Introduction to SAQ Samples PDF

**Introduction to SAQ Samples** - - - - - 1. Before the advent of modern technology, psychologists had to rely on studying human behavior through case studies of patients with brain damage or autopsies to understand the brain. In modern times neuro-imaging technology has allowed psyc...

**Introduction to SAQ Samples** - - - - - 1. Before the advent of modern technology, psychologists had to rely on studying human behavior through case studies of patients with brain damage or autopsies to understand the brain. In modern times neuro-imaging technology has allowed psychologists to look at a living participant\'s brain in a non-invasive way. One such example is the MRI (magnetic resonance imaging), which allows psychologists to look at the structure of the brain. By applying a strong magnetic field to the brain, the MRI causes the proton spins in hydrogen atoms to align to the magnetic field polarization. Hydrogen is present across the brain as so much of the brain is made of water. A static image is created through a compilation of many different snapshots of the brain. It is possible to create either a 2D slice or a 3D model of the brain. This image indicates the structure of the brain, but it does not provide any indication of function. A study by Dragansky used and MRI to measure brain differences in participants after learning a new skill. Twenty-four young adult volunteers, initially non-jugglers, were divided into two groups: jugglers and non-jugglers (control). Jugglers learned a three-ball cascade routine and underwent MRI scans at the beginning, after mastering the skill, and three months later. Non-jugglers had scans at the beginning and end. Using voxel-based morphometry (VBM), researchers analyzed the participants' brains for their density of grey matter. Initially, no significant differences were found between groups. However, after juggling training, jugglers showed increased grey matter in the mid-temporal area of both hemispheres, associated with visual memory. Three months post-training, this increase subsided. The non-juggling group exhibited no changes. These findings suggest that learning a new motor skill can induce structural changes in the brain, specifically in areas related to the learned skill. However, these changes may be temporary, diminishing as practice ceases. Dragansky's study shows how imaging techniques such as MRI can be used to study brain structure. Because the MRI allowed him to compare density of grey matter before and after the learning, Dragansky was able to show how the brain formed new neural networks in response to the learning, but also removed grey matter (pruning) after learning ceased. **358 words** 2. Localization is the theory that specific parts of the brain have specific functions that are related to specific behaviors. Often, however, behaviors are quite complex and involve several different parts of the brain. Although specific parts of the brain may have specific functions, they work together with other parts of the brain to create behaviors. One example of localization is the role of the medial temporal lobes in visual memory. A study by Dragansky aimed to investigate changes to the brain after learning a new skill. Twenty-four young adult volunteers, initially non-jugglers, were divided into two groups: jugglers and non-jugglers (control). Jugglers learned a three-ball cascade routine and underwent MRI scans at the beginning, after mastering the skill, and three months later. Non-jugglers had scans at the beginning and end. Using voxel-based morphometry (VBM), researchers analyzed the participants' brains for their density of grey matter. Initially, no significant differences were found between groups. However, after juggling training, jugglers showed increased grey matter in the mid-temporal area of both hemispheres, associated with visual memory. Three months post-training, this increase subsided. The non-juggling group exhibited no changes. These findings suggest that learning a new motor skill can induce structural changes in the brain, specifically in areas related to the learned skill. In this case, localization of function is demonstrated as the study showed that changes to brain were localized in the MTL. Although other brain areas were certainly activated while learning the juggling skill, it seems as though memory for the visual processing was primarily localized here. **248** 3. The process by which neural networks are formed is part of the concept of neuroplasticity. When a neuron is stimulated, an action potential (an electrical charge) travels down the axon. Neural networks are created when a neuron or set of neurons are repeatedly stimulated. This repeated firing of the neurons, called long-term potentiation, results in gene expression which causes the neurons to sprout new dendrites -- known as dendritic branching. This increases the number of synapses available for the behavior. The branching of neurons in the brain is called grey matter. Dendritic branching as a result of stimulation in the environment is seen in a study by Dragansky. Dragansky aimed to investigate changes to the rain after learning a new skill. Twenty-four young adult volunteers, initially non-jugglers, were divided into two groups: jugglers and non-jugglers (control). Jugglers learned a three-ball cascade routine and underwent MRI scans at the beginning, after mastering the skill, and three months later. Non-jugglers had scans at the beginning and end. Using voxel-based morphometry (VBM), researchers analyzed the participants' brains for their density of grey matter. Initially, no significant differences were found between groups. However, after juggling training, jugglers showed increased grey matter in the mid-temporal area of both hemispheres, associated with visual memory. Three months post-training, this increase subsided. The non-juggling group exhibited no changes. These findings suggest that learning a new motor skill can induce structural changes in the brain, specifically in areas related to the learned skill. In this case, the long term potentiation of neurons in the MTL resulted in increased dendritic branching and density of grey matter in this part of the brain, demonstrating the growth of neural networks or neuroplasticity. **279** 4. Neuroplasticity is the process by which our brains adapt to changes in the environment. One of the ways that our brains change is through the creation of neural networks. This happens because of long-term potentiation - that is, the repeated firing of neurons. This leads to an increase in dendritic branching which leads to an increase in the number of synapses. Another way that our brain can change is through neural pruning - which is a decrease in the number of synapses as a result of the removal of dendritic branches. Pruning can be the result of neuron cell death, hormones such as cortisol, or the lack of use of a neural pathway. The exact mechanism of neural pruning is not yet fully understood. A study by Draganski showed that when neural pathways are not used, they may be pruned. The sample was made up of 24 non-jugglers. Each participant had an MRI scan at the beginning of the study in order to see the structure of the brain prior to the experiment. The participants were randomly allocated to one of two conditions. In one condition, they were asked to learn a juggling routine and to practice it daily until they had mastered it. When they did, they had a second MRI. Then they were told not to juggle anymore. Three months later they had a third MRI. The other group of participants simply served as a control group. Using voxel-based morphometry the researchers measured the density of the grey matter in the brains of jugglers vs. non-jugglers. The jugglers showed a significantly larger amount of grey matter in the mid-temporal area in both hemispheres - an area associated with visual memory. Three months after the participants stopped juggling, the amount of grey matter in these parts of the brain decreased. This shows that when learning a new skill, new neural networks were created. However, when the behavior stopped and those neurons were no longer activated, the neurons were pruned. Researchers hypothesize that neural pruning is a way to increase the efficiency of the brain. ***342*** 5. Psychologists in the biological approach often use experiments to establish cause-and-effect relationships between the brain and behavior. An experiment investigates a hypothesis, and allows researchers to manipulate an independent variable and measure its effect on a dependent variable while keeping other variables constant through controlled variables. In addition, participants are randomly allocated to two or more conditions. One study that used an experiment was conducted by Dragansky. Dragansky hypothesized that learning a a juggling routine would cause changes to teh brains of participants.Twenty-four young adult volunteers, initially non-jugglers, were randomly divided into two groups: jugglers and non-jugglers (control). Jugglers learned a three-ball cascade routine and underwent MRI scans at the beginning, after mastering the skill, and three months later. Non-jugglers had scans at the beginning and end. The IV was whether they learned the juggling routine or not and teh DV was the amount of change shown in the brain using an MRI. Using voxel-based morphometry (VBM), researchers analyzed the participants' brains for their density of grey matter. Initially, no significant differences were found between groups. However, after juggling training, jugglers showed increased grey matter in the mid-temporal area of both hemispheres, associated with visual memory. Three months post-training, this increase subsided. The non-juggling group exhibited no changes. By randomly allocating participants to conditions, carefully controlling variables such as experience with juggling, and measuring the changes to participants' brains before and after the independent variable was implemented, Drangansky showed a cause and effect relationship between learning a juggling routine and changes to the medial temporal lobes. 256 words