originally posted by Greg Hirson:
I'll stipulate to be working from the abstract (will you do the same?), but I believe the 'shut-down' of cognitive perception describes a shutdown of olfactory perception as measured by the OERP.
no. message me and i can send you the paper if you like. the cognitive perception was measured by a psychometric test -- subjects had to push a button when they smelled a stimulus.
what the oerps show is that the subjects soon adapt to the stimuli -- they fail to smell them, even though their brains can clearly detect them. and that adaptation rates for perception and detection are different.
Agreed, though it doesn't follow from this line of reasoning that one can smell acidity, merely that an associating between an aroma and a taste can lead to the perception of acidity.
From
Odor/taste integration and the perception of flavor (
full-text pdf here)
"Like the acquisition of taste qualities by odors, the ability of these odors to influence taste perceptions has also been shown to be a function of associative
learning. Odors that initially either had either no impact on sucrose sweetness or actually suppressed sweetness were both found to enhance sweetness
following an exposure phase of repeated pairings with sucrose in solution (Prescott )."
this is a good paper, but this particular quotation is neatly indicative of the appalling circle jerk that is most neuroscience. as a characterisation of learning, i give the content of the above an f. any behavioural response will be driven by a mixture of the priors determined by an individual's specific detectors and learning. and since we usually measure perception by behavioural responses (and, in our own cases, by our subjective experiences), what happens prior to behaviour and experience is interesting but moot. as we normally use the word "smell," it makes little sense to tell me i can smell something if i don't experience it and it doesn't affect me behaviourally.
which means that while this sounds like a useful distinction:
The associations between odor and taste are real, but they are learned, not sensed.
in practice, it is kind of irrelevant. we don't experience what our senses detect. what we call perception is actually a discriminative inference made by our brains based on the mix of priors i described above. the origin of the information in those priors is largely irrelevant to what we experience as perception. what you smell and what you see are inferences made by your brain, they are not veridical reports of what is detected (if that even makes sense -- see borges' story of the 1-1 map of the world).
so, for simple reasons of resource allocation, we do a fair less amount of distorting of visual perception than olfactory or auditory perception, but even in vision, our brain is busy making shit up: the photoreceptors in you eyes detect exactly the same information from both of these horses:
once the photoreceptors have done their job, the brain has to make sense of that information. some of the shit it makes up is based on priors from the detectors and some of that shit is based on priors from learning. does it really help to say that you see the two horses in this context as being the same colour?
and does it really help you to perceive them "veridically" to know they are the same colour?
Perhaps the question to be answered: Is there any reason to make a distinction between the physiological response to acidity (or any sensory stimulus) and the perception of acidity (or any sensory stimulus) as a higher brain function when discussing food and drink? I believe there is. Discussions over actual sweetness (RS) versus perceived sweetness (no RS, seems sweet) would be moot.
there all sort of reasons to make distinctions. like, it really is interesting to know that the two horses are identical in the picture above, even if it doesn't mean that you can "see" them as they really are. for example, we see the horses in this context as different, but if we cut them out and put them on a black background we see them as identical. similarly, a wine that tastes sweet in one context might not do so with food. in this case, knowing about the rs would be useful (in the same way that knowing the colours of the pixels in the above picture is useful).
but the contrast in each case is meaningful in terms of context, not of higher brain function.
which is why i said this shit will soon drive you to drink.
fb.
