Sunday, January 31, 2010

Why do we comprehend anything as "all at once" ?

Scientists, testing the reason we sometimes perceive the rotation of a tire (on a car, when its spinning at a certain speed) as going the opposite direction - known as the Wagon-wheel effect - found that "The continuity of our perception is an illusion...The experiment even put a number on our visual frame rate - around 13 frames per second." As there was a specific visual frame rate , the implication was...
...that there is not a single "film roll" in the brain, but many separate streams, each recording a separate piece of information. [In a separate experiment to further examine this] VanRullen examined another neural function, called near-threshold luminance detection. He exposed his subjects to flashes of light barely bright enough to see, and found that the likelihood of them noticing the light depended on the phase of another wave in the front of the brain, which rises and falls about 7 times per second. It turned out that subjects were more likely to detect the flash when the wave was near its trough, and miss it when the wave was near its peak.

So it seems that each separate neural process that governs our perception might be recorded in its own stream of discrete frames. But how might all these streams fit together to give us a consistent picture of the world? Ernst Pöppel, a neuroscientist at the Ludwig Maximilian University in Munich, Germany, suggests all of the separate snapshots from the senses may feed into blocks of information in a higher processing stream. He calls these the "building blocks of consciousness" and reckons they underlie our perception of time (Philosophical Transactions of the Royal Society B, vol 364, p 1887).

It's an appealing idea, since patching together a chronological order of events hitting our senses is no mean feat. Sounds tend to be processed faster than images, so without some sort of grouping system we might, say, hear a vase smashing before we see it happen. Pöppel's building blocks of consciousness would neatly solve this problem: if two events fall into the same building block, they are perceived as simultaneous; if they fall into consecutive buildings blocks, they seem successive. "Perception cannot be continuous because of [the limits of] neural processing," says Pöppel. "A space of 30 to 50 milliseconds is necessary to bring together in one time-window the distributed activity in the neural system."
Pöppel's theory is an interesting one to tie together the discoveries about our processing. Before we had the capability to examine these sorts of questions of cognition (the past few decades?), the historical language used to explore them had been more purely theoretical and philosophical. This shift complicates the responses one can make to a theory such as Pöppel's.

Flash-Flooded Desert in Sinai, Egypt - Click image for LARGE - source: This Fab Trek

Sunday, January 10, 2010

A Seventy-Eight Year Old Has a Good Idea About the Internet

From Interview with Umberto Eco (who inspired this previous post on conversation and comedy):
SPIEGEL: Are you saying that teachers should instruct students on the difference between good and bad? If so, how should they do that?

Eco: Education should return to the way it was in the workshops of the Renaissance. There, the masters may not necessarily have been able to explain to their students why a painting was good in theoretical terms, but they did so in more practical ways. Look, this is what your finger can look like, and this is what it has to look like. Look, this is a good mixing of colors. The same approach should be used in school when dealing with the Internet. The teacher should say: "Choose any old subject, whether it be German history or the life of ants. Search 25 different Web pages and, by comparing them, try to figure out which one has good information." If 10 pages describe the same thing, it can be a sign that the information printed there is correct. But it can also be a sign that some sites merely copied the others' mistakes.

not bad

Saturday, January 9, 2010

Non-Zero Correlations, or, Robert Wright Rips Me Off

Robert Wright's Non-Zero is a very readable non-fiction book that uses game theory to look at our history (social and biological). He traces a through-line in these fields that seems to show a positive direction to our development, defined by (Wright's term) "non-zero-sumness": meaning essentially, both parties in an exchange benefit (a win-win situation). As social and biological complexity grows, non-zero-sumness grows with it - enlarging our "circle of empathy" (first family, then friends- expanding globally).
Below is an excerpt from one of the final chapters, reflecting on the effects (and future possibilities) that the internet could play in this area of non-zero-sumness:
"...But it is evidence that, as global interdependence thickens, long-distance amity can in principle grow even in the absence of external enmity. And it's something to build on. There is no telling what it could mean as technology keeps advancing; as the World Wide Web goes broad bandwidth, so that two people anywhere can meet and chat virtually, visually (perhaps someday assisted, where necessary, by accurate automated translation). One can well imagine, as the Internet nurtures more and more communities of interest, true friendships more and more crossing the most dangerous fault lines - boundaries of religion, of nationality, of ethnicity, of culture.

The common interests that support these friendships needn't be high in gravitas. They can range from stopping ozone depletion to preserving Gaelic folklore to stamp collecting to playing online chess. The main thing is that they be far-flung and cross-cutting. Maybe this is the most ambitious realistic hope for the future expansion of amity - a world in which just about everyone holds allegiance to enough different groups, with enough different kinds of people, so that plain old-fashioned bigotry would entail discomfiting cognitive dissonance. It isn't that everyone will love everyone, but rather that everyone will like enough different kinds of people to make hating any given type problematic...Maybe the world of tomorrow will be a collage of noospheres with enough overlap to vastly complicate the geography of hatred. It wouldn't be 'Point Omega', but it would be progress." pg. 328
If this isn't basically the same argument I put out in part three of this post, regarding the bayonet-loving, vengeful bigot on a houseboat in the Atlantic, I don't know what is. Just kiddin' about the ripping-off part. Wrights got brains like I've got ill-advised purchases. Just kiddin' about the just kiddin part. Just kiddin' about the just kiddin about the just kiddin part.