Understanding the Brain: The Case of Phineas Cage

What impairments would you expect to see following lesions to the ventromedial prefrontal cortex? Compare and contrast with lesions affecting the dorsolateral prefontal cortex.

In 1948 Phineas Gage, an American railroad construction foreman, was involved in a terrible accident during which a tamping iron was explosively forced upwards through his left cheek and exiting the top of his head (Harlow, 1948). He stunned his colleagues by not only surviving the event and swiftly regaining consciousness but by also by walking to a nearby cart. Gage regained many of his physical and mental abilities but remained altered in his personality to the extent that he was considered “gross, profane, coarse and vulgar” (Bigelow, 1851), having previously been considered diligent and pleasant. The curious case of this gentleman with extensive brain damage but nevertheless much retained function has fueled interest and research into the localization of function within the brain. Although the exact nature of Gage’s injuries has been subject to extensive debate (Ratiu et al., 2004), it is generally accepted that a large part of his left prefrontal cortex was damaged, including the medial and lateral orbito-frontal and the dorsolateral prefrontal regions.

Stuss and colleagues (2002) argue that clinical neuropsychology at its simplest is “the understanding of brain-behaviour links and their applications to clinical situations”. In their review of the history of clinical neuropsychology, they speak of three fields that have contributed to our current understanding of brain behaviour links including 1) behavioural neurology, 2) neuropsychiatry and 3) clinical neuropsychology. Within these disciplines, a range of techniques are used to investigate loca...

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...rior temporal cortices during word generation. However, dlPFC changes are not seen during tasks when they are required to made lexical decisions about hear words suggesting that the dlPFC plays a role in modulating the generation of words (Frith et al., 1991). In a study of the effects of focal anterior and posterior brain regions on verbal fluency, Stuss and colleagues (1998) suggest that although deficits are seen with superior medial frontal damage, those with left dlPFC, striatal and left parietal damage are most impaired on letter-based fluency. Patients with right dlPFC lesions do not show deficits in this task. The same lesions also produced deficits on category-based fluency, but so did right dlPFC damage. They are that the specific role of the dlPFC in these tasks is initiation and activation, verbal articulatory rehearsal and sustained production.