An emphasis on separable functions has characterized much recent theorising about executive abilities at the expense of interest in structural divisions within the brain. The first chapter by Stuss argues that a return to a neuroanatomical approach to frontal lobe function offers the best chance of identifying functional relationships and fractionation of function. He concludes that the current evidence points to four major functions: deficient energization, executive deficits, impaired behavioural and emotional self-regulation and deficits in metacognition. He argues that careful delineation of precise impairments may be crucial to targetting pharmacological and cognitive rehabilitation interventions.
Siedlecki and Stern in Chapter 2 discuss the related concepts of brain reserve and cognitive reserve. These concepts have arisen in the light of growing evidence revealing a lack of correspondence between the extent of brain damage and the resulting functional impact. Clinicians have always known that recovery from brain injury is very variable and individual characteristics often seem to be more important than intensity of therapy in determining outcome. We considered a chapter on this topic essential to include as the research and theory promises new opportunities for understanding response to rehabilitation. For example, as Siedlecki and Stern describe, experience and education appears to have an influence on cognitive reserve. This suggests the possibility that these factors could influence rehabilitation and gives hope of a degree of plasticity that gives credence to the idea that some restoration of function can occur through educational and experiential means.
In Chapter 3, Oddy, Worthington, and Francis review the confusing area of motivational problems following brain injury. Motivation deficits are commonly encountered in rehabilitation and can challenge the most experienced of therapists. Such problems are frequently cited when clients fail to achieve their potential and clinicians often feel poorly equipped to deal with the difficulties they cause. Oddy et al. suggest a framework for identifying different ways in which goal directed behaviour can break down which in turn can be used as a basis for suggesting different interventions. They argue that motivational disorders are no different from other forms of cognitive disorder, and so-called motivational deficits can be understood in terms of selective breakdown of cognitive and emotional processes within their framework.