To the Best of Our Knowledge: Seeing and Perceiving

In this hour, we'll talk with Oliver Sacks about the neurobiology of vision. We'll also examine the science behind synesthesia - why some people can hear colors or feel the flavor of food on their fingers. First, Oliver Sacks, the celebrated doctor who writes about some of the brain's strangest disorders. His latest book, The Mind's Eye, is a study of rare visual impairments caused by neurological disorders. It's an unusually personal book for Sacks - because it reveals his own struggle with a disorder called facial blindness. Steve Paulson talked to Sacks recently about some case histories.

Next, Susan Krieger is not completely blind, but her vision is bad enough to make her legally blind. Although she prizes her self-sufficiency, she recently got a guide dog, Teela, who is now her constant companion. She tells Jim Fleming that this raises some basic questions about how Susan Krieger thinks of herself, things she writes about in a memoir called Traveling Blind.

Then, Ken Nordine recites his word poem "yellow," which leads to a discussion of synethesia. a neurological condition which causes one sense to cross paths with another.

After that, David Eagleman is a neurologist and the co-author of the book Wednesday is Indigo Blue: Discovering the Brain of Synesthesia. Anne Strainchamps asked him to describe the condition.

Following that, Jim Fleming reads a short excerpt from Speak Memory, by one of the literary world's most famous synesthetes was Russian novelist Vladimir Nabokov, who wrote about his "colored hearing."

And finally, Chuck Close, a painter famous for his huge canvases and his uncanny ability to portray his subjects with almost photographic realism. He has a neurological condition that prevents him from recognizing people's faces. Today, Chuck Close is in his early 70s - still painting, with brushes strapped to his hand - and now the subject of a biography by his friend Christopher Fin...