biopsychology Flashcards
<div><strong>What is the differences between localisation and holistic theory?</strong></div>
“<p class>Wernicke and Broca in the 19th century looked at how certain aspects of the brain performed certain physical and psychological functions. Before the likes of Phineas Gage, scientists believed that the brain functioned holistically (that all parts were involved in the process of thought and action). They instead argued for the localisation of function (cortical specialisation) due to certain illnesses or injuries in the brain lead to specific types of malfunction. </p><p class> </p><p class> </p>”
<div><strong>Describe + locate the motor, somatosensory, visual and auditory centres?</strong></div>
“<p class>(These are in the 4 main lobes - parietal, occipital, frontal and temporal)</p><p class>Back of the frontal lobe - Motor Area = damage may mean loss of control of movement.</p><p class>Front of the parietal lobe - Somatosensory Area = damage would lead to an inability to detect sensory information from the skin.</p><p class>The occipital lobe - Visual Area - the damage could lead to limited vision or blindness (overlap).</p><p class>The temporal lobe - Auditory Area - damage to this area could lead to a lack of hearing, comprehension of speech or ability to. </p>”
<div><strong>Describe the features of language in the brain?</strong></div>
“<p class>Language in most people is on the left side of the brain. In the 1880s Broca discovered a small area in the left frontal lobe that, if damaged would lead to slow, malformed speech. While Wernicke, around the same time, looked at patients who could speak fine but struggled to understand speech. The area of the brain damaged had Wernicke’s aphasia when damaged (these patients often produce neologisms as part of their speech. </p>”
<div><strong>What are the sections of the brain and their function?</strong></div>
“<a><img></img></a>”
<div><em><strong>Empirical Support...</strong></em></div>
“<p class>There is a large amount of supporting evidence that points towards the neurological functions of the brain being localised, especially when it comes to language and memory. Petersen (1988) used brain scans to show that the Wernicke’s area was active during listening while the Broca’s area was active during a reading task. Tulving et al (1994) also demonstrated that the semantic and episodic memories reside in different parts of the prefrontal cortex. Both of which have been possible because of the progression of technology. Therefore there is valid, highly reliable evidence that strongly supports the localisation in our brains.</p>”
<div><em><strong>Support of Neurosurgical Evidence...</strong></em></div>
“<p class>In the 1950’s it became a practice to surgically remove parts of the brain in order to control behaviour. One example of this is the lobotomy in which the frontal lobe was severed in an attempt to control aggressive behaviour. Although this was very inaccurate and procedures were often not delicate - neurosurgery is still used in extreme cases of OCD and Depression today. For example, Dougherty (2002) reported that 44 OCD patients had undergone cingulotomy and the third had a successful response and 14% had at least a partial response. This suggests that mental health disorders can also be localised in a patient and therefore supports the theory.</p><p class>Another example of lobotomy being used in society is in 1950s America where housewives were having their frontal lobe severed ( a prefrontal lobotomy) in order to make them more sedate and less depressed with their lives in domesticity. </p>”
<div><em><strong>Case Study Support...</strong></em></div>
“<p class>Case study = Phineas Gage</p>”
<div><strong><em>How is Lashley's Research an Issue?</em></strong></div>
“<p class>Lashley (1950) looked at how aspects such as learning may not be localised within the brain (and other ‘higher’ cognitive functions). Lashley removed between 10-50% of rats brains and no specific area inhibited their ability to learn a maze. Therefore this suggests that learning is too complex to be localised to one area of the brain. (However issue of animal research)</p>”
<div><em><strong>How is Plasticity a criticism for Localisation?</strong></em></div>
“<p class>The brain can go through what is known as <em>cortical remapping </em>when the brain becomes damaged and then the brain is able to reorganise its functions in order to cope with a lost or damaged element. Lashley described this as the <em>law of equipotentuality </em>and this is documented in many cases of stroke victims. Therefore there is some contradictory evidence that goes against the theory of localisation.</p>”
<div><strong>What is neuroplasticity?</strong></div>
“<p class>This refers to the brain’s ability to adapt or change. When we are younger we have more synapses but synaptic pruning occurs at a greater rate in order to prioritise those that are needed and prune ones that are not used anymore.</p>”
<div><strong>What is a study that researched Plasticity?</strong></div>
“<p class>Maguire (2000) studied the brains of London taxi drivers and found a significantly higher volume of grey matter in their brains in the posterior hippocampus which links to their navigational and spacial skills. To analyse this they were given tasks to recall city streets in London. It was also shown that the longer that they had been a taxi driver the more significant the changes in the brain.</p><p class>Another study looking at Plasticity was carried out by Draganski (2006) who looked at the brains of medical students in the months before and after their exams. They found that there were changes in the posterior hippocampus and the parietal cortex due to the exam. </p><p class>Mellichi (2004) also found that those who were bilingual had larger parietal cortex in comparison to matched monolingual controls.</p>”
<div><strong>What is neurorehabilitation?</strong></div>
“<p class>When there is damage to certain areas of the brain the functions that are necessary to live are relocated within the brain - this happens very quickly after the trauma occurs. This form of therapy seeks to aid this process and to make it most effective to achieve a full recovery. This has been beneficial most often for people who have suffered a stroke.</p>”
<div><strong>How does this process actually take place?</strong></div>
“<p class>Doidge (2007) stated the brain reorganises itself by forming new synaptic connections close to the sight of the damage. Enabling the function of where the area should have been to continue elsewhere. There are a couple of structural changes that occur:</p><ul class=""><li style=""><em>Axonal</em> <em>Sprouting</em> - the growth of nerve endings which connect the other undamaged nerves to form new neural pathways.</li></ul><ul class=""><li style=""><em>Reforming blood vessels </em></li></ul><ul class=""><li style=""><em>Homologous</em> areas of the brain in the other hemisphere are used if accessible. </li></ul>”
<div><strong>What is phantom limb syndrome? + risk of drugs</strong></div>
“<p class>Rammachandran and Hirstien (1998) found that 60-70% of amputees develop this due to the reorganisation of the somatosensory cortex with the missing never impulses from the missing limb.</p><p class>Negative Plasticity - the brain goes through the process of reorganising but it does not work correctly eg. above</p><p class>Medina et al (2007) also found that prolonged drug usage can lead to poorer cognitive functions and risk of dementia as the rewiring of the brain is less stable.</p>”
<div><strong>How can this relate to the Dutch learning of languages?</strong></div>
“<ul class=""><li style="">start young when the brain can rewire faster which increases learning capacity</li></ul><ul class=""><li style="">Calero and Navarro (2003) looked at this as the best explanation for dementia - if we decline both physically and in the activities we do in the way of accessing neural plasticity we are more likely to get dementia.</li></ul>”
<div><strong>What did Hubel and Wiesel do?</strong></div>
“<ul class=""><li style="">Sewed now eye of a kitten shut from birth</li></ul><ul class=""><li style="">later scanned the brain for activity and found the occipital lobe was being repurposed to process visual information from the other eye. </li></ul><ul class=""><li style="">This demonstrates the capability of the brain to be malleable and neural plasticity can be actively triggered.</li></ul>”
<div><strong>What does split-brain research look at?</strong></div>
“<ul class=""><li style="">Hemispheric lateralisation</li></ul><ul class=""><li style="">To understand the nature of split functions in different sides of the brain</li></ul>”
<div><strong>What happens when a person's brain is split in two?</strong></div>
“<p class>Communication no longer takes place between the left and right hemispheres of the brain via the corpus callosum that has been severed. The split-brain syndrome can lead to many conditions such as the inability for the right side of the brain, communicating with the left eye to articulate with language what it is seeing while being able to still draw what has been seen or a condition called alien-hand syndrome where hand movements happen that are seemingly involuntary.</p>”
<div><strong>How is the brain described from the hemispherical lateralisation explanation?</strong></div>
“<ul class=""><li style="">Functions are carried out in different parts of the brain and there is no direct symmetry in the function of both sides of the brain.</li></ul><ul class=""><li style="">When it comes to language we only use the left hemisphere of the brain. In the right, we tend to deal with visual and spatial information.</li></ul>”
<div><strong>Who discovered HL?</strong></div>
“<p class>Sperry in 1968, he was later awarded the Nobel prize in 1981.</p>”
<div><strong>Explain the aim, method, p/pants and procedure of Sperry's experiment.</strong></div>
“<p class>Aim: To demonstrate that the hemispheres have different functions/abilities - each hemisphere has its own consciousness and awareness. </p><p class>Method: Natural Experiment (he didn’t operate on them!)</p><p class>P/pants: 11 male epileptics who had all had a commisectory in order to stop fits that occur due to the rapid sending of electrical systems between the two sides of the brain.</p><p class>Procedure: The subjects has one eye covered and gazes at a fixed point on a translucent screen (tachistoscope). They are the given…</p><ul class=""><li style="">Visual Stimulus Tests - where slides are projected on either side or both of the screen at a fixed rate of 1/10 of a second, they are then asked to write or say what they have seen.</li></ul><ul class=""><li style="">Tactile Stimulus Tests - Objects are presented to the left or right hand (or both) behind the screen and then are asked to point to, feel or draw the objects.</li></ul><ul class=""><li style="">Tests to the Right Hemisphere - range of tests/puzzles</li></ul>”
<div><strong>What were the findings of this study?</strong></div>
“<ol class=""><li>Objects/words shown to the left hemisphere could be verbalised easily while objects/words shown to the right hemisphere were hard to verbalise but could still be drawn. = language is in the left hemisphere.</li></ol><ol class=""><li>P/pants could not verbally describe objects in the left visual field but were still able to select objects with their left hand that matched the word shown. = right hemisphere still understands what it perceives in the world.</li></ol><ol class=""><li>Composite words - if the p/pant was presented with two different words on either side (eg. a key on the left and a hat on the right) then they would draw a key but say hat. = separate and different processing in each hemisphere.</li></ol><ol class=""><li>The right hemisphere was dominant at recognising faces as when a face was presented and then asked to be selected in both visual fields the left was ignored and the face presented to the right hemisphere would be preferred. = demonstration of a separate and dominant function in one hemisphere. </li></ol>”
<div><strong><em>How does this demonstrate lateralisation of brain function?</em></strong></div>
“<p class>Sperry and later Gazzaniga’s work has grouped together a large body of work that demonstrates that the left hemisphere of the brain is better at processing the verbal and analytical tasks that we do while the right seems better at performing spatial tasks and music. Therefore this demonstrates distinctly different functions into the separate hemispheres of the brain.</p>”
<div><strong><em>What is a strength of the method?</em></strong></div>
“<p class>The procedures used in the split-brain research are highly standardised and also ingenious for his time. His method of blindfolding, having the patient focus on a fixed spot and only showing the word for 1/10 allowed him to make variations of the experiments while not increasing the potential for extraneous variables. Therefore this leads to high levels of internal validity as we can be sure there was no interference between the hemispheres.</p>”
<div><em><strong>What is the issue of generalisation?</strong></em></div>
“<p class>The split-brain patients are not only a very small number of the population - leading to issues over whether this research truly provides evidence for a pre-surgery brain analysis - but are also part of a very small sample size with an androcentric bias. The control group also had no links to epilepsy so it may be the epileptic brains only have this feature of lateralisation. This limits the generalizability of these findings to a wider populace as they may not be representative.</p>”
<div><em><strong>How could the difference in function be over-stated? </strong></em></div>
“<p class>Since Sperry’s research, there has been a major practice of over-simplification and over-simplifies this research with the distinctions of functions in the left and right sides of the brain. Modern neuroscientists believe that the distinction is less clear cut and connected hemispheres communicate a lot to perform similar functions daily. Most functions also have evidence baking that they can take place in the other hemisphere. Therefore this research may not be as absolute when it comes to the function of HL. (give examples)</p>”
<div><strong>What are the two main functions of the Nervous System?</strong></div>
“<ul class=""><li style="">To collect information from the senses</li></ul><ul class=""><li style="">To relay instryctions to our body’s systems so that they cna respond to the environment.</li></ul>”
<div><strong>What are the two sub-systems of the nervous system?</strong></div>
“<p class><span><strong>CNS</strong></span> - This is the brain and the spinal chord.</p><ul class=""><li style="">The brain provides us with concious awareness due to our cereberal cortex which seperates us from lower order animals</li></ul><ul class=""><li style="">The spinal chordis responsible for basic functions such as regulating our breathing</li></ul><p class>This is proved by our ability to be brain dead but still live when in a coma.</p><p class><span><strong>PNS</strong></span> - Transfers messages through the body via neurons.</p><ul class=""><li style="">Automatic Nervous System - Governs that vital functions in the body eg. heart rate.</li></ul><ul class=""><li><strong>SNS and PNS</strong><ul class=""><li style="">sns = sympathetic nervous system (fight or flight)</li></ul><ul class=""><li style="">pns = parasympathetic nervous system (back to normal level)</li></ul></li></ul><ul class=""><li style="">Somatic Nervous System - This controls the muscle movements as it receives information form receptors.</li></ul>”
<div><strong>What are the Types of Neurons?</strong></div>
“<ul class=""><li style="">Sensory Neurons - nerve cells within the nevous system</li></ul><ul class=""><li style="">Interneurons - enables communicaiton between sensoty, motor neurons and the nervous systems</li></ul><ul class=""><li style="">Motor Neurons - theses interact with muscles and glands causing them to respond</li></ul><p class> </p>”
<div><strong>What are Post-Mortem Examinations?</strong></div>
“<p class>This is the oldest method of studying the brain that involves comparing the dead brains of those with brain abnormalities to that of neurotypical brains via dissections. Notes are compared from several cases until a pattern emerges.</p>”
<div><em><strong>What are some disadvantages of this approach?</strong></em></div>
“<ul class=""><li style="">the patient must be dead - we cannot see the active functions of the brain.</li></ul><ul class=""><li style="">other techniques are able to show the functions of the brain while they are active.</li></ul>”
<div><em><strong>What are some advantages of this approach?</strong></em></div>
“<p class>This was an innovation in its field with the beginnings of looking at the functions of the brain and how certain areas can be impaired. </p>”
<div><strong>What is an EEG?</strong></div>
“<p class>(electroencephalogram)</p><p class>This recorded the electrical waves of activity in the brain from the surface via electrodes that are placed on different areas of a person’s scalp, filled with an electrolyte gel and plugged into a recording device.</p><p class>The brain waves are attracted by the electrodes and travel to the recording device where they are then amplified so that they can be more easily seen and examined. </p><p class>This can be used to look at a variety of brain functions including sleep and the stages of sleep as well as psychological disorders. </p><p class>It is used to evaluate the electrical activity of the brain and help to look for certain issues associated with this activity. </p>”
