Figure The Brain Stem and the Thalamus. The brain stem is an extension of the spinal cord, including the medulla, the pons, the thalamus, and the reticular formation. Above the brain stem are other parts of the old brain that also are involved in the processing of behaviour and emotions (see Figure , “The Limbic System”) And towards the back of the forebrain is the hindbrain, which is composed of the pons, medulla and cerebellum. This part of the brain controls coordination, movement and balance. The brainstem is composed of the medulla and pons, and it is responsible for actions such as blinking, digestion, swallowing, breathing, heart rate and blood pressure cerebellum. located at the base of the brain, attached to the brain stem - controls balance, fine motor skills, coordination and learning/memory associated with movement. medulla. controls vital life functions: swallowing, breathing, heart rate, blood pressure, vomiting, salivating, coughing, sneezing
How does damage to the medulla affect your mental processes and behavior? - Answers
If you were someone who understood brain anatomy and were to look at the brain of an animal that you had never seen before, you would nevertheless be able to deduce the likely capacities of the animal. This is because the brains of all animals are very similar in overall form. In each animal the brain is layered, and the basic structures of the brain are similar see Figure 4.
The innermost structures of the brain — the parts nearest the spinal cord — are the oldest part of the brain, and these areas carry out the same functions they did for our distant ancestors. Mammals, including humans, have developed further brain layers that provide more advanced functions — for instance, better memory, more sophisticated social interactions, and the ability to experience emotions. Humans have a very large and highly developed outer layer known as the cerebral cortex see Figure 4.
The brain stem is the oldest and innermost region of the brain. The brain stem begins where the spinal cord enters the skull and forms the medullathe area of the brain stem that controls heart rate and breathing. In many cases the medulla alone is sufficient to maintain life — animals that have the remainder of their brains above the medulla severed are still able to eat, breathe, and even move.
The spherical shape above the medulla is the ponsa structure in the brain stem that helps control the movements of the body, playing a particularly important role in balance and walking. Running through the medulla and the pons is a long, narrow network of neurons known as the reticular formation. The job of the reticular formation is to filter out some of the stimuli that are coming into the brain from the spinal cord and to relay the remainder of the signals to other areas of the brain.
The reticular formation also plays important roles in walking, damage medulla affects on mental processes and behaviour, eating, sexual activity, and sleeping. When electrical stimulation is applied to the reticular formation of an animal, it immediately becomes fully awake, and when the reticular formation is severed from the higher brain regions, the animal falls into a deep coma.
Above the brain stem are other parts of the old brain that also are involved in the processing of behaviour and emotions see Figure 4.
The thalamus is also important in sleep because it shuts off incoming signals from the senses, allowing us to rest. It functions to coordinate voluntary movement. People who have damage to the cerebellum have difficulty walking, keeping their balance, and holding their hands steady.
Consuming alcohol influences the cerebellum, which is why people who are drunk have more difficulty walking in a straight line. Whereas the primary function of the brain stem is to regulate the most basic aspects of life, including motor functions, the limbic system is largely responsible for memory and emotions, including our responses to reward and punishment.
The limbic system is a brain area, located between the brain stem and the two cerebral hemispheres, that governs emotion and memory. It includes the amygdala, the hypothalamus, damage medulla affects on mental processes and behaviour, and the hippocampus. The amygdala has connections to other bodily systems related to fear, including the sympathetic nervous system which we will see later is important in fear responsesfacial responses which perceive and express emotionsthe processing of smells, and the release of neurotransmitters related to stress and aggression Best, In one early study, Klüver and Bucy damaged the amygdala of an aggressive rhesus monkey.
They found that the once angry animal immediately became passive and no longer responded to fearful situations with aggressive behaviour. Electrical stimulation of the amygdala in other animals also influences aggression. In addition to helping us experience fear, the amygdala also helps us learn from situations that create fear.
Located just under the thalamus hence its namethe hypothalamus is a brain structure that contains a number of small areas that perform a variety of functions, including the regulation of hunger and sexual behaviour, as well as linking the nervous system to the endocrine system via the pituitary gland.
Through its many interactions with other parts of the brain, the hypothalamus helps regulate body temperature, hunger, thirst, and sex, and responds to the satisfaction of these needs by creating feelings of pleasure. Olds and Milner discovered these reward centres accidentally after they had momentarily stimulated the hypothalamus of a rat. The researchers noticed that after being stimulated, the rat continued to move to the exact spot in its cage where the stimulation had occurred, as if it were trying to re-create the circumstances surrounding its original experience.
Upon further research into these reward damage medulla affects on mental processes and behaviour, Olds discovered that animals would do almost anything to re-create enjoyable stimulation, including crossing a painful electrified grid to receive it.
In one experiment a rat was given the opportunity to electrically stimulate its own hypothalamus by pressing a pedal, damage medulla affects on mental processes and behaviour. The rat enjoyed the experience so much that it pressed the pedal more than 7, times per hour until it collapsed from sheer exhaustion. The hippocampus is important in storing information in long-term memory.
If the hippocampus is damaged, a person cannot build new memories, living instead in a strange world where everything he or she experiences just fades away, even while older memories from the time before the damage are untouched. All animals have adapted to their environments by developing abilities that help them survive. Some animals have hard shells, others run extremely fast, and some have acute hearing.
Human beings do not have any of these particular characteristics, but we do have one big advantage over other animals — we are very, very smart. But this does not really work. Despite these comparisons, elephants do not seem 10 times smarter than whales, and humans definitely seem smarter than mice. The key to the advanced intelligence of humans is not found in the size of our brains. What sets humans apart from other animals is our larger cerebral cortex — the outer bark-like layer of our brain that allows us to so successfully use language, acquire complex skills, create tools, and live in social groups Gibson, In humans, the cerebral cortex is wrinkled and folded, rather than smooth as it is in most other animals.
This creates a much greater surface area and size, and allows increased capacities for learning, remembering, and thinking. The folding of the cerebral cortex is referred to as corticalization.
The cortex contains about 20 billion nerve cells and trillion synaptic connections de Courten-Myers, Supporting all these neurons are billions more glial cells gliacells that surround and link to the neurons, protecting them, providing them with nutrients, and absorbing unused neurotransmitters. The glia come in different forms and have different functions. For instance, the myelin sheath surrounding the axon of many neurons is a type of glial cell.
The glia are essential partners of damage medulla affects on mental processes and behaviour, without which the neurons could not survive or function Miller, The cerebral cortex is divided into two damage medulla affects on mental processes and behaviourand each hemisphere is divided into four lobeseach separated by folds known as fissures.
If we look at the cortex starting at the front of the brain and moving over the top see Figure 4, damage medulla affects on mental processes and behaviour. Following the frontal lobe is the parietal lobe, which extends from the middle to the back of the skull and which is responsible primarily for processing information about touch.
Then comes the occipital lobe at the very back of the skull, which processes visual information. Finally, in front of the occipital lobe pretty much between the ears is the temporal loberesponsible primarily for hearing and language. Furthermore, they discovered an important and unexpected principle of brain activity. This finding follows from a general principle about how the brain is structured, called contralateral control, meaning the brain is wired such that in most cases the left hemisphere receives sensations from and controls the right side of the body, and vice versa.
Fritsch and Hitzig also found that the movement that followed the brain stimulation only occurred when they stimulated a specific arch-shaped region that runs across the top of the brain from ear to ear, just at the front of the parietal lobe see Figure 4. Fritsch and Hitzig had discovered the motor cortexthe part of the cortex that controls and executes movements of the body by sending signals to the cerebellum and the spinal cord.
More recent research has mapped the motor cortex even more fully, by providing mild electronic stimulation to different damage medulla affects on mental processes and behaviour of the motor cortex in fully conscious patients while observing their bodily responses because the brain has no sensory receptors, these patients feel no pain. As you can see in Figure 4. Again, the more sensitive the body damage medulla affects on mental processes and behaviour, the more area is dedicated to it in the sensory cortex.
Our sensitive lips, for example, occupy a large area in the sensory cortex, as do our fingers and genitals. Other areas of the cortex process other types of sensory information.
The visual cortex is the area located in the occipital lobe at the very back of the brain that processes visual information. The temporal lobe, located on the lower side of each hemisphere, contains the auditory cortexwhich is responsible for hearing and language. The temporal lobe also processes some visual information, providing us with the ability to name the objects around us Martin, The motor and sensory areas of the cortex account for a relatively small part of the total cortex.
The remainder of the cortex is made up of association areas in which sensory and motor information is combined and associated with our stored knowledge. These association areas are the places in the brain that are responsible for most of the things that make human beings seem human. The association areas are involved in higher mental functions, such as learning, thinking, planning, judging, moral reflecting, figuring, and spatial reasoning.
The control of some specific bodily functions, such as movement, vision, and hearing, is performed in specified areas of the cortex, and if these areas are damaged, the individual will likely lose the ability to perform the corresponding function. On the other hand, the brain is not divided up in an entirely rigid way. As a result, the brain constantly creates new neural communication routes and rewires existing ones. Neuroplasticity enables us to learn and remember new things and adjust to new experiences.
The principles of neuroplasticity help us understand how our brains develop to reflect our experiences. For instance, accomplished musicians have a larger auditory cortex compared with the general population Bengtsson et al. These observations reflect the changes in the brain that follow our experiences. Plasticity is also observed when there is damage to the brain or to parts of the body that are represented in the motor and sensory cortexes.
When a tumour in the left hemisphere of the brain impairs language, the right hemisphere will begin to compensate to help the person recover the ability to speak Thiel et al.
And if a person loses a finger, the area of the sensory cortex that previously received information from the missing finger will begin to receive input from adjacent fingers, causing the remaining digits to become more sensitive to touch Fox, These new neurons originate deep in the brain and may then migrate to other brain areas, where they form new connections with other neurons Gould, We have seen that the left hemisphere of the brain primarily senses and controls the motor movements on the damage medulla affects on mental processes and behaviour side of the body, and vice versa.
This fact provides an interesting way to study brain lateralization — the idea that the left and the right hemispheres of the brain are specialized to perform different functions. Gazzaniga, Bogen, and Sperry studied a patient, known as W. In this surgery, the region that normally connects the two halves of the brain and supports communication damage medulla affects on mental processes and behaviour the hemispheresknown as the corpus callosumis severed, damage medulla affects on mental processes and behaviour.
As a result, the patient essentially becomes a person with two separate brains. Because the left and right hemispheres are separated, each hemisphere develops a mind of its own, with its own sensations, concepts, and motivations Gazzaniga, In their research, Gazzaniga and his colleagues tested the ability of W.
to recognize and respond to objects and written passages that were presented to only the left or to only the right brain hemispheres see Figure 4. The researchers had W. look straight ahead and then flashed, for a fraction of a second, a picture of a geometrical shape to the left of where he was looking.
By doing so, they ensured that — because the two hemispheres had been separated — the image of the shape was experienced only in the right brain hemisphere remember that sensory input from the left side of the body is sent to the right side of the brain.
Gazzaniga and his colleagues found that W. was able to identify what he had been shown when he was asked to pick the object from a series of shapes, using his left hand, but that he could not do this when the object was shown in the right visual field. On the other hand, W. could easily read written material presented in the right visual field and thus experienced in the left hemisphere but not when it was presented in the left visual field. This research, and many other studies following it, has demonstrated that the two brain hemispheres specialize in different abilities.
The Brain
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Start studying Unit 1 Psychology - Role of the Brain in Mental Processes and Behaviour. Learn vocabulary, terms, and more with flashcards, games, and other study tools Figure The Brain Stem and the Thalamus. The brain stem is an extension of the spinal cord, including the medulla, the pons, the thalamus, and the reticular formation. Above the brain stem are other parts of the old brain that also are involved in the processing of behaviour and emotions (see Figure , “The Limbic System”) Damage Medulla Affects On Mental Processes And Behaviour; By / May 21, 0 Likes 1 View 0. Uncategorized. Damage Medulla Affects On Mental Processes And Behaviour
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