Michael Graziano facts for kids
Michael Steven Anthony Graziano, born on May 22, 1967, is an American scientist and novelist. He is a professor of Psychology and Neuroscience at Princeton University. His science work focuses on how our brain creates awareness. He developed the "attention schema" theory. This theory explains how brains understand and use the idea of awareness, both for themselves and for others. Before this, his research looked at how the cerebral cortex (the outer part of the brain) keeps track of the space around our bodies and controls how we move within that space. He also suggested that the classic map of the body in the motor cortex, called the homunculus, might not be completely accurate. Instead, he thinks it's more like a map of complex actions we often do. His ideas have made a big impact on neuroscientists, but they have also caused some controversy. Graziano's novels often use his psychology background and are known for being surreal or having magic realism. He also writes music, including symphonies and string quartets.
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About Michael Graziano
Michael Graziano was born in Bridgeport, Connecticut, in 1967. He grew up in Buffalo, New York. He earned his first degree in Psychology from Princeton University in 1989. He then studied neuroscience at MIT from 1989 to 1991. After that, he returned to Princeton University. He finished his advanced degree in Neuroscience and Psychology there in 1996. He has stayed at Princeton University ever since, first as a researcher and then as a professor of neuroscience and psychology.
Brain Discoveries
Graziano has made important discoveries in three main areas of neuroscience. These include how brain cells in monkeys understand the space around the body. He also studied how the motor cortex controls complex movements. Finally, he explored how the brain might create consciousness. Let's look at these discoveries in more detail.
Space Around the Body
In the 1990s, Graziano and Charles Gross studied special brain cells in monkeys. These cells reacted to more than one sense. They built on earlier work by other scientists. Graziano and Gross found a network of brain areas that seemed to understand the space right around the body.
Each of these special cells reacted to a touch on a specific part of the body. This area was called the "tactile receptive field." The same cell also reacted to something seen or moving near that body part. This "visual receptive field" was a space linked to the body part. Some cells even reacted to sounds near the body part. Other cells remembered where objects were. They became active when a body part moved toward a remembered object in the dark. So, these cells told the brain if something was near or touching a body part. It didn't matter if the object was felt, seen, heard, or just remembered.
When scientists used electricity to stimulate these cells, it almost always caused a complex movement. These movements looked like flinching, blocking, or protecting actions. If these cells were stopped from working, the monkeys became very calm. They didn't flinch or react defensively. But if these cells were made more active, the monkeys became "super flinchers." Even a small movement toward their face caused a full flinching reaction.
Graziano believes these special cells form a network in the brain. This network understands the space near the body. It helps the brain figure out how safe that space is. It also helps coordinate movements related to nearby objects. These movements often involve pulling away or blocking. A small activation of these cells might help avoid bumping into things. A strong activation clearly causes a full defensive action.
These cells that understand the space around the body might also explain "personal space." Personal space is the invisible bubble around each person. It's a space we like to keep clear of other people. It was first described by a scientist named Hall. These cells might also be important for the "body schema." This is like an internal map the brain creates of our own body.
Brain's Action Map
In the 2000s, Graziano's lab found something new about the motor cortex. This part of the brain controls movement. Scientists used to think it had a simple map of the body's muscles. This was like the "motor homunculus" described by Penfield. But Graziano's team found evidence that the motor cortex might instead have a map of useful, coordinated actions. These are the actions we do every day.
In their first experiments, Graziano and his team used small electrical pulses on the motor cortex of monkeys. Most earlier studies used very short pulses, like a hundredth of a second. Graziano used longer pulses, about half a second. This matched the typical time a monkey takes to reach and grab something. The longer pulses caused complex movements. These movements involved many joints and looked like actions the monkeys did naturally.
For example, stimulating one spot always made the hand close into a grip. It also made the arm bring the hand to the mouth, and the mouth open. Stimulating another spot always made the grip open. It also made the palm face away from the body, and the arm extend. This looked like the monkey was reaching to grab something. Other spots caused other complex movements. It seemed like the animal's natural actions were mapped onto the brain's surface.
This first work caused some discussion because of the longer stimulation time. This method was not common for studying the motor cortex. However, other ways of studying the action map also supported the idea. For example, computer models show that if a monkey's complex movements are arranged on a flat map, with similar movements close together, the map looks a lot like the motor cortex.
Graziano suggests that many complex features of the motor cortex make sense with this "action map" idea. For example, why different parts of the motor cortex have slightly different jobs. He thinks the action map helps explain why the motor cortex is divided into different areas. It also explains why these areas are arranged the way they are.
Other scientists have since found similar action-based organization in the motor cortex of other animals. These include monkeys, lemurs, cats, and rats. However, some direct tests of this idea have not fully supported it. For example, changing the starting position of a monkey's arm does not change the muscle groups activated by stimulating a point in the motor cortex. This means the movements reach almost the same final position. But the path of the movement can be very different depending on where the arm started. The movement path is most natural when the arm hangs straight down. From other starting positions, the movements don't look natural. This shows that while stimulating a brain point can cause a coordinated movement from a resting position, it doesn't control the exact path of the movement from other starting points. So, natural movements likely need many brain points working together.
How the Brain Creates Awareness
Since 2010, Graziano's lab has studied how the brain creates consciousness, or awareness. Graziano suggested that special parts of the brain figure out what awareness is. They then use this idea to understand other people. According to his idea, the same brain parts also apply this idea of awareness to ourselves. If these brain parts are damaged, a person's own awareness can be disrupted.
The attention schema theory (AST) tries to explain how a machine that processes information could act like people do. It explains why we say we have consciousness. It explains why we describe consciousness in certain ways. It also explains why we might feel like our inner experience is magical, even if it's just information processing. The AST is now being used in artificial intelligence systems. This is happening through the international Astound project.
The AST idea came from two main sets of earlier discoveries.
First, certain brain areas become active when people try to understand what others are thinking. These areas include the superior temporal sulcus (STS) and the temporoparietal junction (TPJ). These areas are active on both sides of the brain, but especially on the right side.
Second, when these same brain areas are damaged, people can lose their awareness of things around them. For example, people with hemispatial neglect lose awareness of one side of space. This is especially severe after damage to the TPJ or STS in the right side of the brain.
These two findings together led to the idea that awareness might be something the brain calculates. It's like an expert system in the brain creates it. This system partly involves the TPJ and STS. In this idea, the brain can use this calculated awareness to understand other people. It can also use it to understand itself, which creates our own awareness.
Why would the brain create this idea of awareness and apply it to others? To understand and predict what other people will do, it's helpful to know what they are paying attention to. Attention is how the brain focuses on some signals more than others. According to the AST, when your brain thinks person X is aware of thing Y, it's actually modeling that person X is paying special attention to signal Y. So, awareness is like a map of attention. In this theory, the same process can be applied to yourself. Your own awareness is a simplified map of your own attention.
Books Written
Graziano writes novels for adults under his own name. He writes children's novels using the pen name B. B. Wurge. He says he uses a different name for children's books so kids don't accidentally read his adult books. His novels have been praised for being original, vivid, and imaginative. His children's book, The Last Notebook of Leonardo, won the 2011 Moonbeam Award.
His books include:
Literary Novels (for adults):
- The Love Song of Monkey (2008)
- Cretaceous Dawn (2008)
- The Divine Farce (2009)
- Death My Own Way (2012)
Children's Novels (written as B. B. Wurge):
- Billy and the Birdfrogs (2008)
- Squiggle (2009)
- The Last Notebook of Leonardo (2010)
Books on Neuroscience:
- The Intelligent Movement Machine (2008)
- God, Soul, Mind, Brain (2010)
- Consciousness and the Social Brain (2013)
- The Spaces Between Us: A Story of Neuroscience, Evolution, and Human Nature (2018)
- Rethinking Consciousness: A Scientific Theory of Subjective Experience (2019)
Books of Music:
- Three Modern Symphonies (2011)
- Symphonies 4, 5, and 6 (2012)
- Five String Quartets (2012)
