The Israeli researchers, on the other hand, gave their subjects complete freedom in watching the movie. Volunteers were placed in an MRI machine. Equipped with earphones, they watched the film on a screen inside the MRI machine while their brains were scanned.
Malach says the researchers chose The Good, the Bad, and the Ugly partly because it is one of the favorite movies of the lead author of the study, Uri Hasson.
"We just let [the movie] run for half an hour," Malach said. "The movie contains many object categories at the same time. It is dynamic, audiovisual, and has rapidly changing language and emotional aspects.
Although the subjects had complete freedom in watching the movie, researchers found a striking similarity in the activity pattern across large parts of the subjects' brains.
"It appears that all the brains of the subjects watching the movie tick together in a similar fashion," Malach said.
The study also showed that different brain areas focus on certain frames and short scenes that fit the brain area's specialization. Using special computer software, the scientists were able to identify what images different brain areas pick up on.
"An area that was suspected as being involved in face recognition selected from the movie only those scenes that contained close-ups of faces. While a nearby area that was suspected of dealing with navigation was active mainly when outdoor scenes were shown," Malach said.
"Perhaps most interesting of all, we found that an area of the brain associated with the sense of touch was active whenever delicate hand movements were shown."
However, the researchers did find some regions of the activated cortex that could not be predicted from another individual's brain activity. Embedded among the more "cooperative" portions of the brain, this region showed a completely individualistic pattern of activation during the movie, without any similarity between subjects.
"We speculate that these might be related to some function which is indeed intrinsic to each [person] and not related to external stimuli," Malach said.
The scientists hope the movie experiment may offer a model for probing unknown brain-activity patterns in regions that are typically not reached by conventional experiments.
"This opens the way to rapid discovery of new specializations in the human brain, because it has the advantage of allowing us to study the brain without the need to assume ahead of time what each area is doing," Malach said.
Malach believes the research will help scientists map little-understood brain areas, and give scientists better insight into what kinds of images engage us and attract our attention and focus.
"We also anticipate that it could be used as a rapid and sensitive diagnostic tool for mental cases, such as autism, Alzheimer's, retardation, and perhaps even schizophrenia," Malach said.
SOURCES AND RELATED WEB SITES