Baloo

oops.

tribalbeeyatch

Keep in mind, seebs, that taste doesn't occur in the mouth; it occurs in the brain. There are multiple receptor types for each of the basic flavors, each responding to somewhat different chemical groups, with the relative activation states of the various types and subtypes yielding a sort of population code from which the brain constructs the sensory experience. Either through training or through a biological sensitization, the brain can weight the various components of a flavor differently. In general, people have an extremely steep response to bitter flavors (which makes sense considering that this flavor is so often associated with harmful compounds), so very small alterations in threshold can yield a very large sensitization or desensitization. Maybe you are particularly sensitive to bitter or your friend is particularly insensitive? Oh, and regarding the lemon juice vs. vinegar test, don't forget that pH is a log scale, so a difference like 2.2 vs. 3.4 should make an enormous difference.

simian

Also, what you have done to your sensors recently will impact them. Drink some orange juice right after brushing your teeth - the sweet sensors on your tongue are dulled, so the other taste (bitter? sour? how the hell am I supposed to know, I am only an engineer). Salt and sucrose also interact. If I remember correctly, salt increased your perception of the sucrose.

Ah, fun.

Simian

Dominus Paradoxum

Tribalbeeyatch, you seem to know alot about how the brain works. So what do you think is the neural basis for qualia? And do you know of any possible solutions to the binding problem?

tribalbeeyatch

I know a lot about a very little of what the brain does, but any dedicated amateur likely knows as much or more than me about the brain as a whole. For example, I know very little about qualia other than that I can't quite see what all of the fuss is about. I would love it if somebody were to start a thread on the topic [hint, hint], but past threads of that sort seem to quickly spin off into a philosophical direction without any obvious grounding in neuroscience. I just don't have the philosophy chops to keep up, I guess.

As for the binding problem, I certainly don't have any answers. I think that some of the difficulty arises from the non-intuitive nature of the problem. It's very hard (for me at least) to shake the habit of inserting some sort of conscious viewer (whether it is an abstract entity or a particular brain region) as the assimilator of the various sensory aspects -- even though I know perfectly well that the science suggests otherwise. It's like looking separately at the different parts of a car and trying to figure out where driving comes from.

Corey Hammer

Part of the problem is that the concept of qualia is inherently untestable. I had a debate with someone over this a few months ago.

That said...sensory testing is very subjective, but you rely on there being consistent differences that occur between two different groups of samples rather than differences that arise due to individual participants.