[Paleopsych] NS: Knowledge of gravity hard-wired in the brain
checker at panix.com
Sat Apr 23 23:41:34 UTC 2005
Knowledge of gravity hard-wired in the brain
* 23 April 2005
NEWTON may have discovered the laws of gravity while relaxing under an
apple tree, but his brain knew about them all along, according to an
imaging study. It suggests that our brains have an internal model of
gravity that helps us understand how objects move under its influence.
Francesco Lacquaniti at the Santa Lucia Foundation and the University
of Rome, and his colleagues came up with this idea after observing how
poor astronauts are at predicting the motion of objects in zero
gravity. Now, using brain imaging, they have pinned down the brain
region involved to the vestibular cortex, which handles information
from the balance organs in the inner ear. It lit up when subjects saw
objects moving normally under the influence of gravity, but was much
less active when the movements were unnatural. So the region must be
responding to gravity, not just movement.
The vestibular cortex seems to build up an internal model of gravity
to help predict an object's motion. This is much more efficient than
mentally running through thousands of possible types of motion, when
most objects move in quite predictable ways, says Lacquaniti. And
links to the balance organs may "calibrate" the gravity model.
More information about the paleopsych