(Credit: iStockphoto/Vasiliy Yakobchuk)
ScienceDaily — The speed at which we react to threatening situations can have life or death implications. In the more primitive past, it could have meant escaping a wild animal; today it might mean swerving to avoid a head-on car crash.
It has been thought for some years that mammals have two decision-making systems in their brains which operate at different speeds to cope with different situations. New research from the University of Bristol supports this theory and has shown that the evolutionary pressures arising from the older, faster, but less accurate, part of the brain may have shaped the more recent development of the slower-acting but more precise cortex, found in humans and higher animals.
Pete Trimmer, lead author on the study, explained: "If we compare the brain of a human with that of a reptile, we find they are very similar except that mammals have a large 'outer cortex' around the outside of the existing 'sub-cortical' brain, that is common to other vertebrates.
"The fact that lizards make decisions indicates that the sub-cortical brain in humans is also likely to be used in decision-making. However, fMRI scans now reveal that parts of the outer cortex (which developed more recently in our evolutionary past) are also used when making decisions."Read more