what is roger sperry best known for

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What is Roger Wolcott Sperry known for?

In fact, Roger Wolcott Sperry became widely known for an astonishing career in science, pioneering ideas about the functional specialization of the cerebral hemispheres in what came to be known as “left brain” and “right brain.” Sperry was born in 1913 and grew up on a farm near Hartford, Connecticut.

What did Roger W Sperry discover?

Roger W. Sperry was an American Psychobiologist who discovered that the human brain is actually made up of two parts. He found out that both the left and right parts of the human brain have specialized functions and that the two sides can operate independently. Roger Sperry was born on August 20, 1913 in Hartford, Connecticut.

What did Sperry win the Nobel Prize for?

Sperry won this award for his work with "split-brain" patients. The brain is divided into two hemispheres, the left and right hemispheres, connected in the middle by a part of the brain called the corpus callosum.

Where was Roger Sperry born?

Roger Sperry was born in Hartford, Connecticut, USA. His father worked at a bank and his mother was also schooled in economics. Roger Sperry studied psychology and other subjects at Oberlin College and zoology at the University of Chicago.

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What did Roger Sperry won the Nobel Prize for?

Sperry won half the prize for his success in demonstrating that the hemispheres of the brain are highly specialized and that many higher functions are centered in the right hemisphere. Hubel and Wiesel shared the other half of the prize for their research on information processing in the visual system.

What theory did Sperry invent?

Sperry received the 1981 Nobel Prize in Physiology or Medicine for his split-brain research. Sperry discovered that the left hemisphere of the brain was responsible for language understanding and articulation, while the right hemisphere could recognize a word, but could not articulate it.

What was the aim of the Sperry study?

The aim of Sperry (1968) was to show the independent streams of conscious awareness possessed by each hemisphere and to show how each hemisphere has its own memories.

What is split-brain theory?

The split-brain phenomenon is caused by the surgical severing of the corpus callosum, the main route of communication between the cerebral hemispheres. The classical view of this syndrome asserts that conscious unity is abolished.

Why is split-brain important?

For several decades, split-brain research has provided valuable insight into the fields of psychology and neuroscience. These studies have progressed our knowledge of hemispheric specialization, language processing, the role of the corpus callosum, cognition, and even human consciousness.

How do split-brain patients see?

Perception appears to be more split, while responding remains largely unified. Whether a stimulus appears in the left or the right visual hemifield strongly impacts performance of split-brain patients. However, response type (left hand, right hand or verbally) seems to have a much smaller, or no effect at all.

How does Sperry link to the key theme?

How does Sperry's study link to its key theme? It demonstrated the importance of the corpus callosum as a communication pathway between the left and right hemisphere and provided evidence of the different functions each hemisphere performs.

Was sperrys study reliable?

Reliability. Sperry found general trends in the lateralisation of brain function in the split-brain participants, and the similarities from split-brain participant to split-brain participant suggest that some of these findings are reliable.

What causes split-brain syndrome?

The primary cause of split-brain syndrome is intentional severing of the corpus callosum, partially or completely, through a surgical procedure known as corpus callosotomy.

Who proposed the split-brain theory?

Brain Theory. In the mid-1800's, Paul Broca proposed the classic hemispheric dominance theory that particular characteristics were associated with each side of the brain.

Who invented the left and right brain theory?

The right brain left brain theory originated in the work of Roger W. Sperry, who was awarded the Nobel Prize in 1981. 5 He studied brain functioning in patients who had their corpus callosum (the structure that connects the two hemispheres of the brain) surgically severed to treat refractory epilepsy.

Can a person have two consciousness?

Dual consciousness is a theoretical concept in neuroscience. It is proposed that it is possible that a person may develop two separate conscious entities within their one brain after undergoing a corpus callosotomy.

What did split-brain research reveal about the hemispheres of the brain?

What came out of the split brain experiments? The studies demonstrated that the left and right hemispheres are specialized in different tasks. The left side of the brain is normally specialized in taking care of the analytical and verbal tasks.

Who conducted the first experiments using split-brain patients?

Michael Gazzaniga, a cognitive neuroscientist at the University of California, Santa Barbara, and the godfather of modern split-brain science, says that even after working with these patients for five decades, he still finds it thrilling to observe the disconnection effects first-hand.

What happened to Sperry?

Sperry ceased to exist in 1986 following a prolonged hostile takeover bid engineered by Burroughs Corporation, which merged the combined operation under the new name Unisys. Some of Sperry's former divisions became part of Honeywell, Lockheed Martin, Raytheon Technologies, and Northrop Grumman.

What happens in split-brain surgery Why is it performed what does it reveal about brain functioning?

The surgery, which was a treatment for severe epilepsy, involved severing the corpus callosum, which carries signals between the left-brain hemisphere, the seat of speech and analytical capacity, and the right-brain hemisphere, which helps recognize visual patterns.

Roger Sperry's Contribution to Psychology

Roger Sperry was most notably interested in the brain's functions and would often experiment on monkeys, cats, and even humans. As you continue reading, you will see that Sperry was interested in the workings and functions of the corpus callosum but did not stop at this area of the brain.

Roger Sperry and Michael Gazzaniga

In the 1960s, Sperry and Michael Gazzaniga conducted experiments with the assistance of a participant with epilepsy who had undergone brain surgery to treat his seizures.

Roger Sperry Split-Brain Experiments

The corpus callosum interested Sperry for many reasons. How did Sperry use this area of the brain for experiments?

Split-Brain Surgery Effects

Of course, permanently changing the brain can have major effects. What happens to the brain after split-brain surgery? Sperry noticed that after each split-brain surgery, no major complications occurred in the patient, including both mental and physical capacities.

Roger Sperry - Key takeaways

In the 1960s, Roger Sperry theorized about the chemicals and axons that were in the brain. This theory is known as Sperry's chemoaffinity hypothesis.

How did Sperry learn neuronal specificity?from en.wikipedia.org

Under the supervision of Paul Weiss while earning his Ph.D. at the University of Chicago, Sperry became interested in neuronal specificity and brain circuitry and began questioning the existing concepts about these two topics. He asked the simple question first asked in his Introduction to Psychology class at Oberlin: Nature or nurture? He began a series of experiments in an attempt to answer this question. Sperry crosswired the motor nerves of rats' legs so the left nerve controlled the right leg and vice versa. He would then place the rats in a cage that had an electric grid on the bottom separated into four sections. Each leg of the rat was placed into one of the four sections of the electric grid. A shock was administered to a specific section of the grid, for example the grid where the rat's left back leg was located would receive a shock. Every time the left paw was shocked the rat would lift his right paw and vice versa. Sperry wanted to know how long it would take the rat to realize he was lifting the wrong paw. After repeated tests Sperry found that the rats never learned to lift up the correct paw, leading him to the conclusion that some things are just hardwired and cannot be relearned. In Sperry's words, "no adaptive functioning of the nervous system took place." During Sperry's postdoctoral years with Karl Lashley at Harvard and at the Yerkes Laboratories of Primate Biology in Orange Park, Florida, he continued his work on neuronal specificity that he had begun as a doctoral student and initiated a new series of studies involving salamanders. The optic nerves were sectioned and the eyes rotated 180 degrees. The question was whether vision would be normal after regeneration or would the animal forever view the world as "upside down" and right-left reversed. Should the latter prove to be the case, it would mean that the nerves were somehow "guided" back to their original sites of termination. Restoration of normal vision (i.e., "seeing" the world in a "right-side-up" orientation) would mean that the regenerating nerves had terminated in new sites, quite different from the original ones. The animals reacted as though the world was upside down and reversed from right to left. Furthermore, no amount of training could change the response. These studies, which provided strong evidence for nerve guidance by "intricate chemical codes under genetic control" (1963) culminated in Sperry's chemoaffinity hypothesis (1951).

How many children did Sperry have?from en.wikipedia.org

They had one son, Glenn Michael, and one daughter, Janeth Hope. Sperry was a quiet, thoughtful, and modest man with an insatiable curiosity. He never stopped working, questioning, or learning up until his death in 1994 of ALS or Lou Gehrig's Disease.

What is the significance of Sperry's chemoaffinity hypothesis?from en.wikipedia.org

In addition to his contribution in establishing the lateralized function of the brain, Sperry is noted for his " chemoaffinity hypothesis ", which has not only been influential in formation of testable hypotheses in how precise neuronal wiring diagram is established in the brain, but the hypothesis itself has been verified by numerous experiments.

What did Sperry cut in cats?from en.wikipedia.org

Sperry cut nerves in the eyes of cats so the left eye was connected to the left hemisphere and the right eye was connected to the right hemisphere; he also cut the corpus callosum. The cats were then taught to distinguish a triangle from a square with the right eye covered.

What nerves did Sperry use to control the left and right legs?from en.wikipedia.org

Sperry crosswired the motor nerves of rats' legs so the left nerve controlled the right leg and vice versa. He would then place the rats in a cage that had an electric grid on the bottom separated into four sections. Each leg of the rat was placed into one of the four sections of the electric grid.

What did Sperry do in the 1960s?from famouspsychologists.org

By late 1960s, Sperry had begun publishing technical papers on his split-brain findings.

How old was Sperry when his father died?from famouspsychologists.org

Sperry was raised by his mother since his father died when he was only 11 years old. Up till high school, Sperry was educated at local public schools after which he obtained a scholarship to Oberlin College in Ohio where he majored in English.

How did Sperry learn neuronal specificity?

Under the supervision of Paul Weiss while earning his Ph.D. at the University of Chicago, Sperry became interested in neuronal specificity and brain circuitry and began questioning the existing concepts about these two topics. He asked the simple question first asked in his Introduction to Psychology class at Oberlin: Nature or nurture? He began a series of experiments in an attempt to answer this question. Sperry crosswired the motor nerves of rats' legs so the left nerve controlled the right leg and vice versa. He would then place the rats in a cage that had an electric grid on the bottom separated into four sections. Each leg of the rat was placed into one of the four sections of the electric grid. A shock was administered to a specific section of the grid, for example the grid where the rat's left back leg was located would receive a shock. Every time the left paw was shocked the rat would lift his right paw and vice versa. Sperry wanted to know how long it would take the rat to realize he was lifting the wrong paw. After repeated tests Sperry found that the rats never learned to lift up the correct paw, leading him to the conclusion that some things are just hardwired and cannot be relearned. In Sperry's words, "no adaptive functioning of the nervous system took place." During Sperry's postdoctoral years with Karl Lashley at Harvard and at the Yerkes Laboratories of Primate Biology in Orange Park, Florida, he continued his work on neuronal specificity that he had begun as a doctoral student and initiated a new series of studies involving salamanders. The optic nerves were sectioned and the eyes rotated 180 degrees. The question was whether vision would be normal after regeneration or would the animal forever view the world as "upside down" and right-left reversed. Should the latter prove to be the case, it would mean that the nerves were somehow "guided" back to their original sites of termination. Restoration of normal vision (i.e., "seeing" the world in a "right-side-up" orientation) would mean that the regenerating nerves had terminated in new sites, quite different from the original ones. The animals reacted as though the world was upside down and reversed from right to left. Furthermore, no amount of training could change the response. These studies, which provided strong evidence for nerve guidance by "intricate chemical codes under genetic control" (1963) culminated in Sperry's chemoaffinity hypothesis (1951).

How many children did Sperry have?

They had one son, Glenn Michael, and one daughter, Janeth Hope. Sperry was a quiet, thoughtful, and modest man with an insatiable curiosity. He never stopped working, questioning, or learning up until his death in 1994 of ALS or Lou Gehrig's Disease.

What is the significance of Sperry's chemoaffinity hypothesis?

In addition to his contribution in establishing the lateralized function of the brain, Sperry is noted for his " chemoaffinity hypothesis ", which has not only been influential in formation of testable hypotheses in how precise neuronal wiring diagram is established in the brain, but the hypothesis itself has been verified by numerous experiments.

What nerves did Sperry use to control the left and right legs?

Sperry crosswired the motor nerves of rats' legs so the left nerve controlled the right leg and vice versa. He would then place the rats in a cage that had an electric grid on the bottom separated into four sections. Each leg of the rat was placed into one of the four sections of the electric grid.

What did Sperry do at a cafe?

He also worked at a cafe on campus to help support himself. Sperry was an English major, but he took an Intro to Psychology class taught by a Professor named R. H. Stetson who had worked with William James, the father of American Psychology.

What are the four major ideas that Sperry's experiments focused on?

The experiments conducted by Sperry focused on four major ideas which were also called "turnarounds": equipotentiality, split brain studies, nerve regeneration and plasticity, and psychology of the consciousness.

What is the purpose of the split brain test?

These tests were designed to test the patients' language, vision, and motor skills. When a person views something in the left visual field (that is on the left side of their body), the information travels to the right hemisphere of the brain and vice versa. In the first series of tests, Sperry would present a word to either the left or right visual field for a short period of time. If the word was shown to the right visual field, meaning the left hemisphere would process it, then the patient could report seeing the word. If the word was shown to the left visual field, meaning the right hemisphere would process it, then the patient could not report seeing the word. This led Sperry to believe that only the left side of the brain could articulate speech. However, in a follow-up experiment, Sperry discovered that the right hemisphere does have some language abilities. In this experiment, he had the patients place their left hands in a tray full of objects located under a partition so the patient would not be able to see the objects. Then a word was shown to the patient's left visual field, which was processed by the right side of the brain. This word described one of the objects in the tray, so the patient's left hand picked up the object corresponding to the word. When participants were asked about the word and the object in their hand, they claimed they had not seen the word and had no idea why they were holding the object. The right side of the brain had recognized the word and told the left hand to pick it up, but because the right side of the brain cannot speak and the left side of the brain had not seen the word, the patient could not articulate what they had seen.

How did Sperry solve the problem of the eye?

That required separation of visual fields, or making sure that the right eye saw a circle, while the left eye saw a cross, like in the cat experiment, but without an eye patch and both eyes would see something at the same time instead of interchanging between the open eyes. Sperry solved that by using two projectors that were positioned side-by-side at an angle and showed mutually exclusive images. For example, the projector on the right showed a circle on the left and a cross on the right, while the projector on the left showed a cross on the left and a circle on the right. Sperry placed special light filters in front of each of the monkey´s eyes. The light filters made it so that each eye saw the images from only one of the projectors. That meant one of the eyes saw the circle on the right and the cross on the left, while the other eye saw the cross on the right and the circle on the left. From his experiments with cats, Sperry knew that there was no sharing of information from right and the left hemispheres, so he made the monkeys memorize two different scenarios at the same time.

What did Sperry postulate about the consequences of cutting the brain?

Sperry postulated that there should be major consequences from cutting the brain structure, as the corpus callosum connected the two hemispheres of the brain, was large, and must have an important function. Sperry began designing experiments to document the effects of a severed corpus callosum.

Why did Sperry test the split brain?

The split-brain enabled animals to memorize double the information. Later, Sperry tested the same idea in humans with their corpus callosum severed as treatment for epilepsy, a seizure disorder. He found that the hemispheres in human brains had different functions.

How did Sperry test cats?

To test how the cutting of the corpus callosum affected mammals, Sperry cut the corpus callosum of multiple cats and had them perform some tasks that involved their vision and response to a visual stimulus. After severing each cat´s corpus callosum, he covered one of the cat´s eyes to monitor with which eye the cat could see. Sperry could switch the eye patch from one eye to the other, depending on which visual field he wanted the cat to use. Next, Sperry showed the cats two wooden blocks with different designs, a cross and a circle. Sperry put food for the cat under one of the blocks. He taught the cats that when they saw the blocks with one eye, for instance, the right eye, the food was under the circle block, but when they saw it with the left eye, the food was under the block with a cross. Sperry taught the cats to differentiate between those two objects with their paws, pushing the correct wooden block away to get the food.

What did Roger Sperry do to study the brain?

To do so he studied the corpus callosum, which is a large bundle of neurons that connects the two hemispheres of the brain. Sperry severed the corpus callosum in cats and monkeys to study the function of each side of the brain. He found that if hemispheres were not connected, they functioned independently of one another, which he called a split-brain. The split-brain enabled animals to memorize double the information. Later, Sperry tested the same idea in humans with their corpus callosum severed as treatment for epilepsy, a seizure disorder. He found that the hemispheres in human brains had different functions. The left hemisphere interpreted language but not the right. Sperry shared the Nobel Prize in Physiology or Medicine in 1981for his split-brain research.

Why did Sperry break the corpus callosum?

Sperry severed the corpus callosum in cats and monkeys to study the function of each side of the brain. He found that if hemispheres were not connected, they functioned independently of one another, which he called a split-brain. The split-brain enabled animals to memorize double the information. Later, Sperry tested the same idea in humans ...

Why did the eyes see the same button?

Ultimately, it was the same button, but the eyes saw it differently because of two projectors and special light filters. Sperry concluded that both hemispheres of the brain were learning two different, reversed, problems at the same time.

What did Sperry find about the brain?

But in dramatic experiments, Sperry found that human brain circuitry started out much more hardwired, already formed, than previously thought. That is, once the chemical nature of a specific nerve cell was set very early in development-in the embryo-that chemical nature wasn’t fundamentally changed by experience. This is why, as Sperry found, a lab animal with its nerve circuits switched from, say, the right to the left arm, wasn’t able to relearn and rewire to correct the routing. When the animal wanted to move its right arm, the left always moved instead. And this didn’t change over time.

What did Sperry believe about free will?

“It is possible to see today,” he believed, “an objective, explanatory model of brain function that neither contradicts nor degrades but rather affirms age-old humanist values, ideals, and meaning in human endeavor.”

What is the mind body quandary?

Scientists and philosophers have long argued over what is known as the mind-body quandary, the relationship between our mind and the physical brain. Some scientists saw the work of Sperry and others as supporting the notion that the brain operates almost entirely mechanically, and that consciousness, reasoning and free will have almost no effect.

Which hemisphere of the brain is most likely to be unable to understand reading or speech?

The right, or “minor,” hemisphere was considered less highly evolved and unable to understand reading or speech.

Who wrote Sperry on Consciousness?

Pucetti (1977). Sperry on Consciousness: A Critical Appreciation. The Journal of Medicine and Philosophy, 2 (2), 127.

Did Sperry test for split brains?

Yet, when Sperry started testing patients with split brains, he and other scientists were surprised. He found that not only could these patients continue to carry on most everyday functions after the two hemispheres were disconnected, but that the right brain wasn’t as word-deaf and word-blind as once thought.

Is the right side of the brain a whiz?

True, the right side was a whiz at recognizing faces, reading maps and dealing with other spatial relationships. Still, some scientists considered the right brain so mentally retarded that it wasn’t even conscious. Yet, when Sperry started testing patients with split brains, he and other scientists were surprised.

Why is Roger Sperry important?

Roger W. Sperry was an American Psychobiologist who discovered that the human brain is actually made up of two parts. He found out that both the left and right parts of the human brain have specialized functions and that the two sides can operate independently.

What did Roger Sperry focus on?

Roger Wolcott Sperry studied the function of the nervous system in the United States during the twentieth century. He studied split-brain patterns in cats and humans that result from separating the two hemispheres of the brain after cutting the corpus callosum, the bridge between the two hemispheres of the brain.

What does split-brain research tell us?

For several decades, split-brain research has provided valuable insight into the fields of psychology and neuroscience. These studies have progressed our knowledge of hemispheric specialization, language processing, the role of the corpus callosum, cognition, and even human consciousness.

What makes the brain of a split-brain patient unique?

Since information cannot be directly shared between the two hemispheres, split-brain patients display unusual behaviours, particularly concerning speech and object recognition.

Why was Sperry so interested in split-brain?

In “split-brain” patients, the corpus callosum has been severed due to the patients suffering from epilepsy, a disease that causes intense and persistent seizures. This led Sperry to believe that the left and right hemispheres function separately when not connected by the corpus callosum.

Why did Sperry win a Nobel Prize?

Sperry received the 1981 Nobel Prize in Physiology or Medicine for his split-brain research. Sperry discovered that the left hemisphere of the brain was responsible for language understanding and articulation, while the right hemisphere could recognize a word, but could not articulate it.

What does the right side of the brain control?

Our brains have two sides, or hemispheres. In most people, language skills are in the left side of the brain. The right side controls attention, memory, reasoning, and problem solving. RHD may lead to problems with these important thinking skills.

Overview

Early life and education

Career

Nobel Prize

Personal life

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