Biopsychology

Question 1

List the components of the nervous system

Answer 1

Central Nervous System (CNS):
-brain
-spinal cord

Peripheral Nervous System (PNS)
-Somatic Nervous System
-Autonomic Nervous System (consists of sympathetic nervous system and parasympathetic nervous system)

Question 2

Outline the role of the brain in the CNS

Answer 2

-provides conscious awareness and is involved in all psychological processes

-consists of different lobes with different functions

-occipital lobe processes visual information

-temporal lobe processes auditory information

-parietal lobe = spatial navigation

-frontal lobe is associated with higher order functions, e.g. planning, abstract reasoning

Question 3

Outline the role of the spinal cord in the CNS

Answer 3

-transfers messages to and from the brain, and the rest of the body
-controls simple reflex actions that do not involve the brain, e.g. moving hand away from something hot

Question 4

What connects the brain to the spinal cord in the CNS

Answer 4

brain stem/medulla

Question 5

Outline the general role of the CNS

Answer 5

receiving, processing, and responding to sensory information

Question 6

Outline the role of the PNS

Answer 6

relays nerve impulses from the CNS to the rest of the body

Question 7

Outline the structure and role of the somatic nervous system

Answer 7

-has no further subcomponents
-carries sensory information from the outside world to the brain and provides muscle responses via the motor pathways

Question 8

Outline the role of the components of autonomic nervous system

Answer 8

-plays an important role in homeostasis, which maintains internal processes like body temperature, heart rate and blood pressure

sympathetic nervous system:
-involved in fight or flight
-impulses travels from the SNS to organs
-prepares body for action in a dangerous situation
-e.g. heart rate, blood pressure, and breathing increase, but trivial processes like digestion, salivation and the desire to urinate are suppressed

parasympathetic nervous system
-relaxes body and returns it to its normal ‘resting’ state
-consequently, heart rate, breathing rate and blood pressure decrease
-any functions that were previously slowed down are started again (e.g. digestion)

Question 9

Outline the structure of the autonomic nervous system

Answer 9

-only consists of motor pathways
-consists of two further components: sympathetic nervous system, parasympathetic nervous system

Question 10

Outline the similarities between the components of the CNS

Answer 10

-brain stem and spinal cord both control involuntary processes (e.g. brain stem controls breathing and spinal cord controls involuntary reflexes)

Question 11

Outline the differences between the components of the CNS

Answer 11

-brain provides conscious awareness and higher-order thinking, whereas the spinal cord allows for simple reflex responses

-brain has many components for different functions, whereas spinal cord only has one main function

Question 12

Outline the similarities between the components of the PNS

Answer 12

-sympathetic nervous system (part of the autonomic nervous system) and the somatic nervous system both respond to external stimuli
-sympathetic nervous system responds to external stimuli by preparing for fight or flight response
-somatic nervous system responds to external stimuli by carrying information from sensory receptors to the spinal cord and brain

Question 13

Outline the differences between the components of the PNS

Answer 13

-autonomic nervous system has two sub-components, whereas somatic nervous system only has one
-somatic nervous system has both sensory receptors and motor pathways, whereas autonomic nervous system only has motor pathways
-autonomic nervous system controls internal organs and glands, while the somatic nervous system controls muscles and movement

Question 14

What are the three main types of neurons?

Answer 14

sensory, relay and motor

Question 15

Compare the structures of sensory, motor and relay neurons

Answer 15

-all have axons and cell body
–relay neurons don’t have myelin sheath

Question 16

Outline the function of a sensory neuron

Answer 16

-found in receptors in the eyes, ears, tongue and skin
-carry nerve impulses to the spinal cord and brain
-nerve impulses that reach the brain are transited into sensations
-some sensory neurons don’t reach the brain; stop at spinal cord, allowing for quick reflex actions

Question 17

Outline the function of a relay neuron

Answer 17

-found between sensory input and motor output
-found in brain and spinal cord
-allow for sensory and motor neurons to communicate

Question 18

Outline the function of a motor neuron

Answer 18

-control muscle movement
-when stimulated, motor neurons release neurotransmitters that bind to receptors on muscles to trigger a response which lead to movement

Question 19

Outline the process of synaptic transmission and explain the difference between excitation and inhibition

Answer 19

-information is passed down the axon of the neuron as an electrical impulse known as action potential

-action potential needs to be transferred to another neuron or tissue when it reaches the end of the axon

-it must cross over the synaptic gap (between pre-synaptic cell and post-synaptic cell)

-synaptic vesicles in the axon terminal at the end of the neuron contain neurotransmitters (chemical messengers)

-when action potential reaches synaptic vesicles, they release their neurotransmitters

-neurotransmitters carry the signal across the synaptic gap

-they bind to receptor sites on the post-synaptic cell which are activated

-once activated, receptors produce either excitatory or inhibitory effects on the post-synaptic cell

-excitatory neurotransmitters (e.g. noradrenaline)
-inhibitory neurotransmitters (e.g. GABA)

-an excitatory neurotransmitter binds to post-synaptic receptors = an excitatory post-synaptic potential (EPSP)
-makes post-synaptic cell more likely to fire

-inhibitory neurotransmitter binds to the post-synaptic receptors = results in an inhibitory post-synaptic potential (IPSP)
-makes post-synaptic cell less likely to fire

Question 20

What is the main function of the endocrine system?

Answer 20

-works alongside nervous system but uses blood vessels rather than nerves
-network of glands across the body that secrete hormones (chemical messages)

Question 21

Role of the hypothalamus?

Answer 21

-stimulates pituitary glands to release hormones
-hence control system for the whole endocrine system

Question 22

Role of the pituitary gland including any hormones it produces and its effects?

Answer 22

-master gland
-releases hormones that control/stimulate release of hormones from other glands
-posterior lobe release oxytocin which is responsible for uterus contractions during childbirth
-anterior lobe releases adrenocortical trophic hormone (ACTH) which stimulates adrenal cortex to release cortisol, during the stress response.

Question 23

Role of the ovaries, including any hormones it produces and its effects

Answer 23

–releases oestrogen, which controls regulation of female reproductive system, including menstrual cycle and pregnancy

Question 24

Role of the testes, including any hormones it produces and its effects

Answer 24

-release androgens, which include testosterone hormone
-tester one is responsible for development of male sex characteristics during puberty
-promotes muscle growth in females

Question 25

Role of the pineal gland, including any hormones it produces and its effects

Answer 25

-releases melatonin
-controls important biologial rhythms such as the sleep-wake cycle

Question 26

Role of the adrenal glands, including any hormones it produces and its effects

Answer 26

-divided into two parts
-adrenal medulla is responsible for releasing adrenaline and noradrenaline, which play a key role in fight or flight response
-adrenal cortex releases cortisol, which stimulates release of glucose to provide body with energy while suppressing the immune system

Question 27

Role of the thyroid glands, including any hormones it produces and its effects

Answer 27

-releases thyroxine
-responsible for regulating metabolism

Question 28

Role of thymus gland?

Answer 28

Regulates immune system

Question 29

Outline the fight or flight response including the role of adrenaline

Answer 29

-amygdala (part of the limbic system) is activated when someone enters a potentially stressful situation
-amygdala responds to sensory input and connects it with emotions like fear or anger
-sends distress signal to hypothalamus if the situation is stressful/dangerous
-communicates with body through sympathetic nervous system by the sympathomedullary (SAM) pathway
-SNS stimulates adrenal medulla
-secretes adrenaline and noradrenaline into bloodstream
-causes physiological changes in the body to prepare for the fight or flight response:

increased heart rate:
-increases blood flow to organs
-increases movement of adrenaline around the body

increased breathing rate:
-increases oxygen intake

pupil dilation:
-increases light entry into eye and enhance vision (especially in the dark)

sweat production:
-regulates temperature

reduction of non-essential functions:
-e.g. digestion, salivation
-increases energy for other essential functions

-after the fight or flight response, parasympathetic nervous system activated
-brings body back to resting state
-heart rate and breathing rate decrease
-functions of non-essential organs are restarted

Question 30

Evaluate the fight or flight response

Answer 30

limitation - contradictory idea that human response to danger is not limited to fight or flight
-instead we engage in an initial ‘freeze’ response
-Gray (1988) suggests that humans instinctively avoid confrontation altogether
-hence animals and humans are hyper-vigilant in the freeze response, while they assess the situation to decide the best course of action for the particular threat

limitation - contradictory research suggesting that fight or flight does not apply to everyone
-typically a male response to danger
-(Taylor et al. 2000) found that women are more likely to protect their offspring and form alliances with other women
-known as a ‘tend and befriend’ approach
-furthermore, fight or flight might be counterintuitive for women, as running (flight) might be seen as a sign of weakness and and puts their offspring at risk of danger

limitation - suffers from androcentrism/beta bias
-early research into fight or flight was typically conducted on males
-consequently, researchers assumed findings could be generalised
-hence suffers from beta bias
-however, Taylor provided evidence later, proving that women adapt a ‘tend and befriend’ response to danger

-limitation - fight or flight is not as useful a survival mechanism to us compared to our ancestors
-we rarely face genuinely life-threatening situations (e.g. predators) that would require such an intense biological response
-furthermore, stressors from modern-day life can repeatedly activate fight or flight response, which can harm our health
-e.g. someone who continually activates sympathetic nervous system keeps increasing blood sugar levels, which can damaged blood vessels and lead to heart disease
-hence suggests that fight or flight is a maladaptive response in modern-day life

Question 31

Define localisation of brain function and explain how it is related to the case study of Phineas Gage

Answer 31

-certain functions have certain locations within the brain
-supported by recent neuroimaging studies but also supported by early research using case studies

Phineas Gage Case Study:
-while working on a rail line in 1848, a piece of iron went through his skull
-he survived but experienced a change in personality
-more anger and loss of inhibition
-provided evidence to support the theory of localisation of brain function, as the area damaged was the area responsible for personality

Question 32

Describe what the motor area is

Answer 32

-located in frontal lobe
-controls voluntary movements by sending signals to muscles
-Hitzig and Fritsch (1870) found different muscles coordinated by different areas of motor cortex by electrically stimulating motor area of dogs
-caused muscular contractions in various regions
-regions in the motor areas are arranged logically (e.g. area that controls finger is next to area that controls arm, etc)

Question 33

Describe what the somatosensory area is

Answer 33

-located in parietal lobe
-receives information from skin to produce sensations related to pressure, pain, temperature, etc
-different parts receive information from different areas in the body
-Robertson (1995) found Braille readers had larger areas in the somatosensory area for their fingertips compared to other body parts, hence this area is highly adaptable

Question 34

Describe what the visual area is

Answer 34

-located in the occipital lobe (back of the brain)
-receives and processes visual information
-information from the right visual field is processed by the left hemisphere
-information from the left visual field is processed by the right hemisphere
-different parts to process different information e.g. colour, shape, movement

Question 35

Describe what the auditory area is

Answer 35

-located in temporal lobe
-analyses and processes acoustic information
-information from left ear primarily goes to right hemisphere
-information from right ear primarily goes to left hemisphere
-contains different parts
-primary auditory area processes simple features, e.g. volume, pitch and tempo

Question 36

Describe what Broca’s area is

Answer 36

-was discovered when a patient called Leborgne/Tan was being treated
-could understand spoken language, but could not produce coherent words
-post-mortem examination on Tan’s brain showed he had a lesion in his left frontal lobe
-led Broca to conclude that this area was responsible for speech production
-people with damage to this area experience Broca’s aphasia, resulting in slow and inarticulate speech

Question 37

Describe what Wernicke’s area is and what conclusions Wernicke made

Answer 37

-Wernicke found another area of the brain that was involved in understanding speech
-patients with lesions in this area could speak, but were unable to comprehend language
-found in left temporal lobe
-involved in language processing/comprehension
-people with damage to this area often produce sentences that are fluent yet meaningless (known as Wernicke’s aphasia)

-Wernicke concluded that language involved a separate motor and sensory region
-the motor region = Broca’s area
-the sensory region = Wernicke’s area

Question 38

Evaluate localisation of function

Answer 38

limitation - alternative theory known as the equipotentiality theory was proposed
-suggests that only basic motor and sensory functions are localised
-higher mental functions are not localised, as intact areas of the cortex could take over responsibility for specific cognitive functions, following brain injury
-therefore casts doubt on theory of localisation of brain function, suggesting that brain functions are not always localised to one specific region

-strength - case studies to support the functions of Broca’s and Wernicke’s areas
-e.g. Broca’s area is an impaired ability to produce language
-mostly caused by brain damage to this area
-Wernicke’s aphasia is an impairment of language perception
-demonstrates its role in language comprehension
-therefore, case studies of these impairments enable psychologists to conclude that functions in the brain are localised and that damage to an area will only affect the function associated with it
-however, more recent research has provided contradictory evidence for this theory, despite case studies to support localisation of brain function
-Dronker’s et al. conducted an MRI scan on Tan’s brain to confirm Broca’s findings
-although there was a lesion in Broca’s area, there was also evidence to suggest other areas have contributed to the failure of speech production
-suggests that Broca’s area may not be the only area involved in speech production
-deficits found in patients with Broca’s aphasia may be due to damaged neighbouring areas

limitation - individual differences not considered
-size of brain areas observed were not considered
-Herasty (1997) found women have proportionally larger Broca’s and Wernicke’s areas than men
-explains the greater ease of language use amongst women
-suggests level of beta bias in the theory
-as differences between men and women were overlooked
-furthermore, variations in the pattern of activation were not considered during observations, which once again lowers the external validity of the theory, as it cannot be generalised to both genders

limitation - does not consider how brain regions communicate with each other
-only looks at specific functions of individual areas
-Wernicke claimed that while all brain areas are independent they must interact with each other to function
-e.g. Dejerine reported that a man lost the ability to read following damage to the connection between the visual cortex and Wernicke’s area
-suggests interactions between different areas produce complex behaviours (e.g. language)
-hence damage to connection between any 2 points can result in impairments that resemble damage to the localised brain region associated with that specific function
-reduces reliability
-furthermore, critics argue that localisation is biologically reductionist in nature
-tries to reduce complex human behaviours and cognitive processes to a specific region
-suggests more thorough understanding of brain is required to truly understand complex cognitive processes like language

Question 39

Explain what hemispheric lateralisation is

Answer 39

-idea that the two halves of the brain are functionally different
-each hemisphere has functional specialisations
-e.g. left is dominant for language, whereas right is dominant for visual-motor tasks
-both hemispheres are connected through nerve fibres called the corpus callosum, which facilitates interhemispheric communication

Question 40

Outline Sperry and Gazzaniga’s (1967) split brain research

Answer 40

Aim:
to examine the extent to which the two hemispheres are specialised for different functions

Method:
-when information is presented to one hemisphere of a split brain patient, it is not transferred to the other hemisphere, as the corpus callosum is cut
-many different experiments were conducted:
➤Describe what you see task: picture was presented to either left or right visual field, and participant had to describe what they could see
➤Tactile test: object was placed in participant’s left or right hand, and they had to describe what they felt or select a similar object from a set of alternate objects
➤Drawing task: picture was presented to either left or right visual field, and participant had to draw what they could see

Findings:
Describe what you see task:
➤When picture presented to right visual field, patient could describe what they saw
➤When picture presented to left visual field, patient could not describe what was present, ad often reported nothing was there
➤hence left hemisphere is superior in terms of language production

Tactile test:
➤When picture presented to right hand, they could describe verbally what they felt or identify the object from a set of similar ones
➤When picture presented to left hand, they could not describe what they felt, but could identify the test object from a series of alternate objects

Drawing task:
➤When picture presented to right visual field, picture was never as clear as the left hand
➤When picture presented to left visual field, left hand would consistently draw better pictures than right hand (even though all participants were right-handed)
➤demonstrates superiority of right hemisphere for visual-motor tasks

Conclusion:
-highlights key differences between the two hemispheres
-left hemisphere is dominant in terms of speech and language
-right hemisphere is dominant in terms of visual-motor tasks.

Question 41

Evaluate research into hemispheric lateralisation

Answer 41

strength - increases neural processing capacity
-Rogers et al. (2004) found that in a domestic chicken, brain lateralisation is associated with an enhanced ability to perform two tasks simultaneously (finding food and being vigilant for predators)
-using only one hemisphere to engage in a task leaves the other hemisphere free to engage in other functions
-provides evidence for the advantages of brain lateralisation
-demonstrates how it can enhance brain efficiency in cognitive tasks
-however, research was carried out on animals
-hence impossible to conclude the same of humans

limitation - split-brain procedure is rarely carried out now
-patients are difficult to come by
-such studies often include very few participants, and often takes an idiographic approach
-hence any conclusions drawn only represent individuals who had a confounding physical disorder that made the procedure necessary
-problematic as results cannot be generalised to the wider population

Limitation - suggested that lateralisation changes with age
-Szaflarki et al. (2006) found language became more lateralised to the left hemisphere with increasing age in children and adolescents
-but after age of 25, lateralisation decreased with each decade of life
-raises questions about lateralisation, e.g. whether everyone has one hemisphere that is dominant over the other and whether this dominance changes with age

Limitation - could be argued that language may not be restricted to the left hemisphere
-Turk et al. (2002) discovered a patient who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere
-eventually led to ability to speak about the information presented to either side of the brain
-suggests that perhaps lateralisation is not fixed and that the brain can adapt following damage to certain areas.

Question 42

What is neural processing capacity

Answer 42

the ability to perform multiple tasks simultaneously

Question 43

Explain plasticity and functional recovery

Answer 43

Brain plasticity:
-refers to the brain’s ability to adapt because of experience
-brain creates new neural pathways and alter existing ones in response to experiences

Functional recovery:
-transfer of functions from a damaged area of the brain after trauma to other undamaged areas
-can be done through neuronal unmasking where ‘dormant’ synapses open connections to compensate for a nearby damaged area of the brain
-allows new connections in the brain to be activated
-hence recovers any damage occurring in specific regions.

Question 44

Evaluation of evidence of plasticity and functional recovery

Answer 44

Strength - research support:
-Kuhn et al. found significant increase in grey matter in various brain regions after participants played video games for 30 minutes a day over a two-month period
-Similarly, Davidson et al. demonstrated the permanent change in the brain generated by prolonged meditation
-Buddhist monks who meditated frequently had a much greater activation of gamma waves than students with no experience of meditation
-both studies highlight idea of plasticity and brain’s ability to adapt as a result of new experience

Strength - further research to support the notion of brain plasticity
-Maguire et al. found that the posterior hippocampal volume of London taxi drivers’ brains was positively correlated with their time as a taxi driver
-there were significant differences between the taxi drivers’ brains and those of controls
-shows that the brain can permanently change in response to frequent exposure to a particular task

Strength - research support for claim of functional recovery
-Tajiri et al. (2013) found that stem cells provided to rats after brain trauma showed a clear development of neuron-like cells in the area of injury
-demonstrates ability of brain to create new connections using neurons manufactured by stem cells

Limitation - evidence shows functional recovery can deteriorate with age
-Elbert et al. concluded that the capacity for neural reorganisation is much greater in children than in adults
-hence neural regeneration is less effective in older brains
-may explain why adults find change more demanding than young people
-furthermore we must consider individual differences when assessing the likelihood of functional recovery in the brain after trauma, as factors like age were ignored

Strength - application of findings to field of neurorehabilitation
-understanding processes of plasticity and functional recovery led to development of neurorehabilitation
-which uses motor therapy and electrical stimulation of the brain to counter deficits in motor/cognitive functions following accidents, injuries or strokes
-demonstrates positive application of research in this area to help improve the cognitive functions of people suffering from injuries

Question 45

Outline and evaluate fMRI as a method of studying the brain

Answer 45

measures blood flow in the brain when a person performs a task
-works on basis that neurons in the brain that are the most active during a task use the most energy
-energy requires glucose and oxygen. -oxygen is carried in bloodstream attached to haemoglobin (found in red blood cells) and is released for use by these active neurons, at which point the haemoglobin becomes deoxygenated
-deoxygenated haemoglobin has a different magnetic quality from oxygenated haemoglobin
-fMRI can detect these different magnetic qualities and create a dynamic 3D map of the brain, highlighting which areas are involved in different neural activities
-fMRI images show activity approximately 1-4 seconds after it occurs and are thought to be accurate within 1-2 mm
-increase in blood flow is a response to the need for more oxygen in that area of the brain when it becomes active, suggesting an increase in neural activity.

Evaluation:
Strength - non-invasive
-unlike other scanning techniques, fMRI does not use radiation or involve inserting instruments directly into the brain
-hence virtually risk-free
-consequently, this should allow more patients/participants to undertake fMRI scans
-this could help psychologists to gather further data on the functioning human brain
-therefore develops our understanding of localisation of function

Strength - Spatial Resolution
-good spatial resolution of approximately 1-2 mm which is significantly greater than the other techniques (EEG, ERP, etc.)
-hence psychologists can determine the activity of different brain regions with greater accuracy when using fMRI, in comparison to when using EEG and/or ERP

Limitation - Temporal Resolution:
-poor temporal resolution of 1-4 seconds -worse than other techniques (e.g. EEG/ERP which have a temporal resolution of 1-10 milliseconds)
-consequently, psychologists are unable to predict with a high degree of accuracy the onset of brain activity

Limitation - fMRI scans do not provide a direct measure of neural activity
-simply measure changes in blood flow
-hence it is impossible to infer causation (at a neural level)
-as while any change in blood flow may indicate activity within a certain brain area, psychologists are unable to conclude whether this brain region is associated with a particular function.

Limitation - some psychologists argue that fMRI scans can only show localisation of function within a particular area of the brain
-unable to show the communication between different areas of the brain
-which might be critical to neural functioning

Question 46

Outline and evaluate EEG as a method of studying the brain

Answer 46

-works on the basis that the brain processes information in the form of action potentials transmitted along neurons

-EEG scanners measure this electrical activity through electrodes attached to the scalp

-small electrical charges detected by the electrodes are graphed over a period of time, indicating the level of brain activity

-4 types of EEG patterns: alpha waves, beta waves, theta waves and delta waves

-Each pattern has two basic properties that psychologists can examine:
-Amplitude: intensity of activity
-Frequency: speed of activity

-EEG patterns produce two distinctive states: synchronised and desynchronized patterns
-synchronised pattern: a recognised waveform (alpha, beta, delta and theta) can be detected
-desynchronised pattern: no pattern can be detected
-fast desynchronized patterns are found when awake
-synchronised patterns are found during sleep
-(alpha waves are associated with light sleep, and theta/delta waves are associated with deep sleep)
-EEG scanning helped develop our understanding of REM (dream) sleep (associated with fast, desynchronised activity, indicative of dreaming)
-also used to detect illnesses (e.g. epilepsy, sleep disorders, Alzheimer’s disease)

Evaluation:
Strength - non-invasive
-unlike techniques, e.g. Positron Emission Tomography (PET), does not involve radiation or inserting instruments directly into the brain
-hence virtually risk-free
-consequently, this should allow more patients/participants to undertake EEG/ERPs
-may help psychologists to gather further data on the functioning human brain
-therefore develops our understanding of different psychological phenomena, such as sleeping or Alzheimer’s
-furthermore, much cheaper technique than fMRI scanning and are therefore more readily available

Limitation - poor spatial resolution
-greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy
-but EEGs only detect the activity in superficial regions of the brain
-hence unable to provide information on what is happening in the deeper regions of the brain (e.g. hypothalamus)
-makes this technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm.

Strength - good temporal resolution
-takes readings every millisecond, hence it can record the brain’s activity in real time as opposed to looking at a passive brain
-leads to accurate measurement of electrical activity when undertaking a specific task

Limitation - uncomfortable for the participant
-electrodes are attached to the scalp
-could result in unrepresentative readings as patient’s discomfort may be affecting cognitive responses to situations
-however, fMRI scans are less invasive and would not cause the participants any discomfort, leading to potentially more accurate recordings

Limitation - electrical activity is often detected in several regions of the brain simultaneously
-hence it can be difficult pinpoint the exact area of activity
-makes it difficult for researchers to draw accurate conclusions.

Question 47

Outline and evaluate ERP as a method of studying the brain

Answer 47

-use similar equipment to EEG, i.e. electrodes attached to the scalp
-key difference is that stimulus is presented to a participant (e.g. a picture/sound) and researcher looks for activity related to that stimulus
-stimulus presented many times (usually hundreds), and an average response is graphed
- ‘averaging’ reduces any extraneous neural activity which makes the specific response to the stimulus stand out

-interval between the presentation of the stimulus and the response is referred to as latency
-ERPs have a very short latency and can be divided into two broad categories:
-sensory ERPs: waves that occur within 100 milliseconds following the presentation of a stimulus reflect a sensory response to the stimulus
-cognitive ERPs: occur after 100 milliseconds demonstrate some information processing

Evaluation:
Strength - non-invasive
-unlike techniques, e.g. Positron Emission Tomography (PET), does not involve radiation or inserting instruments directly into the brain
-hence virtually risk-free
-consequently, this should allow more patients/participants to undertake EEG/ERPs
-may help psychologists to gather further data on the functioning human brain
-therefore develops our understanding of different psychological phenomena, such as sleeping or Alzheimer’s
-furthermore, much cheaper technique than fMRI scanning and are therefore more readily available.

Limitation - poor spatial resolution
-greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy
-ERPs only detect the activity in superficial regions of the brain
-hence unable to provide information on what is happening in the deeper regions of the brain (e.g. hypothalamus)
-makes this technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm.

Strength - good temporal resolution
-takes readings every millisecond, hence it can record the brain’s activity in real time as opposed to looking at a passive brain
-leads to accurate measurement of electrical activity when undertaking a specific task

Limitation - uncomfortable for the participant
-electrodes are attached to the scalp
-could result in unrepresentative readings as patient’s discomfort may be affecting cognitive responses to situations
-however, fMRI scans are less invasive and would not cause the participants any discomfort, leading to potentially more accurate recordings

Strength - enables determination of how processing is affected by a specific experimental manipulation
-makes ERP use a more experimentally robust method as it can eliminate extraneous neutral activity, something that other scanning techniques like EEG may struggle to do.

Question 48

Outline and evaluate post-mortem examination as a method of studying the brain

Answer 48

-study of physical brain of a person who displayed a particular behaviour while they were alive that suggested possible brain damage.
-e.g. the work of Broca, who examined the brain of a man who displayed speech problems when he was alive
-was discovered that he had a lesion in the area of the brain important for speech production
-later became known as Broca’s area.
-similarly, Wernicke discovered a region in the left temporal lobe, which is important for language comprehension and processing
-now known as Wernicke’s area.

Evaluation:
Limitation - causation
-deficit a patient displays during their lifetime (e.g. an inability to speak) may not be linked to the deficits found in the brain (e.g. a damaged Broca’s area)
-deficits reported could have been the result of another illness
-therefore psychologists are unable to conclude that the deficit is caused by the damage found in the brain

Limitation - many extraneous factors can affect the results of post-mortem examinations
-e.g. people die at different stages of their life and for a variety of different reasons
-furthermore, any medication a person may have been taking, their age, and the length of time between death and post-mortem examination, are all factors that make the conclusions of such research questionable

Strength - provide a detailed examination of the anatomical structure and neurochemical aspects of the brain that is not possible with other scanning techniques
-post-mortem examinations can access areas like the hypothalamus and hippocampus
-hence provides researchers with an insight into these deeper brain regions
-often provide a useful basis for further research
-e.g. Iverson found a higher concentration of dopamine in the limbic system of patients with schizophrenia
-this has prompted a whole area of research looking into the neural correlates of this disorder

Limitation - questionable ethics
-‘invasive’, but not an issue because the patient is dead
-However, there are ethical issues in relation to informed consent and whether or not a patient provides consent before his/her death. -Furthermore, many post-mortem examinations are carried out on patients with severe psychological deficits (e.g. patient HM who suffered from severe amnesia) who would be unable to provide fully informed consent, and yet a post-mortem examination has been conducted on his brain
-raises severe ethical concerns

Question 49

Explain what spatial resolution and temporal resolution is

Answer 49

Spatial resolution:
-smallest measurement that a scanner can detect
-greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy

Temporal resolution:
-accuracy of the scanner in relation of time or how quickly the scanner can detect changes in brain activity

Question 50

Outline examples of circadian rhythms

Answer 50

sleep-wake cycle, which dictates when humans/animals should be asleep/awake

-light acts as the external cue for sleeping or waking

-light is first detected by the eye, which then sends messages concerning the level of brightness to suprachiasmatic nuclei (SCN)

-the SCN then uses this information to coordinate the activity of the entire circadian system

-sleeping and wakefulness are not determined by the circadian rhythm alone, but also by homoeostasis

-when an individual has been awake for a long time, homeostasis tells the body that there is a need for sleep because of energy consumption

-this homeostatic drive for sleep increases throughout the day, reaching its maximum in the late evening, when most people fall asleep

Body temperature is another circadian rhythm
-human body temperature is at its lowest in early morning and highest in early evening
-sleep typically occurs when the core temperature starts to drop
-body temperature starts to rise towards the end of a sleep cycle promoting feelings of alertness first thing in the morning

Question 51

Main difference between circadian, infradian and ultradian biological rhythms

Answer 51

Circadian = 24 hours
Infradian = longer than 24 hours
Ultradian = shorter than 24 hours

Question 52

Evaluate research into circadian rhythms

Answer 52

Strength - Research Support
-Siffre (1975) investigated circadian rhythms and found that absence of external cues significantly altered his circadian rhythm
-When he returned from an underground stay with no clocks or light, he believed the date to be a month earlier than it was
-suggests that his 24-hour sleep-wake cycle was increased by the lack of external cues
-made him believe one day was longer than it was
-led to his thinking that fewer days had passed.
-however, Siffre’s case study has beencriticised
-as the researcher and sole participant in his case study, there are severe issues with generalisability

Strength - further research support
-further research by Aschoff & Weber (1962) on participants living in a bunker
-had no windows and only artificial light, which the participants were free to turn on and off as they pleased
-found that participants settled into a longer sleep/wake cycle of between 25-27 hours
-these results, along with Siffre’s findings, suggest that humans use natural light (exogenous zeitgebers) to regulate a 24-hour circadian sleep-wake cycle
-demonstrates importance of light for this circadian rhythm.

Limitation - Individual Differences not considered
-Duffy et al. (2001) found that ‘morning people’ prefer to rise and go to bed early (about 6 am and 10 pm)
-whereas ‘evening people’ prefer to wake and go to bed later (about 10 am and 1 am)
-demonstrates that there may be innate individual differences in circadian rhythms
-suggests that researchers should focus on these differences during investigations.

Limitation - contradictory idea that temperature may be more important than light in determining circadian rhythms
-Buhr et al. (2010) found that fluctuations in temperature set the timing of cells in the body
-caused tissues and organs to become active or inactive
-Buhr claimed that information about light levels is transformed into neural messages that set the body’s temperature
-body temperature fluctuates on a 24-hour circadian rhythm and even small changes in it can send a powerful signal to our body clocks
-shows that circadian rhythms are controlled and affected by several different factors
-suggests that a more holistic approach to research might be preferable.

Question 53

Outline examples of infradian rhythms

Answer 53

female menstrual cycle (monthly)

-regulated by hormones that either promote ovulation or stimulate the uterus for fertilisation

-ovulation occurs roughly halfway through the cycle when oestrogen levels are at their highest, and usually lasts for 16-32 hours

-after the ovulatory phase, progesterone levels increase in preparation for the possible implantation of an embryo in the uterus

-although the usual menstrual cycle is around 28 days, there is considerable variation

Question 54

Evaluate research into infradian rhythms

Answer 54

Strength - Research support that the menstrual cycle is partly governed by exogenous zeitgebers (external factors)
-Reinberg (1967) examined a woman who spent three months in a cave with only a small lamp to provide light
-he noted that her menstrual cycle shortened from the usual 28 days to 25.7 days
-suggests that the lack of light (an exogenous zeitgeber) in the cave affected her menstrual cycle
-therefore this demonstrates the effect of external factors on infradian rhythms

Strength - further research support suggests that exogenous zeitgebers can affect infradian rhythms
-Russell et al. (1980) found that female menstrual cycles became synchronised with other females through odour exposure
-in a study, sweat samples from one group of women were rubbed onto the upper lip of another group
-despite the fact that the two groups were separate, their menstrual cycles synchronised
-suggests that the synchronisation of me can be affected by pheromones, which have an effect on people nearby rather than on the person producing them
-indicates that external factors must be considered when investigating infradian rhythms
-perhaps a more holistic approach should be taken, as opposed to reductionist approach that considers only endogenous influences
-furthermore, evolutionary psychologists claim that the synchronised menstrual cycle provides an evolutionary advantage for groups of women, as the synchronisation of pregnancies means that childcare can be shared among multiple mothers who have children at the same time.

Strength - research support to suggest that infradian rhythms such as the menstrual cycle are also important regulators of behaviour
-Penton-Volk et al. (1999) found that woman expressed a preference for feminised faces at the least fertile stage of their menstrual cycle, and for a more masculine face at their most fertile point
-indicates that women’s sexual behaviour is motivated by their infradian rhythms
-highlights importance of studying infradian rhythms in relation to human behaviour

Strength - evidence for role of melatonin in SAD
-Terman (1988) found higher rate of SAD in Northern countries where the winter nights are longer
-e.g.Terman found that SAD affects roughly 10% of people living in New Hampshire (a northern part of the US) and only 2% of residents in southern Florida
-suggest that SAD is in part affected by light (exogenous zeitgeber) that results in increased levels of melatonin.

Question 55

Evaluate research into ultradian rhythms

Answer 55

Limitation - Individual Differences makes investigating patterns difficult
-Tucker et al. (2007) found significant differences between participants in terms of the duration of each stage, particularly stages 3 and 4 (just before REM sleep)
-demonstrates that there may be innate individual differences in ultradian rhythms
-means that it is worth focusing on these differences during investigations into sleep cycles.
-furthermore, this study was carried out in a controlled lab setting
-meant that differences in sleep patterns could not be attributed to situational factors, but only to biological differences between participants
-while this study provide convincing support for the role of innate biological factors and ultradian rhythms, psychologists should examine other situational factors that may also play a role

Limitation - methodological issues may affect conclusions about ultradian rhythms in humans
-when investigating sleep patterns, participants must be subjected to a specific level of control and be attached to monitors that measure such rhythms
-may be invasive for the participant, leading them to sleep in a way that does not represent their ordinary sleep cycle
-makes investigating ultradian rhythms, such as the sleep cycle, extremely difficult due to their lack of ecological validity leading to false conclusions being drawn

Strength - research support from case study for the flexibility of ultradian rhythms
-Randy Gardener remained awake for 264 hours
-while he experienced numerous problems such as blurred vision and disorganised speech, he coped well with the massive sleep loss
-after this experience, Randy slept for just 15 hours and over several nights he recovered only 25% of his lost sleep. Interestingly, he recovered 70% of Stage 4 sleep, 50% of his REM sleep, and very little of the other stages
-results highlight the large degree of flexibility in terms of the different stages within the sleep cycle and the variable nature of this ultradian rhythm.

Question 56

Outline examples of ultradian rhythms

Answer 56

-pattern of human sleep
-alternates between REM (rapid eye movement) and NREM (non-rapid movement) sleep and consists of five stages
-cycle starts at light sleep, progressing to deep sleep and then REM sleep, where brain waves speed up and dreaming occurs
-repeats itself about every 90 minutes throughout the night
-complete sleep cycle goes through the four stages of NREM sleep before entering REM (Stage 5) and then repeating
-research using EEG has highlighted distinct brain waves patterns during the different stages of sleep

1. Stages 1 and 2 are ‘light sleep’ stages. Brainwave patterns become slower and more rhythmic, starting with alpha waves progress to theta waves.
2. Stages 3 and 4 are ‘deep sleep’, where it is difficult to wake someone up. associated with slower delta waves.
3. Finally, Stage 5 is REM (or dream) sleep. Here is the body is paralysed (to stop the person acting out their dream) and brain activity resembles that of an awake person

-on average, the entire cycle repeats every 90 minutes and a person can experience up to five full cycles in a night

Question 57

What are endogenous pacemakers

Answer 57

-internal mechanisms that govern biological rhythms, in particular, the circadian sleep-wake cycle
-can be altered and affected by the environment
-e.g. although the circadian sleep-wave cycle continues to function without natural cues from light, research suggests that light is required to reset the cycle every 24 hours

Suprachiasmatic Nucleus:
-most important endogenous pacemaker
-lies in hypothalamus
-closely linked to the pineal gland, both of which are influential in maintaining the circadian sleep/wake cycle
-controls other biological rhythms, as it links to other areas of the brain responsible for sleep and arousal
-receives information about light levels (an exogenous zeitgeber) from the optic nerve, which sets circadian rhythm so that it is in synchronisation with the outside world, e.g. day and night.
-SCN sends signals to pineal gland
-leads to increased production of melatonin at night, helping to induce sleep
-SCN and pineal glands work together as endogenous pacemakers; however, their activity is responsive to the external cue of light

Question 58

What are exogenous zeitgebers

Answer 58

-influence biological rhythms
-environmental events that are responsible for resetting the biological clock of an organism
-include social cues such as meal times and social activities
-most important zeitgeber is light, (responsible for resetting the body clock each day, keeping it on a 24-hour cycle)
-SCN contains receptors that are sensitive to light
-this external cue is used to synchronise the body’s internal organs and glands
-melanopsin (protein in the eye) is sensitive to light and carries signals to the SCN to set the 24-hour daily body cycle
-social cues, such as mealtimes, can also act as zeitgeber
-humans can compensate for the lack of natural light, by using social cues instead

Question 59

Evaluate endogenous pacemakers and exogenous zeitgebers

Answer 59

Strength - research supports importance of SCN
-Morgan (1955) bred hamsters so that they had circadian rhythms of 20 hours rather than 24
-SCN neurons from these abnormal hamsters were transplanted into the brains of normal hamsters, which subsequently displayed the same abnormal circadian rhythm of 20 hours,
-showed that the transplanted SCN had imposed its pattern onto the hamsters
-demonstrates the significance of the SCN and endogenous pacemakers for biological circadian rhythms.
-however, flawed due to use of hamsters
-humans respond very differently to manipulations of their biological rhythms, due to both biological and environmental differences
-makes research carried out on other animals unable to explain the role of endogenous pacemakers in the biological processes of humans
-lacks generalisability

Strength - research support for role of melanopsin
-Skene and Arendt (2007) claimed that majority of blind people who still have some light perception have normal circadian rhythms
-whereas those without any light perception show abnormal circadian rhythms
-demonstrates importance of exogenous zeitgebers as a biological mechanism and their impact on biological circadian rhythms
-further research support for the role of exogenous zeitgebers
-when Siffre returned from an underground stay with no clocks or light, he believed the date to be a month earlier than it was
-suggests that his 24-hour sleep-wake cycle was increased by the lack of external cues, making him believe one day was longer than it was
-highlights impact of external factors on bodily rhythms.

Limitation - biologically reductionist
-e.g. behaviourist approach would suggest that bodily rhythms are influenced by other people and social norms
-i.e. sleep occurs when it is dark because that is the social norm and it wouldn’t be socially acceptable for a person to conduct their daily routines during the night
-research discussed here could be criticised for only considering a singular biological mechanism
-fails to consider the other widely divergent viewpoints.

Question 60

Exam Question:

Describe the structure and function of a neuron. (6 marks)

Answer 60

Possible content:
• Neurons enable communication within the nervous system
• the cell body (soma) contains the genetic material
• branch-like dendrites extend from the cell body (often with dendritic spines)
• dendrites carry functional information towards the cell body
• dendrites can receive information from other neurons
• axons carry messages away from the cell body
• axons can be myelinated to increase speed of nerve transmission (saltatory conduction between nodes of Ranvier)
• terminal boutons are at the end of axons, these make synaptic connections with other cells
• axon terminals contain neurotransmitters

Question 61

Outline similarities and differences between sensory neurons, relay neurons and motor neurons. (4 marks)

Answer 61

Sensory neurons:
-carry sensory impulse from sensory organs to the central nervous system
-Comprises of a short axon
-Found in eyes, skin, ears, tongue and nose
-has myelin sheath

Relay neuron:
-no myelin sheath
-allows communication between sensory and motor neurons

Motor neurons:
-carries motor impulses from the central nervous system to specific effectors
-comprised of a long axon
-Found in muscles and glands
-has myelin sheath