ABSTRACT

The two lobes of the frontal cortex comprise just under one-third of the cortex and comparisons with other species indicate that it has, in proportional terms, undergone its greatest enlargement in humans (Fuster, 1989). This suggests that the role of the frontal cortex is likely to be complex and that the functions it subserves will include many of those that are thought by some to set humans aside from other animals. Aristotle believed that there was a ‘common sense’ which was common to all the ’special senses’. Figure 10.1 shows Blumenbach’s illustration of the human brain from 1840 and you can see that the ‘communis sensus’ is placed in the frontal cortex with specific abilities located in more posterior parts of the brain. The positioning of a common sense mechanism overseeing the rest of the brain’s activity in the frontal lobes may well have been for completely spurious reasons, but that is now how the major role of the frontal cortex is viewed. Indeed the first neuropsychological evidence supporting this idea of frontal function arose just a few years after Blumenbach’s diagram was published.