Saturday, August 25, 2012

A thought about thinking

I understand that neuroscientists have not solved the problem of how the brain combines information from different sensory inputs. For example, how does the brain recognize that a sound and a sight are related and use inputs from the two to help interpret each.

I suppose that this ability is important for survival and thus selected for by evolution. An animal hears a sound and looks to see if a predator is approaching. Eyesight is more precise in locating things but it is possible to hear things one can not see.

I note that the human brain devotes a great deal of processing capacity to faces. This is true for animal faces, face-like images, but especially for human faces. While there is considerable variance in the number of faced recognized by different people, the average person recognizes a great many faces and can do so not only in person, but in a video or a photograph -- even without color.

The human brain also devotes a great deal of processing capacity to language. I suppose that this too is a facet of our evolution as a species of social beings.

I was thinking about these things when a ventriloquist appeared on TV with her dummy. My brain combined the video of a human head with a very quiet mouth and a dummy head with the mouth moving to the speech to perceive the dummy to be talking. My mind recognized that people talk and dummies don't. I suppose that divergence is somehow entertaining.

Then I realized that the sound was coming from the television speakers, not from either the human nor the dummy. My brain seems to identify speech coming from a general direction with "the most probable source" in that general direction.

There followed on the TV a clip that showed President Correa of Ecuador speaking in Spanish, but broadcast the English translation. The difference between what I was hearing and what the person was mouthing turns out to be annoying. There is the same annoyance watching a dubbed foreign film. My mind recognizes what is happening but my brain can't make the link it seeks to make between vision and hearing.

I guess we think with our minds and our brains, although our minds must be one of the functions of our brains.

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