From Aristotle’s Error:
[C]ells in early-processing brain areas are each sensitive mainly to changes in just one visual parameter, not to others. For instance, in the primary visual cortex (V1, also called area 17), the main feature extracted is the orientation of edges. In the area known as V4 in the temporal lobes, cells react to color (or, strictly speaking, to wavelengths of light, with different cells responding to different wavelengths). Cells in the area called MT are mainly interested in direction of movement.
That’s relevant because a few years ago I came across (in here, I think) the easily-offended aboriginal anthropologist Alice Beck Kehoe trying to refute the idea that primitive cave-paintings of form constants had anything to do with the perceptions in altered states of consciousness, by bringing up an artist-friend of hers who had drawn similar images, but explicitly with no spiritual origins—rather, he was just exploring the edges of objects in his paintings.
Why did the suggestion that cave paintings are accurate transcriptions of forms seen in altered states of consciousness bug Kehoe so much? Simply because she thought it meant that (esp. white) anthropologists were saying that such primitive people couldn’t distinguish between reality and their drug/dancing-induced (primary visual cortex) hallucinations. She’s utterly wrong about that, of course: It’s precisely because people such as the Jivaro can distinguish between hallucinated form constants and their daily lives that they take the former as being the archetypal basis of the latter.
[...] March 15, 2010: Aristotle’s Error [...]