinois, Urbana-Champaign, and Ken Paller of Northwestern University in Evanston, Illinois, report that implicit memory may be at work when we recall images that we have seen before.

Voss and Paller showed 12 people a series of kaleidoscopic images. Participants were allowed to devote their full attention to half of the images, but were distracted by a number task while viewing the remaining half. That distraction made it harder to consciously remember the pictures.

Don't I know?

Then, 45 seconds after studying the images, participants were tested on how well they could distinguish an image they had previously seen from a new, but very similar picture.

Each time they selected an image, they were asked to gauge how certain they were of the choice. Did they clearly remember the picture? Was it merely familiar? Or was it simply a guess?

Overall, it seemed that a guess was not always a guess. When tested on the images they had seen, participants 'guessed' correctly more often than they 'remembered' correctly.

But that's not all! They also found a unique electrical brain signature that corresponds to a 'correct guess' of an image they had viewed while distracted. It appears 200 milliseconds after the image is shown, before one has time to think about it.

Similarly, Daniel Schacter (Harvard) and Scott Slotnick (Boston College) have found differences in brain activity in the visual cortex depending on whether the participants got it right or wrong. Perhaps it's related?

Don't get too excited. This doesn't mean that a whole new generation of subliminal messages is about to be snapped up by the next Dr. Nociceptor. That might not work, according to Voss, because it is too early to tell. After all, there's a large difference between influencing folks to think something in particular and recalling meaningless kaleidoscope images.