Damasio (Brain)
Damasio et al (1994) The Case of Phineas Gage (textbook pg. 90-92)
“Understand the aims, procedures and findings (results and conclusions), strengths and weaknesses of: Damasio et al (1994) The Return of Phineas Gage: Clues About the Brain from the Skull of a Famous Patient.”
Background to Phineas Gage: In 1848, Phineas Gage was 25
years old and working on a railway line, when an explosion caused
an iron rod to be fired through his skull and through his brain. He
recovered from his physical injuries, but the neurological damage to
the prefrontal cortex caused permanent changes to his personality.
Before the incident, Gage was a pleasant, polite and responsible
man. After the brain damage, he became rude and irresponsible – as
if he was a completely different person.
After Phineas Gage died, his skull was kept at Harvard University in
the USA, and Damasio and her colleagues have studied the skull
using modern technology.
Description: APRC
| A | • Damasio aimed to create a 3D computerised model of Phineas Gage’s skull (based on his actual skull) including the holes made by the iron rod. • Damasio also aimed to identify which areas of the brain had been damaged by the iron rod, specifically if any areas had been damaged in addition to the frontal lobe. |
| P | • The researchers took photographs and measurements of Gage’s skull, and from this, they created a 3D computerised model of his skull. They also took measurements of the iron rod, which was 3cm in diameter and 109cm in length. • They matched the possible entry and exit points of the iron rod to Gage’s skull, to track the likely path the iron rod took through his skull. 20 different entry points and 16 different exit points were tested to try to find the most likely path. • After finding the 5 most likely routes, they used the 3D virtual model to map out which areas of Gage’s brain would have been damaged in each case. |
| R | • There was likely to have been damage to both the left and right hemispheres of the frontal lobe. • It was likely that the damage was only in Gage’s frontal lobe, and no other areas of his brain. • The iron bar passed through his left eye socket, meaning there was likely more damage to white matter in the left hemisphere of the frontal lobe, compared to the right hemisphere. This means he couldn’t pass neural messages in this part of his brain. • Damage seemed to be worse in the middle of the underside of the hemisphere (ventromedial area) compared to the upper part of the hemisphere (dorsolateral area). |
| C | • Damasio concluded that the ventromedial area of the frontal lobe seems to control our impulses around people and control of emotions. • Damasio had supporting evidence for this conclusion from 12 other patients with frontal lobe damage, who all had impulse control and emotional control damage. |
Evaluation: GRAVE
| G | • The conclusions drawn are based on one rare case, therefore the results may lack generalisability. • However, Damasio found the same conclusions from 12 other cases, meaning the results have a reasonable level of generalisability. |
| R | • The information gathered about Gage’s accident and his behaviour are based on accounts from 1848, which could be inaccurate. It is not possible to replicate these interviews/accounts, therefore the data may lack reliability. |
| A | • The conclusions drawn are useful for society as we can now make predictions of what might happen if someone damages their frontal lobe (poor impulse and emotional control). Knowing this could help the patient’s family in understanding their behaviour, and could help doctors in treating them. |
| V | • Researchers were able to use modern technology to make conclusions about data from 1848, meaning the investigation was scientific. Their data was objective (gained from computerised models, which aren’t prone to opinion). |
| E | • There were no ethical issues in this research, as they were using a computerised model rather than any live participants. |
Damasio et al (1994) Key Term Glossary
| Frontal lobe | Area at the front of the brain that processes decision making, problem solving, attention and voluntary movements. |
| White matter | Brain and spinal cord tissue, consisting of nerve fibres (axons). |
| Hemisphere | One half of the brain (left of right half). |
| Need more help? Want to stretch your understanding? Need a video example? |
| http://bigthink.com/going-mental/the-odd-case-of-phineas-gage https://en.wikipedia.org/wiki/Phineas_Gage |
| https://www.youtube.com/watch?v=yXbAMHzYGJ0 (2 min summary of Phineas Gage) https://www.youtube.com/watch?v=NJ9a0sN-Qd0 (5 min summary of Phineas Gage) https://www.youtube.com/watch?v=flRamGBSoP4 (5 min summary of Phineas Gage) |
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