But my point, and Gnome's, was that with a blind control, the subjects do not know what condition they are in and cannot skew the results in any direction. Lying may increase variability, but does not confound the experiment.jzs said:
I think this view is a bit naive, and I would suggest that you read up a bit on the signal-detection model used by psychophysics, and the elegant designs which allow us to separate out different influences on our response pattern (for instance, sensitivity and bias, as mentioned above). You are no more likely to get deception in such experiments than you are in the physical sciences--it would take either a serious conspiracy to overcome the experimental controls, or fraud on the part of the experimenter. And of course, the peer-review and replication processes act as safeguards-- the findings of psychophysics are strongly replicable in any lab.jzs said:
No. As Corey said, we can measure non-verbal behaviors--it is just that verbal responses are tremendously convenient. But we can, through operant discrimination or respondent conditioning, demonstrate perceptual or memory effects without relying on verbal responses. Indeed, although we can, as rppa says, take physiological measures, I have seen studies in which the auditory sensitivities of manatees were determined both by invasive methods and by operant discrimination, and the operant task revealed a wider range of sensitivity than was found in cell readings.Kumar said:
Sorry--the opening post specified sensation/perception stuff, and my response was that psychophysics is the area for studying this. Corey's use of "memory" should be read in that context, as a relatively narrow definition, rather than, say, as long-term-memory storage or retrieval problem.jzs said:
MRC_Hans said:
I am not certain I understand your question. Perhaps you are asking whether non-verbal and verbal reports are of equal use. If that is the case, the answer is that it depends. Sometimes one will be more accurate, sometimes the other will be more convenient, sometimes either will do, sometimes we take both and compare.Kumar said:
Yes. We not only ask for verbal reports ("how are you feeling today?"), but we of course take non-verbal reports (pulse, blood pressure, x-rays, cat scans, etc.). To take an example, one person might verbally report feeling better after taking a pill, but we might find that this person's tumor is still growing. A person might report a greater range of motion in an injured limb after guzzling some tapwater (er, I mean, taking a homeopathic remedy), but not be able to actually demonstrate any increase in mobility at all objectively. Conversely, one's physical condition may improve dramatically without a corresponding change in one's verbal report of symptoms. And of course, there is always the possibility that verbal and non-verbal indices of recovery are positively correlated with one another.
So...by dissecting out the brain from the body, rendering it unable to sense in the first place, or to report (verbally or nonverbally) on its sensations in the second, you are trying to accomplish what, exactly? I am afraid that once more your preconditions and a priori assumptions have rendered your question meaningless. It is a little like asking us to explain how it is that birds can fly, given that we have removed their wings and cut their heads off. It is not so much that the birds could not fly when examined appropriately, it is that the method you are forcing on your examination is precluding you from finding the answer.Kumar said:
um...what is ok? Subjective perception? My point was that it is flawed. Is the fact that it is flawed "ok"? It need not be ok, it is reality so we deal with it whether it is ok or not.
No, Kumar. Our brain's processing (and I feel I must include the processing that takes place in the retina itself), is extraordinarily complicated, and processed along multiple pathways. At this point, there is no location in the brain to probe to see a copy of the photograph. On the other hand, we can do single-cell readings in optical cortex and find that particular cells do fire to particular stimuli (so-called "feature recognition cells") such that particular line orientations, or grid frequencies, or motion, or color, or emotional valence, or whatever that particular pathway processes, can be assessed. One could, in principle (but remember the degree of complexity we are talking about here, and you will see how difficult it would be to accomplish in practice), perform a sort of fourier synthesis of the output of each of these feature-recognition (or movement, color, etc.) systems and recombine them meaningfully.
No, you are not. Not meaningfully, anyway. Again, without the subject's behavioral report (verbal or non) there is no possible way for you to verify "sensations in the brain", even if you had a perfect reading device. The brain does not exist by itself, Kumar; it is one complex part of an even more complex whole. The way you are trying to examine it would be like cutting open a person's leg to see where he had walked! If you are truly interested in these questions, and are not merely pushing some agenda, then take the time to learn about the experimental methodology already in use. Do not hobble your research by imposing restrictions based on your preconceptions of what the answers must be. Take advantage of the century or so of people who have started with the same or similar questions you did, and worked to develop a methodology.
Reminds me of the advice to those who love to empirically examine the behavior of our friend drosophila...to treat ourselves to the joy of measuring the duration of their various activities at times when we are already enjoying ourselves, thus multiplying our pleasure many-fold by the interactive effect of both prior mood and the sheer joy of doing science! I can remember the words my biology teacher used in conveying this advice to me, lo those many years--decades, now--ago...he said...Jeff Corey said:
Mercutio said:
It is not that simple. What, specifically, do you wish to measure? The thing is, it is not always commonsensical which method will be most reliable--and even then, the question you are asking may or may not be answerable as you ask it. I am concerned that you are still trying to limit your examination to "results/effects in brain or in nervous system", because it seems to me that you will unnecessarily limit the usable information. This would not be a limitation of the methodology, but a limitation of the question. If Donks is right in guessing your intent here, that could be very important. If you are trying to claim that the methodology is inadequate to find the effects you already know are there....well then, the answer is again "no"; it is not the methodology, but the question. You are introducing limitations that are unwarranted.Kumar said:
Donks said:
Great. Now that I know the question, the answer is fairly straightforward (funny how that works). Although I do not know of any such tests (I will, however, take a quick look on a couple of databases), there is absolutely no reason that such tests could not be done. The trick, of course, will be in finding an appropriate placebo condition as a control. But the testing itself would be quite possible. Given the interest in pharmacological effects on the nervous system, and the tremendous potential profits in identifying active substances, I should think that any remedy which showed promise would be immediately examined in great detail. Given the number of years people have been touting homeopathic cures, and the number of years people have been searching for neurological agents, my gut tells me that this is yet another area where there is no evidence whatsoever of any effect of homeopathic remedies having an effect. But I will look to the literature, just to be sure...Kumar said: