Scientists Digitally Map Damaged Connections in Phineas Gage's Brain
Posted on May 17, 2012
Phineas Gage is famous for suffering and surviving a horrific work-related accident. He was a supervisor for the Rutland and Burlington Railroad in Vermont in 1848. Gage was using a 13-pound, 3-foot-7-inch rod to pack blasting powder into a rock when he triggered an explosion that drove the rod through his left cheek and out of the top of his head. The rod was found smeared with blood and brains.
Gage, 25, survived the accident, but he was never the same. Much of his left front lobe was destroyed in the accident. His behavior and personality changed from affable to fitful, irrevent and profane. Despite his changed personality, Gage was still able to find employment as a stagecoach driver in South America. He died in San Francisco, 12 years after the rod accident. Gage's bizarre accident became a famous case in neuroscience history.
UCLA researcher have used brain-imaging data that was lost to science for a decade to re-examine the case. The researchers looked at the damage to the white matter pathways that connect various regions of the brain. They also recovered the computed tomographic data files and reconstructed the scans, which revealed the highest-quality resolution available for modeling Gage's skull. Then they utilized advanced computational methods to model and determine the exact trajectory of the tamping iron that shot through his skull. Gage's original brain tissue was long gone, but the researchers used modern-day brain images of males that matched Gage's age and (right) handedness, then used software to position a composite of these 110 images into Gage's virtual skull. Here is a short animation the researchers made of Gage's rod accident. Take a look:
Jack Van Horn, a UCLA assistant professor of neurology, and colleagues note that while approximately 4% of the cerebral cortex was intersected by the rod's passage, more than 10% 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. The researchers say that "because white matter and its myelin sheath - the fatty coating around the nerve fibers that form the basic wiring of the brain - connect the billions of neurons that allow us to reason and remember, the research not only adds to the lore of Phineas Gage but may eventually lead to a better understanding of multiple brain disorders that are caused in part by similar damage to these connections."
Van Horn, a member of UCLA's Laboratory of Neuro Imaging (LONI), says, "What we found was a significant loss of white matter connecting the left frontal regions and the rest of the brain. We suggest that the disruption of the brain's 'network' considerably compromised it. This may have had an even greater impact on Mr. Gage than the damage to the cortex alone in terms of his purported personality change."
Van Horn also says, "The extensive loss of white matter connectivity, affecting both hemispheres, plus the direct damage by the rod, which was limited to the left cerebral hemisphere, is not unlike modern patients who have suffered a traumatic brain injury. And it is analogous to certain forms of degenerative diseases, such as Alzheimer's disease or frontal temporal dementia, in which neural pathways in the frontal lobes are degraded, which is known to result in profound behavioral changes."
LONI is part of an ambitious joint effort with Massachusetts General Hospital and the National Institutes of Health to document the trillions of microscopic links between every one of the brain's 100 billion neurons. The Phineas Gage research was published here in PLoS One.