Biopsychology - Paper 2

Question 1

What is the nervous system?

Answer 1

A specialised network of cells in the body. It is our primary internal communication system, communicating using electrical and chemical signals

Question 2

What are the 2 main functions of the nervous system?

Answer 2

. To collect, process, and respond to information in the environment
. The co-ordinate the working of different cells and organs in the body

Question 3

Name the subsystems of the nervous system

Answer 3

Central Nervous System
Peripheral Nervous System

Question 4

Name the parts of the central nervous system

Answer 4

. Brain - center of all conscious awareness, divided into two hemispheres. Responsible for processing information
. Spinal cord - Passes messages to and from the brain, connects nerves to the peripheral nervous system. It is responsible for reflex actions

Question 5

What is the peripheral nervous system?

Answer 5

Subsection of the nervous system, made up of nerves outside the CNS. It transmits messages via neurons to and from the central nervous system. It connects the CNS to the outside world and muscles/glands in the body.

Question 6

Name the parts of the peripheral nervous system

Answer 6

. Autonomic Nervous System - Controls vital functions such as digestion, breathing, heart rate, stress responses etc.. —-
—- Can be split into the sympathetic branch (involved in the fight or flight response) and the parasympathetic branch (responsible for rest and digest)
. Somatic Nervous System - Controls muscle movement and receives information from the sensory receptors - connects the nervous system and the senses

Question 7

What is the endocrine system?

Answer 7

One of the bodies major information systems, instructs glands to release hormones directly into the bloodstream. These hormones are then carried to target organs. Communicates via chemicals

Question 8

What are glands?

Answer 8

An organ in the body that synthesises hormones

Question 9

What are hormones?

Answer 9

Biochemical substances that are secreted into the blood and affect target organs. They are produced in large quantities but disappear quickly. Their effects are powerful.

Question 10

What does the pancreas do?

Answer 10

Regulates insulin and aids digestion by producing enzymes

Question 11

What does the adrenal gland do?

Answer 11

Releases adrenaline and noradrenaline in order to trigger biological responses to ‘fight or flight’ - to stressors

Question 12

What do the ovaries do?

Answer 12

Produces oestrogen and progesterone in the ovaries to regulate reproduction and cause sex differences

Question 13

What do the testes do?

Answer 13

Produces testosterone in order to regulate reproduction and cause sex differences

Question 14

What does the thyroid gland do?

Answer 14

Produces thyroxine in order to regulate growth and metabolism

Question 15

What does the hypothalamus do?

Answer 15

Controls the actions of the pituitary gland, is the link to the central nervous system

Question 16

What does the pituitary gland do?

Answer 16

The ‘master gland’ - it monitors hormone levels and produces it’s own hormones to instruct other glands to secrete theirs

Question 17

What does the pineal gland do?

Answer 17

Converts seratonin to melatonin when light levels are low to make us tired.

Question 18

What is the ‘fight or flight’ response?

Answer 18

The way an animal responds when stressed - the body becomes physiologically aroused in readiness to fight an aggressor, or flee.

Question 19

What are the stages involved in the fight or flight response

Answer 19

Stressful situation —- Sympathomedullary pathway activated —- Amygdala sends a distress signal to the hypothalamus —- Hypothalamus activates the pituitary gland —- Sympathetic branch of the autonomic nervous system is activated, and the ANS changes from the parasympathetic state to the sympathetic state —- Adrenal Medulla is instructed to release adrenaline —- Adrenaline triggers physiological arousal in target organs in the body to deal with the stressor

Question 20

What happens when the threat has passed?

Answer 20

The parasympathetic system returns the body to its resting state. The parasympathetic branch of the autonomic nervous system has actions that are antagonistic to the sympathetic branch eg. reducing heart rate, constricting pupils. It acts as a brake, reducing the activities caused by the sympathetic branch - ‘rest and digest’ response

Question 21

What physiological changes occur during the fight or flight response?

Answer 21

Increased heart rate, Increased breathing rate, Dilated pupils, Inhibited digestion, Inhibited saliva production, Contracts rectum

Question 22

What is a limitation of fight or flight - androcentrism?

Answer 22

Early research into fight or flight was largely conducted on males (as they were seen as preferable to females due to them being less affected by hormonal changes) and assumed both males and females responded to stressful situations with fight or flight. However Taylor et.al (2000) suggested women are more likely to ‘tend and befriend’, with the ‘love’ hormone oxytocin being more plentiful in women than men, and with it’s production being increased in women in stressful situations. Therefore the generalisability of the theory is limited as it can’t be applied to both genders

Question 23

What is a limitation of fight or flight - simplistic?

Answer 23

When faced with dangerous situations, our reactions aren’t limited to just fight or flight. Some psychologists suggest there may be a ‘freeze’ element involved, with Gray (1998) suggesting that a humans’ first response is to avoid confrontation altogether. In the freeze stage humans are hypervigilant as they judge the best response to the situation. So the fight or flight theory is too simplistic to explain human behaviour on it’s own, limiting its usefulness.

Question 24

What is a neuron?

Answer 24

The basic building blocks of the nervous system, they are nerve cells which process and transmit messages through chemical and electrical signals

Question 25

What are the 3 kinds of neuron?

Answer 25

Sensory, Motor, Relay

Question 26

What do sensory neurons do?

Answer 26

Carry messages from the peripheral nervous system to the central nervous system.
Long dendrites, short axons.

Question 27

What do relay neurons do?

Answer 27

Connect sensory neurons to motor or other relay neurons.
Short dendrites, short axons

Question 28

What do motor neurons do?

Answer 28

Connect the central nervous system to effectors eg. muscles and glands.
Short dendrites, long axons.

Question 29

List the different parts of a neuron

Answer 29

. Cell body - Includes a nucleus, containing the genetic information of the cell
. Dendrites - Protrude from cell body, carry nerve impulses from other neurons to the cell body
. Axon - Carries the impulses from the cell body down the length of the neuron
. Myelin Sheath - Fatty layer which covers the axon, insulating it and in turn speeding up the transmission of electrical impulses eg. Schwann cells
. Nodes of ranvier - Gaps in the myelin sheath that speed up transmission of electrical impulses by forcing it to jump the gap
. Axon terminals - Found at the end of the axon, communicate with the next neuron in the chain across a gap known as the synapse

Question 30

Where are neurons found?

Answer 30

. Cell bodies of motor neurons - central nervous system
. Axons of motor neurons - form part of the peripheral nervous system
. Sensory neurons - peripheral nervous system
. Relay neurons - make up 97% of all neurons, mostly found in brain (so CNS)

Question 31

What is action potential

Answer 31

The electrical impulse that travels down the axon of a neuron after the neuron becomes positively charged after being activated by a stimulus

Question 32

What is synaptic transmission?

Answer 32

The process by which neighbouring neurons communicate with each other by sending chemical messages across the synapse that separates them

Question 33

What is chemical transmission?

Answer 33

Where signals between neurons are transmitted chemically across the synapse

Question 34

What is a neurotransmitter?

Answer 34

Brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another. Some neurotransmitters are excitatory and others are inhibitory

Question 35

What is excitation?

Answer 35

Excitation refers to where a neurotransmitter increases the positive charge of the post-synaptic neuron, increasing the likelihood that it will pass on the electric impulse eg. adrenaline

Question 36

What is inhibition?

Answer 36

Refers to where the neurotransmitter increases the negative charge of the postsynaptic neuron, decreasing the likelihood that the post-synaptic neuron will pass on the electrical impulse

Question 37

What is summation?

Answer 37

Where the excitatory and inhibitory influences are summed and a net total effect is calculated. If the net effect on the postsynaptic neuron is inhibitory, the neuron is less likely to fire, if it is excitatory it is more likely to fire.

Question 38

Outline the full process by which neurons communicate with eachother across the synapse

Answer 38

A neuron becomes positively charged in response to a stimulus and an electrical impulse (action potential) travels down the axon of the neuron to the pre-synaptic terminal. Here, a chemical message is carried by the neurotransmitter and fired from the synaptic vesicles, across the synapse. Then, these neurotransmitters bind to the receptor sites on the dendrites of the post-synaptic neuron. Each neurotransmitter eg. dopamine can only bind to a specific receptor site. These chemical messages can also only travel in one direction. If the neurotransmitter has an excitatory effect, the post-synaptic neuron is more likely to fire an action potential. If it is inhibitory, it is less likely to fire.

Question 39

What is localisation of function?

Answer 39

Initially scientists believed the brain was holistic - all areas worked together to perform a task.
However research led to localisation theory - the theory that different areas of the brain are responsible for specific behaviours, processes, or activities

Question 40

What does the left hemisphere control?

Answer 40

The right side of the body

Question 41

What does the right hemisphere control?

Answer 41

The left side of the body

Question 42

What is the corpus callosum?

Answer 42

A thick band of neural fibers, consisting of about 200 million axons. It allows the 2 hemispheres of the cerebrum to communicate with each other so information processed on one side of the brain can be shared with the other side.

Question 43

What is the cerebral cortex?

Answer 43

The outer layer of the right and left hemisphere. It is divided into 4 lobes : the frontal lobe, the parietal lobe, the temporal lobe, and the occipital lobe

Question 44

What does the frontal lobe do?

Answer 44

. Located in the top/forward part of the brain, extending back to the central sulcus
. It is involved in reasoning, motor control, emotion and language

Question 45

What does the parietal lobe do?

Answer 45

. Located at the top/back of the brain
. It is important in integrating information from the body’s senses in order to build a coherent picture of the world around us. It allows us to co-ordinate movement in response to objects in our environment —- process what and where things are

Question 46

What does the occipital lobe do?

Answer 46

. Located at the back of the brain
. Responsible for interpreting incoming visual information. It receives sensory information from the retinas, which is then encoded into different visual data eg. colour

Question 47

What does the temporal lobe do?

Answer 47

. Located near the temples of the head
. Involved in understanding language, memory, perception, object recognition, processing auditory information, facial recognition

Question 48

What does the motor cortex do?

Answer 48

. Found at the back of the frontal lobe in each hemisphere
. Controls voluntary movement on the opposite side of the body. Damage to this area can result in a loss of control over fine motor movements

Question 49

What does the somatosensory cortex do?

Answer 49

. Found at the front of the parietal lobe in each hemisphere
. Sensory information from receptor sites on the skin is processed in this area of the brain. Each body part has a separate area in the somatosensory cortex - the more sensitive the body part, the larger its area in the cortex

Question 50

What does the visual cortex do?

Answer 50

. Found at the back of the occipital lobe in each hemisphere
. It takes information from each eye and sends this to the opposite visual cortex to be processed

Question 51

What does the auditory cortex do?

Answer 51

. Found at the top of the temporal lobes in each hemisphere, underneath the somatosensory cortex
. It processes speech/sound information and will often send this information to the Wernicke’s area

Question 52

What is Broca’s area?

Answer 52

. Found at the bottom of the LEFT frontal lobe/above the temporal lobe
. Discovered by Paul Broca when he noticed that the area plays a key role in speech production based on the case study of ‘Tan’
. Damage to this area can lead to Broca’s aphasia

Question 53

What is the case study of ‘Tan’

Answer 53

Studied Louis Victor Leborgne who was admitted to hospital aged 30 and could only say the syllable ‘tan’, though it cognitive abilities were otherwise unaffected. After his death, a post-mortem revealed a lesion to the posterior inferior frontal gyrus (Broca’s area)

Question 54

What is Broca’s aphasia?

Answer 54

A disorder which is characterised by slow, laborious speech which is lacking in fluency. Patients with this disorder can understand language, but struggle to process speech and often struggle with grammar. They often have difficulty with prepositions and conjunctions (eg. a, the, and)

Question 55

What is Wernicke’s area?

Answer 55

Identified by Karl Wernicke. It is believed to be involved in language understanding/comprehension.
It is found in the back of the LEFT temporal lobe. It is connected to Broca’s area by the arcuate fasciculus - it is thought that language is first processed by Wernicke’s area and then transferred to Broca’s
Damage to this area leads to Wernicke’s aphasia

Question 56

What is Wernicke’s aphasia?

Answer 56

A disorder where patients can produce speech, but cannot understand language so their speech is often meaningless. They often produce nonsense words (neologisms) as part of their speech

Question 57

What is a strength of localisation of function - evidence of neurosurgery?

Answer 57

Damage to areas of the brain has been linked to mental disorders. Dougherty et.al (2002) reported on 44 people with OCD who had undergone neurosurgery isolating a specific area. At a post-surgical follow up after 32 weeks, about 30% had met the criteria for successful response, and 14% for partial response. The success of these procedures indicates that behaviors associated with serious mental disorders may be localised

Question 58

What is a strength of localisation of function - evidence from brain scans?

Answer 58

Evidence from brain scans supports the idea that everyday brain functions may be localised. Petersen et.al (1988) used brain scans to show how Wernicke’s area was active during a listening task, while Broca’s area was active during a reading task. Furthermore, Buckner and Petersen (1996) reviewed long-term memory studies and found that semantic and episodic memories reside in different areas of the prefrontal cortex. These studies confirm localised areas for everyday behaviors , and have used objective methods to do so, giving localisation theory scientific credibility.

Question 59

What is a counterargument from the brain scans argument - localisation of function?

Answer 59

Lashley (1950) studied rats after removing areas of their cortex’s (between 10 and 50%). No area was proven to be more important than any other in helping the rats to learn a route through a maze. Instead, the process of learning seemed to require every part of the cortex, suggesting that higher cognitive processes may not be localised, but instead distributed holistically through the brain.

Question 60

What is a limitation of localisation of function - language may not be exclusive to Broca and Wernicke’s areas?

Answer 60

Dick and Tremblay (2016) found that only 2% of modern researchers think the brain is completely controlled by Broca and Wernicke’s areas. The use of modern brain imaging techniques has led some researchers to suggest that language function is distributed more holistically in the brain than initially thought, with so-called ‘language streams’ being identified across the cortex (including regions in the right hemisphere) and subcortical regions (eg. the thalamus). This suggests language functioning isn’t restricted to certain key areas, contradicting localisation theory

Question 61

What is a limitation of localisation of function - case study evidence?

Answer 61

Individual cases of neurological damage have been used to support localisation theory eg. Phineas Gage. However case studies tend to lack generalisability, not only due to the small sample size but also due to the fact that the individuals being studied often have traumas or illnesses not shared by the majority of the population. This limits the applicability of evidence from case studies

Question 62

What is the case study of Phineas Gage?

Answer 62

1848 - Railroad worker Phineas Gage was injured during an accident at work which resulted in an metre length iron pole impaling his head, taking most of his frontal lobe. Miraculously, Gage survived, but his personality changed to become more short tempered, rude and ‘no longer Gage’. This led to the suggestion that mood may be localised to the frontal lobe.

Question 63

What is (hemispheric) lateralisation?

Answer 63

The idea that the two hemispheres of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere eg. language is usually controlled by the left hemisphere

Question 64

What is meant by the idea that the left hemisphere is the analyser and the right hemisphere the synthesiser

Answer 64

The right hemisphere can only produce rudimentary words and phrases, but contributes to the emotional context of what is being said. Meanwhile the left hemisphere contains both key language areas (Broca’s and Wernicke’s)

Question 65

How does vision work?

Answer 65

Each eye receives information from the left visual field and the right visual field
The left visual field of both eyes is connected to the right hemisphere, and the right visual field of both eyes is connected to the left hemisphere
Then, the right hemisphere controls movement on the left side of the body, and the left hemisphere controls movement on the right side of the body

Question 66

What does contralateral mean?

Answer 66

Where an area/function of the brain is cross wired, so that an area on one side of the body has an effect on the opposite side eg. left hemisphere controls movement on the right side

Question 67

What does ipsilateral mean?

Answer 67

Where an area/function of the brain has an effect on the same side of the body

Question 68

What is the purpose of the way vision is organised in the brain?

Answer 68

Visual areas can compare the slightly different perspectives from each eye, which aids depth perception

Question 69

What is split-brain research?

Answer 69

A split brain operation means severing the connection between the Right and Left hemispheres through a corpus callosotomy. It is often done to treat epilepsy
Split brain research studies how hemispheres function when they can’t communicate with eachother - it studies the lateral functions of the brain in isolation

Question 70

What was the aim and procedure of Sperry (1968)?

Answer 70

To investigate the effects of a corpus callosotomy ie. having a split brain on how the brain deals with certain tasks.
11 people who had undergone a split brain operation were studied
Sperry projected an image on a computer screen which would either be seen by the participants right visual field and be processed by the left hemisphere, or be seen by the left visual field and be processed by the right hemisphere

Question 71

What were the findings of Sperry (1968)?

Answer 71

. When a picture of an object was shown to the participants right visual field, they could describe what was seen.
. However when it was shown to the left visual field, they said there was nothing there. However they could select a matching object out of sight using their left hand. This is because in a split brain messages from the right hemisphere can’t be relayed to the language centres in the left hemisphere#
. Shows that certain functions are lateralised in the brain and supports the view that the left hemisphere plays a greater role in language, while the right hemisphere is more silent but emotional

Question 72

What is a strength of lateralisation - research support?

Answer 72

. RESEARCH SUPPORT, DEMONSTRATING THAT EVEN IN CONNECTED BRAINS, THE TWO HEMISPHERES PROCESS INFORMATION DIFFERENTLY - Fink et.al (1996) used PET scans to identify which brain areas were active during a visual processing task. When participants with connected brains were asked to attend to global elements of an image eg. looking at the picture of a whole forest, regions of the right hemisphere were more active. When required to look at finer details, the left hemisphere was more dominant. This suggests that in terms of visual processing - and perhaps in other areas - hemispheric lateralisation is a feature of the brain, whether it is a connected or split-brain.

Question 73

What is a limitation of lateralisation - conflicting research?

Answer 73

. THERE IS RESEARCH WHICH ARGUES AGAINST THE IDEA OF THE LEFT HEMISPHERE AS AN ANALYSER AND THE RIGHT HEMISPHERE AS A SYNTHESISER - While there may be different functions of the right and left hemisphere, research suggests that people don’t have a dominant side of the brain which dictates personality. Nielsen et.al (2013) analysed over 1000 brain scans from people aged 7-29, and found that while people did use different hemispheres for different tasks, there was no evidence for a dominant side. This suggests that the notion of a ‘right brained’ or ‘left brained’ person is wrong

Question 74

What is a strength of split brain research - research support?

Answer 74

Gazzaniga demonstrated that split-brain participants performed better than their connected counterparts on certain tasks eg. they were faster at identifying the ‘odd one out’ in a lineup of similar objects. It is believed that in the ‘normal brain’ the left hemispheres better cognitive strategies are weakened by the inferior right hemisphere (Kingstone et.al 1995)

Question 75

What is a strength of split brain research - within ethical guidelines?

Answer 75

The split brain operation wasn’t performed purely for the purpose of the research, so Sperry’s participants weren’t deliberately harmed, and the nature of the research was fully explained and informed consent was obtained.

Question 76

What is a limitation of split brain research - difficult to establish causal relationships?

Answer 76

Sperry’s split brain participants were compared to a control group of connected brain individuals - however none of the control group had epilepsy. This serves as a major confounding variable, as any differences observed between the groups may be a result of epilepsy rather than having a split brain. This calls the internal validity of the findings into question.

Question 77

What is plasticity?

Answer 77

The brains ability to change and adapt as a result of new experience and new learning throughout life. This generally involves the growth of new connections

Question 78

What did Maguire et.al (2000) find about plasticity in London cab drivers?

Answer 78

He compared London cab drivers to bus drivers. Bus drivers have to learn specific, repeated routes, while cab drivers have to know different routes in a general area and select the best one depending on that days conditions. Maguire et.al found that cab drivers had more grey matter in the hippocampus, indicating that their brains had changed as a result of their job

Question 79

What did Draganski et.al (2006) find about plasticity in medical students in the exam period?

Answer 79

Brain images were taken from medical students 3 months before their final exams, and after. Learning induced changes were seen to have occurred in the hippocampus and parietal cortex

Question 80

What is functional recovery?

Answer 80

A form of neural plasticity which occurs after damage is caused by trauma to the brain. The brain redistributes and transfers the functions normally peformed by the damaged area to other healthy areas.
Neuroscientists suggest this happens quickly after trauma (spontaneous recovery) before slowing down in later weeks/months where the individual may need rehabilitative therapy

Question 81

What structural changes happen in the brain during functional recovery?

Answer 81

. The brain reorganises itself by forming new synaptic connections close to the area of damage
. Secondary neural pathways that would not normally be used to carry out certain functions are activated or ‘unmasked’ to enable functioning to continue. This process is supported structurally by:
. Axonal sprouting - The growth of new nerve endings which connect to other undamaged nerve cells to form new neuronal pathways
. Denervation supersensitivity - Where axons that normally do a similar job become aroused to a higher level in order to compensate for lost ones. However it can cause oversensitivity to messages such as pain
. Recruitment of homologous areas on the opposite side of the brain - Allows specific tasks to still be performed by using the corresponding area eg. Broca’s area on the left is damaged, so the right side equivalent carries out it’s functions. After a period of time functionality may switch back to the left side

Question 82

What is a strength of plasticity - research support for lifelong ability?

Answer 82

Research suggests that plasticity may be a lifelong ability. Generally speaking, plasticity reduces with age. However Bezzola et.al (2012) found that 40 hours of golf training produced changes in the neural representation of movement in participants aged 40-60. Researchers observed increased motor cortex activity in the novice golfers when compared to a control group, suggesting that neural representations were more efficient after training. This supports the idea that plasticity continues throughout life.

Question 83

What is a limitation of plasticity - behavioural consequences?

Answer 83

Evidence suggests that the brain adapting to prolonged drug use actually results in poorer cognitive functioning later in life, as well as an increased risk of dementia (Medina et.al 2007). Furthermore, 60-80% of amputees experience ‘phantom limb’ syndrome, where they continue to experience sensations as though their limb was still there - this often leads to pain and discomfort. This is thought to be due to cortical reorganisation in the somatosensory cortex. This suggests that the brains ability to adapt to damage isn’t always beneficial.

Question 84

What is a strength of functional recovery - real world application?

Answer 84

Understanding processes involved in plasticity has contributed to the field of neurorehabilitation - simply understanding that axonal growth is possible encourages new therapies eg. constraint induced movement therapy in treating stroke patients. This shows that research into functional recovery is beneficial as it can help professionals in situations where medical intervention is required

Question 85

What is a limitation of functional recovery - individual differences?

Answer 85

Recent research suggests that levels of education may affect recovery rates. Schneider et.al (2014) revealed that the more time people with a brain injury had spent in education, the greater their chances of a disability free recovery, with around 40% of those who achieved this having been in education for more than 16 years vs 10% of those who had less than 12 years of education. These findings imply that recovery from brain damage is limited by levels of education. This serves as a limitation for the theory of functional recovery as we can’t be certain that all brains have the capacity to recover in the same way, so the idea has limited generalisability.

Question 86

What are the 4 different ways of studying the brain?

Answer 86

. Functional magnetic resonance imaging (fMRI)
. Electroencephalogram (EEG)
. Event related potentials (ERP’s)
. Post-mortem examinations

Question 87

What is functional Magnetic Resonance Imaging?

Answer 87

. Detects changes in blood oxygenation and blood flow that occurs as a result of brain activity - when a specific area of the brain is active, it consumes more oxygen so a greater blood flow is necessary
. It produces 3 dimensional images and can be used to show which parts of the brain are active when different tasks are being performed - useful for localisation of function

Question 88

What is an Electroencephalogram?

Answer 88

. Measures electrical activity in the brain via electrodes which are fixed to an individuals scalp using a skull cap
. The scan recording represents brainwave patterns that are generated from the action of thousands of neurons which are picked up by electrodes
. EEG is often used in diagnosing arrhythmic patterns of activities which can indicate neurological disorders eg. epilepsy
. Participants are normally studies in states of arousal or sleep - aren’t asked to do anything

Question 89

What are Event Related Potentials?

Answer 89

. Isolate neural responses associated with specific sensory, motor and cognitive events
. An EEG is given at first, which measures a more general picture of brain activity, then electrical activity is picked out with a statistical averaging technique
. The remaining data is referred to as ERP’s and can be categorised as either sensory or cognitive ERP’s
- Sensory - early waves immediately after exposure
- Cognitive - later waves from when the patient has had a chance to mentally process the stimulus

Question 90

What is a post-mortem examination?

Answer 90

. Involves the analysis of a persons brain after their death
. Brain of the deceased person is dissected in order to find neural reasons for behaviours ( the individual usually would have displayed unusual behaviours or have had a rare condition )
. Areas of damage are examined and may be compared to a neurotypical brain to assess the extent of damage

Question 91

What are some strengths of fMRI? (2)

Answer 91

. NON-INVASIVE - fMRI scans don’t rely on the use of radiation, and if administered correctly it is virtually risk free and straightforward to use
. HIGH SPATIAL RESOLUTION - fMRI scans can depict details by the millimeter, so the image produced is a clear picture of brain activity and how it is localised

Question 92

What are some limitations of fMRI? (2)

Answer 92

. EXPENSIVE - Especially when compared to other neuroimaging techniques, which could make it impractical in research as psychologists might not be able to afford the cost of using an fMRI machine
. POOR TEMPORAL RESOLUTION - There is around a 5 second delay between neural activity firing and this activity being presented, so fMRI might not truly present moment to moment brain activity

Question 93

What are some strengths of EEG? (3)

Answer 93

. USEFUL IN AREAS OF PSYCHOLOGY - Has been useful in studying the stages of sleep and in diagnosing conditions such as epilepsy - real world benefit
. HIGH TEMPORAL RESOLUTION - Modern EEG technology can detect brain activity at a resolution of a single millisecond
. CHEAPER THAN OTHER BRAIN SCANNING TECHNIQUES

Question 94

What are some limitations of EEG? (2)

Answer 94

. ONLY PROVIDES A GENERALISED PICTURE - Electrical activity is often detected simultaneously across several regions of the brain, making it difficult to pinpoint the exact areas of the brain responsible for a particular activity
. POOR SPATIAL RESOLUTION - EEG’s are unable to produce an image of deeper areas of the brain - they can only pick up on activity in it’s outer regions

Question 95

What are some strengths of ERP’s? (2)

Answer 95

. HIGH TEMPORAL RESOLUTION (especially when compared to fMRI) - Brain activity is first measured using an EEG, so is detected at high speeds. This makes them valuable in studying cognitive functions such as working memory
. COST EFFECTIVE - They are less expensive than some other forms of brain scanning techniques

Question 96

What are some limitations of ERP’s? (3)

Answer 96

. LACK OF STANDARDISATION - Lack of standardisation in ERP methodology between different studies, making it difficult to replicate and confirm findings
. CONCERNS OVER THE ACCURACY OF DATA PRODUCED - In order to establish pure data in ERP studies, ‘background’ electrical activity and extraneous material must first be removed. However doing so may reduce the accuracy of data provided
. POOR SPATIAL RESOLUTION - ERP’s are unable to produce an image of deeper areas of the brain and instead can only pick up on electrical activity in the outer regions

Question 97

What are some strengths of post-mortems? (2)

Answer 97

. HAVE BEEN USEFUL IN STUDYING LANGUAGE CENTRES - Post-mortems have been vital in early understanding of key processes and structures in the brain eg. the case of ‘Tan’ - Broca and Wernicke both relied on post mortems to make links between language, brain and behaviour - these were studied decades before neuroimaging was a possibility
. MORE IN DEPTH IMAGE OF THE BRAIN PROVIDED - Post mortems allow a researcher to study the structure of the brain, rather than just seeing an image of it

Question 98

What are some limitations of post-mortems? (3)

Answer 98

. DIFFUCULT TO ESTABLISH CAUSE AND EFFECT - As the subject is deceased, researchers can’t manipulate variables to establish cause and effect. This means they can’t be sure that observed damage to the brain is actually linked to what is being studied - it may be due to unrelated trauma
. ETHICAL CONCERNS - Participants may be unable to provide informed consent, eg. in the case of HM who was not mentally able to give consent for the use of his brain
. IMPRACTICAL - There is not an endless supply of brains that have been donated to medical science to use

Question 99

What are biological rhythms?

Answer 99

Distinct patterns of change in body activity that conform to cyclical time periods. They are governed by internal body clocks (endogenous pacemakers) and external changes to the environment (exogenous zeitgebers)

Question 100

What are the different kinds of biological rhythms?

Answer 100

. Circadian rhythms - Cycles which last around 24 hours eg. the sleep/wake cycle, body temperature

. Infradian rhythms - Cycles which last longer than 24 hours. They can last weeks, months or even years eg. the female menstrual cycle which averages a 28 day cycle, or Seasonal Affective Disorder (SAD)

. Ultradian rhythms - Cycles which last less than 24 hours eg. the stages of sleep.

Question 101

What affects circadian rhythms?

Answer 101

. It is suggested that both internal (endogenous pacemakers) and external (exogenous zeitgebers) factors influence circadian rhythms.
. Exogenous Zeitgebers - The fact that we feel drowsy at night time and awake/alert during the day demonstrates the effect of daylight, which is an important EZ, on the sleep/wake cycle
. Endogenous pacemakers - The Suprachiasmatic Nucleus (SCN) also regulates the sleep/wake cycle. This lies just above the optic chasm and receives information about light directly from this structure.
. Light (an exogenous zeitgeber) can reset the Suprachiasmatic nucleus

Question 102

What are some examples of research about circadian rhythms?

Answer 102

. Michel Siffre
. Folkard et.al (1985)
. Aschoff and Wever (1976)

Question 103

What was Siffre’s research into Circadian rhythms?

Answer 103

Siffre spent 2 months in a cave in Texas. He was removed from all natural light and temperature changes, using artificial light instead. His sleep/wake cycle was initially erratic, but settled into a 25 hour rhythm - just above the normal 24 hours. This indicates that the sleep/wake cycle may be naturally longer than 24 hours, but external cues such as light affect and shorten it.

Question 104

What was Folkard et.al’s (1985) research into Circadian rhythms?

Answer 104

Studied a group of 12 people who agreed to live in a dark cave for 3 weeks, going to bed when a clock said 11.45 pm and rising when it said 7.45 am. During the study, researchers gradually sped up the clock so a day that appeared to be 24 hours was actually 22 hours. Only one participant adjusted comfortably to the new regime, supporting the idea of a strong free running circadian rhythm which is not easily overridden by changes in the external environment

Question 105

What was Aschoff and Wever’s (1976) research into Circadian rhythms?

Answer 105

Studied a group of participants 4 weeks in a WW2 bunker deprived of natural light. Only one participant had an extended sleep/wake cycle (29 hours) - all the rest displayed a sleep/wake cycle between 24 and 25 hours. This suggests that the natural sleep/wake cycle may be longer than 24 hours but is limited by exogenous zeitgebers - links to Siffre

Question 106

Describe research on body temperature

Answer 106

. Body temperature is another example of a circadian rhythm - it varies during the day, at it’s lowest (36 degrees) at 4am and its highest (38 degrees) at 6pm
. Folkard et.al (1977) provided evidence to support the idea that there is a link between higher body temperature and improved cognitive performance. He found that children who had stories read to them at 3pm showed superior recall to those who had stories read to them at 9pm after a week.
. Gupta (1991) found improved performance on IQ tests when participants were assessed at 7pm, as opposed to 2pm and 9am

Question 107

What are some strengths of circadian rhythms - useful real world implications?

Answer 107

Research into circadian rhythms has been used to improve medical treatments, particularly in the field of chronotheraputics. It also provides a greater understanding of the effects of desynchronisation. For example, Boivin et.al (1996) found that night shift workers engaged in shift work experienced a period of reduced concentration around 6 in the morning (referred to as a circadian trough) making mistakes and accidents more likely. Also, Knutsson (2003) found a positive correlation between shift work and increased risk of heart disease. These studies show how research into circadian rhythms has bettered our understanding of their impact on human health and behaviour. They also have real world economic implications, with some companies paying employees more for nightshifts due to their health impacts

Question 108

What is a counterpoint to the useful implications argument (circadian rhythms)

Answer 108

However research into the effects of shift work tend to use correlational methods, making it difficult to establish a cause and effect relationship between the desynchronisation of the sleep/wake cycle and negative effects. Solomon (1993) suggested that other factors may be responsible - for example, high divorce rates in shift workers may be due to the strain of sleep deprivation and missing out on important family events. So it may not be biological factors alone creating the adverse consequences associated with shift work

Question 109

What is a limitation of circadian rhythms - individual differences?

Answer 109

Studies into circadian rhythms, such as Siffre or Aschoff and Wever are based on single individuals, or a small group of participants. However there are individual differences in sleep/wake cycles from person to person - Duffy et.al (2001) stated that some people had a natural inclination for going to bed early and rising early (referred to as ‘larks) while others preferred sleeping and rising late (‘owls’). Even Siffre later observed that his sleep/wake cycle had slowed with age. The existence of individual differences only further reduces the value of studies in terms of their generalisability, which naturally exist with case or small scale studies. Data produced is arguably meaningless.

Question 110

What are Infradian rhythms, and what affects them?

Answer 110

A type of biological rhythm which has a frequency of less than one cycle in 24 hours - takes more than 24 hours to complete. Commonly studied Infradian rhythms include the Menstrual cycle and Seasonal Affective disorder.
. The Menstrual Cycle - The 28 day cycle where a woman’s womb lining thickens to prepare for pregnancy and is shed if fertilisation doesn’t occur. It is an endogenous process - governed by hormones such as oestrogen and progesterone, however it may be influenced by some exogenous factors eg. other women
. Seasonal Affective Disorder (SAD) - A depressive disorder which has a seasonal pattern of onset. It is most common in the winter months when daylight hours are shorter. It’s main symptoms include a persistent low mood, lack of interest in life and activities.

Question 111

What exogenous factors can influence the menstrual cycle?

Answer 111

The Menstrual cycle can be influenced by proximity to other menstruating women.
Stern and McClintock (1998) showed how menstrual cycles may synchronise as a result of pheromones - studied 29 women with a history of irregular periods, gathering armpit samples of pheromones from 9 of the women at different stages of their cycle. The samples were then given to the other participants - pheromones taken on day 1 from the subjects cycle given on day 1 and so on - 68% of the women experienced changes to their cycle which brought them closer to the cycle of their ‘odor donor’

Question 112

What factors are thought to cause Seasonal Affective Disorder (SAD)?

Answer 112

Scientists theorise that the hormone melatonin is implicated in the cause of SAD, as during the night melatonin is secreted by the pineal gland, and a a lack of light in the mornings during winter months means melatonin is secreted for longer, which is thought to have a knock on effect on the production of serotonin, which is linked to the onset of depressive symptoms

Question 113

What are some strengths of Infradian rhythms - supported by evolutionary principles?

Answer 113

According to Stern and McClintock’s research, menstrual cycles often sync. This is theorised to have been used advantageously by our distant ancestors to allow women to be pregnant at the same time, meaning babies who had lost their mothers could have access to breast milk. Modern women therefore subconsciously sync with others to increase their babies chance of survival. This supports the idea that Infradian rhythms are influenced by our biology

Question 114

What are some limitations of Infradian rhythms - methodological shortcomings in research?

Answer 114

Environmental factors can affect the menstrual cycle, such as stress, changes in diet, exercise etc.. These may act as confounding variables, so patterns of synchronisation such as those found by Stern and McClintock could simply be due to chance. This could explain why other studies have failed to replicate the findings. The existence of these methodological shortcomings limits the reliability of research into Infradian rhythms.

Question 115

What are Ultradian rhythms and what affects them?

Answer 115

A type of biological rhythm with a frequency of more than one cycle in 24 hours - cycles last less than 24 hours. A commonly studied type of Ultradian rhythm is the stages of sleep. Psychologists have identified 5 stages of sleep spanning around 90 minutes, which continues throughout the course of the night. Each stage is characterised by a different level of brainwave activity. These can be measured by an EEG (electroencephalograms).

Question 116

What are the different stages of sleep?

Answer 116

– Stage 1 and 2 - Light sleep - brain waves are alpha waves with a high frequency and short amplitude (stage 1) this continues in stage 2 but there may be random patterns in activity called sleep spindles
– Stage 3 and 4 - Deep sleep/Slow wave sleep where it is difficult to wake someone, and some dreams may be experienced - brain waves are delta waves with lower frequency and higher amplitude
– Stage 5 - REM sleep (rapid eye movement) - the body is paralysed, but brain activity is similar as to when awake. Brain waves are theta waves (looks similar to stage 1 but with a slightly lower frequency) . Dreams normally occur in this stage

Question 117

What is a strength of Ultradian rhythms - positive implications?

Answer 117

Sleep scientists have observed that slow wave sleep reduces with age - growth hormone is mostly produced in this stage, so is reduced in older people. Van Cauter et.al (2000) said that the resulting sleep deficit may explain reduced alertness in old people. In order to increase slow wave sleep, medication and relaxation may be used. This suggests that research into Ultradian rhythms has practical value, with the potential to improve the lives of elderly people.

Question 118

What is a strength of Ultradian rhythms - research conducted in controlled environments?

Answer 118

Research into the stages of sleep frequently involves the use of EEG’s (electroencephelograms) so is often conducted in a lab setting. This allows for the control of extraneous variables eg. noise, which could affect sleep. As such, the internal validity of the studies is increased.
— However these lab studies are connected to complex machinery, which could lead to participants sleeping in a way that is different to normal. This could limit the internal validity of findings.

Question 119

What is a limitation of Ultradian rhythms - individual differences?

Answer 119

Key areas of research, such as into the stages of sleep, arguably have too many individual differences to account for. Tucker et.al (2007) found large differences between participants in terms of the length of each stage of sleep, particular stages 3 and 4, and suggested that the biological factors that differ from person to person may explain their different cycles. This limits research into the stages of sleep, and by extension into ultradian rhythms, as it is difficult to describe the cycle in a meaningful way, as findings cannot be generalised to the wider population.

Question 120

What are Endogenous Pacemakers?

Answer 120

Internal body clocks that regulate many of our biological rhythms eg. the suprachiasmatic nucleus on the sleep wake cycle - internal factors

Question 121

What is the Suprachiasmatic Nucleus?

Answer 121

SCN
- A small bundle of nerve cells located in the hypothalamus in each hemisphere of the brain
- One of the primary endogenous pacemakers in mammalian species, and the human bodies main EP
- Influential in regulating circadian rhythms eg. the sleep wake cycle - Nerve fibers connected to the eye meet in the optic chasm and travel to the left and right visual areas of the cerebral cortex. The SCN is just above the optic chasm and receives information about light from it, enabling our biological clocks to adjust to information about daylight patterns, even when we are asleep

Question 122

Describe research on the Suprachiasmatic Nucleus

Answer 122

. DeCoursey et.al (2000) - destroyed the SCN connections in 30 chipmunks, who were then returned to their natural environment and observed for 80 days. The sleep/wake cycle of the chipmunks disappeared, and by the end of the study a significant number had been killed by predators
. Ralph et.al (1990) - Bred ‘mutant’ hamsters with a 20 hour sleep/wake cycle. When SCN cells were transferred from foetal tissue of the mutant hamsters to normal hamsters, the cycles of the second group defaulted to 20 hours

Question 123

What role does the Pineal Gland play?

Answer 123

The Pineal Gland is an endogenous mechanism. It’s part of the endocrine system, found in the brain behind the hypothalamus, which produces melatonin. The Suprachiasmatic Nucleus passes information about light and day length to the pineal gland, which then increases or decreases melatonin production in accordance. If it is dark, the pineal gland increases melatonin production, inducing sleep. If it is light, the pineal gland decreases melatonin production, leading to us feeling more alert and awake.

Question 124

What are some strengths of Endogenous Pacemakers?

Answer 124

. Can refer to earlier studies as research support making the theories more reliable eg. Siffre

Question 125

What is a limitation of Endogenous Pacemakers - research ignores other body clocks?

Answer 125

. RESEARCH INTO THE SUPRACHIASMATIC NUCLEUS MAY OBSCURE OTHER BODY CLOCKS - Research has shown that there are multiple body clocks (known as peripheral oscillators) in different organs and cells such as the lungs, liver, skin, pancreas etc.. They are influenced by the SCN, but act independently. Damiola et.al (2000) showed how changing the feeding patterns of mice altered the circadian rhythms of liver cells, but left the rhythm of the SCN unaffected. This suggests that there may be other complex influences on the sleep/wake cycle other than the SCN, but this is largely ignored due to the emphasis placed on the SCN

Question 126

What is a limitation of Endogenous Pacemakers - ethical concerns?

Answer 126

THERE ARE ETHICAL CONCERNS ATTACHED TO RESEARCH INTO ENDOGENOUS PACEMAKERS - For example, DeCoursey et.al (2000) and their research on chipmunks resulted in many of the subjects being killed by predators due to their altered sleep/wake cycle. While animal studies such as this are justified because of the similarities in brain mechanisms across species allows for greater understanding of human behaviour, the fact that chipmunks’ brains are similar enough to humans’ for generalisations to be made makes the research even more immoral, as their suffering may have been human-like. Arguably then, the ethical concerns could be considered to be in violation of ethical guidelines, such as maximising benefit and minimising harm - a greater threat was created by the study than would have been found in real life.

Question 127

What are Exogenous Zeitgebers?

Answer 127

External/environmental factors which affect or entrain our biological rhythms, such as the influence of light on the sleep/wake cycle, or social cues eg. mealtimes

Question 128

How is light an example of an Exogenous Zeitgeber?

Answer 128

Light is a key zeitgeber - it can reset the SCN, so plays a key role in the sleep/wake cycle. It also has an indirect influence on processes such as hormone secretion and blood circulation

Question 129

What was Campbell and Murphy’s study (1998)?

Answer 129

Campbell and Murphy demonstrated that light may be detected by skin receptor sites on the body, even when it is not detected by the eyes
15 participants were woken at various times and a light pad was shone on the back of their knees
The researchers produced a deviation in the participants usual sleep/wake cycle - up to 3 hours in some cases
This suggests that light is a powerful exogenous zeitgeber and that it doesn’t necessarily need to rely on the eyes to have an effect

Question 130

How are social cues an example of Exogenous Zeitgebers?

Answer 130

Social cues such as mealtimes and bedtimes can alter circadian rhythms
Where newborn babies have irregular sleep/wake schedules, by 16 weeks their circadian rhythms have been entrained by the schedules imposed by parents such as adult determined mealtimes and regular bedtimes
Research on jet lag has suggested that adapting to local times for sleeping and eating, rather than responding to your own feelings of hunger and fatigue, is effective in entraining circadian rhythms and beating jetlag - Klein and Wegmann (1974) studied jetlag and found that adjustment to a new time zone happened faster when people spent more time outside - interacting with the society and social cues of their area

Question 131

What is a strength of Exogenous Zeitgebers - research support?

Answer 131

Evidence suggests that people have poorer quality of sleep as they get older. This may be due to natural changes in circadian rhythms as we age, with older people typically falling asleep earlier and having broken sleep at night (Duffy et.al 2015). However some studies suggest that exogenous factors may be more responsible for changes in sleep patterns as we age. Hood et.al (2004) found that management of insomnia was improved if elderly people were more active and had more exposure to natural light. This strengthens the idea that exogenous zeitgebers do have a significant impact on biological rhythms.

Question 132

What is a limitation of Exogenous Zeitgebers - influence may be overstated?

Answer 132

Exogenous zeitgebers do not have the same effect in all environments. People who live in the arctic region eg. the Inuit’s of Greenland show regular sleep patterns all year round, despite the fact that the sun doesn’t set in the summer months in these regions - so prolonged exposure to light doesn’t appear to have a significant impact. Similarly, Miles et.al (1977) looked at the case study of a man who was blind from birth and had an irregular circadian rhythm of 24.9 hours. His sleep/wake cycle couldn’t adjust to social cues eg. regular mealtimes, so he had to take sedatives and stimulants in order to align with the 24 hour world. This suggests that exogenous zeitgebers alone can’t account for rhythms, and that endogenous pacemakers may be more significant.
.

Question 133

What is an overall limitation for Endogenous Pacemakers and Exogenous Zeitgebers - not exclusive?

Answer 133

. ENDONGENOUS PACEMAKERS AND EXOGENOUS ZEITGEBERS INTERACT IN REAL LIFE - Only in exceptional circumstances do endogenous pacemakers run unaffected by exogenous zeitgebers - for example the impact of the Suprachiasmatic Nucleus (an EP) is directly related to light (an EZ). Total isolation cases such as Michel Siffre’s are extremely rare, and present an unrealistic example of circadian rhythms. If Endogenous Pacemakers and Exogenous Zeitgebers interact in real life, it makes little sense to separate them for research purposes, and doing so limits the external validity of the theories.