Autism and the brain
Sheldon Cooper, Sherlock, according to the BBC and Ebed from Community , go to the bar. The bartender looks up and says: "Is this a joke about the excessive use of the autistic image in the cinema?"
Symptoms of autism: unusual treatment of toys; inability to build relationships with others; laughter or crying out of place; hyperactivity or passivity; too much or too little sound sensitivity; strange attachment to objects; bad speech or lack of it; difficulty changing habits; inattention to danger.
If you put aside my amazing sense of humor, then if there is any mental disorder that is too often mentioned in the media, then this is ( highly functional ) autism. Script writers love to include in the narration of ingenious, socially unsuitable nerds, solving insoluble riddles and making ordinary people look illogical. But how much is such a stereotype true? And what is autism if it's not Sheldon Cooper? Some people think that it can be equated to the possibility of a " rain man " counting the number of matches in a box after a quick glance at him, while others may decide that this leads to a lack of social skills and a large collection of bottle caps. For the most part, the truth is somewhere in the middle: autism is a very broad concept (it is not for nothing that it is called an autism spectrum disorder ), and there are no two identical diagnoses in this area. So let's see what it really is, and what part the brain takes here.
Autism Spectrum Disorder (ASD) is the name of a group of brain development disorders. This disorder is quite common: about 1% of all people have it (it is 4-7 times more often in men than in women). In addition to autism itself, this disorder includes Asperger syndrome , known as a more benign and highly functional version of autism, and a penetrating developmental disorder (something like an intermediate state between Asperger and autism). All of these states are characterized by impaired socialization and communication skills and repetitive / structured behavior and attachments. The severity of certain violations determines where the person is on the spectrum. Someone may remain silent and spend hours completely immersed in some repetitive activity, someone may talk about their interests without interruption, not perceiving allusions to stopping the story and not understanding irony or sarcasm.
')
ASD does not imply a genius intellect by default (sorry, Sheldon!). The level of cognitive function in autism ranges from disability to super-intelligence . And although associating autism with a small IQ is no longer fashionable (scientists are beginning to recognize that this may be due to the fact that standard IQ tests do not reflect the cognitive abilities of autistic children), recent studies have shown that almost half of children with ASD have average intelligence or slightly above average. In addition, in order to confuse the topic, I will mention that in a fairly recent study published in Nature , it was shown that genes associated with an increased risk of autism can be associated with high intelligence (besides, people who have this genetic combination but have not demonstrated ASD) coped better with cognitive tests).
RAS has no one known reason. It is believed that genetics plays an important role in it (autism occurs in relatives, the likelihood of its occurrence in both identical twins is higher than in dvuyaytsev, etc.). However, it is not clear what is happening: there is no one “autism gene”, but only a complex set of interactions ( 1 , 2 , 3 ). However, it is clear that at least some genes are responsible for abnormal brain development in ASD.
The brain with autism is quite different from the "neurotypical" in many aspects. First, in children with ASD, the brain is larger ( 1 , 2 , 3 ). One possible reason is more white matter than people without autism. Between 6 and 14 months, children usually go through a phase of rapid growth of synapses (connections between nerve cells), followed by a “cleansing” process, when unnecessary connections are eliminated. It is believed that in children with ASD this cleansing goes wrong, and they have an unusually large number of synapses that prevent the normal dissemination of information. In one study, the brains of autistic children of different ages (who died under different circumstances) were studied. It turned out that in the last stages of childhood, the number of synapses in their brains fell by only 16%, in contrast to the control cases in which this number was halved . They also discovered a possible reason for this: damage to the protein, which under normal conditions should help the cells, however harsh it may sound, destroy some of their parts (autophagy). As a result, extra synapses remained in the brain, and its cells were clogged with old and damaged parts that could not be eliminated. Scientists were able to restore autophagy and cleansing, and reverse autistic behavior in mice, providing them with medication, restoring the functioning of this protein.
Another factor that may play a role in increasing the size of the brain is the number of neurons in the prefrontal cortex, which is responsible for such complex things as reasoning, communication, social interactions, etc. It was found that boys with autists in the prefrontal cortex have 67% more neurons, and their brains weigh 17% more than their peers without autism. In this case, the quantity is not equal to quality: this leads to a sharp increase in potential connections, and consequently, potential problems in the networks of nerve cells. It is also worth mentioning that neurons of the prefrontal cortex are born during pregnancy, that is, autism may begin in the womb. This will help to understand the exact molecular mechanisms associated with the appearance of an excessive number of neurons, and perhaps - we dream a little - to develop methods of treatment.
Small white pimples (dendritic spines) are places where neuron connections are attached. On the left - there are too many of them. On the right, the autophagy protein works, and the number of spines decreases to normal.
Speaking of connections. We know that autistic brains are arranged differently, but we don’t know exactly how exactly (since the results of the research of connections contradict each other due to different methods and tests). In some studies, it was found that the brain with ASD has too strong connections , and others that are too weak . However, scientists believe that in this confusion, patterns begin to appear, for example , fewer connections between distant parts of the brain (and these connections are weaker), and more connections at short distances.
On these discoveries based theory of the " intense world ". She argues that local hyperactivity in certain parts of the brain leads to excessive functioning, which, in turn, leads to hypersensitivity to information and the extreme work of attention and sensation processing. This does not sound so bad, and may explain the possibilities of geniuses, but the weak connection of distant sites complicates the awareness of all this incoming information and the ability to choose a priority source of information (since the information cannot be correctly integrated). This quickly overloads the mind, so people with ASD are trying to cope with sensory overload, moving away from society or delving into repetitive actions (which help create a sense of stability and keep the world too bright in some kind of framework). And although this is actually a very interesting theory, it must be treated with caution until it is properly studied.
Top row: weaker connections in patients with ASD compared with healthy people.
Bottom row: those connections that people with ASD are stronger.
One of the main signs of ASD is a disorder of social interactions. Autists may look like people who are not interested in social hints, or like people who are unable to read them. Among the most common problems, in varying degrees of severity, there is the impossibility of deciphering facial expressions, sarcasm, irony, feelings and points of view of other people. There are a couple of things in the brain that can explain this phenomenon. In one of the social skills development models , it is stated that we have an innate ability to recognize faces, and that the amygdala, one of the emotional centers, enhances this ability in infants, giving them pleasure when looking at the faces of the people caring for them. As a result, we often look at faces and gain a lot of experience, processing and reading their expressions. This is done with the help of the “fusiform face area” (FFA), which, thanks to the experience gained, increases the ability to analyze facial expressions. In the model, it is believed that this experience becomes a reference in understanding non-verbal communication and complex social interactions. And in the case of children with autism, it seems that FFA and the amygdala are developing abnormally, which weakens the development of social experience.
There is evidence for this idea. Tracking eye movements shows that people with ASD have a certain pattern: they either spend less time studying faces than healthy people, when watching a video with people, or when studying faces look at the mouth and not at the eyes (unlike healthy subjects). ). This pattern of view coincides with the omission of social hints and the problems of communicating with people who are often shown by people with ASD. Another study shows that autists tend to look away from other people's eyes , and the longer the eye contact is maintained, the more active the amygdala is - which means trying to avoid discomfort (the amygdala is also responsible for avoiding unpleasant experiences).
Moreover, with age, the amygdala decreases with autists more than with neurotypical people. The spindle-shaped area also undergoes atypical changes: it responds much less to autistic individuals, and its connections with the amygdala are weakened (which coincides with a study showing that children with autism have problems recognizing facial expressions).
Moreover, in a recent study, scientists were able to turn empathic behavior on and off in rats by manipulating a specific circuit in the amygdala. When the middle part of the amygdala is turned off, the rats were calmly perceived as their rodent friend beats the current. When it turned on, they suddenly showed empathy again (in the case of the rats, this means that they froze in solidarity with the injured comrade). Another potential target for pharmacological intervention!
The red line is the way of looking in people with (right column) and without (left) autism.
Another thing with which autists may have problems is empathy (there are two types: cognitive, that is, “I understand what a person feels” and emotional, “I feel the same”) and with a model of the human psyche . MPS means being able to understand that other people have their own thoughts, emotions, and points of view. It allows us to predict the behavior of others based on what we think about what they may think. Of course, it would be too big a simplification to say that autists do not understand that other people have their own points of view, beliefs, etc. Depending on the position on the scale of the spectrum, many of them understand this. Simply, these beliefs often represent a secret to them. A typical test for the lack of an IPU in a child is the “Sally-Ann” task presented in the picture. Autistic children usually fail to solve it correctly.
It is usually more difficult for autistic children to understand that Sally will first look for the ball in the basket where she first put it.
With problems with empathy, too, is not so simple. Some studies suggest that people with MPS problems have problems with cognitive empathy - it is difficult for them to “take the place of another person” and understand what they feel ( 1 , 2 , 3 ). But with emotional empathy, there seem to be less - if they can understand what the other person is feeling, they will be able to experience the same feelings and demonstrate the same emotional reaction. But psychopaths demonstrate the opposite: they are well aware of how other people feel, but can not show sympathy at all , either in unpleasant or in pleasant situations.
There are several candidates for the role of the foundations of the IPU. The temporal-parietal node (VTU) is one of the main members of this network. It is said that he is responsible for determining the thoughts of another person (what he feels and what he thinks), assessing the visual perception of another person (as he sees it), and other processes necessary for the IPU. It was shown that in patients with ASD, it is activated less in tasks related to MPS, and this activation correlates with the severity of symptoms (the stronger they are, the less activation). In addition, it was found that for autists the entire network of the sites involved in the IPU is hypoactive .
In a couple more studies, scientists figured out whether it is possible to influence the empathy or perception of a person’s IPS using non-invasive brain stimulation (by controlling brain activity through electromagnetic fields or electric current). And when the work of VTU was suppressed, people showed the worst results in tests for cognitive abilities and empathy. When he was excited, people began to better assess the visual point of view of other people. Interestingly, in one study, not specifically aimed at emotional awakening (they just tried to measure the effect of stimulation on how people recognize objects), the six-month course of transcranial magnetic stimulation made a person suffering from Asperger's syndrome feel the following : "" Somehow I I read her facial expressions and reacted instinctively and correctly to them. Most people take such abilities as a matter of course, but all my life I didn’t know how to recognize such things and said no oh, what is needed - sometimes the worst of everything possible - in response to logical words spoken to me by others. An inner voice told me that I could look into their souls. Then I felt a new surge of emotions and I had to go out when this wave rolled on me. The eyes of people turned into windows, and the flow of emotions pouring from them was very strong. Somehow my ability seemed instinctive and natural, as if she was with me always. ”Wow. I feel emotions every day, and they still stun me. For him, all this had to be quite difficult.
Summarizing all this, we can say that non-invasive brain stimulation offers promising possibilities for the treatment of ASD. Several studies have successfully adapted transcranial stimulation to facilitate obsessive repetition, improve speech, and the like. Transcranial stimulation with direct current, tDCS, in spite of its cheapness and simplicity, also seems to be worth trying. Wouldn't it be cool if we could unambiguously identify the switch, by clicking on which, we could connect empathy and the IPU?
And last but not least. Do vaccines cause autism? Not.
Wait a second ... After all, there are quite a few people in science with autism spectrum disorders. This means ... What autism leads to vaccines!
Symptoms of autism: unusual treatment of toys; inability to build relationships with others; laughter or crying out of place; hyperactivity or passivity; too much or too little sound sensitivity; strange attachment to objects; bad speech or lack of it; difficulty changing habits; inattention to danger.
If you put aside my amazing sense of humor, then if there is any mental disorder that is too often mentioned in the media, then this is ( highly functional ) autism. Script writers love to include in the narration of ingenious, socially unsuitable nerds, solving insoluble riddles and making ordinary people look illogical. But how much is such a stereotype true? And what is autism if it's not Sheldon Cooper? Some people think that it can be equated to the possibility of a " rain man " counting the number of matches in a box after a quick glance at him, while others may decide that this leads to a lack of social skills and a large collection of bottle caps. For the most part, the truth is somewhere in the middle: autism is a very broad concept (it is not for nothing that it is called an autism spectrum disorder ), and there are no two identical diagnoses in this area. So let's see what it really is, and what part the brain takes here.
Autism Spectrum Disorder
Autism Spectrum Disorder (ASD) is the name of a group of brain development disorders. This disorder is quite common: about 1% of all people have it (it is 4-7 times more often in men than in women). In addition to autism itself, this disorder includes Asperger syndrome , known as a more benign and highly functional version of autism, and a penetrating developmental disorder (something like an intermediate state between Asperger and autism). All of these states are characterized by impaired socialization and communication skills and repetitive / structured behavior and attachments. The severity of certain violations determines where the person is on the spectrum. Someone may remain silent and spend hours completely immersed in some repetitive activity, someone may talk about their interests without interruption, not perceiving allusions to stopping the story and not understanding irony or sarcasm.
')
ASD does not imply a genius intellect by default (sorry, Sheldon!). The level of cognitive function in autism ranges from disability to super-intelligence . And although associating autism with a small IQ is no longer fashionable (scientists are beginning to recognize that this may be due to the fact that standard IQ tests do not reflect the cognitive abilities of autistic children), recent studies have shown that almost half of children with ASD have average intelligence or slightly above average. In addition, in order to confuse the topic, I will mention that in a fairly recent study published in Nature , it was shown that genes associated with an increased risk of autism can be associated with high intelligence (besides, people who have this genetic combination but have not demonstrated ASD) coped better with cognitive tests).
RAS has no one known reason. It is believed that genetics plays an important role in it (autism occurs in relatives, the likelihood of its occurrence in both identical twins is higher than in dvuyaytsev, etc.). However, it is not clear what is happening: there is no one “autism gene”, but only a complex set of interactions ( 1 , 2 , 3 ). However, it is clear that at least some genes are responsible for abnormal brain development in ASD.
Brain in autism
The brain with autism is quite different from the "neurotypical" in many aspects. First, in children with ASD, the brain is larger ( 1 , 2 , 3 ). One possible reason is more white matter than people without autism. Between 6 and 14 months, children usually go through a phase of rapid growth of synapses (connections between nerve cells), followed by a “cleansing” process, when unnecessary connections are eliminated. It is believed that in children with ASD this cleansing goes wrong, and they have an unusually large number of synapses that prevent the normal dissemination of information. In one study, the brains of autistic children of different ages (who died under different circumstances) were studied. It turned out that in the last stages of childhood, the number of synapses in their brains fell by only 16%, in contrast to the control cases in which this number was halved . They also discovered a possible reason for this: damage to the protein, which under normal conditions should help the cells, however harsh it may sound, destroy some of their parts (autophagy). As a result, extra synapses remained in the brain, and its cells were clogged with old and damaged parts that could not be eliminated. Scientists were able to restore autophagy and cleansing, and reverse autistic behavior in mice, providing them with medication, restoring the functioning of this protein.
Another factor that may play a role in increasing the size of the brain is the number of neurons in the prefrontal cortex, which is responsible for such complex things as reasoning, communication, social interactions, etc. It was found that boys with autists in the prefrontal cortex have 67% more neurons, and their brains weigh 17% more than their peers without autism. In this case, the quantity is not equal to quality: this leads to a sharp increase in potential connections, and consequently, potential problems in the networks of nerve cells. It is also worth mentioning that neurons of the prefrontal cortex are born during pregnancy, that is, autism may begin in the womb. This will help to understand the exact molecular mechanisms associated with the appearance of an excessive number of neurons, and perhaps - we dream a little - to develop methods of treatment.
Small white pimples (dendritic spines) are places where neuron connections are attached. On the left - there are too many of them. On the right, the autophagy protein works, and the number of spines decreases to normal.
Speaking of connections. We know that autistic brains are arranged differently, but we don’t know exactly how exactly (since the results of the research of connections contradict each other due to different methods and tests). In some studies, it was found that the brain with ASD has too strong connections , and others that are too weak . However, scientists believe that in this confusion, patterns begin to appear, for example , fewer connections between distant parts of the brain (and these connections are weaker), and more connections at short distances.
On these discoveries based theory of the " intense world ". She argues that local hyperactivity in certain parts of the brain leads to excessive functioning, which, in turn, leads to hypersensitivity to information and the extreme work of attention and sensation processing. This does not sound so bad, and may explain the possibilities of geniuses, but the weak connection of distant sites complicates the awareness of all this incoming information and the ability to choose a priority source of information (since the information cannot be correctly integrated). This quickly overloads the mind, so people with ASD are trying to cope with sensory overload, moving away from society or delving into repetitive actions (which help create a sense of stability and keep the world too bright in some kind of framework). And although this is actually a very interesting theory, it must be treated with caution until it is properly studied.
Top row: weaker connections in patients with ASD compared with healthy people.
Bottom row: those connections that people with ASD are stronger.
One of the main signs of ASD is a disorder of social interactions. Autists may look like people who are not interested in social hints, or like people who are unable to read them. Among the most common problems, in varying degrees of severity, there is the impossibility of deciphering facial expressions, sarcasm, irony, feelings and points of view of other people. There are a couple of things in the brain that can explain this phenomenon. In one of the social skills development models , it is stated that we have an innate ability to recognize faces, and that the amygdala, one of the emotional centers, enhances this ability in infants, giving them pleasure when looking at the faces of the people caring for them. As a result, we often look at faces and gain a lot of experience, processing and reading their expressions. This is done with the help of the “fusiform face area” (FFA), which, thanks to the experience gained, increases the ability to analyze facial expressions. In the model, it is believed that this experience becomes a reference in understanding non-verbal communication and complex social interactions. And in the case of children with autism, it seems that FFA and the amygdala are developing abnormally, which weakens the development of social experience.
There is evidence for this idea. Tracking eye movements shows that people with ASD have a certain pattern: they either spend less time studying faces than healthy people, when watching a video with people, or when studying faces look at the mouth and not at the eyes (unlike healthy subjects). ). This pattern of view coincides with the omission of social hints and the problems of communicating with people who are often shown by people with ASD. Another study shows that autists tend to look away from other people's eyes , and the longer the eye contact is maintained, the more active the amygdala is - which means trying to avoid discomfort (the amygdala is also responsible for avoiding unpleasant experiences).
Moreover, with age, the amygdala decreases with autists more than with neurotypical people. The spindle-shaped area also undergoes atypical changes: it responds much less to autistic individuals, and its connections with the amygdala are weakened (which coincides with a study showing that children with autism have problems recognizing facial expressions).
Moreover, in a recent study, scientists were able to turn empathic behavior on and off in rats by manipulating a specific circuit in the amygdala. When the middle part of the amygdala is turned off, the rats were calmly perceived as their rodent friend beats the current. When it turned on, they suddenly showed empathy again (in the case of the rats, this means that they froze in solidarity with the injured comrade). Another potential target for pharmacological intervention!
The red line is the way of looking in people with (right column) and without (left) autism.
Another thing with which autists may have problems is empathy (there are two types: cognitive, that is, “I understand what a person feels” and emotional, “I feel the same”) and with a model of the human psyche . MPS means being able to understand that other people have their own thoughts, emotions, and points of view. It allows us to predict the behavior of others based on what we think about what they may think. Of course, it would be too big a simplification to say that autists do not understand that other people have their own points of view, beliefs, etc. Depending on the position on the scale of the spectrum, many of them understand this. Simply, these beliefs often represent a secret to them. A typical test for the lack of an IPU in a child is the “Sally-Ann” task presented in the picture. Autistic children usually fail to solve it correctly.
It is usually more difficult for autistic children to understand that Sally will first look for the ball in the basket where she first put it.
With problems with empathy, too, is not so simple. Some studies suggest that people with MPS problems have problems with cognitive empathy - it is difficult for them to “take the place of another person” and understand what they feel ( 1 , 2 , 3 ). But with emotional empathy, there seem to be less - if they can understand what the other person is feeling, they will be able to experience the same feelings and demonstrate the same emotional reaction. But psychopaths demonstrate the opposite: they are well aware of how other people feel, but can not show sympathy at all , either in unpleasant or in pleasant situations.
There are several candidates for the role of the foundations of the IPU. The temporal-parietal node (VTU) is one of the main members of this network. It is said that he is responsible for determining the thoughts of another person (what he feels and what he thinks), assessing the visual perception of another person (as he sees it), and other processes necessary for the IPU. It was shown that in patients with ASD, it is activated less in tasks related to MPS, and this activation correlates with the severity of symptoms (the stronger they are, the less activation). In addition, it was found that for autists the entire network of the sites involved in the IPU is hypoactive .
In a couple more studies, scientists figured out whether it is possible to influence the empathy or perception of a person’s IPS using non-invasive brain stimulation (by controlling brain activity through electromagnetic fields or electric current). And when the work of VTU was suppressed, people showed the worst results in tests for cognitive abilities and empathy. When he was excited, people began to better assess the visual point of view of other people. Interestingly, in one study, not specifically aimed at emotional awakening (they just tried to measure the effect of stimulation on how people recognize objects), the six-month course of transcranial magnetic stimulation made a person suffering from Asperger's syndrome feel the following : "" Somehow I I read her facial expressions and reacted instinctively and correctly to them. Most people take such abilities as a matter of course, but all my life I didn’t know how to recognize such things and said no oh, what is needed - sometimes the worst of everything possible - in response to logical words spoken to me by others. An inner voice told me that I could look into their souls. Then I felt a new surge of emotions and I had to go out when this wave rolled on me. The eyes of people turned into windows, and the flow of emotions pouring from them was very strong. Somehow my ability seemed instinctive and natural, as if she was with me always. ”Wow. I feel emotions every day, and they still stun me. For him, all this had to be quite difficult.
Summarizing all this, we can say that non-invasive brain stimulation offers promising possibilities for the treatment of ASD. Several studies have successfully adapted transcranial stimulation to facilitate obsessive repetition, improve speech, and the like. Transcranial stimulation with direct current, tDCS, in spite of its cheapness and simplicity, also seems to be worth trying. Wouldn't it be cool if we could unambiguously identify the switch, by clicking on which, we could connect empathy and the IPU?
And last but not least. Do vaccines cause autism? Not.
Wait a second ... After all, there are quite a few people in science with autism spectrum disorders. This means ... What autism leads to vaccines!
Source: https://habr.com/ru/post/402453/
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