Biopsychology Flashcards

Question

Somatosensory centres

Answer 1

− Somatosensory: sensations/touch − Located in the parietal lobe of the brain along the postcentral gyrus (both hemispheres) − The somatosensory cortex perceives touch, using sensory information from the skin it produces sensations of touch, pressure, pain + temperature − More neuronal connections + therefore a larger amount of the somatosensory cortex are needed for touch sensitive areas of the body e.g. the face, particularly the lips

Answer 2

− The brain has two visual cortices (one in each hemisphere) the visual cortex in the right hemisphere receives input from the left hand side of the visual field and visa-versa − Its located in the occipital lobe at the back of the brain (both hemispheres) − Light enters the eyes is received by the retina hitting the photoreceptors (rods + cones) at the back of the retina, nerve impulses then travel down the optic nerve to the brain where they are received by the thalamus, the thalamus acts as a relay station transmitting information to the visual cortex − Within the main visual centre there is an area called Area V1 which seems to be necessary for visual perception, research has found that individuals with damage to this area report no vision of any kind: conscious vision, visual imagery while awake or in their dreams (Hurovitz et al) − However some research has found that damage to Area V1 can lead to a condition known as ‘blindsight’ in which individuals report no vision so appear blind but are able to locate objects in a visual field by pointing at them – this suggests that some of the processing in the visual cortex is not conscious as they respond to visual stimuli that they do not consciously see therefore they may be two types of vision: one conscious + the other unconscious − Overgaard et al.: → Conducted a case study about a 31 yr old women who experienced ‘blindsight’ following damage within her visual cortex which occurred as a result of brain haemorrhage → Researchers tested her with tests asking her to detect a letter shown on a screen she could not identify the letter but she did report awareness of something despite seeing nothing → This continued with many of the stimuli + when tested statistically there was found to be a sig relationship bet awareness of stimuli + accuracy

Answer 3

− Located within the temporal lobes (both hemispheres) the information received from the right ear is processed mainly by the left hemisphere + visa-versa − Concerned with hearing + processing sound information from both ears, information is transmitted about what the sound is + its location − The auditory pathway begins in the cochlea in the inner ear where sound waves are converted to nerve impulses which travel via the auditory nerve to the auditory cortex in the brain − On the journey to the cochlea to the brain nerve impulses passes through the brain stem+ thalamus: → In the brainstem information id processed through basic decoding i.e. duration + intensity of sound → In the thalamus further processing occurs of auditory stimulus + relay station − If the primary auditory cortex in damaged it does not lead to total deafness, sounds can still be heard but if they require complex processing e.g. listening to music then this ability is compromised − Research has found that the auditory cortex is not just involved with conscious sound it also processes auditory imagery, Meyer et al: → Found that when ppts watched silent films their primary auditory cortex in both hemispheres activated if a door is shut with force because they imagine a bang → The primary auditory cortex also processes auditory imagery

Answer 4

− Located in the posterior portion of the frontal lobe of the left hemisphere (the left hemisphere is where the most language processing in the majority of the pop is situated) − Responsible for speech production − Broca’s aphasia (expressive aphasia): is the term used to describe patience’s with problems producing speech − However individuals with Broca’s aphasia are not always unable to say all words e.g. Gardner + Zurif: → Found that nouns + verbs seem relatively unaffected in some patients with damage in Broca’s area but other classes of words e.g. prepositions + conjunctions cannot be spoken e.g. people with Broca’s aphasia can’t read out loud ‘to be or not to be’ but can say ‘two bee oar knot two bee’

Answer 5

− Leborgne suffered with epilepsy throughout his childhood + eventually lost his ability to speak except for the word ‘Tan’ − When Broca conducted a post mortem of Leborgnes brain he found a lesion (area of damage – caused by his epilepsy) on the left frontal lobe − As this was the only area of damage he concluded that it was the areas responsible for production of speech based on the deficit Leborgne exhibited

Answer 6

− Located in the posterior portion of the left temporal lobe of the left hemisphere − Involved in understanding language + accessing words − Wernicke’s aphasia (receptive aphasia) is an impaired ability to understand language + and inability to extract meaning from spoken or written words − Wernicke found that patients who had damage to this area close to the auditory cortex had specific language impairments whereby they could speak but were unable to understand language + displayed anomia (when someone struggles to find the word they need) − Wernicke also noticed that people were able to speak fluently when they were able to access words quickly suggesting that damage to this area of the brain does not affect speech production

Answer 7

− These two areas work together so we can understand + produce speech − When someone speaks the sound travels through the ear + through the auditory cortex to the Wernicke’s area − The motor region (located in the Broca’s area) is close to the area that controls the mouth, tongue + vocal cords − The sensory region (located in the Wernicke’s area) is close to regions of the brain responsible for auditory + visual input − Input from these regions is transferred to the Wernicke’s area where it is recognised as language + associated with meaning − There is a neural loop (arcuate fasciculus) running bet. the Broca’s + Wernicke’s areas

Answer 8

P: The holistic theory of brain function argues that localisation of function is largely incorrect E: Research conducted by Lashley on rats brains didn’t find any specific area included in memory, it appeared to be stored all over the brain – Lashley referred to this as the equipotentiality theory (the idea that basic motor + sensory functions are localised but higher mental functions e.g. cognitive memory were not C: This casts doubt on the idea that specific areas perform specific functions however it may be difficult to extrapolate these findings to humans as there are psychological difference bet the two species

Answer 9

P: The fact that rehabilitation can help individuals to overcome brain trauma suggests that there is no localisation or lateralisation E: If there were task specific areas then there would be no brain plasticity, Lashley claimed that intact areas of the cortex could take over responsibility for specific cognitive function following damage to the area normally responsible for the function e.g. in the case of E.B. had his left hemisphere remove yet regained most of his language abilities C: HOWEVER as he never fully recovered function then there is some localisation within certain areas of the brain

Answer 10

P: Research suggests that what might be more important is how brain areas communicate with each other rather than the idea that specific brain regions control a particular cognitive process/function E: Wernicke claimed that although different regions of the brain had different specialist functions there are interdependent (in order to work they must interact with each other) e.g. complex behaviours like language, reading + movement are built up gradually as a stimulus enters the brain + moves through different structures before a response is produced C: Therefore damage to the connection bet any two points in this process results in impairments that resemble damage to the localised brain region associated with a specific function

Answer 11

P: Language production may not be confined to Broca’s area alone. E: Dronkers et al. (2007) re-examined the preserved brain of Leborgne (Tan), using MRI brain imaging to reveal that other areas besides Broca’s area could have also contributed to the patients’ reduced speech abilities. Therefore, although lesions to Broca’s area alone can cause temporary speech disruption, they do not usually result in severe disruption of spoken language. C: This suggests that language and cognition are far more complicated than once thought and involve networks of brain regions rather than being localised to specific areas

Answer 12

P: There are individual differences in language areas in that the pattern of activation observed in response to various language activities can vary from one person to the next. E: For example, in a study of silent reading, Bavelier et al. (1997) found a large variability in individual patterns of activation across different individuals. Other studies have found significant gender differences in the size of the brain areas associated with language – Harasty et al. (1997) found that women have proportionally larger Broca’s and Wernicke’s areas than men. C: This suggests that the size of these areas are related to the use of language i.e. there is generally a greater use of language amongst women.

Answer 13

− Measures changes in brain activity while a person performs a task − Measures changes in blood flow in particular areas of the rain which indicates increased neural activity in those areas − If an area of the brain becomes more active there is an increased demand for oxygen in that area – the brain responds to those extra demand by increasing blood flow by delivering oxygen in red blood cells fMRI provides a moving picture of brain activity showing activity 1 sec after it occurs, it is also accurate to within 1-2mm in the brain

Answer 14

− It is non-invasive nor does it expose the brain to potentially harmful radiation − It offers objective + reliable measure of psychological processed than is possible with verbal reports It provides a moving picture which means that patterns of activity can be compare rather than just the physiology of the brain (e.g. in a CAT scan)

Answer 15

− The complexity of the brain activity means that interpreting an fMRI scan is a difficult task made more challenging by the time delay of the scan − fMRI machines are expensive + they require trained operators which makes research expensive + difficult to organise − The sample size in studies are often small due to limited availability + funding – the cost per ppts. is high which makes results difficult to generalise from − Because fMRI measures changes in blood flow in the brain then it is not a direct measure of neural activity in particular brain areas Critics argue that fMRI overlooks the networked nature of brain activity as it only focuses on localised brain activity

Answer 16

− An EEG measures electrical activity in the brain − Electrodes placed on the scalp detect small electrical charges resulting from the activity of brain cells − Electrodes measure the activity of the cells immediately under the electrode so using more electrodes gives a fuller picture − EEG data can be used to detect various types of brain disorder that influence brain activity: → Patients with epilepsy show spikes of electrical activity Patients with brain disease/injury show overall slowing of electrical activity

Answer 17

− It provided a recording of the brain’s activity in real time rather than I still image of the passive brain – the researcher can therefore accurately measure a particular task with the brain activity associated with it − It is useful in clinical diagnosis e.g. by recording the abnormal neural activity associated with epilepsy Both EEGs + ERPs are cheaper methods than scanning so they are more widely available to researchers

Answer 18

− It can only detect the activity in superficial regions of the brain + cannot reveal what is going on in deeper regions i.e. the hypothalamus – electrodes can be implanted in non-humans to achieve this but it is not ethically permissible to do this with humans because this would be too invasive Electrical activity can be picked up by several neighbouring electrodes therefore the EEG signal is not useful for pinpointing the exact source of an activity

Answer 19

− A measure of brain activity in response to a specific stimulus (using the same equipment as EEG) − ERPs are difficult to distinguish from all the other electrical activity being generated with the brain at a given time − To establish a specific response to a target stimulus requires many presentations of the stimulus + these responses are then averaged together − Any extraneous neural activity that is not related to the specific stimulus will not occur consistently whereas activity linked to the stimulus will − Waves occurring within the first 100ms after presentation of the stimulus are ‘sensory’ ERPs as they reflect an initial response to the physical characteristics of the stimulus ERPs generated after the first 100ms are ‘cognitive’ ERPs as they reflect the manner in which the subject evaluates the stimulus + demonstrates information processing

Answer 20

− An ERP can measure the processing od stimuli even in the absence of a behavioural response Because ERPs provide a continuous measure of processing in response to a particular stimulus it makes it possible to determine how processing is affected by a specific experimental manipulation

Answer 21

− Because ERPs are so small + difficult to pick out from other electrical activity in the brain it requires a large number of trails to gain meaningful data – this places limitations in the type of question that ERP readings can realistically answer Only sufficiently strong voltage changes generated across the scalp are recordable – important electrical activities occurring deep in the brain are not recorded meaning that the generation of ERPs tend to be restricted to the neocortex

Answer 22

− Post-mortem examinations are used to establish the underlying neurobiology of a particular behaviour − A person’s body inc. the brain is examined after death − Examinations can be used to see where damage had occurred in the brain + how that might explain behaviour exhibited by the individual prior to death One of the most famous cause studies is Leborgne

Answer 23

− Allows for a more detailed examination of anatomical + neurochemical aspects of the brain than would be possible with non-invasive techniques – it enables researchers to examine deeper regions of the brain Harrison: post-mortem studies have played a central part in our understanding of the origins of schizophrenia – researchers have discovered structural abnormalities + changes in neurotransmitter systems which are associate with the disorder

Answer 24

− It is retrospective as the person is already dead – the researcher is unable to follow up on anything that arises from the post-mortem concerning a possible relationship bet brain abnormalities + cognitive functioning Some brains may have been affected by the reason for death i.e. disease, similarly the length of time bet. death + post-mortem + age of death are possible confounding variables

Answer 25

− Biological rhythms that last about 24 hrs + are set/reset be environmental light levels

Answer 26

− It dictates when we should be sleeping but also when we should be awake with dips + rises at different point of the day − Our strongest sleep drive when we feel most sleepy usually occurs bet. 2-4am + 1-3pm (‘post lunch dip’) – the circadian rhythm therefore keeps us awake as long as there is daylight prompting us to sleep as it becomes dark − The sleep-wake cycle is under homeostatic control: when we have been awake from a long period of time homeostasis tells us that the need for sleep is increasing because of the amount of energy used during wakefulness – this homeostatic drive for sleep increases gradually throughout the day reaching its max. in the late evening when most people fall asleep − The internal circadian clock is ‘free-running’: it will maintain a cycle of about 24-25 hrs even in the absence of external causes − Jet travel + shift work have a sig. impact on the sleep-wake cycle as they cause the biological clock (+internal physiological systems dependent on this) to become completely out of balance

Answer 27

− Michel Siffre – French cave explorer: → Siffre spent 6 months in a cave with no day light or cues as to the day or time e.g. a clock → He was wired up to machines that recorded various bodily functions → The researcher put lights on when Michel was awake + turned them off when he went to bed – he ate + slept whenever he wanted → Findings: he settled into a sleep-wake cycle of 25-30 hrs – this suggests that circadian rhythms persist despite isolation from natural light which demonstrates the existence of an endogenous clock BUT it also shows that external cues are important as the clock want perfectly accurate − Aschoff + Weber: → Ppts were placed in an underground WWII bunker where there was an absence of environmental time cues as there were no windows but there was electric light in the bunker → Findings: most ppts displayed circadian rhythms bet. 24-25 hrs although some were as long as 29 hrs – shows that the cycle operates in the absence of external cues + that the natural free-running cycle is about 24-25 hrs − Folkard et al: → 12 ppts lived in a temporal isolation unit for 3 weeks isolated from light + other time cues → The volunteers went to bed when the clock said 11:45 and got up at 7:45 → The clock initially run normally but gradually quickened to become a 22 hr day → Findings: at the beginning the volunteers circadian rhythms matched the clock but as it quickened their rhythms ceased to matched the clock + continued to follow a 24 hr cycle rather than 22 hrs imposed by the experiment (except for 1 ppts)

Answer 28

− Evaluation of research: → Although ppts were isolated from variables e.g. clocks + daylight which could affect their circadian rhythm they were not isolated from artificial light → Czeisler et al found that it was possible to alter ppts circadian rhythms down to 22 hrs + up to 28 hrs using dim lighting → Individual differences e.g. cycle length (Czeisler et al suggested that cycles can vary from 13-65 hrs) + cycle onset (there are differences in terms of when circadian rhythms reach their peak – Duffy et al identified morning + evening types) → Age may also play a role in determining an individual’s sleep-wake cycle

Answer 29

− Core body temp. rises to its highest at about 6pm (38 degrees Celsius) + falls by about 2 degrees Celsius over the next 10 hrs to a low at about 4:40am − Sleep occurs when core temp. begins to drop + alertness increases a core body temp. starts to rise in the last few hrs of sleep − There is a slight drop in body temp. in the afternoon (2-4pm) which could explain feelings of sleepiness + cognitive behaviour − The circadian temp. rhythm is different from the circadian sleep-wake cycle as they both peak at different times thus there must be at least 2 biological clocks → Hawkins + Armstrong-Esther found that nurses on shift duty were able to adjust their sleep-wake cycle quite quickly to their shift pattern but their temp. cycle took at least a week to change − This information regarding circadian rhythms can be out use in everyday life e.g. through Chrono-therapeutics where treatment of an illness or disorder (e.g. drugs) are administered at a time of day believed to be in harmony with the body’s natural rhythms i.e. at a time when it will be more effective → E.g. you are at greatest risk of having a heart attack in the early hrs of the morning –aspirin would therefore be most effective if taken around 11pm as it takes bet. 2-4 hrs to peak in the blood stream → Cancer treatment – chromotheraphy drugs are administered at certain times of the day when good cells are less active (4am + 4pm), this results in the drug being 5x less likely to kill good healthy cells + 2x more likely to kill bad cancerous cells

Answer 30

− Hormone release follows a circadian rhythm e.g. the production + release of melatonin from the pineal gland in the brain follows a certain circadian rhythm with levels peaking during the hours of darkness + decreasing in response to light in the morning – melatonin encourages sleep − Cortisol levels have also been found to fluctuate throughout the day + increase about an hr before a person wakes up helping with alertness

Answer 31

− Biological rhythms that last more than 24 hrs e.g. monthly cycles (e.g. the female menstrual cycle) + yearly cycles also known as circannual rhythms (e.g. seasonal affective disorder [SAD])

Answer 32

− The menstrual cycle id driven by the endocrine system as hormone levels (oestrogen + progesterone) fluctuate under the control of the pituitary gland which regulate the ovaries – however exogenous zeitgebers e.g. light + odour (pheromones) are also thought to be involved − The average length of the cycle is 28 days + ovulation occurs halfway through the menstrual cycle (14 days) when oestrogen levels peak + usually lasts for 16-32 hrs − McClinton + Stern: → Investigated the effects of female pheromone (an exogenous zeitgeber) on the menstrual cycle → They collected daily samples of ‘odourless compounds’ (sweat) from the armpits of a group of 9 women which was then rubbed on the upper lips of a group of 20 women → A record was kept of the ppts menstrual cycles → 68% of women responded to the odourless compounds – when women received the odourless compound from the women in the latter half of their menstrual cycle their menstrual cycle was shortened + if the sweat was collected from the women at the beginning of their cycle this lengthened the cycle of those who received it → this shows that the menstrual cycle of women can be altered by communication via pheromones – the effects of pheromones could explain menstrual synchrony − Menstrual synchrony may occur amongst women who spend a lot of time together as it means that there could potentially be synchronised pregnancies (given that they would be ovulating at the same time) – this means that childcare could be shared when babies are born − However how close women have to live together + for how long for menstrual synchronisation occur is not clear + the extent to which pheromones have an effect still requires research − It is also questionable as to whether menstrual synchronicity actually occurs or not – Wilson challenged its existence stating that experiment evidence was exaggerated − Reinberg: → Documented the duration of a women menstrual cycle during + after she spent 3 months in a cave with only dim lighting → Her sleep-wake cycle lengthened slightly + her menstrual cycle became shorter during her stay in the cave – her menstrual cycle shortened to 25.7 days + it took a further yr. for her cycle to return to normal → This study shows that the levels of light in the cave could have affected the woman’s menstrual cycle – it shows how infradian biological rhythms can be influenced by exogenous zeitgebers i.e. light

Answer 33

− Seasonal affective disorder (SAD) – individuals experience severe depression during the winter months + recover during the summer − The hormones melatonin + serotonin are secreted when it is dark by the pineal glands – more darkness means more melatonin which means less serotonin (because melatonin is produced from serotonin) + low levels of serotonin are associated with depression − Treatment: phototherapy – uses very strong light (equivalent to full daylight) in the evening +/or early morning to change levels of melatonin + serotonin, SAD sufferers have reported that daily phototherapy has relieved them of lethargy, depression + other related symptoms

Answer 34

− Corpus callosum: a braid bundle of 55 million connecting nerve fibres that joins the two hemispheres of the brain allowing information received by one hemisphere to be sent to the other − To treat sever epilepsy (in the past) surgeons cut the corpus callosum so that he epilepsy + accompanying electoral storms are contained within one hemisphere of the brain – this reduces the number of epileptic fits as the hemispheres rebounding off each other can prompt seizures

Answer 35

− Sperry + Gazzangia studied split-brain patients to test the capabilities of the separate hemispheres − In a typical study: → Patients fixate on a dot/cross in the centre of a screen (creating a split visual field) while information (e.g. faces, words, digits) is presented to either the left or the right visual field → They might be asked to make responses with either their left hand (controlled by the right hemisphere) of their right hand (controlled by the left hemisphere) or verbally (controlled by the left hemisphere) which out being able to see what their hands were doing − Key findings: → Left hemisphere (right visual field): Patients could say any words that flashed to the right visual field demonstrating the left hemispheres ability to produce speech (presence of Broca’s area) + patients identified a painting of a face made up of fruit as ‘FRUITS’ instead of “FACE” demonstrating how the left hemisphere focuses on detail → Right hemisphere (left visual field): Patients could not say words flashed up on the left side of the screen but they could draw it with their left hand demonstrating processing of the word + patients identified a painting of a face made up of fruits as a ‘FACE” showing how the right hemisphere processes faces (+ emotions)

Answer 36

− Karen suffered from epilepsy + at the age of 27 the decision was taken to operate + cut the connection bet. the two hemispheres by severing the corpus callosum − After the surgery it became apparent that her left hand functioned separately from the rest of her body – she was diagnosed with alien hand syndrome − This case study shows how movement is lateralised into two hemispheres

Answer 37

P: Brain lateralisation increases neural processing capacity – by using only one hemisphere to engage in a particular task this would leave the other hemisphere free to engage in another function E: Rogers et al – in the domestic chicken brain lateralisation is associated with an enhanced ability to perform two tasks simultaneously, finding food + being vigilant for predators C: This study provided some evidence that brain lateralisation enhances brain efficiency in cognitive tasks that demand the simultaneous but different use of both hemispheres HOWEVER there is very little empirical evidence to support this assertion

Answer 38

P: Research has suggested that lateralisation of function changes with age E: Across many types of tasks + many brain areas lateralised patterns found in younger individuals tend to switch to bilateral patterns in healthy older adults e.g. the extent to which language is dominated by the left hemisphere is not fixed, it increases through childhood + adolescence + then this trend reverses in old age with signs of greater sharing of language function across the brain hemispheres in later life E: This was supported by research that found that language became more lateralised to the left hemisphere with increasing age in children + adolescents but after age 25 lateralisation decreased with each decade of life C: Therefore perhaps the extra (cognitive) processing resources of the other hemisphere compensates for general age-related declines in function

Answer 39

P: Research suggests that language may not be restricted to the left hemisphere – slit-brain research had suggested that he right hemisphere was unable to handle even the most rudimentary language + that damage to the left hemisphere was far more detrimental to language function E: However Turk et al conducted a case study of split-brain patient J.W. who developed the capacity to speck out of the right hemisphere such that J.W. can now speak about information presented to the left or right hemisphere E: The case of E.B. further demonstrates the language capabilities of the right hemisphere, E.B.’s right hemisphere compensated for the loss of his left hemisphere in that he was found to be functioning linguistically well when tested at the age of 17 (having had his left hemisphere removed at 2½) C: This therefore suggests that the right hemisphere is capable of processing language + developing that function when required

Answer 40

P: It is problematic to assume that split-brain research is not methodologically flawed E: The extent to which split brain were indicative of normal function prior to surgery is an issue especially as the spilt brain surgery was to treat a problem within the brain – it is also possible that were other effects on the brain of the split brain surgery of that the hemispheres were not entirely disconnected for one another, some patients had experiences drug therapy for longer than others beforehand E: Furthermore the split brain procedure is rarely carried out now days + patients who have had this procedure are not encounter in sufficient numbers to be useful for research purposes – Andrews argues that many studies involve as few as 3 ppts or just a single ppt which then makes it difficult to generalise the findings to others C: This therefore suggest that we should be cautious when interpreting the findings of split-brain research + drawing conclusions about hemispheric lateralisation

Answer 41

P: The data of Sperry + Gazzaniga’s research were artificially produced E: Because in real life a severed corpus callosum can be compensated for by the unrestricted use of 2 eye to enable both hemispheres to process visual stimuli rather than patients fixating on a point + different information being presented to each visual field C: This therefore makes it difficult to generalise the findings of Sperry + Gazzaniga’s research beyond the experimental setting to explain the capabilities of split-brain patients in everyday life – they said that their research provided a useful insight into the functions of the 2 hemispheres thus developing a clearers understanding of hemispheric lateralization

Answer 42

− Brain plasticity (or neuroplasticity) refers to the brains ability to change + adapt, modifying its own structure + function as a result of experience – research has demonstrated that the brain continues to create new neural pathways + alter existing ones to adapt to new experiences as a result of learning − Neuroplasticity occur in the brain: 1. At the beginning of life – when the immature brain organises itself 2. In the case of brain injury – to compensate for lost functions or maximise remaining functions 3. Through adulthood – whenever something new is learnt + memorised

Answer 43

− Negative neuroplasticity means that something in the environment of the individual is affecting the ongoing function + physical structure of the brain – these are thought to cause atrophy in the brain, a reduced number of dendrites connecting neurons + unfavourable levels of certain types of neurotransmitters − The result is that the brain over time shrinks, becomes less efficient, is less protected (e.g. from age) + is inessentially older than it otherwise would be − E.g. if you have experience anxiety for a number of yrs. your brain structures, the neuro pathways + neurochemistry associated with experiencing anxiety strengthen while the structures, pathways + chemistry involved in feeling relaxed + secure weaken so you become better at experiencing anxiety + less able to experience calm

Answer 44

− Poor sleep − Mood disorder − Substance abuse e.g. alcohol

Answer 45

− Learning a language − Playing a musical instrument − Learning abstract information

Answer 46

− New experiences enable never pathways that are used frequently to develop stringer connections whereas neurons that are rarely or never used eventually dies – the brain therefore has the ability to adapt to a changing environment

Answer 47

− Studied London taxi drivers to discover whether changes in the brain could be detected as a result of their extensive experiences of spatial navigation – the researchers compared MRI scans of 16 male London taxi drivers vs 50 male non taxi drivers − Results: The hippocampus of the taxi drivers was sig. larger than the non-taxi drivers + hippocampal volume correlated positively with the amount of time spent as a taxi driver − Conclusion: This study demonstrates plasticity of the hippocampus in response to environmental demands − Further research: Maguire et al also found that London taxi drivers had a larger hippocampus (in the posterior region) than London bus drivers – this is because this region of the hippocampus is specialised in acquiring + using complex spatial information in order to navigate efficiently, taxi drivers have to navigate around London whereas bus drivers follow a limited set of routes

Answer 48

− However there is a natural decline in cognitive functioning with age that can be attributed to changes in the brain which has motivated researchers to look as how new connections can be made to reverse this effect − Boyke et al found evidence of bran plasticity in 60 yr. olds taught a new skill, juggling – they found increases in grey matter in the visual cortex although when practicing stopped these changes reversed supporting the idea that neurons that aren’t used eventually die

Answer 49

− Kuhn et al compared a control group with a video game training group that was trained for 2 months for at least 30 mins per day on the game super Mario − They found a sig. increase in grey matter in various brain areas including the cortex, hippocampus + cerebellum – this increase was not evident in the control group that did not play super Mario − The research concluded that video game training had resulted in new synaptic connections in the brain areas involved in spatial navigation, strategic planning, working memory + motor performance – skills that were important in playing the game successfully

Answer 50

− Research working with Tibetan monks have discovered that meditation can change the inner workings of the brain − Davidson et al compared 8 practitioners of Tibetan meditation with 10 student volunteers with no previous meditation experience – both groups were fitted with electrical sensors + asked to meditate for a short period − The electrodes picked up much greater activation of gamma waves (important because they coordinate neuron activity) in monks with the students only showing a slight increase while meditating – it was concluded that meditation changes the workings of the brain in the short term + is capable of producing permanent changes as the monks showed more gamma wave activity than the control group even before they started meditating

Answer 51

− Functional recovery: the recovery of abilities + mental processes that have been comprised as a result of brain injury or disease − Much recovery after trauma is due to anatomic compensation brought about by intensive rehabilitation − The brain learns to compensate for function – the brain can be taught to learn how to use other working faculties in the brain to take over the functions that were lost

Answer 52

− As neurons are damage there is an effect on neighboring neurons as they no longer have input − This happens with the hemisphere too – damage to one hemisphere means the other hemisphere has reduced input + so functions at a lower level If the undamaged hemisphere is stimulated recovery from a stroke can be improved as the damaged hemisphere can compensate for the loss of function in the damaged hemisphere by remodeling neuronal circuits + establishing new sensory processing

Answer 53

− When an axon is damaged its connection with a neighboring neuron is lost − In some cases other axons that already connect with that neuron will sprout extra connections to the neuron replacing the ones that have been destroyed It helps reduce function but only if that damaged axon + compensatory axons do a similar job

Answer 54

− Axons that do similar a job become aroused to a higher level to compensate for the ones that are lost However it can have the consequence of over-sensitivity to messages e.g. pain

Answer 55

− Sometimes a function may appear to be lost but that may be because the individuals affected may not be trying + takes the view that it is unrecoverable Taub + Berman: A monkey with a ‘deafferented limb (lost sensory input) will try not to use it, if the functioning of the other limbs become damages then it will have no other option that to use the deafferented one – the motor nerves are still connected to the limb but because the sensory nerve connecting is damages the monkey does not feel that it can move the limb

Answer 56

− When function is recovered in an individual it is used with considerable effort + although the person can do task they are often fatigued by effort Stress + alcohol consumption can negatively affect the ability to use any function that had been regained

Answer 57

− Deterioration of the brain in old age affects the extent + speed of recovery − Marquez de la Plata et al: Following brain trauma older patients (40 yrs.+) regained less function in treatment than younger patients + were also more likely to decline in terms of function for the 5 yrs. following the trauma By contrast the case of E.B. illustrates the extent to which a young brain can regain functioning following severe damage

Answer 58

− Research suggests that women recover better from brain injury as their function is not as lateralized (concentrated in one hemisphere) − Ratcliffe at al examined 325 patients with brain trauma for their responsiveness to cognitive skills following rehabilitations – results showed that women performed sig. better than men in tests of attention/working memory + language whereas me outperformed females in visual analytic skills, overall the results suggested a better recovery for women however the result did not control for performance pre-injury which could have influenced results Research in this area is mixed so clear overall conclusions cannot be drawn

Answer 59

Schneider et al: − A study of 1769 patients who suffered from head injuries + had been treated, patients followed a rehabilitation programme + progress was monitor − Of the 769 patients: 25% did not finish school, 51% had 12-15 yrs. of education + 25% graduated from university with an undergraduates degree − One yr. after the injury 28% of the patients made a full recovery – 39% of the graduates were left free of disability compared to only 10% of those who had left school early − Patients with the equivalent of a college education were 7x more likely to make a full recovery than people who did not finish school − The researchers argues that more educated people make more effective use of their brain which strengthens them − Conclusions: People who have remained in education longer have a greater ‘cognitive reserve’ – they are less likely to be left permanently disabled after a head injury, their brains are better able to maintain function in spite of damage which makes them more likely to regain function following a brain trauma

Answer 60

− Biological rhythms that last less than 24 hrs – they occur more than once in an 24 hr period e.g. the sleep stages + basic-activity rest cycle (BRAC)

Answer 61

− Each cycle of sleep consists of both REM + NREM sleep – the first 4 stages are NREM (non-rapid eye movement) + the 5th stage is REM (rapid eye movement), − One cycle goes through all 5 stages + lasts 60 minutes – the number of sleep cycles depends on how long an individual sleeps for − The different stages of sleep are measured by the electrical activities of the brain with each stage showing a distinct EEG pattern − Stages 1 + 2 are light sleep − As the person enters deep sleep (stages 3 +4) their brainwaves slow + their breathing + heart rate decreases – in deep sleep (SWS) most of the body’s physiological ‘repair work’ is undertaken + important biochemical processes occur e.g. the production of growth hormones − During the 5th stage (REM) the EEG pattern resembles that of an awake person + it is in this stage that most dreaming occurs

Answer 62

− Connected 9 ppts (7 males + 2 females) to an EEG machine in a lab which took measurements throughout a night’s sleep − Findings: → Everyone had periods of REM every night → There were high incidences of dream recall when ppts are awake during REM sleep – if awakened in the other stages very few reported dreaming → The brain activity of very vivid dreams was different to the less clear dreams → The rapid eye movements of REM sleep varied according to dream type + mirrored brain activity whilst awake + completing a similar task to the one they had dreamt about − Criticisms: Ppts were studies in a sleep lab which could have caused an atypical reaction from ppts – the frequency of occurrence of REM sleep light be different in a non-experimental setting

Answer 63

− Kleitman referred to the 90 minuet cycle of sleep as the basic rest activity cycle (BRAC) – he suggested that this ultradian rhythm continues during the day even when we are awake, we move progressively from a state of alertness into a state of physiological fatigue every 90 minuets − Research suggests that the human mind can focus for a period if 90 mins + towards the end of these 90 mins the body begins to run out of resources resulting in loss of concentration, fatigue + hunger − Friedman + Fisher observed the eating + drinking behaviour in a group of psychiatric patients over a period if 6 hours + found a 90 min cycle in eating + drinking behaviour supporting the BRAC

Answer 64

− Internal body clocks that regulate biological rhythms such as regular times of sleep linked to light levels e.g. the superchiasmatic nucleus (SCN) + the pineal gland + melatonin

Answer 65

− This is thought to be the main endogenous pacemaker + is located in the hypothalamus just above the optic nerve − The SCN obtains information on light from the optic nerve even when our eyes are shut as light penetrates the eyelids – special photoreceptors in the eye pick up light signals + carry them to the SCN − If out endogenous clock is running slow the morning light shifts that clock ahead so that the rhythm is in sync with the outside world – our circadian rhythms are therefore entrained by the light − The SCN also regulated the manufacture + secretion if melatonin in the pineal gland via an interconnecting neural pathway

Answer 66

− Ralph et al: → Removed the SCN out if genetically abnormal hamsters which only had a circadian cycle of 20 hrs, they transplanted the SCN cells into rates which had no such abnormality + functioned on the normal 24 hr cycle → Following the transplant the circadian rhythm of the rats shortened to 20 hrs – this suggests the importance of the SCN in regulating circadian rhythms − Morgan: Found that when the SCN from normally functioning hamsters was removed their circadian rhythms disappeared – when the SCN cells were transplanted back the rhythm returned − DeCoursey et al: → Functionally removed the SCN in 30 chipmunks + then returned them to their natural habitat – they were then observed alongside chipmunks whose SCN remained intact → It was found that the SCN-lesioned chipmunks were much more active at nigh than the normal control group of chipmunks putting them at risk from nocturnal predators – in fact after 80 days a sig higher number of the lesioned chipmunks had been killed by weasels in comparison to the control group, presumably these chipmunks remained awake in their burrow + the weasels could hear the noise + were able to locate the chipmunks → This research suggest that biological rhythms have adaptive value – they allow an animal to anticipate daily environmental events e.g. patterns of light + dark

Answer 67

− The pineal gland contains light-sensitive cells which receives signals from the SCN – when light is sensed the production of melatonin in the pineal gland in inhibited − Melatonin induces sleep (levels of melatonin increase when light levels decreases) by inhibiting the brain mechanisms that promote wakefulness

Answer 68

− Environmental cues/external stimuli that are responsible for entraining the biological clock of an organism

Answer 69

− Receptors in the SCN are sensitive to changes in light levels during the day + use this information to synchronise the activity of the body’s organs + glands – light resets the internal biological clock each day keeping it in a 24 hr cycle − Melanopsin: is a protein contained in a small number of retinal cells which is sensitive to natural light – it gauges overall brightness + sends these signals to the SCN to help reset the internal biological clock

Answer 70

− Some blind people are still able to reliably entrain their circadian rhythm in response to light despite a total lack of image-forming visual perception (i.e. non-functioning rods + cones) – this suggests that the pathway from the retinol cells containing melanopsin to the SCN is still intact + that there is therefore more than one visual pathway: one responsible for communisation light information + another for communicating images − Further support comes from the fact that people without light perception show abnormal circadian entrainment

Answer 71

− Campbell + Murphy: → Monitored the body temperatures of 15 volunteers who slept in a lab – they introduced light to them during the night by waking them at a series of intervals + shining light onto the back of their knees → The volunteers circadian rhythms were disrupted by up to 3 hrs suggesting that it is not necessary for light to just enter they eyes to have a physiological effect on biological rhythms − Steel et al → Investigated the effects of constant daylight on circadian rhythms by monitoring 6 ppts living in isolation in the arctic for 6 weeks – the ppts kept sleep logs → Results showed that 5/6 ppts developed a free-running sleep/wake cycle longer than 24hrs → They also found that the sleep patterns were individual + no synchronised patterns emerged

Answer 72

− Although light is the dominant zeitgeber human circadian rhythms may also be entrained by social stimuli + convention − E.g. socially determined mealtimes, social activities, clocks, going to bed/waking up at time designated as appropriate for our age

Answer 73

− Burgess et al: → Exposed to bright light prior to an east-west flight decreased the time needed to readjust to local time on arrival → Volunteers ppts in 1/3 treatments (continuous bright light, intermittent bright light, dim light) each of which shifted their sleep wake cycle back one hr a day over three days → Ppts exposed to continuous bright light shifted their circadian rhythms by 2.1 hrs over the course of the study, those exposed to intermittent bright light shifted their rhythm by 1.5 hrs + those exposed to dim light shifted by 0.6 hrs → Ppts in the first treatment group felt sleepier 2 hrs earlier in the evening + woke 2 hrs earlier in the morning i.e. closer to the local time conditions they would find after an east-west flight

Biopsychology Flashcards

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