Physically, the phenomenon of Phineas Gage was largely understood over a century ago. During a railroad construction accident in Vermont, a 13.5 lb., 3 foot 7 inch long and 1.5 inch thick tamping iron was rammed under the left cheek bone and out the top of the head of the likable foreman, Mr. Gage. The bar landed 25-30 yards behind him. Miraculously, he never lost consciousness, was able to walk, talk, and was largely recovered within 10 weeks of the accident. Neither his memory nor his intelligence were compromised by the force of the blast or the movement of the bar.
The lasting effects of the accident, however, were in Gage's personality. A previously kind and thoughtful man was now rude and antisocial. "Gage," his friends said, was "no longer Gage." His physician at the time, Dr. Harlow, said in 1868 that "his equilibrium, or balance, so to speak, between his intellectual faculties and animal propensities seems to have been destroyed. He is fitful, irreverent, indulging in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires." The emotional and social behavior of Phineas Gage was distinctly and permanently altered due to brain damage.
Although Dr. Harlow reasoned that the damage was done to the frontal lobes of Gage's brain, "nineteenth century science had a hard time accepting the notion that a dollop of gray jelly could govern something so transcendent as social behavior ." The exact location of the trauma was found recently (1994) during examinations of Gage's skull using photography, x-rays and 3-D computer modeling. These have shown that the regions of the frontal lobes essential for intellectual, motor and language function, the motor strip and Broca's area, were left intact. The lower middle portions of both frontal lobes, however, were damaged. More specifically, the ventromedial region of the frontal lobe was destroyed, particularly on the left side. This localized damage seems to have been responsible for the temperamental and behavioral alterations. "The process of an individual's education and maturation can be seen as the establishment of plans of actions and responses that are influenced by basic drives, but...achieved through socially acceptable means. (Particular frontal areas) may be the structures in which most such patterns of behavior are inscribed and through which most of the pertinent information travels."
The legacy of Phineas Gage was in many ways the impetus for the ongoing study of the biological and neurological bases for behavior. The localization of control for certain behaviors was avidly studied and it soon became more clear that social behavior could be altered through biological alterations of the brain. Interestingly, some cite the Gage case as the first well-studied, but very crude neurosurgery. It is often considered a major contributor to the development of brain surgery, particularly to the frontal lobotomy, a surgical attempt to permanently change temperament and control impulsive behavior.
More recently, the symptoms exhibited by Phineas Gage and other similar cases due to accident, tumor or surgery have been combined to describe this particular type of brain damage. Known collectively as Frontal Lobe Dysfunction, it is "a sly form of brain damage affecting judgment without injuring intelligence, speech or strength." While there many symptoms involved, there is no single set of criteria that can be used to make a diagnosis of Frontal Lobe Dysfunction. In general, however, some common symptoms are: altered mood, decreased concern with social propriety, apathy, depression, restlessness, disinhibition, social withdrawal, outbursts of irritability, impulsiveness, lack of judgment, lack of ambition, lack of restraint, and outwardly directed behavior and social sense. The FLD patient is "a very simplified human organism with only rudimentary mechanisms for social adjustment...limited and lacking in the kind of potential needed for growth and self-realization." The patient suffers from social weakness and lacks any "physiology of insight."
Once the physical location of the injury to the frontal lobes and the possible behavioral effects have been identified, the next big question is in terms of the processes. What was taking place in Phineas Gage's brain when the pole sliced through it? Did the pole somehow dislodge Gage's "nice" and "social" neuronal connections? Did the pole re-route and somehow connect the "mean" and "nasty" ones? It is now obvious that the prefrontal lobes are responsible for motivation, control, judgment and sense of self. But, how? What does this mean? How do they work? What can we say is happening when there has been no trauma? In this sense, this part of the brain is "silent" and we must use inferences and theories to deduce the innerworkings of this part of the brain.
At a recent conference in Washington, several scientists claimed that "the capacity to be pleasant toward a fellow creature is in a sense hard work. It is not the default mode. Instead, affiliative behavior requires a hormonal and neural substrate, an activation of circuitry every bit as intricate as the mechanisms controlling the body's ability to fight an opponent or flee from danger." Looking at Gage from this light, his accident seems to have deactivated that part of his nervous system which controlled or inhibited his natural tendency to be immoral, antisocial and rude. In other words, no tucked away "poor temperament" buttons were pushed. Instead, the tendency that we all have to be socially inappropriate and lacking in good judgment was simply allowed to manifest itself.
A French neurologist, L'Hermitte, describes frontal lobe disease as a "powerlessness in the face of influences from the outside world" and he calls this "environmental autonomy." In his view, the frontal lobes exert control over the parietal lobe of the brain, which receives signals from the outside world. It is the role of the frontal lobes to select the signals appropriate for particular circumstances. The lobes act as a "meaning-filter," pulling out only certain stimuli and allowing people with intact frontal lobes to respond to these incoming pieces of information with judgment and logic. Damage to the frontal lobes causes people to lose this control. They are now overwhelmed by all signals, become overstimulated and respond in seemingly irrational ways. In this light, at the time of the accident, Gage lost control over the signals that he received. His prior knowledge of sociability was overcome by the need to respond, however inappropriately to the surplus of incoming information .
Although it is a vast topic that can only be touched upon here, it is interesting to also look at the role of the brain in sociability and temperament in terms of reason and emotion. The traditional dichotomy between rationality and emotion, espoused by Descartes and others, says that one opposes the other, that the use of reason is most effective when separate from emotion. In this way, errors in reason caused by emotion can be kept to a minimum. Antonio Damasio claims, however, that emotion and reason are tied together closely. Emotions, then, add to the decision-making process. The emotional, social person is accounted for in the same place in the nervous system as that part of us which is responsible for good judgment, moral decisions and the sense of self. These can be cut out, damaged or otherwise made inactive. Again, the control over this part of the brain is lost, making the social person into something entirely different.
It may never be known what, exactly, is taking place in the brain before and after frontal lobe damage. Is it enough to say that damage is being done to a region of the brain responsible for motivation, sociability, judgment and temperament? Maybe. Maybe it is also enough to say that this region is set free to act uninhibited and oblivious to prior learning and social norms. Due to the silent nature of the brain, we may have to be satisfied with knowing, with certainty, only what happens when something goes wrong. There is satisfaction in knowing how Gage is no longer Gage, in seeing how he was constructed into something new. But we may not have the full answer to why Gage is no longer Gage.
Damasio, Antonio R. Descartes Error. G.P. Putnam's Sons, New York, 1994, p.31-33.
"One Way Cartesianism," by R. Carpenter
Suss, Gow and Hetherington in "Frontal Lobes and the Perception of Emotion," by C. Lebson
"Illuminating How Bodies Are Built for Sociability," by Angier N.
The Brain of Phineas Gage, at UT Southwestern Dept. of Neurology
Summarized from The Physiology of Insight, Elissa Ely, MD
Eslinger and Damasio quoted in "The Physiology of Insight," by Ely, E.
"A Short History of the Lobotomy" adapted from 'Medical Blunders,' by R. Youngson and I. Schott
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