BIOPSYCHOLOGY Flashcards
(114 cards)
1
Q
What is the nervous system
A
Specialised network of neurons in the human body and is our primary internal communication system i.e., it allows the brain, spinal cord and rest of the body to communicate.
2
Q
What are the 2 main functions of the nervous system?
A
To collect, process and respond to information in the environment
To coordinate the working of different organs and cells in the body
3
Q
What are the two sub-systems of the nervous system
A
the CNS (controls behaviour and regulates physiological processes) and the PNS (all other processes)
4
Q
What are the two sub-systems of the CNS
A
The brain and the spinal cord
5
Q
What are the two sub-systems of the PNS
A
The Autonomic and the somatic nervous system
6
Q
What are the two subsystems of the autonomic nervous system
A
The sympathetic and the parasympathetic nervous system
7
Q
What is the role of the brain in the CNS
A
Centre of all conscious awareness. The brain’s outer later is highly developed in humans and is what distinguishes our higher mental functions.
8
Q
What is the role of the spinal cord in the CNS
A
Relays information between the brain and the rest of the body. It allows the brain to monitor and regulate bodily processes e.g., digestion and breathing and to control voluntary movement.
9
Q
Outline the role of the somatic nervous system
A
Made up of sensory and motor neurons.
Sensory neurons receive information from the sensory receptors and relay these messages to the CNS.
Motor neurons relay messages from the CNS to other areas of the body, and so control voluntary muscle movement.
The somatic nervous system is also involved in reflex actions, which allows the reflex to occur very quickly.
10
Q
Outline the role of the autonomic nervous system
A
Governs the internal organs and glands of vital functions without conscious awareness. Involuntary actions are regulated by the ANS. It is necessary because without it, vital bodily processes would not work as efficiently.
Made up of motor neurons only
11
Q
Outline the role of the sympathetic nervous system
A
Primarily involved in responses that help us deal with emergencies
It responds to a perceived threat
Neurons from the SNS travel to virtually every organ and gland within the body to produce physiological changes that prepare the body for fight or flight
E.g., pupils dilate, causes the body to release stored energy, heart rate and breathing increase, non-vital functions are inhibited e.g., digestion and urination
12
Q
Outline the role of the parasympathetic nervous system
A
Restores normal physiological functioning when the threat has passed e.g., heart rate and breathing slow down, blood pressure is reduced, digestion begins
Because the PNS is involved with energy conservation and digestion, it is sometimes referred to as the body’s rest and digest system.
13
Q
What are neurons?
A
Cells of the nervous system that produce and transmit messages through electrical and chemical signals.
They are specialised cells whose function is to move electrical impulses to and from the CNS (action potentials)
When neurons are in a resting state, the inside of the cell is negatively charged compared to the outside
When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing an action potential to occur. This causes the electrical impulse to travel down the axon towards the end of the neuron.
14
Q
Outline the structure and function of a sensory neuron
A
Carry nerve impulses to the spinal cord and brain
They are characterised by short dendrites and long axons
15
Q
Outline the structure and function of a relay neuron
A
They are found in between sensory input and motor output. They are found in the brain and spinal cord and allow sensory and motor neurons to communicate
They are characterised by short dendrites and short axons
16
Q
Outline the structure and function of a motor neuron
A
They are found in the CNS and control muscle movements. When motor neurons are stimulated, they release neurotransmitters that bind to the receptors on muscles to trigger a response, which lead to a movement.
They are characterised by short dendrites and long axons
17
Q
Outline the process of synaptic transmission
A
- When the action potential reaches the presynaptic terminal, it triggers the synaptic vesicles to release neurotransmitters into the synaptic gap
- Neurotransmitters diffuse across the synaptic gap between the pre and post-synaptic cells
- The neurotransmitters bind to the post-synaptic receptor sites on the membrane of the post-synaptic neuron’s dendrite
- This stimulation of the post-synaptic receptors converts the chemical message back to an electrical impulse and the process of transmission begins again in the post-synaptic neuron
- The effects are terminated by a process called reuptake. The neurotransmitters are taken up by the pre-synaptic neuron where they are again stores in synaptic vesicles ready for later release.
18
Q
Why can neurons only transmit information in one direction at the synapse?
A
- The synaptic vesicles containing the neurotransmitter are only present on the presynaptic membrane
- The receptors for the neurotransmitters are only present on the post synaptic membrane
- It is the binding of the neurotransmitter to the receptor which enables the signal/information to be passed onto the next neuron
- Diffusion of the neurotransmitters mean they can only go from high to low concentration, so can only travel from the presynaptic to the post synaptic membrane
19
Q
What is an excitatory neurotransmitter?
A
If a neurotransmitter is excitatory, this causes excitation of the post-synaptic membrane, and so the post-synaptic neuron is more likely to fire an electrical impulse
20
Q
What is an inhibitory neurotransmitter?
A
If the neurotransmitter is inhibitory, this causes inhibition of the post synaptic membrane, and so the post-synaptic neuron is less likely to fire an electrical impulse.
21
Q
Outline the process of summation
A
If the net effect on the post synaptic neuron is inhibitory, the neuron will be less likely to fire and if the net effect is excitatory, the neuron will be more likely to fire. Summation is when the excitatory and inhibitory influences are summed.
22
Q
What is the endocrine system?
A
One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream. These hormones are carried towards organs in the body. Communication is via chemicals.
23
Q
What is a hormone
A
Chemical messenger, trigger a response in target. Made from amino acids or derived lipids.
24
Q
How is the endocrine system regulated
A
Hormones (through the negative feedback process)
25
What are the two key roles of the pituitary gland
- Produces hormones that control the release of hormones from other glands
- Master gland that regulates many of the body's functions
26
What hormones are released from the pituitary gland
ACTH, FSH, LH and oxytocin
27
What do the hormones released from the pituitary gland do to effect behaviour
- In females, they stimulate the ovaries to produce oestrogen and progesterone. In males, it stimulates the testes to produce testosterone
- When released, it stimulates contraction of the womb in childbirth
- In response to stress, it stimulates the adrenal glands to release cortisol
28
Outline the role of the adrenal glands, as well as the hormones and their effect on behaviour
- Causes physiological changes associated with arousal and prepares the body for f/f
- Supports bodily functions
- Cortisol, adrenaline and noradrenaline
- Helps the body to respond to stressful situations
- Released in response to stress
29
Outline the role of the ovaries, as well as the hormones and their effect on behaviour
- Production of effs and female sex hormones
- Oestrogen and progesterone
- Associated with increased sensitivity to social cues
- Female reproductive function
30
Outline the role of the testes, as well as the hormones and their effect on behaviour
- Produce sperm and male sex hormones
- Testosterone
- Important for sex drive, sperm production and muscle strength, and is associated with general health and well-being in men
- The development of male characteristics such as facial hair, deepening of the voice, and growth spurts.
31
Give a definition of the fight/flight response
When we experience a threatening or stressful situation, out bodies react in specific ways e.g., our heart beats faster, our breathing becomes more rapid and our muscles tense. These reactions to stressful situations are known as the f/f response. They occur when the body prepares itself for defending/attacking (fight) or running away (flight).
32
Where does the f/f response take place?
- The hypothalamus
- The adrenal medulla
- The sympathetic nervous system
33
Give the 8 step process of the f/f response
1. Threat/stressor is perceived
2. Hypothalamus prepares the body for action by triggering the sympathetic NS
3. Body switches from parasympathetic to sympathetic state
4. This begins the process of preparing for the rapid action necessary for f/f
5. Sympathetic NS sends a signal to the adrenal medulla
6. This prepares the body for f/f
7. Parasympathetic NS is activated
8. Body returns to its resting state
34
Give some examples of how the body prepares the body for f/f
- Heart rate, respiration and sweating increase
- Oxygen to support skeletal muscles and the brain increase
- Blood vessels are constricted, blood is diverted away from the skin
- Kidneys and digestive system and glucose and fats are released
35
Give some examples about how the body returns to its resting state in the f/f response
- Heart rate and blood pressure are reduced
- Digestion begins again
36
Give a weakness of the f/f response (modern day stressors)
The physiological responses associated with f/f may be adaptive for a stress response that requires energetic behaviour. However, the stressors of modern life rarely require such physical activity. The problem for modern humans is when the stress response is repeatedly activated. The increased blood pressure can lead to physical damage to the blood vessels and eventually to heart disease. This suggests that the response may no longer be adaptive for stressors we face today.
37
Give a weakness about the f/f response (first phase of a reaction)
It has been suggested that the first phase of a reaction to a threat is not f/f, but it is instead to avoid confrontation. He suggests that before responding with attacking or running away, most animals typically display a 'freeze' response. This is essentially a 'stop, look and listen' response, where the animal is hyper-vigilant. This would have been adaptive for humans as it focuses attention and makes them look for new information in order to make the best response for the particular threat. Consequently, f/f may not be a complete explanation of our response to stress.
38
Give a piece of undermining evidence for the f/f response
Speisman et al asked students to watch a primitive and gruesome medical procedure on film whilst their heart rates were monitored. Beforehand, some ppts were told that the initiation rites were voluntary and joyful rite of passage (signalled manhood); others were told that the experience was traumatic and painful. They found that the heart rates of those in the first group actually decreased, but the heart rates of those in the second group increased. This suggests that humans aren't passive in the face of stressors or threats like the f/f response theory would assume. Cognitions are also important and therefore the theory is a limited explanation of our response to stress.
39
Define lateralisation
The idea that some functions are dominated by one hemisphere e.g., the left hemisphere controls language
40
What is the outer layer of both hemispheres called?
The cerebral cortex. Each hemisphere of the cerebral cortex is made up of 4 sections called lobes. Within each lobe there are distinct areas that are thought to have different specific functions (localisation).
41
Outline the theory of localisation of function
This is the theory that different areas of the brain are responsible for different behaviours, cognitive processes or activities and are associated with different parts of the body.
42
Outline the role of the motor cortex and what were to happen if there was damage to this area
- Responsible for the generation of voluntary motor movements. It is located in the frontal lobe, along the region known as the precentral gyrus.
- Both hemispheres of the brain have a motor cortex.
- Different parts of the motor cortex control different parts of the body. These parts are arranged logically next to one another
- DAMAGE: Loss of control over fine motor movements
43
Outline the role of the somatosensory cortex and what were to happen if there was damage to this area
- Region that processes input from sensory receptors in the body that are sensitive to touch.
- It is located in the parietal lobe, along a region known as the postcentral gyrus.
- Produces sensations of touch, pressure, pain and temperature, which it them localises to specific body regions.
- Both hemispheres have a somatosensory cortex
- The amount of somatosensory area devoted to a particular body part denotes its sensitivity
- DAMAGE: numbness or sometimes parathesia (tingling sensation in parts of the body)
44
Outline the role of visual centres and what were to happen if there was damage to this area
- The primary VC is located in the visual cortex, in the occipital lobe
- It receives and processes visual information
- Visual processing begins in the retina at the back of the eye, where light enters and strikes photoreceptors. Action potentials from the retina are then transmitted to the brain via the optic nerve. Most of the action potentials terminate in the thalamus.
- Spans both hemispheres
- DAMAGE: vision and perception problems, mostly blindness and visual hallucinations (seeing things that are not really there).
45
Outline the role of auditory centres and what were to happen if there was damage to this area
- Concerned with the analysis of speech based information
- Lies within the temporal lobes on both sides of the brain, where we find the auditory cortex
- The auditory pathway begins in the cochlea in the inner ear, where sound waves are converted to action potentials, which travel via the auditory cortex in the brain.
- DAMAGE: partial hearing loss, the more extensive the damage, the most extensive the loss
46
Outline the role of Broca's area and what were to happen if there was damage to this area
- Language centres are lateralised to the left hemisphere
- Located in the posterior portion of the frontal lobe of the left hemisphere
- DAMAGE: Broca's aphasia = can only talk in short, meaningful sentences which take great effort. Speech lacks fluency as there is a difficulty with words that help sentences to function
47
Outline the role of Wernicke's area and what were to happen if there was damage to this area
- Located in the posterior portion of the left temporal love
- DAMAGE: Wernicke's aphasia = can speak but can only understand language (such that the speech they produced was fluent but meaningless). They often pronounce neologisms as part of the content of their speech.
48
What to include in a 6 mark outline for localisation of function
1. Define localisation of function
2. There are specific areas of the brain that are localised + two examples
3. Some functions are more localised than others
4. Other functions seem more widely distributed
5. Localisation can involve restricted areas of cortex
49
Give a piece of supporting evidence for the theory of localisation of function (PG)
Phineas Gage survived a metre-length pole passing through his left cheek, left and and exiting his skull. The damage to his frontal lobe left a mark on his personality - he turned from a calm reserved person to someone who was quick-tempered and rude. This suggests that the frontal lobe may be responsible for regulating mood, supporting localisation theory.
50
Give a piece of undermining evidence for localisation of function (Lashley)
Lashley removed areas of the cortex (10-50%) in rats that were learning a maze. No area was proven to be more important than any other area in terms of the rat's ability to learn the maze. The process of learning appeared to require every part of the cortex, rather than being confined to one particular area. This seems to suggest that learning is too complex to be localised, and requires the involvement of the whole of the brain. Therefore, processes involved in learning may be distributed in a more holistic way in the brain.
51
Give a piece of supporting evidence for the localisation of function theory (Broca's studies)
Studies of people with Broca's aphasia have found an impaired ability to produce language, and in most cases this is caused by damage in Broca's area. People with Wernicke's aphasia have been found to have an impaired ability to understand language and is usually the result of damage in Wernicke's area. These studies support the importance of Broca's area in the production of language and Wernicke's area in the comprehension of language Therefore, they support that some components of the language system are localised.
52
Define hemispheric lateralisation
This is the idea that the two halves of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other
53
What is the corpus callosum + its role
- Thick bundle of nerves which connects the two hemispheres of the brain
- It allows the two sides of the brain to communicate with each other so that the whole brain can work as one complete organ
54
What does the left hemisphere control?
The right side of the body
Logical thinking
Analytical tasks
Right visual field
Speech
55
What does the right hemisphere control?
The left side of the body
Emotional content of language
Left visual field
Spatial awareness
Recognising faces
Creativity
56
Give an overview of Sperry and Gazziniga's research
- They studied 11 individuals who had undergone the same surgical procedure in which the corpus collosum was cut in order to control frequent and severe epileptic seizures.
- They were compared to a control group who had no history of epilepsy
57
Outline the procedure and findings of the 'Describing what you see' method in Sperry and Gazziniga's research
A picture was shown to either the LVF or the RVF and the ppt was asked to name the object.
If the object was shown to the RVF, it could be named easily - because it got sent to the LH (suggesting ppts can articulate an answer because the LH is responsible for language). If the picture was shown to the LVF, the ppt could not describe it and typically reported nothing being there
58
Outline the procedure and findings of the 'Recognition by touch' method in Sperry and Gazziniga's research
Objects were shown to the ppts LVF and they were asked to select a matching object from a bag using their left hand. Pts were sometimes asked to select a related object. The left hand was able to select a matching object and related object, but they couldn't describe the object. They could 'understand' the object and respond accordingly. This suggests that the left hemisphere is responsible for language, because ppts were not able to describe the object.
59
Give a strength of S and G's research (contribution)
S and G's work into the split-brain phenomenon has produced an impressive and sizeable body of research findings, with the main conclusion being that the LH is more geared towards analytical and verbal tasks, whilst the right is more adept at performing spatial tasks and music. This is a key contribution to our understanding of brain processes and can influence future treatments.
60
Give a strength of S and G's research (standardised)
Split-brain research made use of highly specialised and standardised procedures. The method of presenting visual information to one hemispheric field at a time was ingenious. The image projected would be flashed up for 1/10 of a second, meaning the split-brain would not have time to move their eye across the image and so spread the information across both sides of the VF. Therefore, the procedure developed was very useful and well controlled. Consequently, we can determine cause and effect from the research and so support the IV of the theory of HL.
61
Give a weakness for hemispheric lateralisation and split-brain research
The sample size was very small as there was only 11 who took part in all variations of the basic procedure, all of whom had a history of epileptic seizures. it has been argued that this may have caused unique changes in the brain that may have influenced the findings. The control group may have been inappropriate because they were people who had no history of epileptic seizures. This suggests that the research cannot be considered to be completely valid either internally or externally, and so we cannot confidently support the theory of hemispheric lateralisation from the split brain research.
62
Define plasticity
Plasticity describes the brain's tendency to change and adapt (functionally and structurally) as a result of experience (positive or negative), new learning or training.
63
How does plasticity change throught life?
Existing neural connections can change, or new neural connections can be formed as a result of learning and experience.
64
Why does functional plasticity reduce with age?
- The brain has a greater propensity for reorganisation in childhood as it is constantly adapting to new experiences and learning
- During infancy, the brain experiences a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 at 2-3 years.
65
Define synaptic pruning
As we age, rarely used connections are deleted and frequently used connections are strengthened.
66
What was the procedure and findings of Macquire et al's research
- They studied the brains of London taxi drivers.
- There was significantly more volume of grey matter in the posterior portion of the hippocampus of the taxi drivers compared to match controls
- This part of the brain is associated with the development of spatial and navigational skills in humans and other animals. The longer they had been in the job, the more pronounced the structural difference
67
What was the procedure and findings of Draganski's research
- They imaged the brains of medical students three months before and after their final exams
- There were changes in the posterior hippocampus and parietal cortex, presumably because of the exam
68
What is functional recovery after trauma?
- The brain's ability to redistribute/transfer functions usually performed by damaged areas to oether, undamaged areas
69
What sorts of traumas can lead to functional recovery?
Road accidents, strokes
70
Why is functional recovery easier when we are younger?
When the brain is still maturing, recovery from trauma is more likely because maturing brains are constantly adapting to new experiences and learning
71
In the brain, what happens to allow functional recovery?
- The transfer of functions to an undamaged area is known as neural reorganisation
- New neurons may grow and/or connections may grow to compensate for the damaged areas where neurons are lost. This is known as neural regeneration and can explain how people are able to recover from trauma.
72
How else does plasticity aid recovery?
Plasticity allows the brain to cope better with 'indirect' effects of brain damage e.g., swelling, haemorrhages that may occur after road accidents, effects of brain damage from inadequate blood supply following a stroke.
73
Give two pieces of supporting evidence for plasticity
- Macguire et al
- Draganski et al
74
Give a piece of undermining evidence for plasticity and functional recovery from trauma
Schneider et al found that patients with the equivalent of a college education are seven times more likely than those who didn't finish high school to be disability-free one year after a moderate to severe brain injury. This suggests that educational attainment may influence how well the brain functionally adapts after injury and therefore acts as a moderating factor meaning that we cannot see simple cause and effect.
75
Is fMRI a way of looking at structure or function?
Function (measures brain activity in regions of interest)
76
How does an fMRI work and what does it measure?
Measures blood flow in the brain when a person performs a task. fMRI works on the premise that neurons in the brain which are the most active (during a task), use the most energy. An fMRI creates a dynamic (moving) 3D map of the brain, highlighting which areas are involved in different neural activities.
77
Give two strengths of using fMRIs
(+) Non-invasive; does not use radiation or involve inserting instruments directly into the brain, and is therefore virtually risk free (so more people will do fMRIs).
(+) Good spatial resolution; greater SR allows psychologists to discriminate between different brain regions with greater accuracy. Psychologists can determine the activity of different brain regions with greater accuracy when using fMRI.
78
Give one weakness of using fMRIs
(-) Poor temporal resolution (1-4 seconds is worse than other techniques). Consequently, psychologists are unable to predict with a high degree of accuracy the onset of brain activity.
79
How do EEG's work and what results do they produce?
- They work on the premise that info is processed in the brain as electrical activity in the form of action potentials or nerve impulses, transmitted along neurons
- EEGs measure this activity through electrodes attached to the scalp.
- There are 4 types of EEG pattern
- EEGs can also be used to detect illnesses like epilepsy and sleep disorders, and to diagnose other disorders that affect brain activity, like Alzheimer's disease.
80
How do ERP's work and what results do they produce?
- Similar equipment to EEG
- Stimulus is presented to a ppt and the researcher looks for activity related to that stimulus
- The stimulus may be presented hundreds of times, and an average response is graphed
- This reduces any neural extraneous activity which makes the specific response to the stimulus stand out.
81
Give two advantages of EEGs and ERPs
(+) They are both relatively non-invasive. They do not use radiation or involve inserting instruments directly into the brain and are therefore virtually risk-free. This means that more patients will undertake EEGs/ERPs, which could help psychologists to gather further data on the functioning human brain and therefore develop our understanding of different psychological phenomena, such as sleeping and different disorders such as Alzheimer's.
(+) They have good temporal resolution: it takes readings every millisecond, meaning it can record the brain's activity in real time as opposed to looking at passive rain activity. This leads to an accurate measurement of electrical activity when undertaking a specific task.
82
Give a disadvantage of using EEG's/ERPs
(-) Poor spatial resolution (smallest feature that a scanner can detect). They caa only detect the activity in superficial regions of the brain. Consequently, EEGs and ERPs are unable to provide information on what is happening in the deeper regions of the brain, making this technique limited in comparison to the fMRI.
83
Outline post mortem examinations as a way of studying the brain
- Researchers will study the physical brain of a person who displayed a particular behaviour while alive that suggested possible brain damage
- E.g., Broca's study of Tan
- This has successfully contributed to the understanding of many disorders
- Post mortem studies allow for a more detailed examination of anatomical and neurochemical aspects of the brain than would be possible with other techniques.
84
Give two weaknesses for post-mortem examinations
(-) Issue of causation; the deficit of a patent displayed during a lifetime may not be linked to the deficits found in the brain. The deficits reported could have been the result of another illness, and therefore psychologists are unable to conclude that the deficit is caused by the damage found in the brain
(-) 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 (HM) who would be unable to provide fully informed consent, and yet a post-mortem examination has been conducted on his brain. This raises severe ethical questions surrounding the nature of such investigations.
85
Give one strength of using post-mortem examinations
(+) They 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, which other canning techniques cannot, and therefore provide researchers with an insight into these deeper brain regions, which often provide a useful basis for further research.
86
What are circadian rhythms?
A type of rhythms in which a pattern of behaviour occurs or recurs approximately every 24 hours. It is set and reset by environmental light levels.
87
What are the two examples of circadian rhythms we have to know about?
- Sleep-wake cycle
- Body temperature
88
What is the master circadian pacemaker, and where is it found?
- The suprachiasmatic nucleus (SCN)
-Hypothalamus
89
What happens in the morning according to the sleep wake cycle?
- Cells in the eye detect light and so messages are sent via the optic nerve to the SCN which sends messages to raise our body temperature and blood pressure, and delay the release of hormones like melatonin from the pineal gland.
- We have our sharpest rise in blood pressure, and there is a reduction in the secretion of melatonin causing us to feel awake
- We have our highest level of cortisol which makes us feel awake.
90
What happens in the evening according to the sleep-wake cycle?
- The SCN picks up changing signals of light from our eyes, and so it sends messages to ensure that our body temperature cools, and sleep inducing hormones like melatonin are released.
- Our body temperature begins to decrease and the secretion of melatonin increases, signalling that it is time to sleep/
91
When does our strongest sleep drive usuallly occur?
In two 'dips', between 2am and 4am as well as between 1pm and 3pm
92
How does homeostasis influence sleep and wakefulness?
When we have been awake for long periods of time, homeostasis tells us that the need for sleep is increasing because of the amount of energy 'used up' during wakefulness.
93
Why is the circadian rhythm intolerant to any major alterations?
This causes the biological clock to become completely out off balance
94
Give some supporting evidence for circadian rhythms
There is research which supports the existence of CR. Michael Siffre spent two months in the caves of the southern Alps deprived of light and sound, determining that his circadian rhythm, remained between 24-25 hours. This suggests that the body's internal clock is set 24-25 hours in the absence of external cues, and is intolerant of any major alterations to sleep and wake cycles, through processes such as shift work and jet lag. This is a strength as it shows that the concept has research support, and therefore may be valid.
95
Give a piece of real world application for circadian rhythms
Shift work has been found the lead to the desynchronization of CR and can lead to adverse cognitive and physiological effects. Research has shown that night shift workers suffer a concentration lapse at 6 am, increasing the likelihood of accidents, and shift workers are also three times more likely to suffer from heart disease as a result of the stress of adjusting to sleep/wake cycles. This is a strength of the research on circadian rhythms as it has many practical and economic implications, in terms of maintaining worker productivity and preventing accidents in the workplace.
96
Gives a disadvantage of the supporting evidence for circadian rhythms
In the cave studies, the exposure to artificial lights such as torches/phones was not controlled. It was assumed it was only natural light that has an influence on our biological rhythms. However, research by Czeisler found that dim artificial lighting could adjust the circadian rhythm between 22-28 hours. This is a weakness as it means that the results of the original studies may lack validity and the sleep-wake cycle may vary considerably more.
97
What is an ultradian rhythm?
A type of biological rhythm that lasts less than 24 hours.
98
What happens in the sleep cycle, and how is that an example of an ultradian rhythm?
5 distinct stages of sleep that altogether span 90-100 minutes. This is a cycle that repeats throughout the course of the night and therefore occurs more than once in every 24 hours. Each stage (5) is characterised by a different level of brainwave activity. As a person enters deep sleep, their brainwaves slow and their breathing and heart rate decreases. During the 5th stage (REM), the EEG pattern resembles that of an awake person and it is in the stage that most dreaming occurs.
99
What is the basic rest-activity cycle, and how is that an example of an ultradian rhythm?
That a similar 90-minute rhythm cycle continues during waking hours (BRAC). This is characterised by a period of alertness followed by a spell of psychological fatigue. This 90 minute cycle recurs throughout the course of the day.
100
What did Derment and Kleitman find out about dreaming and REM sleep?
Monitored the sleep patterns of 9 adult ppts in a sleep lab. Brainwave activity was recorded on an EEG and the researchers controlled for the effects of caffeine and alcohol. REM activity during sleep was highly correlated with the experience of dreaming and brain activity varied according to how vivid dreams were, and ppts woken during dreaming reported very accurate recall of their dream.
101
How do the Derment and Kleitman findings support ultradian rhythms (specifically, the stages of sleep)?
This suggests that REM sleep is an important component of the ultradian sleep cycle and that there are distinct stages of sleep. Replications of this investigation have noted similar findings, although the size of the original sample has been criticised.
102
What did Ericsson et al find out about elite violinists’ practise regime?
The best performers in a study of violists were those who tended to practise for three sessions during the course of the day. Each session lasted no more than 90 minutes, and there was a break between each in order to 'recharge'.
103
How do the Ericsson et al findings support ultradian rhythms (specifically, the basic rest-activity cycle)?
This consists with the claim that fatigue is a characteristic of the end of the BRAC cycle, which occurs in a roughly 90 minute cycle, and therefore supports theories behind ultradian rhythms.
104
What is an infradian rhythm?
A type of biological rhythm with a duration of over 24 hours
105
What happens in seasonal affective disorder, and how is that an example of an infradian rhythm?
Depressive disorder which has a seasonal pattern of onset and is described and diagnosed in the DSM-5. Symptoms include a persistent low mood with lack of motivation and activity. These symptoms are triggered during the winter months when the number of daylight hours becomes shorter. It is an infradian rhythm because it occurs less frequently than every 24 hours.
106
Explain the processes involved in the menstrual cycle, and how that makes the menstrual cycle an example of an infradian rhythm
The pituitary gland releases FSH and LH. This encourages eggs to grow and mature, and the follicles respond by releasing oestrogen. This inhibits the production of FSH and tells pituitary gland to release more LH. This causes the most mature egg cell to burst out of the follicle. Empty follicle releases progesterone to tell womb liming to plump up with blood and nutrients. If the egg doesn't embed, oestrogen and progesterone levels plummet. The womb lining degenerated, causing the period.
107
How is Stern and McClintock’s pheromones study both evidence for the menstrual cycle being endogenous (internal), and having an exogenous (external) influence?
Studied 29 women with irregular periods. Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit. The pads were treated with alcohol and frozen, to be rubbed onto the upper lip of the other 20 ppts. On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day 2 they were given a pad from the second day of the cycle etc. They found that 68% of women experienced changes to their menstrual cycle which brought them closer to the cycle of their 'odour donor'. Supports endogenous = only 68 experienced changes to their menstrual cycle, not 100%. Supports exogenous = menstrual cycle acts as an exogenous zeitgeber (via pheromones).
108
Why might it have been evolutionarily adaptive for females to be menstruating at the same time (showing this infradian rhythm may have evolved to have both endogenous and exogenous features in order to promote the species)?
It may have been advantageous for females to menstruate together and therefore fall pregnant at the same time, so that new-borns could be cared for collectively within a social group increasing the chances of the offspring's survival.
109
What is the counterargument to the above – i.e. that in some ways it is not evolutionarily advantageous for women to be menstruating (and therefore ovulating) at the same time (and thus it would not have evolutionary benefit for the menstrual cycle to have evolved to have both endogenous and exogenous features)?
The validity of this evolutionary perspective has been questioned. If there were too many females cycling together within a social group, this would produce competition for the highest quality males (and therefore lower the fitness of any potential offspring).
110
What is an endogenous pacemaker?
Internal body clocks that regulate many of our biological rhythms, such as the influence of the SCN and pineal gland on the sleep-wake cycle
111
What is an exogenous zeitgeber?
Cues in the environment e.g., the light cues of sunrise and sunset.
112
What does the De Coursey et al chipmunk study suggest about the strength of endogenous pacemakers in regulating body function and behaviour?
They destroyed the SCN connections in the brains of 30 chipmunks who were then returned to their natural habitat and observed for 80 days. The sleep-wake cycle of the chipmunks disappeared and by the end of the study, a significant proportion of them had been killed by predators. This supports the role of endogenous pacemakers because it shows how when the SCN connections are destroyed, there is no longer a biological clock present.
113
What does the Campbell and Murphy (light > back of knee) study suggest about the strength of exogenous zeitgebers in regulating body function and behaviour?
They demonstrated that light may be detected by skin receptor sites on the body even when the same information is not received by the eyes. 15 ppts were woken at various time and a light pad was shone on the back of the knees. The researchers managed to produce a deviation in the ppts usual sleep-wake cycle of up to 3 hours in some cases.
114
Most of the research on endogenous pacemakers and exogenous zeitgebers has involved attempting to isolate the influence of each. Why does doing this make little sense in real life?
In real life, pacemakers and zeitgebers interact, and it may make little sense to separate the two for the purpose of research.
