If you’re like me, you know a few people who are constantly on the go doing different things and you know some people who are chronic couch potatoes. What makes people act so differently? Well, it could be a number of things but it is largely due to the three pound organ between your ears – your brain. The brain is a funny thing. It likes to do whatever it is doing. If we give it stimulation, then it will crave more variety. If we are lazy, then it is content not to do much. So, what causes this disparity?
We each have a kind of gear shift in our brains called the anterior cingulate cortex (ACC). The ACC acts as a mediator between our emotional brain and the front of the brain. The front of the brain is the executive part of the brain. It directs our decisions and plans our actions. The ACC helps us change the focus of our attention. Lowered ACC function has been implicated in people who have ADD. When we dwell on things, we are in effect getting our ACC stuck in neutral. Once it gets stuck, it can be hard to change gears.
This is where cognitive-behavioral intervention is useful. If we find ourselves stuck in a rut, we should make ourselves do something else. If we ruminate and worry about things too much, we should change what we are thinking about and redirect our thoughts. This can be very hard to do since the brain gets used to doing whatever it is doing. With a little effort we can get ourselves going again. The first change of action is the hardest, but once we retrain our brains we can get out of neutral and kick ourselves into a higher gear!
Tuesday, September 22, 2009
Mental Time Travel
People can recall things that happened to them years ago. We can also contemplate what might happen to us in the future. This is what some psychologists refer to as mental time travel. The front of the brain gives us the ability to project ourselves into the future, while an area called the hippocampus in the temporal lobes helps us create memories. What would happen if we didn’t have a hippocampus?
To answer this question, we need to look at what happened to a man called H.M. in 1953 (people are not identifed by name in the medical literature). H.M. had severe epileptic seizures that originated in his temporal lobes. His doctors decided that the best course of treatment would be to give him a bilateral temporal lobectomy (they cut out the temporal lobes on both sides of his brain). At the time, the relationship of the hippocampus to memory formation was not know.
After the surgery, H.M. no longer had seizures but he had a unique memory problem. He could no longer remember things that happened to him. Here is an example – someone could come into the room and greet H.M., leave for a couple minutes and return, and H.M. would act as though it were the first time he saw the person. He was in an infinite present, so to speak. Yet, the surgery didn't destroy H.M’s memory completely. He was still able to learn simple procedural tasks. The procedure H.M. had isn’t performed much anymore since anti-convulsive medications have improved vastly since the 1950s.
The case of H.M. was important for furthering our understanding of how memories are formed. When we compare the brains of other mammalian species, we find that they have areas that are similar in cellular makeup to our hippocampus. These areas are referred to as “hippocampal formations” in other mammals.
So, what would it mean that other mammals have a hippocampal formation? It suggests that they might have memories of their past. Of course, we cannot prove this idea since we cannot ask an animal about what they remember. It’s an interesting thing to ponder, though. Your dog just might have memories of when she was a puppy.
To answer this question, we need to look at what happened to a man called H.M. in 1953 (people are not identifed by name in the medical literature). H.M. had severe epileptic seizures that originated in his temporal lobes. His doctors decided that the best course of treatment would be to give him a bilateral temporal lobectomy (they cut out the temporal lobes on both sides of his brain). At the time, the relationship of the hippocampus to memory formation was not know.
After the surgery, H.M. no longer had seizures but he had a unique memory problem. He could no longer remember things that happened to him. Here is an example – someone could come into the room and greet H.M., leave for a couple minutes and return, and H.M. would act as though it were the first time he saw the person. He was in an infinite present, so to speak. Yet, the surgery didn't destroy H.M’s memory completely. He was still able to learn simple procedural tasks. The procedure H.M. had isn’t performed much anymore since anti-convulsive medications have improved vastly since the 1950s.
The case of H.M. was important for furthering our understanding of how memories are formed. When we compare the brains of other mammalian species, we find that they have areas that are similar in cellular makeup to our hippocampus. These areas are referred to as “hippocampal formations” in other mammals.
So, what would it mean that other mammals have a hippocampal formation? It suggests that they might have memories of their past. Of course, we cannot prove this idea since we cannot ask an animal about what they remember. It’s an interesting thing to ponder, though. Your dog just might have memories of when she was a puppy.
There's Something Extra
There are two schools of thought regarding the nature of the mind and brain – materialism and dualism. Materialism contends that the mind is entirely physical (the result of brain activity) while dualism suggests that the mind and brain are separate entities. Dualism is sort of like the “ghost in the machine” point of view. Now, most contemporary philosophers and psychologists endorse the materialist viewpoint. All the neuroscience evidence points to the fact that you need a functioning brain to experience consciousness. Another way to put it is that the mind depends on the brain.
There is one major problem with materialism that has not been resolved -the problem of qualia. Qualia are attributes related to what it is like to have an experience. We describe things as how they look, smell, feel, etc. The problem of qualia can be illustrated by a thought experiment put forth by the philosopher Frank Jackson about a color scientist named Mary.
Mary, as I just said, is a color scientist. She has studied everything about seeing color. She knows about the various wavelengths of light, the different hues and saturations of color, etc. The thing is, Mary lives in a black and white world. Everything she sees is either black or white. So, one day she sees the color red. Is there something about seeing red that differs from her knowledge about that color? Of course there is. It’s the personal experience of seeing the color. All her knowledge about the color red would not equate to the first hand experience of what the color actually looks like. There’s something extra about the experience that Mary did not know.
So, why is this a problem for the materialists? If the mind is a purely physical thing then we should be able to describe it in purely physical terms. Yet, there is no way to quantify the experience that someone has when, say, they are seeing the color red. We can identify specific neurons that are activated when we see red but we still do not know how they produce the experience of red. A totally physical explanation of mind should be able to explain this experience.
Still, the problem of qualia is no reason to discard materialism. Science provides us with an objective third-person (observer) description of the world. It cannot account for our first-person experiences. Knowledge of neural activity does not provide a complete explantaion for what it is like for an individual to have a given experience. This has been referred to as the “explanatory gap” by the philosopher David Chalmers. However, just because our experiences cannot be explained fully in physical terms does not mean that materialism is incorrect. What this points to is the nature of our inner mental life. The experience of having a nervous system that processes information and perceives the world is entirely our own.
There is one major problem with materialism that has not been resolved -the problem of qualia. Qualia are attributes related to what it is like to have an experience. We describe things as how they look, smell, feel, etc. The problem of qualia can be illustrated by a thought experiment put forth by the philosopher Frank Jackson about a color scientist named Mary.
Mary, as I just said, is a color scientist. She has studied everything about seeing color. She knows about the various wavelengths of light, the different hues and saturations of color, etc. The thing is, Mary lives in a black and white world. Everything she sees is either black or white. So, one day she sees the color red. Is there something about seeing red that differs from her knowledge about that color? Of course there is. It’s the personal experience of seeing the color. All her knowledge about the color red would not equate to the first hand experience of what the color actually looks like. There’s something extra about the experience that Mary did not know.
So, why is this a problem for the materialists? If the mind is a purely physical thing then we should be able to describe it in purely physical terms. Yet, there is no way to quantify the experience that someone has when, say, they are seeing the color red. We can identify specific neurons that are activated when we see red but we still do not know how they produce the experience of red. A totally physical explanation of mind should be able to explain this experience.
Still, the problem of qualia is no reason to discard materialism. Science provides us with an objective third-person (observer) description of the world. It cannot account for our first-person experiences. Knowledge of neural activity does not provide a complete explantaion for what it is like for an individual to have a given experience. This has been referred to as the “explanatory gap” by the philosopher David Chalmers. However, just because our experiences cannot be explained fully in physical terms does not mean that materialism is incorrect. What this points to is the nature of our inner mental life. The experience of having a nervous system that processes information and perceives the world is entirely our own.
In You I Trust
It’s widely known that soon after child birth it is important to establish a strong emotional bond between the mother and their child by putting the infant on the mother's chest. Part of how this happens is due to a neurohormone called oxytocin. Oxytocin is released by the infant and the caregiver responds with a feeling of well-being. The same thing happens when you hold an infant which often makes a person feel sleepy. I can attest to this when I’ve held my nieces and nephews.
Oxytocin is a peptide that is released during child birth, breast feeding, and orgasm. It is something that helps bond people together. It helps us build trust with our significant others. Two important studies shed light on how this happens. The first is a study that investigated how likely people would give money to people they didn't know and the second involves a little rodent called the prairie vole.
The money lending study was cleverly designed. Participants were part of teams. As a reward for doing simple tasks they were given small monetary rewards. They were instructed that they could share part of their reward with their team members if they wanted to. People who were given a shot of oxytocin prior to the study distributed bigger rewards to their team mates than those who were not given the oxtytocin. This suggests that oxytocin influences whether we will trust someone.
Next is the prairie vole study. Prairie voles stay with their partners for life after they mate. They raise their pups together in seemingly marital bliss. This is quite rare among mammals. Only about 5% of mammals show monogomous biparental behavior. When researchers injected the prairie voles with chemicals that blocked their oxytocin receptors, the prairie voles no longer formed lasting pair bonds. A relative of the prairie vole, the meadow vole, does not form pair bonds with their mates. When researchers injected meadow voles with oxytocin, the meadow voles formed lasting attachments with female partners.
What is the difference between the two kinds of voles? Dopamine receptors, which are involved with pleasure and reward, overlap oxytocin receptors in the prairie vole. This suggests that the prairie vole finds it rewarding to form a pair bond after oxytocin is released. The meadow vole, on the other hand, does not have the same overlap between their dopamine and oxytocin receptors. So, the meadow vole does not experience the pleasant feelings associated with oxytocin and thus does not form pair bonds.
Humans, too, are hardwired to form pair bonds but we are more complex than voles. We learn how to interact with people by watching our parents, siblings, and friends. We can learn to suppress our emotions if we see other people ignore their feelings. Suppressing our emotions causes the oxytocin-dopamine system not to work as it was intended. Of course, we can't form a life lasting pair bond with each of our lovers, but disconnecting ourselves from our emotions continuously can have a detrimental effect on our ability to form lasting pair bonds later. This sort of thing can be unlearned over time if we make the effort. So you see, oxytocin not only bonds a mother to their child, it helps us build trust and lasting attachments with the people we care about the most.
Oxytocin is a peptide that is released during child birth, breast feeding, and orgasm. It is something that helps bond people together. It helps us build trust with our significant others. Two important studies shed light on how this happens. The first is a study that investigated how likely people would give money to people they didn't know and the second involves a little rodent called the prairie vole.
The money lending study was cleverly designed. Participants were part of teams. As a reward for doing simple tasks they were given small monetary rewards. They were instructed that they could share part of their reward with their team members if they wanted to. People who were given a shot of oxytocin prior to the study distributed bigger rewards to their team mates than those who were not given the oxtytocin. This suggests that oxytocin influences whether we will trust someone.
Next is the prairie vole study. Prairie voles stay with their partners for life after they mate. They raise their pups together in seemingly marital bliss. This is quite rare among mammals. Only about 5% of mammals show monogomous biparental behavior. When researchers injected the prairie voles with chemicals that blocked their oxytocin receptors, the prairie voles no longer formed lasting pair bonds. A relative of the prairie vole, the meadow vole, does not form pair bonds with their mates. When researchers injected meadow voles with oxytocin, the meadow voles formed lasting attachments with female partners.
What is the difference between the two kinds of voles? Dopamine receptors, which are involved with pleasure and reward, overlap oxytocin receptors in the prairie vole. This suggests that the prairie vole finds it rewarding to form a pair bond after oxytocin is released. The meadow vole, on the other hand, does not have the same overlap between their dopamine and oxytocin receptors. So, the meadow vole does not experience the pleasant feelings associated with oxytocin and thus does not form pair bonds.
Humans, too, are hardwired to form pair bonds but we are more complex than voles. We learn how to interact with people by watching our parents, siblings, and friends. We can learn to suppress our emotions if we see other people ignore their feelings. Suppressing our emotions causes the oxytocin-dopamine system not to work as it was intended. Of course, we can't form a life lasting pair bond with each of our lovers, but disconnecting ourselves from our emotions continuously can have a detrimental effect on our ability to form lasting pair bonds later. This sort of thing can be unlearned over time if we make the effort. So you see, oxytocin not only bonds a mother to their child, it helps us build trust and lasting attachments with the people we care about the most.
The Beginning of Empathy
People like to ascribe causes to things. We do this so much that the psychologist James Alcock has postulated that one of the main functions of the human brain is to serve as a belief engine. If we find a cause for an action or event, we can go about out business thinking that some part of the world makes sense. But where does this penchant for finding causes come from? Do we always have it?
The answer is what has been called the theory of mind by developmental psychologists. Basically, the way this works is that the infant starts to make assumptions about how the world works. If I throw my sippee cup off my high chair it falls to the ground. By extension, if someone else does the same thing the sippee cup will also fall to the ground. This starts happening around 18 months of age.
Another thing happens around the same time. We start to develop a sense of self. A child around this age will recognize her reflection in a mirror. The child no longer thinks that the reflection is another child. This is contrasted with an animal such as a dog which spooks when it sees its reflection in a patio window. The dog makes the erroneous assumption that the reflection is another dog and starts barking.
So, it seems that our sense of self is intrinsically linked to our theory of mind. When we begin to see ourselves as individuals we can then start seeing other people as separate entities. This might seem simplistic but it’s something that we internalize without even realizing it. A person who does not develop a “normal” theory of mind would have trouble understanding the motives and actions of other people.
This brings us to autism. In recent years, it has been hypothesized that people with autism do not develop a theory of mind the same way other people do. There is actually physiological evidence to support this. Specific neurons were discovered that fired when a monkey picked up a cup. Interestingly, these same neurons would fire if the monkey watched another monkey pick up a cup. As a result these neurons were initially called “monkey see, monkey do” neurons. They are now usually referred to as mirror neurons.
Now the interesting thing about mirror neurons is that they don’t just respond to actions. They are also involved with empathy. If your friend is sad, you can feel the same thing they do, so to speak, because your mirror neurons become activated by their apparent sadness. In a way then, mirror neurons help make us human.
One of the main problems reported with people who have autism is that they appear to lack empathy and often have impaired social interaction with other people. This has bolstered the case that autism is partly due to a deficit in the mirror neuron system. I say partly because it’s assuredly due to a complex interaction between genetic and environmental factors as well.
So you see, when your child begins to acquire a sense of self it’s a sign that they are developmentally on the right track. Their mirror neurons are working full throttle as they learn to mimic the actions of other people and start to empathize with others as well. Without this happening, your child wouldn't understand you telling them that it's not a good idea to tease their friend because they wouldn’t like it if they did that to them. We couldn’t put ourselves in "someone else’s shoes” without mirror neurons and a normally developed theory of mind.
The answer is what has been called the theory of mind by developmental psychologists. Basically, the way this works is that the infant starts to make assumptions about how the world works. If I throw my sippee cup off my high chair it falls to the ground. By extension, if someone else does the same thing the sippee cup will also fall to the ground. This starts happening around 18 months of age.
Another thing happens around the same time. We start to develop a sense of self. A child around this age will recognize her reflection in a mirror. The child no longer thinks that the reflection is another child. This is contrasted with an animal such as a dog which spooks when it sees its reflection in a patio window. The dog makes the erroneous assumption that the reflection is another dog and starts barking.
So, it seems that our sense of self is intrinsically linked to our theory of mind. When we begin to see ourselves as individuals we can then start seeing other people as separate entities. This might seem simplistic but it’s something that we internalize without even realizing it. A person who does not develop a “normal” theory of mind would have trouble understanding the motives and actions of other people.
This brings us to autism. In recent years, it has been hypothesized that people with autism do not develop a theory of mind the same way other people do. There is actually physiological evidence to support this. Specific neurons were discovered that fired when a monkey picked up a cup. Interestingly, these same neurons would fire if the monkey watched another monkey pick up a cup. As a result these neurons were initially called “monkey see, monkey do” neurons. They are now usually referred to as mirror neurons.
Now the interesting thing about mirror neurons is that they don’t just respond to actions. They are also involved with empathy. If your friend is sad, you can feel the same thing they do, so to speak, because your mirror neurons become activated by their apparent sadness. In a way then, mirror neurons help make us human.
One of the main problems reported with people who have autism is that they appear to lack empathy and often have impaired social interaction with other people. This has bolstered the case that autism is partly due to a deficit in the mirror neuron system. I say partly because it’s assuredly due to a complex interaction between genetic and environmental factors as well.
So you see, when your child begins to acquire a sense of self it’s a sign that they are developmentally on the right track. Their mirror neurons are working full throttle as they learn to mimic the actions of other people and start to empathize with others as well. Without this happening, your child wouldn't understand you telling them that it's not a good idea to tease their friend because they wouldn’t like it if they did that to them. We couldn’t put ourselves in "someone else’s shoes” without mirror neurons and a normally developed theory of mind.
How to Forget Someone
So, you’ve been dating someone for awhile and you break up and then you find that the other person ignores you. This is pretty common. Have you ever wondered why they ignore you? There could be lots of different reasons (need for control, spite, etc.). However, I think the basic reason is related to how memory works. Let’s take a brief look at how we remember and forget things and then we’ll come back to why your ex is ignoring you.
We tend to remember things with increased exposure to them. The more you do something, the more you are going to remember doing whatever it is you are doing. Clearly, repetition or repeated exposure strengthens your memory for something. Attaching meaning or personal significance also increases the likelihood you will remember an event or situation. So that said, what causes forgetting? There are various explanations but the two that probably account for most forgetting are decay and interference.
Decay is basically the effect of time. If I open up my high school yearbook, I won’t remember all the names of classmates. I haven’t thought about them in a very long time. When you don’t access information for a long time, it makes it hard to retrieve from memory. Interference is the effect of intervening information. If I tell you to do something in the morning (and you don’t write it down), all the stuff that happens during the day makes it more likely that you will forget what I asked you in the morning (not always of course). This is a big reason that adults say their memories aren’t as good as when they were younger. It is true that some memory loss is due to aging, but adults usually have more going on than children. This makes the effect of interference much greater for adults.
Another thing is that when you are dating you actually build neural networks specific to the person you are dating. Everytime you see the person, these neural pathways become strengthened. This makes perfect sense. You want to feel a strong connection to the person you are dating. It is debatable whether humans are naturally monogomous or not but the brain is wired to establish solid pair bonds with potential mates. Additionally, the emotional centers that are connected to the memory area also respond every time you see the person. The result is that you have a good feeling when you see your partner.
In coming back to our original question, why is it that your ex is ignoring you? Simple. It’s because of decay and interference. If enough time elapses, the memory of being together fades. If they surround themselves with their friends and busy themselves, they can create enough interference to assist in forgetting about the relationship. So, even though some of our former partners might have malicious motives in how they elect to deal with us after a breakup, the basic reason people ignore each other is that we intuitively know that decay and interference are the best methods for forgetting someone.
We tend to remember things with increased exposure to them. The more you do something, the more you are going to remember doing whatever it is you are doing. Clearly, repetition or repeated exposure strengthens your memory for something. Attaching meaning or personal significance also increases the likelihood you will remember an event or situation. So that said, what causes forgetting? There are various explanations but the two that probably account for most forgetting are decay and interference.
Decay is basically the effect of time. If I open up my high school yearbook, I won’t remember all the names of classmates. I haven’t thought about them in a very long time. When you don’t access information for a long time, it makes it hard to retrieve from memory. Interference is the effect of intervening information. If I tell you to do something in the morning (and you don’t write it down), all the stuff that happens during the day makes it more likely that you will forget what I asked you in the morning (not always of course). This is a big reason that adults say their memories aren’t as good as when they were younger. It is true that some memory loss is due to aging, but adults usually have more going on than children. This makes the effect of interference much greater for adults.
Another thing is that when you are dating you actually build neural networks specific to the person you are dating. Everytime you see the person, these neural pathways become strengthened. This makes perfect sense. You want to feel a strong connection to the person you are dating. It is debatable whether humans are naturally monogomous or not but the brain is wired to establish solid pair bonds with potential mates. Additionally, the emotional centers that are connected to the memory area also respond every time you see the person. The result is that you have a good feeling when you see your partner.
In coming back to our original question, why is it that your ex is ignoring you? Simple. It’s because of decay and interference. If enough time elapses, the memory of being together fades. If they surround themselves with their friends and busy themselves, they can create enough interference to assist in forgetting about the relationship. So, even though some of our former partners might have malicious motives in how they elect to deal with us after a breakup, the basic reason people ignore each other is that we intuitively know that decay and interference are the best methods for forgetting someone.
Capgras Syndrome
Now here’s a real oddity. Imagine waking up in the hospital from an accident and seeing people you don’t know sitting around your bed. The thing is these people are actually people you know. You think they are imposters. It isn’t your mother sitting next to you; it’s an imposter pretending to be your mother. This strange problem is called the Capgras syndrome or delusion. It was named after the person who discovered it, the French psychiatrist Jean Marie Joseph Capgras.
So, what causes this problem? There is a small area in the brain called the fusiform gyrus that is responsible for us recognizing people’s faces. When a trauma such as a stroke effects this part of the brain, we can no longer recognize faces. Can you imagine what that would be like? Weird, huh. Once we recognize someone, the fusiform gyrus sends a signal to a structure called the amygdala which registers the emotional significance of the person you just saw. So, when you see your wife or girlfriend (or son, daughter, etc.) you experience feelings of happiness. Well, in the case of the Capgras delusion the fusiform gyrus is intact but the pathway to the amygdala is not working correctly. The result is that you when you see someone you should recognize you believe they are an imposter posing as someone else.
The interesting thing with this problem is that it only happens you see someone. If your mother calls you on the phone you would have no problem knowing it was her. Since the auditory pathways are not effected by the brain trauma, you do not experience the delusion. This shows that the Capgras delusion is specific to visual processing.
So, what is the prognosis for someone who has Capgras syndrome? The damage to the pathway from the fusiform gyrus to the amygdala is unfortunately irreversible. Treatment usually involves therapy where the person is taught to establish empathy with other people and how not to validate their delusions. Antipsychotics have also been used with variable results. Capgras syndrome is yet another example of how we need a normal functioning brain to experience even simple everyday things.
So, what causes this problem? There is a small area in the brain called the fusiform gyrus that is responsible for us recognizing people’s faces. When a trauma such as a stroke effects this part of the brain, we can no longer recognize faces. Can you imagine what that would be like? Weird, huh. Once we recognize someone, the fusiform gyrus sends a signal to a structure called the amygdala which registers the emotional significance of the person you just saw. So, when you see your wife or girlfriend (or son, daughter, etc.) you experience feelings of happiness. Well, in the case of the Capgras delusion the fusiform gyrus is intact but the pathway to the amygdala is not working correctly. The result is that you when you see someone you should recognize you believe they are an imposter posing as someone else.
The interesting thing with this problem is that it only happens you see someone. If your mother calls you on the phone you would have no problem knowing it was her. Since the auditory pathways are not effected by the brain trauma, you do not experience the delusion. This shows that the Capgras delusion is specific to visual processing.
So, what is the prognosis for someone who has Capgras syndrome? The damage to the pathway from the fusiform gyrus to the amygdala is unfortunately irreversible. Treatment usually involves therapy where the person is taught to establish empathy with other people and how not to validate their delusions. Antipsychotics have also been used with variable results. Capgras syndrome is yet another example of how we need a normal functioning brain to experience even simple everyday things.
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