Where lies the “Person” of our personality?

A queer accident happened about four years ago in 2008.

A long iron rod pierced through the chest of a 25 year old young man in a driving mishap.  Fortunately, the person had access to one of the top hospitals in New Delhi, India. Thanks to the developments in the surgical techniques, he survived the accident, was out of the hospital in a couple of weeks with a sound body and mind. He was Mr. S. Dutta, a software engineer. Neither his expertise nor his personality was affected by the accident. He retained his memories, his knowledge and skills and his temperament also did not change. In effect he continued to be the same person as before the gruesome accident.

S. Dutta, 18 July 2008

Wind backward 160 years.

A similarly strange but ghastlier accident took place in 1848. That too in a remote area where rocks were being blasted to lay railway tracks near Cavendish, Vermont, USA.

Phineas Gage was the dashing and equally young Foreman and Head of a team of railroad workers. He was tamping down explosives in the drill hole of a rock face with a long iron rod.  The powder in the blast hole suddenly exploded. The iron rod pierced straight through the cheek and head of the young man. We do not have the details of how he was taken to the hospital or what the medicos did. Miraculously, he could survive the accident!  But his brain was dmaged.

Phineas Gage – Skull with the tamping rod, 13 Sept 1848

Mr. Gage was a changed man after the incident.

The jovial, friendly, intelligent and restrained Phineas was gone. Instead, as his friends bemoaned, there was now a quarrelsome, hot-headed, impatient and angry man with filthy language and a foul mouth. He was no more the sociable and pleasant person that he had been. Phineas lost his skills, his job and even his family. From being a teetotaler, he turned out to be a drunkard. His personality changed totally.

Phineas Gage holding the tamping rod

That was very unfortunate for Mr. Gage. But his accident proved a watershed for science. His name made history. It has become synonymous to the end of mind – brain duality.

It was clear that the characteristics that describe the personality of an individual, the ‘self’ of the man, lie somewhere in the brain but not in the chest.

If his ‘self’ had its own existence unconnected to the brain, his personality should not have changed. This shows that the brain is a mechanism that generates the ‘self’ rather than an organ that houses it.

Consequently, the study of ‘self’, the imaginary center of ‘personality’, moved from philosophy to science – more specifically to neuroscience.

What were the exact changes in the brain that so vastly changed the personality of Mr. Gage? The answer continues to elude scientists. The problem has been a challenge for research.

It was clear that the left eye ball was thrown out of the socket  and much of his left frontal lobe had been destroyed. “The exact location and the degree of damage to Gage’s cerebral cortex” remained to be a matter of dispute. For the first itme now researchers have been able to find using modern imaging techniues,  “that while approximately 4 percent of the cerebral cortex was intersected by the rod’s passage, more than 10 percent of Gage’s total white matter was damaged. The passage of the tamping iron caused widespread damage to the white matter connections throughout Gage’s brain, which likely was a major contributor to the behavioral changes he experienced” (See a Report here).

But it is also possible to have normal life with only half the brain. This beautiful 9-year old had half her brain removed by surgery in 2010.

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Girl, 9, with miraculous recovery after half her brain (right side) is removed during surgery 26th March 2010

 

 

 

 

 

 

There is a lot of flexibility built in the brain. There are about 100 billion neurons in the brain.  Each neuron on an average is connected to 5,000 other neurons. New neurons can be generated, new connections between neurons can grow, and existing connections can be strengthened or weeded out. Our experiences, the knowledge we acquire, the type of activity we do, our thoughts and even the morning cup of coffee we drink alter neuronal connections.It is these connections  that give rise to our memories, our beliefs and define what we are.

Wrong neural connections can give raise sometimes to either extra-ordinary abilities or even unfortunate debilities. Our brains are not like fixed pre-programmed printed circuit boards.  It is a highly labile situation here.

A stranger case, however, is that of a headless chicken which lived for about 18 months in Colarado, USA. While chopping, “the axe had missed.  Although most of his head was severed, most of his brain stem and one ear were left on his body. Since basic functions (breathing, heart-rate, etc.) as well as most of a chicken’s reflex actions are controlled by the brain stem, it was able to remain quite healthy.”

Headless Chicken, 10 Sep 1945

And, of course, it is routine now in brain labs to experiment on the behavior of flies which live for about a week after beheading.