from the world's big
The Odd Case of Phineas Gage
As we discussed in the previous Going Mental posts, some of the most fundamental mechanisms of the human brain remain a mystery to scientists. Consciousness, intelligence, and sleep are so fascinating largely because they require such complicated interactions among disparate brain areas to produce phenomena we take for granted as normal. But even more fascinating is when something goes wrong, when the brain doesn't function like it should. So this week at Big Think is dedicated to the engrossing—and occasionally lurid—world of abnormal psychology. And to kick things off, we're beginning with perhaps the most famous case in all of abnormal psych, the case of Phineas Gage.
On September 13, 1848, a young railroad foreman named Phineas P. Gage was setting a charge to clear a path for new train tracks. Normally a hole would be drilled into a rock, the hole would be partially filled with gunpowder, covered in sand, and then triggered using a fuse and a tamping iron. But on this fateful day, Gage mistakenly began tamping directly on the gunpowder before his assistant had a chance to cover it with sand. The resulting explosion propelled the iron rod (3 feet long and 1.25 inches in diameter) right through Gage's skull, but he miraculously survived and, after some months of convalescence, returned to work.
Adam Kepecs, Assistant Professor at Cold Spring Harbor Laboratory, tells Big Think about the importance of Gage's case to science:
But as Harvard psychiatry professor John Ratey describes in his neuroscience primer "A User's Guide to the Brain," something was different about Gage after the accident: "Gage's temperament changed so drastically that he lost his job. He had been known as a remarkably responsible and even-tempered individual, but after the accident he was often compared to a wild animal with no moral sense. He cursed in front of women—unheard of in his day—and fought irresponsibly."
Until the advent of brain scans and magnetic resonance imaging, brain lesions studies like this were the only way scientists could study the functions of individual brain areas in humans. Twenty years after Gage's accident, physician John Harlow hypothesized that Gage's drastic behavioral changes were a result of the damage to his frontal lobe. There must be particular structures in the brain
of planning and executing socially-acceptable behaviors, Harlow suspected.
Two other early neurologists, Paul Broca and Carl Wernicke, also used brain lesion cases to predict structures in the brain that controlled certain behaviors. Based on a patient with brain damage who could only produce the single syllable "tan," Broca hypothesized in 1861 that the left inferior frontal gyrus was involved in
language production. 150 years later, this area is still known as Broca's area, and patients with localized damage to this area suffer from Broca's aphasia. Their speech and reading comprehension may be completely intact, but their ability to speak or write is severely damaged. Several years after Broca's discovery, Wernicke described a language problem distinct from Broca's. His patient's problem had nothing to do with speech—he could produce words and could write with no effort—but the words he said or wrote were little more than gibberish. His speech and reading comprehension were highly impaired as well. Based on the patient's brain damage, Wernicke hypothesized that the left posterior superior temporal gyrus, now known as Wernicke's area, governed language comprehension.
In 1994, Hanna Damasio and a team of researchers returned to the Phineas Gage case. Using photos of Gage's skull and new computer technology, they recreated a three-dimensional image of his brain. And the areas most likely to have been damaged by the iron rod were in fact the left anterior prefrontal cortices and the ventromedial prefrontal cortex—areas we now know to be crucial to decision making, thanks to brain-imaging technology.
Aside from being inherently fascinating, abnormal psychology has been crucial to an understanding of how the normal brain works. It is unethical, of course, for scientists to induce injuries in parts of the brain in order to observe resulting behavioral changes. But when injuries like Phineas Gage's happened by accident, scientists got their first glimpse into what behaviors were governed by which parts of the brain.
"The Return of Phineas Gage," (1994) co-published by Hanna Damasio in the journal Science [PDF]
"Paul Broca's Historic Cases," (2007) a modern revisiting of Broca's lesion studies
What would it be like to experience the 4th dimension?
Physicists have understood at least theoretically, that there may be higher dimensions, besides our normal three. The first clue came in 1905 when Einstein developed his theory of special relativity. Of course, by dimensions we’re talking about length, width, and height. Generally speaking, when we talk about a fourth dimension, it’s considered space-time. But here, physicists mean a spatial dimension beyond the normal three, not a parallel universe, as such dimensions are mistaken for in popular sci-fi shows.
If machines develop consciousness, or if we manage to give it to them, the human-robot dynamic will forever be different.
- Does AI—and, more specifically, conscious AI—deserve moral rights? In this thought exploration, evolutionary biologist Richard Dawkins, ethics and tech professor Joanna Bryson, philosopher and cognitive scientist Susan Schneider, physicist Max Tegmark, philosopher Peter Singer, and bioethicist Glenn Cohen all weigh in on the question of AI rights.
- Given the grave tragedy of slavery throughout human history, philosophers and technologists must answer this question ahead of technological development to avoid humanity creating a slave class of conscious beings.
- One potential safeguard against that? Regulation. Once we define the context in which AI requires rights, the simplest solution may be to not build that thing.
Duke University researchers might have solved a half-century old problem.
- Duke University researchers created a hydrogel that appears to be as strong and flexible as human cartilage.
- The blend of three polymers provides enough flexibility and durability to mimic the knee.
- The next step is to test this hydrogel in sheep; human use can take at least three years.
Duke researchers have developed the first gel-based synthetic cartilage with the strength of the real thing. A quarter-sized disc of the material can withstand the weight of a 100-pound kettlebell without tearing or losing its shape.
Photo: Feichen Yang.<p>That's the word from a team in the Department of Chemistry and Department of Mechanical Engineering and Materials Science at Duke University. Their <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202003451" target="_blank">new paper</a>, published in the journal,<em> Advanced Functional Materials</em>, details this exciting evolution of this frustrating joint.<br></p><p>Researchers have sought materials strong and versatile enough to repair a knee since at least the seventies. This new hydrogel, comprised of three polymers, might be it. When two of the polymers are stretched, a third keeps the entire structure intact. When pulled 100,000 times, the cartilage held up as well as materials used in bone implants. The team also rubbed the hydrogel against natural cartilage a million times and found it to be as wear-resistant as the real thing. </p><p>The hydrogel has the appearance of Jell-O and is comprised of 60 percent water. Co-author, Feichen Yang, <a href="https://today.duke.edu/2020/06/lab-first-cartilage-mimicking-gel-strong-enough-knees" target="_blank">says</a> this network of polymers is particularly durable: "Only this combination of all three components is both flexible and stiff and therefore strong." </p><p> As with any new material, a lot of testing must be conducted. They don't foresee this hydrogel being implanted into human bodies for at least three years. The next step is to test it out in sheep. </p><p>Still, this is an exciting step forward in the rehabilitation of one of our trickiest joints. Given the potential reward, the wait is worth it. </p><p><span></span>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
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