This week in Mind Blowing Brain Cases: Phineas Gage.
The human brain has been described as “the most complex thing we have yet discovered in the universe”. In this series, neuroscientist Elisabeth Buhl Thubron takes a closer look at intriguing brain cases that revolutionized the field. Some led to new theories, others to popular brain myths or even more confusion.
Part I: The Man With A Hole In His Head
Name: Phineas Gage (1823-1860)
Age at time of accident: 25 years old
Occupation: Railway construction foreman
Location: Vermont, USA
“A moral man, Phineas Gage,
Tamping powder down holes for his wage,
Blew the last of his probes
Through his two frontal lobes;
Now he drinks, swears, and flies in a rage.”
Phineas Cage and the accident
It is nearing the end of a long working day on the railway tracks. Workmen are drilling holes into the ground, pouring down gunpowder and then using a long iron rod to press it all down. The holes are then refilled and the fuses lit, culminating in an explosion. The aim is to blast rocks out of the ground to make way for new railway tracks. This fateful day, such a simple procedure resulted not only in the destruction of rocks but also that of the life of a foreman named Phineas Gage.
To this day, there is still uncertainty surrounding the cause of the accident. It is popular belief that Gage’s iron rod produced a spark by scratching a rock, subsequently lighting the fuse before he could take cover. The brute force of the explosion threw the one metre-long and 3 centimetres-wide iron rod straight through Gage’s head, entering just below his left jaw and exiting through the top of his skull.
According to case reports the rod was found ‘smeared with blood and brains’. This comes to no surprise considering the size of the rod but it is astounding as Gage went on to live for another 12 years. Dr. John Harlow, who attended to his injuries, wrote a detailed and thus gruesome account of his injuries.
Gage’s brain was not preserved and there are few recorded accounts of his health post-accident, most of which are contradictory. This has resulted in over a century of exaggeration and guesswork surrounding the extent of brain tissue damage. According to records Gage became unreliable, partial to swearing, sexually promiscuous and was unable to keep a job. As said by his friends, “Gage was no longer Gage”. Was the destruction of his frontal lobes to blame?
Unraveling the science 156 years later
Both the left and right halves of your brain are composed of four lobes: the frontal, the parietal, the temporal and the occipital lobes. The left and right frontal lobes, located behind your forehead, control many of the functions that make you human. It is Gage’s story that gave us the first piece of evidence that damage to specific brain regions can result in behavioural and personality changes.
Nevertheless, the degree of Gage’s behavioural changes and the brain regions involved have long been argued. Whilst some records state Gage became permanently disinhibited to the point he molested children, other records claim he recovered many of his mental abilities and took on a job as a bus driver in Chile whilst also lecturing and exhibiting himself at circus-like shows. Unsurprisingly, sensationalists have since distorted the little facts we have for media hype or to support pet theories in science.
David Ferrier used Gage’s case to support his work on monkeys who had their frontal lobes removed. Ferrier reported behavioural changes in these monkeys, whilst other neurological functions remained intact, but he was quite vague when describing these changes. This further encouraged the overriding science myth that both frontal lobes control all behaviour and personality. Today it is relatively well established the frontal lobes play a role in executive function and social cognition, but they are not solely sufficient for carrying out these functions.
Owing to technological advancements such as 3D X-ray imaging, we may well be closer to uncovering more facts surrounding Gage’s case. In 2004, Peter Ratiu and Ion-Florin Talos based at Harvard Medical School digitally reconstructed Gage’s skull and published a video showing the path of the iron rod through Gage’s skull. The authors concluded that the rod did not cross into the right side of the brain, refuting previous theories, but in fact only pierced the left frontal lobe.
What about the brain tissue?
Eight years later, a research team headed by Dr. Van Horn and based at the University of California in Los Angeles, went a little further and digitally reconstructed the wiring within Gage’s brain. This map will provide insight into the indirect effect of the damage on connecting brain regions. If one brain region is damaged it can no longer send or receive information to its connecting region. Your brain is like a computer network whereby the neurons, a type of brain cell, are the computers and the insulated axons connecting neuronal networks are the long cables linking various computers.
As well as providing further evidence to support Ratiu’s and Talos’ finding that the rod never crossed into the right side of the brain, the authors found that the rod induced more damage to the cables than the computers. Although some of these connections would have terminated on the left side of the brain, many would also have crossed into the right side thus affecting regions further afield. This suggests Gage’s brain underwent more damage than previously thought. This could explain the convulsions he later experienced, ultimately leading to his death.
Not an exact science
Although this is all very sophisticated work, it is still speculation. Linking behavioural and personality changes to specific damaged brain regions is tricky. The position of your brain within your skull and the specific location of various brain regions are different when compared to, let’s say, my brain. Millimetre precision is crucial when understanding brain damage, yet in Gage’s case this is information we will never be obtained.
As mentioned earlier, several past reports claim Gage recovered some of his mental abilities but this was ignored at the time. Today, we know that compensatory brain plasticity occurs after damage whereby intact brain regions overtake some of the functions of those that were damaged. Perhaps Gage’s case should bear more emphasis on the mesmerising ability of the brain to not only survive such trauma but, to some extent, recover from it.
Linking a brain region to a specific function is not black and white. To quote from the book The Collapse of Chaos by Professors Ian Stewart and Jack Cohen, “If our brains were simple enough for us to understand them, we’d be so simple that we couldn’t”.
Phineas Gage. It may be a name difficult to remember but it is one that has nonetheless made an unforgettable and ground-breaking mark in the history of Neuroscience.
Harlow JM (1999). Passage of an iron rod through the head. 1848. The Journal of neuropsychiatry and clinical neurosciences, 11 (2), 281-3 PMID: 10334003
Ratiu P, Talos IF, Haker S, Lieberman D, & Everett P (2004). The tale of Phineas Gage, digitally remastered. Journal of neurotrauma, 21 (5), 637-43 PMID: 15165371
Van Horn JD, Irimia A, Torgerson CM, Chambers MC, Kikinis R, & Toga AW (2012). Mapping connectivity damage in the case of Phineas Gage. PloS one, 7 (5) PMID: 22616011