Biopsychology Flashcards

Question

Draw the structure of a basic neuron ? | (Synaptic Transmission)

Answer 1

Function - Carry messages from the sensory receptors in PNS to the CNS Structure: Long dendrites and short axons Located in the PNS in clusters called ganglias

Answer 2

Function - connect sensory neurones to motor or other relay neurons Structure: short dendrites and short axons, they have no myelin sheath Only found in the CNS

Answer 3

Function - Connects the CNS to effectors like muscles and glands Structure: Short dendrites and long axons Located in the CNS but long axons form part of PNS

Answer 4

When a neuron is in resting state the inside of the cell is negatively charged compared to the outside. When a neuron is activated the inside of the cell becomes postivaly charged for a split second causing and action potential to occur. This creates an electrical impulse that travels down the neuron towards the end of the axon.

Answer 5

Signals within neurons are transmitted electrically - signals between neurons are transmitted chemically = synaptic transmission

Answer 6

Neurotransmitters are chemicals that diffuse across the synapse to the next neuron Once it crosses the gao it is taken up in the postsynaptic recpetor site The chemical is converted back to a electical impulse Each neurotransmitter has its own specific molecular structure that fits perfectly into the postsynaptic receptor site They also have specialist functions - acetlylcholine causes muscles to contract

Answer 7

Excitation - When a neurotransmitter increases the positive charge of the postsynaptic neuron. Increasing the likelihood that the neuron will fire and pass on the electrical impulse. Inhibition - When a neurotransmitter makes the charge of a postsynaptic neuron more negative. Decreasing the likelihood the neuron will fire and pass on the electrical impulse. For a postsynaptic nerve to fire it is decided by the process of summation

Answer 8

Symmetrical halves of the brain Left hand side of body controlled by right hemisphere Right hand side of body controlled by left hemisphere

Answer 9

Outer layer of both hemispheres - Humans have a more developed cerebral cortex to animals

Answer 10

Frontal lobe - Voluntary movement, reasoning, mood, personality, impulse control Occipital lobe - Visual processing centre Temporal lobe - Processing auditory stimuli Parietal lobe - Processing the sense of touch, limb position, and spatial awareness

Answer 11

M W B S A V

Answer 12

Location – back of the frontal lobe in both hemispheres Function – controls voluntary movement in the opposite side of the body Damage may result in loss of control over movements

Answer 13

Location – front of parietal lobes in both hemispheres Function – sensory information from the skin is represented Damage – decreased ability to differentiate/feel stimuli

Answer 14

Location – occipital lobe at the back of brain in both hemispheres Function –eye sends information: Images from the right visual field sent to the left visual cortex Images from the left visual field sent to the right visual cortex Damage to: Left hemisphere can produce blindness in part of the right visual field of both eyes Right hemisphere can produce blindness in part of the left visual field of both eyes

Answer 15

Location – temporal lobes in both hemispheres Function – analyses speech-based information Damage - may produce partial hearing loss – the more extensive the damage the more extensive the loss

Answer 16

Identified by Paul Broca in 1880S Location - a small area in the left frontal lobe Function - responsible for speech production Damage – causes Broca’s aphasia – speech which is slow, laborious and lacking in fluency

Answer 17

Identified by Karl Wernicke in 1880s Location – left temporal lobe Function – responsible for language comprehension Damage – causes Wernicke’s aphasia – produce nonsense words as part of speech #

Answer 18

Point - Peterson et al – used brain scans to demonstrate how Wernicke’s area was active during a listening scan and Broca’s area was active during a reading task Further – Tulving et al – studied long-term memory – found that semantic and episodic memories reside in different parts of prefrontal cortex

Answer 19

Point - Peterson et al – used brain scans to demonstrate how Wernicke’s area was active during a listening scan and Broca’s area was active during a reading task Further – Tulving et al – studied long-term memory – found that semantic and episodic memories reside in different parts of prefrontal cortex

Answer 20

Point - Lashley – Plasticity – when the brain has become damaged through illness or accident, and a particular function is compromised or lost, the rest of the brain appears to reorganise itself in an attempt to recover the lost function Further – Lashley – work also suggests that higher cognitive functions, such as processes involved in learning, are not localised but distributed in a more holistic way in the brain

Answer 21

Point - Aphasia studies show that damage to Broca’s and Wernicke’s areas results in different types of aphasia showing that they have different functions. Counter – language production may not be confined to Broca’s area – Dronkers et al – examined preserved brains of two of Broca’s patients using MRI imaging – revealed that other areas besides Broca’s area could have contributed to speech difficulties

Answer 22

The idea that the 2 hemispheres of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by 1 hemisphere rather than the other Left hemisphere – dominant for language and speech Right hemisphere – dominant for visual-motor tasks The 2 hemispheres are connected by a bundle of nerves – corpus callosum - allows for transfer of information between hemispheres

Answer 23

Background - all participants had undergone surgery to reduce epileptic seizures - corpus callosum being cut down the middle to separate the 2 hemispheres means information presented to one hemisphere has no way of travelling to the other hemisphere Aim – to investigate the extent to which the 2 hemispheres are specialised for certain functions and whether the hemispheres perform tasks independently of the other

Answer 24

Ps asked to focus on a dot (fixation point) on the centre of a screen. Images/words projected to the Ps’ right visual field (Left Hemisphere) and some to the left visual field (Right Hemisphere) 3 tests were: Can they describe what they see? (can they say the words they see)? Can they touch an object which matches what they have seen on the board? Can they draw what they see?

Answer 25

Describing what they could see - When picture shown to Ps’ right visual field (LH), P could easily describe what was seen but left could not Recognition by touch - Objects shown in left visual field (RH) Ps were able to select a matching object from a grab bag using their left hand (RH) Drawing Activity - The left hemisphere is not dominant for drawing, if an image was flashed to the right visual field (LH) and they try to draw with right hand (LH), they couldn’t Matching Faces - When completing a face matching task, Ps selected faces shown to left visual field (RH), whilst images presented to right visual field (LH) were ignored

Answer 26

Left hemisphere – responsible for speech and language Right hemisphere – responsible for visual motor tasks and face recognition

Answer 27

Point - Sperry’s method of using the fixation point and the fact that the image/word was only flashed up for 1/10th of a second meant Ps could not have time to move their eye across the image and spread the information across both visual fields and both hemispheres which ensured that information was only being received by 1 hemisphere at a time Counter – the sample used was very unusual – only 11 Ps and all had a history of epileptic seizures which may have caused unique changes to their brains and may have influenced results

Answer 28

Point - Turk et al - Case study of a patient JW evidence that the right hemisphere has the ability to process and produce speech – JW who suffered damage to left hemisphere developed the ability to speak from his right hemisphere I&D– as this is a case study focusing on just one P, it takes an idiographic approach , focusing on an individual case in order to understand behaviour, which means meaningful generalisations can not be made

Answer 29

Point - Sperry’s work has prompted a philosophical debate about the nature of consciousness – Pucetti suggests that the 2 hemispheres are so functionally different that they represent a duality in the brain – we are 2 minds Counter – other researchers argue that the 2 hemispheres do not work in isolation and instead form a highly integrated system which are both involved in everyday tasks

Answer 30

Plasticity – the brain’s tendency to change and adapt as a result of experience and new learning During infancy – brain experiences rapid growth in the number of synaptic connections it has As we age, rarely used connexions are deleted and frequently used connections are strengthened – synaptic pruning at any time in life existing neural connections can change or new neural connections can be formed

Answer 31

After trauma to the brain unaffected areas of the brain are able to adapt and compensate for the damaged areas The brain rewires itself so that some level of function is regained Healthy brain areas take over functions Process can occur quickly after trauma – spontaneous recovery – and then slow down after several weeks or months

Answer 32

Dormant synapses - usually ineffective as the neural input is too low for them to be activated Unmasking - After surrounding brain area damaged there is increased rate of input to these synapses. This opens up connections to regions of the brain that are not usually activated

Answer 33

A number of structural changes occur in the brain: Axonal Sprouting – growth of new nerve endings which connect with other undamaged cells to form new neural pathways Reformation of blood vessels Recruitment of homologous (similar) areas on the opposite side of the brain to perform specific tasks

Answer 34

Point - Maguire et al – found that posterior hippocampal volume of London taxi drivers’ brains positively correlated with their time as a taxi driver and that there were significant differences between taxi drivers’ brains and those of controls Further - Kuhn et al - found a significant increase in grey matter in various regions of the brain after Ps played video games 30 minutes a day over a 2 month period compared to a control group

Answer 35

Point - Elbert et al - Functional recovery tends to reduce with age as the brain has a greater propensity for reorganisation in childhood as it is constantly adapting to new experiences and learning Further – the number of years spent in education also has an impact – Schneider et al - the more time brain injury patients had spent in education, which gives an indication of their “cognitive reserve”, the greater their chances of a disability-free recovery

Answer 36

Point - Understanding the process of plasticity and functional recovery has led to the development of neurorehabilitation which uses motor and electrical stimulation of the brain to counter the negative effects and deficits in motor and cognitive functions following trauma/injury Counter – this may also show the limitations of functional recovery as it highlights that although the brain has the capacity to “fix itself” to a point, this process requires further intervention to be completely successful

Answer 37

Measures changes in brain activity while a person performs a task Detects changes in the blood oxygenation and flow that indicates increased brain activity When bran area more active, it consumes more oxygen. To meet the increased demand blood flow is directed to the active area Produces 3D images (activation maps) showing which parts of the brain are involved

Answer 38

Measures electrical activity within the brain Electrodes that are fixed to an individual’s scalp using a skull cap – detects small electrical charges resulting from activity of brain dells Signals from the different electrodes are graphed over a period of time Provides an overall account of brain activity Can detect various types of brain disorder or diagnose other disorders that influence brain activity

Answer 39

ERPs are very small voltage changes in the brain that are triggered by specific events or stimuli Stimulus presented to P. Researcher looks for brain activity related to stimulus Stimulus presented many times and an average response is graphed Shows the neural responses associated with specific sensory, cognitive and motor events

Answer 40

EEG records general brain activity while ERPs are obtained using specific stimuli and measuring the brain’s responses to specific events

Answer 41

Analysing a person’s brain after their death For psychological purposes, likely to be those who had a rare disorder and have experienced unusual deficits in mental processes or behaviour Areas of damage within brain examined after death Can establish the likely cause of a disorder the person suffered from If compared with a neuro-typical brain will also show the extent of the damage Has also identified some of the brain structures involved in memory

Answer 42

Spatial Resolution – the smallest feature or measurement a scanner can detect. If higher, can discriminate between different brain regions more accurately fMRI – 1-2mm – high – can localise activity specifically EEG/ERP – Low – only looks at superficial and general regions of the brain

Answer 43

Temporal Resolution – The accuracy of the scanner in relation to time – how quickly it detects changes in brain activity fMRI – 1-4 seconds – low EEG/ERP – 1-10 milliseconds – high

Answer 44

Invasive/Non Invasive – whether it uses radiation or instruments in the brain fMRI/EEG/ERP – all non-invasive unlike other techniques

Answer 45

Causation – whether it can show cause and effect fMRI – not a direct measure of neural activity – only measures changes in blood flow not activity of individual neurones EEG – electrical activity often detected in several regions of the brain – difficult to pinpoint the exact region of the activity. Only detects activity in superficial areas – can’t detect activity in deeper regions ERPs – allows determination of how brain processing is affected by a specific experimental manipulation Post-Mortems – the deficit displayed during lifetime may not be linked to the deficits found in the brain. But allows for detailed examination of the brain at a much deeper level

Answer 46

Patterns of changes in body activity that conform to cyclical time periods. Influenced by: Internal body clocks – Endogenous Pacemakers External changes in the environment – Exogenous Zeitgebers

Answer 47

Circadian – 24 hours Infradian – over 24 hours Ultradian – under 24 hours

Answer 48

sleeping and awake is controlled by circadian rhythms External signals (Exogenous Zeitgebers) – light and dark – determine when we feel the need to sleep and wake up Internal circadian clock is free running – maintaining a cycle of 24-25 hours even without external cues Intolerant to major alterations There are dips and rises during the day

Answer 49

Internal body clocks that regulate many of our biological rhythms

Answer 50

Light sensitive cells within the eye act as brightness detectors sending messages about environment light levels to the Suprachiasmatic Nucleus SCN receives information about light from optic nerve even when eyes are shut - adjusts to changing patterns of light while we are asleep Suprachiasmatic Nucleus (SCN) – main endogenous pacemaker in mammals – known as the “master clock”

Answer 51

Temperature lowest at about 4:30am (about 36c) and highest at about 6:00pm (about 38c) Sleep usually occurs when core temperature begins to drop and body temperature starts to rise in the last hours of sleep – makes you more alert

Answer 52

Aim: To investigate the extent to which endogenous pacemakers (internal body clock) governs sleeping behaviour when deprived of exogenous zeitgebers (external cues) Procedure Spent several extended periods underground in caves Deprived of exposure to natural light and sound Spent two months in the caves of the Southern Alps Findings His ‘free-running’ biological rhythm settled down to one that was just beyond the usual 24 hours (it extended to 25 hours) He continued to sleep and wake on a regular schedule

Answer 53

The small difference in his sleep/wake cycle suggests that our sleeping behaviour is controlled mostly by endogenous pacemakers - therefore endogenous pacemakers have a key role to play in circadian rhythms such as the sleep wake cycle Exogeneous zeitgeber’s are somewhat important because without the external cues, his sleep wake cycle changed to 25 hours

Answer 54

Point - Siffre – only thing influencing his behaviour was his “free-running” internal body clock (Endogenous Pacemaker) - settled down to around 25 hours – fell asleep and woke at regular intervals demonstrating that circadian rhythms are free-running even in the absence of external cues I&D– as this is a case study focusing on just one P, it takes an idiographic approach

Answer 55

Point - Duffy et al - Individuals seem to be innately different in terms of when circadian rhythms start – found that morning people rise early and go to bed early (6am-10pm) whereas evening people prefer to wake and go to bed later (10am – 1am) Further Individual differences in cycle length – Czeisler et al – found circadian rhythms can vary from 13-65 hours

Answer 56

Point - Morgan – Bred mutant hamsters that had circadian rhythms of 20 hours rather than 24 hours – SCN neurons from mutant hamsters transplanted into brains of normal hamsters who subsequently displayed the same abnormal circadian rhythm of 20 hours Counter – hamsters and humans are very different biologically and environmentally

Answer 57

Point - Practical application to shift-work – has given researchers a better understanding of the adverse consequences that can occur as a result of the disruption of shift work Further – practical application to drug treatments – circadian rhythms co-ordinate a number of the body’s basic processes which has an effect on the action of drugs on the body and how well they are absorbed and distributed

Biopsychology Flashcards

(83 cards)