if you put a cat in a black cylindrical cage with only white vertical lines painted on its inside for the first portion of their lives, when the animal is removed and placed in the environment, they will not be able to see anything that is not vertical.
during those first months their brains are maturing at a critical period. since during that critical period their brain only saw vertical lines, those are the only ‘visual receptors’ that the brain of the cat developed. so things with angled or horizontal lines in the environment, such as another animal or a horizon, would be completely invisible to this cat. It would be as if they did not exist.
if you stretch your mind there are implications...perhaps infants who do not receive a particular type of emotion or care at a critical period of time may simply not have the ‘receptors’ or capacity to feel or understand certain responses later in their lives. we are such sensitive creatures....take the sensation of touch. infants in orphanages in the 1940's who were fed and changed but never held, stroked, or spoken too, died.
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J Comp Neurol. 1982 Nov 10;211(4):353-62. Related Articles, Links
Exposure to lines of only one orientation modifies dendritic morphology of cells in the visual cortex of the cat.
Tieman SB, Hirsch HV.
To determine whether selective exposure to lines of one orientation modifies the shape of the dendritic fields of cells in visual cortex, we examined the dendritic morphology of neurons in area 17 of five normally reared cats, five cats reared viewing only vertical lines, and three cats reared viewing only horizontal lines. Kittens were placed with their mothers into a totally dark room before their eyes had opened. Beginning at 4 weeks of age, the kittens were brought out for daily periods of exposure wearing masks that limited the vision of each eye to a field of three vertical lines or three horizontal lines. After a minimum of 170 hours of exposure, the animals were killed and blocks of visual cortex were impregnated by the Golgi-Kopsch procedure and cut tangential to the pial surface. Complete neurons from layers III and IV were drawn with the aid of a camera lucida, and the orientations of the dendritic fields wer analyzed using Sholl diagrams. In normal cats, the distributions of the orientations of dendritic fields were uniform, whereas in strip-reared cats, the distributions for the layer III pyramidal cells were shifted. The direction of this shift varied with the experience of the cat: In cats reared viewing only vertical lines, the dendritic fields were oriented orthogonal to the representation of the vertical meridian, and in cats reared viewing only horizontal lines, the fields were oriented parallel to the representation of the vertical meridian. In contrast, the distribution of dentritic orientations for the stellate cells was not affected by stripe-rearing. These results demonstrate a morphological effect of early visual experience that is specific to the particular stimulus presented during rearing and suggest that (1) cortical cells differ in the degree to which they can be modified by such experience, and (2) the dendritic morphology of cortical neurons is related to their preferred orientations.
PMID: 7174898 [PubMed - indexed for MEDLINE]
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