Tuesday, March 16, 2004

Watching Westerns for Science

A group of neuroscientists from Israel wanted to know if the brains of human subjects work in similar ways under natural conditions of processing visual and auditory data. They tested this by having 5 subjects watch "The Good, the Bad, and the Ugly while undergoing functional magnetic resonance imaging of the brain (FMRIB). Basically, in FMRIB increased blood flow to regions of the brain that are activated by a task increases the signal (or light up) in those areas and these changes can be viewed real time by researchers.

Intersubject Synchronization of Cortical Activity During Natural Vision

They found a significant level of synchronization of various brain centers between individuals, including primary and secondary visual and auditory areas and also in association cortices. It's also interesting that viewing a scene where a hand was focused on caused the hand-associated part of the motor cortex to light up in the subjects. While they didn't move their hand, they thought about it.

But there were some areas of the brain that showed more variation between individuals, such as the supramarginal gyrus, angular gyrus, and prefrontal areas. These areas are involved in sensory association, language, and reasoning.

These results are not unexpected given that the human brain collects external stimuli in the same way in most individuals e.g. auditory signals go the the auditory cortex. But processing of the data is expected to vary from person because of the subtle differences in neuronal wiring and memory. For instance, while watching the same movie, two people will see and hear the same things, but may draw different conclusions or form different associations based on their prior experiences.

What do you think of when you see this picture of Clint Eastwood? I think, "Gee what a handsome fellow. Too bad you can't see his eyes though and he smokes. Yuck!" Others may think, "Do you feel lucky today, punk? Huh, well do yah?"


No comments: