4 ms·

Does this matter in practice? We have binocular vision--when I read, I focus on a word with both eyes. The occasions where I'm reading with just one eye or anot

by d4mi3n 8y ago

Does this matter in practice? We have binocular vision--when I read, I focus on a word with both eyes. The occasions where I'm reading with just one eye or another are fairly rare.

kazinator 8y ago
The structural and functional division isn't between the eyes; it is present in both eyes. https://en.wikipedia.org/wiki/Divided_visual_field_paradigm https://en.wikipedia.org/wiki/Divided_visual_field_paradigm So if we are reading horizontally, the not-yet seen text is in a portion of the field of vision of both eyes that is routed to one brain hemisphere; the text already scanned is in the opposite field of vision going to the other hemisphere.
Baeocystin 8y ago
The field of vision split is right down the middle of each eye. One side of the brain gets the two left-halves, the other the right. FWIW. Oliver Sacks' The Man Who Mistook His Wife For A Hat has a chapter on hemispatial neglect which is an interesting read. (The entire book is fascinating.) https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_for_a_Hat https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_f...
- kazinator 8y ago
  Try as I might, I can't find details about the field of vision split. Like how perfectly vertical and straight is the division? What is the microscopic structure like: how crisp is the line at the cellular level? Is there some messiness at the boundary with regard to which hemisphere the cones and rods are routed to? Does the division run precisely through the middle of the fovea?
  - Baeocystin 8y ago
    This paper should help. :) https://www.ncbi.nlm.nih.gov/books/NBK10944/ https://www.ncbi.nlm.nih.gov/books/NBK10944/ Empirically, when running tests where you wanted a clear hemisphere separation, we always used between one and two degrees off the centerline axis. This was undergrad cog sci in the 90's, so take it for what you will.
    - kazinator 8y ago
      Thanks. I see from the side bar have been hitting this site. Let's see, recently viewed items: "Poppy seeds: differences in morphine and codeine content and variation ..." "Spectrum of human tails: A report of six cases ..." "Spontaneous knotting of an agitated string ..." :)
entwife 8y ago
Light is detected at each retina separately, and undegoes some processing in the retina. The optic nerve transmits that information to the thalamus (lateral geniculate nucleus). The lateral geniculate nucleus of the thalamus (LGN) is organized by visual field; the left thalamus receives information from both eyes about the right half of the visual field. Some cats died at the hands of Hubel and Wiesel to give you this information; AFAIK it was not studied by the national socialists in their grusome human experiments. On the original question, neglect dyslexia can be caused by disturbance in one cortical hemisphere.

by d4mi3n 8y ago

Does this matter in practice? We have binocular vision--when I read, I focus on a word with both eyes. The occasions where I'm reading with just one eye or another are fairly rare.

kazinator 8y ago

The structural and functional division isn't between the eyes; it is present in both eyes. https://en.wikipedia.org/wiki/Divided_visual_field_paradigm https://en.wikipedia.org/wiki/Divided_visual_field_paradigm So if we are reading horizontally, the not-yet seen text is in a portion of the field of vision of both eyes that is routed to one brain hemisphere; the text already scanned is in the opposite field of vision going to the other hemisphere.

Baeocystin 8y ago

The field of vision split is right down the middle of each eye. One side of the brain gets the two left-halves, the other the right. FWIW. Oliver Sacks' The Man Who Mistook His Wife For A Hat has a chapter on hemispatial neglect which is an interesting read. (The entire book is fascinating.) https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_for_a_Hat https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_f...

kazinator 8y ago
Try as I might, I can't find details about the field of vision split. Like how perfectly vertical and straight is the division? What is the microscopic structure like: how crisp is the line at the cellular level? Is there some messiness at the boundary with regard to which hemisphere the cones and rods are routed to? Does the division run precisely through the middle of the fovea?
- Baeocystin 8y ago
  This paper should help. :) https://www.ncbi.nlm.nih.gov/books/NBK10944/ https://www.ncbi.nlm.nih.gov/books/NBK10944/ Empirically, when running tests where you wanted a clear hemisphere separation, we always used between one and two degrees off the centerline axis. This was undergrad cog sci in the 90's, so take it for what you will.
  - kazinator 8y ago
    Thanks. I see from the side bar have been hitting this site. Let's see, recently viewed items: "Poppy seeds: differences in morphine and codeine content and variation ..." "Spectrum of human tails: A report of six cases ..." "Spontaneous knotting of an agitated string ..." :)

entwife 8y ago

Light is detected at each retina separately, and undegoes some processing in the retina. The optic nerve transmits that information to the thalamus (lateral geniculate nucleus). The lateral geniculate nucleus of the thalamus (LGN) is organized by visual field; the left thalamus receives information from both eyes about the right half of the visual field. Some cats died at the hands of Hubel and Wiesel to give you this information; AFAIK it was not studied by the national socialists in their grusome human experiments. On the original question, neglect dyslexia can be caused by disturbance in one cortical hemisphere.