Explanations are usually descriptions at a lower level:
Q: Explain vision A: well, light falls on the retina at the back of the eye... Q: retina? A: yeah, it contains rods and cones, and they convert light into neural activity Q: neural activity? A: when the firing threshold is reached, voltage dependent sodium gates open and cause an action potential Q: sodium? A: that is a cation; an atom that misses one electron Q: atom? electron?
Well, you get the idea. Ultimately you get a description that can only be done in mathematical terms. But can I explain vision? No. I can describe it (to some degree), but it is really a miracle to me (not that I am religious BTW)
It is not mentioned very clearly in the NYT article, but it is mentioned in the original Current Biology paper: this patient has BILATERAL lesions in both the left and right visual cortices. IMO, this is what makes this case especially interesting.
Of course, blindsight has been demonstrated many times before, but always in patients with unilateral lesions. This has some methodological advantages (the patients can act as their own control), but the unilaterality has also been criticised. Maybe these patients make microsaccades, maybe some light is reflected by the nose into the other eye halves, etc. In short, maybe some information reached the intact hemisphere.
This is not possible in the present patient, and that is especially interesting. AFAIK, this is the first and only patient with a bilateral blindsight.
Slashdot Mirror
Explanations are usually descriptions at a lower level:
Q: Explain vision
A: well, light falls on the retina at the back of the eye...
Q: retina?
A: yeah, it contains rods and cones, and they convert light into neural activity
Q: neural activity?
A: when the firing threshold is reached, voltage dependent sodium gates open and cause an action potential
Q: sodium?
A: that is a cation; an atom that misses one electron
Q: atom? electron?
Well, you get the idea. Ultimately you get a description that can only be done in mathematical terms. But can I explain vision? No. I can describe it (to some degree), but it is really a miracle to me (not that I am religious BTW)
It is not mentioned very clearly in the NYT article, but it is mentioned in the original Current Biology paper: this patient has BILATERAL lesions in both the left and right visual cortices. IMO, this is what makes this case especially interesting.
Of course, blindsight has been demonstrated many times before, but always in patients with unilateral lesions. This has some methodological advantages (the patients can act as their own control), but the unilaterality has also been criticised. Maybe these patients make microsaccades, maybe some light is reflected by the nose into the other eye halves, etc. In short, maybe some information reached the intact hemisphere.
This is not possible in the present patient, and that is especially interesting. AFAIK, this is the first and only patient with a bilateral blindsight.
-- Geert