Let's talk about that sexy minx Mary who has never seen colour...
Moderators: kiore, Blip, The_Metatron
Quite. The possibility that their language reflects what they see, rather than what they see reflecting their language, seems to have been neglected.DavidMcC wrote:SOS, concerning the Himba's perception of subtle hues of green, I would like confirmation that the experiment takes into account the known genetic variants of the MW (and even LW) opsin genes. If the Himba happen to have a different allele than the control group, then this might have more impact than cultural differences, and should certainly be taken into account.
ramseyoptom wrote:They work by employing the observation that a infant would rather look at a pattern than a blank stimulus ( Fantz RL, Ordy JM and Udelf MS (1962) Maturation of pattern vision in infants during the first six months Child Dev 46 3-18)
ughaibu wrote:Quite. The possibility that their language reflects what they see, rather than what they see reflecting their language, seems to have been neglected.DavidMcC wrote:SOS, concerning the Himba's perception of subtle hues of green, I would like confirmation that the experiment takes into account the known genetic variants of the MW (and even LW) opsin genes. If the Himba happen to have a different allele than the control group, then this might have more impact than cultural differences, and should certainly be taken into account.
Correct me if I am wrong. You are saying that you know better than the researchers in the field of child development and the peer review process because you are a skeptic. What are your credentials here? I don't mean degrees, I mean knowledge.DavidMcC wrote:ramseyoptom wrote:Preferential Looking Techniques (aka baby's gaze) have been shown to be robust and repeatable, even though they are dependent on the examiner's ability and the child's attention.
Repeatable, sure, but that only means that the possible misinterpretation is repeating.SpeedOfSound wrote:So you think you are in a position to peer review and reject all of the cognitive studies on infants based on your thinking that baby-gaze is unreliable. Huh. As a a photobiology kind of guy you believe that it all ends after the retina develops. Where is that? 1 month? 3?
Gross misunderstanding. I am claiming that there has not been adequate peer review of those studies, except by non-skeptics of the method and assumptions of the baby's gaze method. Basically, that is becasuse there are no alternatives avaliable.
I am having a lot of trouble understanding you so forgive me. I have to ask you some questions. It seems clear to me that you are saying that the only changes to the VC are memories of visual images being recorded? During the early postnatal and on up? No changes in how they perceive?
The exact period of time is beside the point, except that it is not years. Any VC changes over such a period are surely about visual memory formation, not the details of perception.
Okay. So this says somewhat the opposite but you believe visual perception of say the color blue is fully developed after two weeks and unchanging after that?
You are also continuing to make the gross error of assuming that I claim no development after the retina has formed. I never said such nonsense. What does occur is that the the thing to which the VC adapts is determined wthin a few weeks of birth.
Also, regarding the video, I think there was a misunderstanding between us over the issue of whether we were talking about major or minor differences in colour perception. I was talking about the subtle differences between different groups of adults, but you were obviously talking about the major changes that occur in a baby's visual system after birth.
SpeedOfSound wrote:Correct me if I am wrong. You are saying that you know better than the researchers in the field of child development and the peer review process because you are a skeptic.DavidMcC wrote:ramseyoptom wrote:Preferential Looking Techniques (aka baby's gaze) have been shown to be robust and repeatable, even though they are dependent on the examiner's ability and the child's attention.
Repeatable, sure, but that only means that the possible misinterpretation is repeating.SpeedOfSound wrote:So you think you are in a position to peer review and reject all of the cognitive studies on infants based on your thinking that baby-gaze is unreliable. Huh. As a a photobiology kind of guy you believe that it all ends after the retina develops. Where is that? 1 month? 3?
Gross misunderstanding. I am claiming that there has not been adequate peer review of those studies, except by non-skeptics of the method and assumptions of the baby's gaze method. Basically, that is becasuse there are no alternatives avaliable.
I am having a lot of trouble understanding you so forgive me. I have to ask you some questions. It seems clear to me that you are saying that the only changes to the VC are memories of visual images being recorded? During the early postnatal and on up? No changes in how they perceive?The exact period of time is beside the point, except that it is not years. Any VC changes over such a period are surely about visual memory formation, not the details of perception.Okay. So this says somewhat the opposite but you believe visual perception of say the color blue is fully developed after two weeks and unchanging after that?
You are also continuing to make the gross error of assuming that I claim no development after the retina has formed. I never said such nonsense. What does occur is that the the thing to which the VC adapts is determined wthin a few weeks of birth.
Also, regarding the video, I think there was a misunderstanding between us over the issue of whether we were talking about major or minor differences in colour perception. I was talking about the subtle differences between different groups of adults, but you were obviously talking about the major changes that occur in a baby's visual system after birth.
Slight correction. I am talking about the major changes that occur in a baby's visual perception after birth.
SpeedOfSound wrote:Okay. So this says somewhat the opposite but you believe visual perception of say the color blue is fully developed after two weeks and unchanging after that?
DavidMcC wrote:Technical aside: It is technically difficult to give a detailed response to a multi-section post, so I recommend splitting long posts into separate, single-issue ones, as I often do.
DavidMcC wrote:SpeedOfSound wrote:Okay. So this says somewhat the opposite but you believe visual perception of say the color blue is fully developed after two weeks and unchanging after that?
No, not at all. I said the retina to which the VC adapts is more or less complete after a couple of weeks. Of course it takes much longer (don't know how long) for the VC to adapt to the retina. However, the end-point of that process is largely determined by the details of the retina. In other words, those who only have two different cone types after a couple of weeks will probably end up with a VC suitable for those two, not three, for example.
EDIT: Also, the overall spectrum of light falling on the retina has to remain as broad as in the first couple of weeks, so that the VC is adapting to the same environment as the retina did.
DavidMcC wrote:My knowledge of brain development comes from papers and articles on the adaptation of the VC to the retina. Unfortunately, a key paper is lost to me, as I have said a couple of times before, to GrahamH, about the nature of the output of cone cells. The model I think makes most sense requires that different cone cell types differ by more than just the actual opsin type.
Rodents have two opsins in each of their cone cells, and are therfore considered to be monochromats with a broad wavelength sensitivity, rather than dichromats with the same overall bandwidth. If our opsins were split between identical cone cells, that would be similar to rodents, except with three opsins. In fact, the SW cones (blue) are distinct from the MW and LW cones, with even the opsin being coded for on a different chromosome from the other two - the SW cones must have evolved much earlier, in deep water, where any light is strongly biassed to the blue.
SpeedOfSound wrote:DavidMcC wrote:My knowledge of brain development comes from papers and articles on the adaptation of the VC to the retina. Unfortunately, a key paper is lost to me, as I have said a couple of times before, to GrahamH, about the nature of the output of cone cells. The model I think makes most sense requires that different cone cell types differ by more than just the actual opsin type.
Rodents have two opsins in each of their cone cells, and are therfore considered to be monochromats with a broad wavelength sensitivity, rather than dichromats with the same overall bandwidth. If our opsins were split between identical cone cells, that would be similar to rodents, except with three opsins. In fact, the SW cones (blue) are distinct from the MW and LW cones, with even the opsin being coded for on a different chromosome from the other two - the SW cones must have evolved much earlier, in deep water, where any light is strongly biassed to the blue.
So you admit to no knowledge about what happens after the LGN? Or V1?
The Himba of northern Namibia ... call the sky black and water white, and for them, blue and green share the same word.
Users viewing this topic: No registered users and 1 guest