Phantoms in the Brain by VS. Ramachandran Chapter 2: Knowing where to scratch A young man named Tom loses his arm in a car accident 3 months before graduation. Experiences phantom limb sensations. Ramachandran postulates that the sensations that are being experienced in his amputated hand come from the face because of the proximity of the face to the hand in the somatosensory cortex. Tests this out on Tom and finds that the sensations are not just limited to touch, but also include temperature and pressure. Sensations in the face and arm are responsible for the sensation in the phantom hand because these areas have grown to encompass the area of the cortex that no longer innervates the hand. Woman experiences sensations in foot when having sex. More support for this theory because the genitals are adjacent to the area that innervates the foot and could have grown to encompass that area. Phantom sensations can include sexual arousal as well. The chapter is calling ?Knowing where to scratch? because Tom always experiences itches in his hand and does not know where to scratch. But can now just scratch his face or his arm when Ramachandran explains the somatosensory cortex to him. Chapter 3: Phantoms in the Brain Phantom limb sensations arise even though we know that our limb is gone. However, when a patient is under the illusion that a phantom limb is actually there, they are suddenly able to control the phantom limb. Another important thing is that those of us that are born without limbs experience phantom limb sensations. Ramachandran postulates that the parietal lobe works in conjunction with other areas such as the visual cortex to create an image of our bodies. The brain often uses statistical analysis to be able to determine what sensations are possible. Example: If you tap the table at the same rate as you tap your hand that is hidden under the table, you begin to experience sensations from the table itself. This suggest that the parietal lobe contains an internal image that is created by nature, but this image can be modified with experience. States that one reason people with phantom limbs cannot control the limb is due to feedback. Each time the brain elicits a command, it receives feedback back from the area under its control through tactile sensations. If the limb is not actually there, the commands are sent over and over and are not sent back to have been received. Thus, the brain tries harder and harder to try to make the part of the body that is missing elicit an action. Another important thing is that when a limb is lost and other cortical areas take over that part of the brain, the re-wiring could result in accidental mishaps that may result in pain receptors being activated when sensations from an area controlled by that part of the cortex are sent to the brain. Thus, painful experiences in the hand can arise whenever we touch the face and so on. The fact that simple experiments can cause us to lose phantom limb sensations, or even distort our perceptions of where our limbs are located in space suggests that although our body images are hard wired, they can be manipulated by experience. It also suggests that different parts of the brain work in conjunction with one another, although we do not know how. Chapter 4: Zombie in the Brain Diane suffers from carbon monoxide poisoning in the shower after the water heater malfunctions. The carbon monoxide binds to her blood and permanently damages certain areas of her brain. She becomes blind as to what things are but can still tell that they are there. The notion that a tiny image read up side down is projected on to our retina and directly interpreted is not right. Can only be read as a series of action potentials but we have no idea how these action potentials are relayed into sensation. Many different areas of the brain work together but we don?t know how. Are thought to be 30 visual cortexes that act as specialized areas for visual acuity. Ex: One might directly interpret movement and one might interpret size. The zombie in the brain is the notion that when the temporal lobe is damaged, we lose complex aspects of vision. However, we can still tell that things are around us but we don?t understand what they are. We will still be able to navigate around the world like a zombie. Thus, we can touch things that are in front of us even we cannot consciously discern that they are there. The zombie effect. The zombie is part of the old visual pathway that can ascertain how objects are arranged around us but the more specialized pathway tells us what they are. With just the old pathway, we would be walking around the world with no comprehension of what things are around us. Patients like Diane illustrate how much of our actions are not under conscious control. Many zombies inhabit our brain and the notion that we are in control could in fact be an illusion that helps us organize life more efficiently. Chapter 5: The Secret Life of James Thurber James Thurber was shot in the eye by a toy arrow at a young age. Suffered the illusion of strange images. His right eye was damaged. Gradually he lost image in his left eye until he became totally blind at 35. Began to replace the lost vision with imaginary images. Our higher brain areas contain imaginary images, as well as past memories of events. However, lower brain areas correct these higher brain areas in telling them that what they are communicating is right or wrong. If we damage lower visual areas, the net effect is that these higher areas take over and we see imaginary images and past memories that are not actually there. Our brains also fill in many non complex objects and images when they are in our blind spot. This is the result of the brain assessing certain areas and logically putting in what it believes should be there in the blank spot. The reason we do not notice our blind spots is because it occurs in a different area in each eye and one eye compensates for the other. Josh suffered damage to his right occipital lobe and had a round gap in his vision as a result. However, he did not really notice this gap because his brain filled in the simple details. The only time he noticed it was when he was reading something, or required complex aspects of vision. He illustrated that different aspects of vision are processed at different speeds and that the brain fills in what is logically believes is the best solution when things are not actually there. Charles Bonnet Syndrome: People who suffer from visual problems such as cataracts and so on gradually begin to see images that are not actually there. When lower brain areas are obstructed, higher brain centers take over, proving that vision is a complex process, requiring many different areas of the brain. Can even be compared to memories and some aspects of our imagination to tell what it is that we are seeing in front of us. Chapter 6: Through the Looking Glass Emma suffers hemispatial neglect from a stroke to her right hemisphere. Combs the right side of her head and puts lipstick on the right side of her face but neglects her left side. Ramachandran proposes that if the left hemisphere is damaged, it loses its searchlight, but the right can compensate because it casts its searchlight on the entire world. This is the reason why a stroke in the left parietal lobe does not result in neglect. Stroke rehabilitation has most recovery from paralysis on a patient?s left side with them moving that side to recover. The brain?s plasticity allows the body to recover. However, this is very hard for neglect patients who completely neglect the left side of their world. Ramachandran tries to get Ellen to notice the left side of her world by orienting a mirror in such a way as to get her to notice the left side of her body. However, the result of this is that she cannot determine where an object on her left side actually is when she sees it through a mirror. She believes that reflections of objects on her left side are actually inside the mirror and tries to reach into the mirror. She then tries to look behind the mirror for the object. This happens in several of Ramachandran?s patients. He coins the term mirror agnosia, or looking glass syndrome. In the end, Ramachandran concludes that not only is the sensory world of a neglect patient warped, but their knowledge base is also twisted. They can no longer recognize that the reflection of objects on their left side are reflections, and not within the mirror itself. Chapter 7: The Sound of One Hand Clapping Consider the case of Mrs. Dodds. She suffered a stroke to he right hemisphere but had no idea that she could not use the left side of her body. To her, when people told her that she was paralyzed on her left side, it was annoying because she thought that she wasn?t. This unawareness of illness is termed asognosia. The patient may consciously believe that they are using the paralyzed the side of their body and when shown their paralyzed, immovable arm, they may come up with the weird assertion that it is someone else?s in an effort to prevent acknowledgement of their own paralysis. Denial of ownership of your own body parts is known as somatoparaphrenia. Freud?s explanation for mechanisms to prevent acknowledgment of disturbing facts about ourselves was we were trying to defend our own egos. However, his theory fails to explain the difference in magnitude of psychological defense mechanisms between patients with anosognosia and normal people. Why are these mechanisms so exaggerated in denial patients as compared with normal ones? Why do patients who suffer left hemisphere damage never experience denial? Ramachandran?s explanation: The left hemisphere creates a belief system or model and folds new experiences into that belief system. If it is presented with information that does not fit the model, it relies on Freudian defense mechanisms to deny, repress or confabulate things to repress the status quo. The right hemisphere plays ?Devil?s Advocate? and questions the status quo to local for global inconsistencies. It decides whether it is time to force a complete revision of the entire model and start from scratch. If the right hemisphere is damaged, all of our experiences become part of our original belief system and Freudian mechanisms are exaggerated. The result is we refuse to acknowledge things that are readily visible to those around us. A patient named Mr. Cooper is asked why he moved his arm even though he didn?t move it. He comes up for an excuse for why he did it even though he didn?t do it. Ramachandran suggests that his whole system of beliefs is deranged that there is no limitation to what he will do to protect these beliefs. What if the patient?s right arm is paralyzed? Will they be oblivious to that as well? Yes. What is damaged in these patients is the manner in which the brain deals with discrepancies in sensory inputs concerning body image. It is not critical whether the discrepancy arises from the left or right side of the body. A mirror box was used to do this, with a student putting his arm into the box and acting like the motionless arm. Mrs. Macken acknowledges her paralysis when cold water is put into her ear. Why is this? Two possibilities. One is that it arouses the right hemisphere and that connections from the vestibular nerve project to the vestibular cortex. Activation of these circuits makes the patient pay attention to the left side and notice that her left arm is lifeless. She recognizes for a brief period of time that she is paralyzed. Another possibility is that rapid eye movements after administration of the cold water activates REM or dream sleep. In dream sleep, we often dredge up material that is ordinarily censored and the same sort of thing may be happening during ?ice water in the ear? stimulations. The 2nd possibility opens up a lot of questions that Ramachandran poses, particularly with Freudian mechanisms. He identifies several key attributes of human nature that Freud proposed, and that he has identified with his patients: Denial: When a patient says a paralyzed limb is working, but it is not. Repression: A patient will sometimes admit a limb is paralyzed, and then revert soon after to denial. Reaction formation: When patients resort to the exact opposite of what is true. Like saying that they can life a book with their left hand when it is paralyzed. Rationalization: When patients say that they cannot move a lifeless limb because they have arthritis or because the limb is tired. Humor: When patients use humor to avoid the situation of admitting that they are paralyzed. Ex: When asked to move a limb, they may say ?I don?t take orders, doctor.? Projection: To avoid confronting a disability, we project it on to someone else. ?This isn?t my limb, it is someone else?s.? Chapter 8: The UnBearable Likeness of Being A patient named Arthur believes that his parents are imposters. Arthur had been involved in a near fatal car accident that left him in a coma. When he regained consciousness and began rehabilitation, everything began to come back to him except that he had the delusion that his parents were impostors. However, when they speak to him on the telephone, he believes that they are his parents. Suffers from Capgras delusion, where a patient comes to regard close aquaintances as imposters. The Freudian explanation is that when an injury occurs, mechanisms of attraction toward a patient?s mother that were repressed resurface again, along with feelings of jealous toward his father. The patient acknowledges that he cannot feel this way about his own parents and begins to believe they are imposters. However, this explanation cannot be true because some patients with Capgras syndrome think their dog is an imposter. Ramachandran proposes that connections between Arthur?s face region and limbic system have been damaged, and that he cannot experience any emotions when he sees their faces. Perhaps his explanation is that if he cannot experience any emotion from seeing his own mother, that she must be an imposter. Did a lie detector test to tell whether or not Arthur could recognize his parents? faces. In response to something or someone we know, we begin to sweat, which is picked up by electrodes on our skin. Arthur?s skin response was uniformly low when shown pictures of his parents. To be sure he had no trouble recognizing faces, another test was done, where he was forced to recognize famous people. The results showed that he had no trouble recognizing the difference between faces. If this is true, how come Arthur can recognize everyone else other than his parents? This is because everyone else isn?t expect to elicit the same warm emotional reaction that his parents are expected to elicit. How come patients that are not born with amygdalas or whose amygdalas are taken out surgically do not experience this phenomena? This is because the experience a general blunting of emotional responses and do not have a baseline for comparison. Ramachandran argues that in Capgras, all of the face recognition areas are disconnected from the amygdala. Why can Arthur recognize his parents on the phone? Perhaps only the visual pathway to the amygdala is damaged, and the auditory pathway remains intact. Testing on Arthur reveals that after looking at several different images of the same person with a slight shift in gaze, Arthur thinks it is a totally different person. Ramachandran concludes that when Arthur meets a stranger, his brain creates a file for them. However, if that person leaves the room, Arthur will start to create a completely new one instead of retrieving the old file. As a result, he creates many different copies of places and even people. When shown a picture of himself, he may even say that this is not the real Arthur. This shows that he cannot properly link his parents to old stored memories in his brain, and as a result, calls them imposters because he does not feel emotional warmth for them. Chapter 9- God and the Limbic System Can stimulations of the temporal lobe result in religious experiences? A Canadian psychologist publishes a story in a Canadian magazine where he stimulated his temporal lobe and experienced god for the first time in his life. Patients with temporal lobe seizures experience intense religious experiences where they believe that god speaks to them. A divine light or an ultimate truth that has finally been revealed to them during the moments of the seizure. These seizures of the temporal lobe can sometimes permanently alter a patient?s personality. Ramachandran proposes that the repeated electrical bursts inside a patient?s brain facilitate certain pathways, or open new channels to the amygdala, enriching a patient?s inner emotional life. Consider the case of Paul, a 31 year old assistant manager of a local Goodwill store who believes he is an expert witness to offer testimony about his relationship with God. Paul documents all his religious experiences and encounters with the divine, and also explains that he receives flashbacks during seizures at times, where he is able to recollect large amounts of information, such as a full book. Ramachandran?s explanation for this bizarre behavior is that certain pathways that certain sensory brain areas that see people, events, and noises become closely linked to emotional centers. When a seizure occurs, a large number of neural signals travel through these pathways, increasing the communication between these brain structures. The result is that every object and event becomes imbued in deep significance. Another hypothesis could be that there are biological genes that code for some aspects of spirituality. However, this is largely speculation. What causes us to develop increased neural connections? Do people that are more intelligent have a greater area devoted to specific parts of the brain (more neural connections in a specific area)? Consider sevants. People that have an IQ below 50 but have extraordinary mathematical, linguistic, and other abilities. These people are not classified as geniuses but have extraordinary abilities for calculation, imagination, and approximation. Ramachandran?s explanation is that their brains may have suffered damage in specific areas at birth or shortly after, and there may have been remapping of the cerebral cortex into different areas that allow them to account for these extraordinary abilities. An angular gyrus doubled in size would lead to a one hundred fold increase in mathematics. Ramandran proposes that the differences in intelligence lie in differences in creativity between different people. Seeing solutions and ways to relate things that others do not readily see even though they have access to the same material. Ex: We all have access to the same words as Shakespeare, but very few of us can string six metaphors into one sentence. Chapter 11: You Forgot to Deliver the Twin Mary Knight has pseudocyesis (desperately wants to be pregnant so she experiences all the signs and symptoms of true pregnancy). Same exact symptoms as normal pregnancy except there is no baby. The doctor doesn?t know how to break news of her condition to her so he gives her ether and tells her the baby was stillborn. Mary is devastated but gets over the news. A week later, she bursts into the office and tells the doctor that she can feel another baby in there kicking: That he forgot to deliver the other twin. What causes pseudocyesis? Cultural factors play a major role, explaining the decline of pseudocyesis from an incidence of one in two hundred in the late 1700s to about one in ten thousand pregnancies today. What causes the physical changes in pseudocyesis? Abdominal swelling is caused by five factors which act together: An accumulation of intestinal gas, a lowering of the diaphragm, a pushing forward of the pelvic portion of the spine, a dramatic growth of the greater omentum (pendulum of fat that hangs in front of intestines) that ma cause actual uterine enlargement, and abnormal hormonal secretions through action of the hypothalamus. The mind can also effect the woman?s pregnancy status. When Mary sees her abdomen enlarge and feels her diaphragm fall, she learns unconsciously that the lower it falls, the more pregnant she becomes. This would cause a combination of air swallowing and autonomic constriction of the gastrointestinal sphincters that increase gas retention to be learned unconsciously. Intense longing for a child and associated depression may also reduce levels of dopamine and norepinephrine (joy-transmitters of brain), causing the reduced production of FSH (causes ovulation) and prolactin inhibition factor. Low levels of these hormones would lead to a stop in ovulation and and elevation of prolactin to cause breast enlargement, and nipple tingling, leading to the overall impression of pregnancy. Pseudocyesis can also occur in men who sympathize deeply with their pregnant spouse, producing sympathetic pregnancy or couvade syndrome. The mere pairing of a sugar with an immunosuppressive drug can cause a mouse immune system to learn the association. Once this association has been established, the mouse?s immune system will collapse when it encounters sugar, making it vulnerable to infections. This is another example of mind affecting body. Chapter 12- Do Martians See Red?
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