Neuroimaging studies of healthy individuals and studies of individuals with frontal lobe brain damage have provided differing 'pictures' of the functions of the frontal lobes. How do they differ and why do you think this difference occurs?

Neuroimaging studies of healthy individuals have provided detailed information about specific regions in the prefrontal cortex PFC) and their role in human cognition. Throughout the past decade or so, more and more information has been provided by these studies so that at present, there are models of the functions of the PFC that show how specific regions interact with other brain regions in tasks involving working memory, voluntary attention, and executive control. While these neuroimaging studies provide many details of localized functional regions in the PFC, a different picture is provided when looking at the deficits that occur when an individual has suffered brain damage to the PFC. Generally, the deficits that occur are complex and effect many aspects of cognition. While frontal lobe syndromes are described, such as the dorsolateral or the orbitofrontal syndromes, in general highly specific deficits are not observed with frontal lobe damage. How do we combine the findings across neuroimaging and brain damage studies? This is a central goal of cognitive neuroscience. At present, our best approach for providing a unified account of frontal lobe function across studies of healthy and brain damaged individuals is to understand that frontal lobe damage likely causes a cascade of damage across local and widespread regions such that the deficits may be more complex and less specific. On the other hand, the findings from neuroimaging studies provide key information about how specific and localized regions in the PFC process information when they are undamaged and intact.