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Biopsychology Flashcards

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1
Q

What is the nervous system? (x3)

A
  • The body’s main communication system which is very fast acting
  • It is a complex network of specialised nerve cells which passes information around the body
  • It passes messages using electrical signals and chemicals using neurons and neurotransmitters
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2
Q

What is the central nervous system made up of?

A

Brain and spinal cord

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3
Q

What is the function of the central nervous system?

A

The brain is the centre of conscious awareness.

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4
Q

What is special about the brain?

A

The cerebral cortex (3mm outer layer) is highly developed in humans and distinguishes our higher mental functions from other animals.

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5
Q

What is the spinal cord? (x2)

A
  • An extension of the brain
  • It is responsible for reflex actions
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6
Q

What is the peripheral nervous system made up of?

A

Nerve fibres (axons) which are connected to the CNS.

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7
Q

What is the peripheral nervous system?

A

It sends information to the CNS from the outside world and transmits messages from the CNS to muscles and glands in the body.

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8
Q

What is the somatic nervous system? (x3)

A
  • It receives instructions from the CNS (motor cortex) for muscle movement
  • It controls conscious movement
  • It also transmits information from receptor cells in sense organs to the CNS
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9
Q

What is the somatic nervous system made up of?

A

Myelinated neurons

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10
Q

What is the autonomic nervous system? (x3)

A
  • Responsible for control of the bodily functions not consciously directed such as breathing, heartbeat, digestive processes and sexual arousal
  • It transmits information to and from internal bodily organs
  • It acts more slowly than the SNS
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11
Q

What is the autonomic nervous system made up of?

A

Unmyelinated nerve fibres

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12
Q

Sympathetic nervous system

A

Gets the body prepared for fight or flight.

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13
Q

Parasympathetic nervous system

A

Returns the body to its normal resting state (rest and digest).

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14
Q

Neuron

A

Nerve cells which are part of the nervous system.

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15
Q

How do neurons transmit information?

A
  • Electrically (through action potentials)
  • Chemically (using neurotransmitters)
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16
Q

What do all neurons consist of?

A
  • Cell body
  • Dendrites
  • Axon
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17
Q

Dendrites (x2)

A
  • Receive signals from other neurons or from sensory receptors.
  • They are connected to the cell body (soma).
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18
Q

What is the function of the cell body?

A

It is the control centre of the neuron which contains all the genetic information of the cell.

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19
Q

Axon

A

The impulse is carried along the axon where it terminates at the axon terminal (terminal button).

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20
Q

Axon terminal

A

At the end of the axon where neurotransmitters are.

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21
Q

Myelin sheath (x3)

A
  • An insulating layer that forms around the axon.
  • This allows nerve impulses to transmit more rapidly along the axon.
  • If the myelin sheath is damaged, impulses slow down.
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22
Q

Sensory neurons (x3)

A
  • Long dendrites and short axons
  • The carry messages from the sense receptors in the PNS to the CNS
  • Cell body is on the axon
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23
Q

Do all messages go to the brain? (x2)

A
  • Not all messages travel to the brain
  • Some terminate in the spinal cord to allow reflex actions to occur quickly without the delay of sending impulses to the brain
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24
Q

Motor neurons (x3)

A
  • Short dendrites and long axons
  • Connect the CNS to effectors such as muscles and glands
  • The cell body is located in the spinal cord, the fibre (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands
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25
Q

Relay neurons (x4)

A
  • Short dendrites and short axons
  • They connect the sensory neurons to the motor or other relay neurons
  • They allow motor and sensory neurons to communicate with each other
  • They are found only in the brain and spinal cord
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26
Q

What is synaptic transmission?

A

The process in which one neuron communicates with another by releasing neurotransmitters to diffuse across the synapse.

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27
Q

What is the synapse? (x3)

A
  • The gap of the end of the axon of one neuron and the dendrite or cell body of another
  • The signal needs to cross this gap to pass on its message
  • This is done using neurotransmitters (chemicals) that diffuse across the gap between the 2 neurons
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28
Q

What is an action potential? (x3)

A
  • An electrical impulse
  • When a neuron is in a resting state it is negatively charged compared to the outside
  • When a neuron is activated by a stimulus it becomes positively charged for a split second causing an action potential to travel down the axon
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29
Q

What are the stages of synaptic transmission? (x5)

A
  1. An action potential travels down the axon of the pre synaptic neuron.
  2. When it reaches the terminal buttons it causes vesicles to migrate and bind with the pre synaptic membrane, triggering the release of neurotransmitters.
  3. Neurotransmitters diffuse across the synapse and bind with post synaptic receptors like a lock and key.
  4. Once activated, the receptors produce either excitatory (positively charged) or inhibitory (negatively charged) effects on the post synaptic neuron.
  5. Neurotransmitters are then released back into the synapse and go through the process of reuptake or get metabolised.
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30
Q

What is the endocrine system? (x3)

A
  • A communication system that instructs glands to release hormones directly into the bloodstream.
  • These hormones are carried in the blood towards target organs in the body.
  • It works alongside the nervous system to control vital functions in the body.
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31
Q

What speed does the endocrine system pass messages compared to the nervous system?

A

It acts much more slowly than the nervous system but still has powerful effects.

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32
Q

What is a hormone? (x3)

A
  • A chemical substance that circulates in the bloodstream and affects target organs.
  • They are produced in large quantities.
  • Their effects are powerful.
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33
Q

Hypothalamus (where, function - 2 points)

A
  • A brain region which is connected to the pituitary gland.
  • It is responsible for stimulating or controlling the release of hormones from the pituitary gland.
  • It is the control system which regulates the endocrine system.
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34
Q

What effects do hormones have?

A

Hormones can affect cells in several organs, leading to a diverse range of responses.

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35
Q

Adrenal medulla (hormone, impact)

A
  • Adrenaline and noradrenaline
  • Key role in fight or flight
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36
Q

Adrenal cortex (hormone, impact)

A
  • Cortisol
  • Triggers the release of glucose to provide the body with energy and suppressing the immune system.
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37
Q

Testes (hormone, impact)

A
  • Testosterone
  • Responsible for male sex characteristics during puberty and muscle growth.
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38
Q

Ovaries (hormone, impact)

A
  • Oestrogen
  • Regulates the female reproductive system (menstrual cycle and pregnancy).
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39
Q

What is the function of serotonin?

A

Regulates mood.

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40
Q

What is the function of dopamine? (x2)

A
  • Feeling of pleasure
  • Reward pathways which lead to addiction
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41
Q

What is the function of GABA?

A

Calming affect on the brain.

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42
Q

What is special about GABA?

A

The only neurotransmitter that is always inhibitory.

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43
Q

What is meant by inhibition? (x3)

A
  • ‘Off switch’
  • Calms the mind and body.
  • A negative charge at the post synaptic membrane will create an inhibitory postsynaptic potential (IPSP) —> less likely to fire an action potential in the next neuron.
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44
Q

What is meant by excitation? (x2)

A
  • ‘On switch’
  • A positive charge at the post synaptic membrane will create an excitatory post synaptic potential (EPSP) —> more likely to fire an action potential in the next neuron.
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45
Q

What is meant by summation? (x3)

A
  • A nerve cell can receive both EPSPs and IPSPs at the same time.
  • Summation is the net sum of the total IPSPs and EPSPs which determines whether or not the cell fires.
  • The threshold is -60V for an action potential to be created.
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46
Q

What is the fight or flight response? (x2)

A
  • A sequence of activity within the body that is triggered when the body prepares itself for defending or attacking (fight) or running away to safety (flight).
  • This activity involves changes in the NS and the secretion of hormones that are necessary to sustain arousal.
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47
Q

What phrase must you always use in the fight or flight topic?

A

‘Make the body prepared’.

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48
Q

How are threats today different to the past?

A

Many of the high-arousal situations we face in the modern world are more psychological in nature (e.g a job interview, exams).

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49
Q

What is the role of the amygdala?

A

The amygdala is your body’s ‘threat’ sensor. It alerts that there is a threat then it will activate a sequence of events (SAM pathway).

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50
Q

Which two communication systems work together in the sympathomedullary pathway?

A

Endocrine system and nervous system.

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51
Q

The process of the SAM pathway:

A
  1. Amygdala alerts
  2. Hypothalamus activates
  3. Sympathetic nervous system which triggers
  4. Adrenal medulla to release
  5. Adrenaline and noradrenaline, which facilitates
  6. The fight or flight response
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52
Q

What is the role of adrenaline? (x5)

A
  • Increased heart rate pushing blood to the muscles
  • Breathing becomes more rapid to take in more oxygen to provide to the muscles
  • Blood sugar (glucose) and fats are released into the bloodstream to provide energy
  • Diversion of blood away from the digestive system to conserve energy by constricting blood cells
  • An increase in sweating to cool the body
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53
Q

Localisation of function

A

Functions, such as movement, speed and memory are performed in distinct regions of the brain (localised).

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54
Q

How does localisation of function contrast to a holistic view? (x2)

A
  • Holistic view is the belief that all parts of the brain are involved in the processing of thought and action.
  • Before scientific study of the brain, it was generally believed that the brain worked holistically.
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55
Q

What is the outer layer of the brain called?

A
  • The cerebral cortex
  • It is about 3mm thick
  • It’s what separates humans from other animals as it is much more developed
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56
Q

What are gyri and sulci? (x2)

A
  • Ridges (gyri) and grooves (sulci) in the brain to increase surface area
  • This increased surface area is crucial for effective functioning as more neurons can be present, in contrast to a brain with a flat surface
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57
Q

What are the 4 lobes of the brain called?

A
  • Occipital lobe
  • Frontal lobe
  • Parietal lobe
  • Temporal lobe
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58
Q

What is the role of the limbic system? (x2)

A
  • This part of the brain is unique to mammals
  • According to Maclean (1990), the limbic system of this mammalian brain is the centre of emotion and learning
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59
Q

Who were 2 neurosurgeons known for identifying areas of the brain associated with speech processing? (x3)

A
  • Broca (1865) and Wernicke (1873)
  • They were the first people to provide scientific evidence for the idea of localisation of function
  • In 1865, Broca identified a small area in the left prosterior frontal lobe for speech production —> damage to this area caused Broca’s aphasia
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60
Q

What is Broca’s aphasia, and how is it caused?

A
  • Characterised by: slow, laborious and lacking in fluency
  • Caused by illness or injury to the brain (e.g a stroke)
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61
Q

What is Wernicke’s aphasia, and how is it caused?

A
  • Studied patients who had no problems producing language but severe difficulty in understanding it
  • He identified an area in the left posterior temporal lobe as being responsible for language comprehension
  • Patients with Wernicke’s aphasia often produce nonsense words (e.g word salad)
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62
Q

How is the case of Phineas Gage seen as evidence for the loacalisation of function?

A
  • The rod only took out one part of his brain
  • He is seen as a landmark case in science as the change in his temperament following the accident suggests that the frontal lobe may be responsible for regulating mood
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63
Q

What is the role of the frontal lobe?

A

Higher cognitive functions, including problem-solving, decision-making, attention, intelligence and voluntary behaviours.

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64
Q

What is the role of the parietal lobe?

A

Integrating information from the body’s senses to allow us to build a coherent picture of the world around us.

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65
Q

What is the role of the occipital lobe?

A

Receive information from the eye’s retinas, which is then encoded into different visual data.

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66
Q

What is the role of the temporal lobe?

A

Understanding, language, memory acquisition, face recognition, object recognition, perception, and auditory information processing.

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67
Q

What is the role of the left frontal lobe?

A

Controlling language related movement.

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68
Q

What is the role of the left temporal lobe?

A

Language, learning, memorising, forming words, and remembering verbal information.

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69
Q

How is the spatial arrangement of the motor cortex linked to its function?

A

The regions of the motor area are arranged in a logical order, so that signals can be transferred as quickly and as directly as possible.

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70
Q

Hemispheric lateralisation

A

The idea that the 2 hemispheres of the brain are functionally different, and that certain mental processes an behaviours are mainly controlled by one hemisphere rather than the other.

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71
Q

What is the difference between localisation and lateralisation?

A

Localisation - identification of a function in a specific region
Lateralisation - identification of a function in 1 hemisphere

72
Q

Which hemisphere processes the left visual field?

A

Right

73
Q

Which hemisphere processes the right visual field?

A

Left

74
Q

Where does the left visual field project to on the retina?

A

To the nasal retina of the left eye, and the temporal retina of the right eye.

75
Q

Which part of the retina sends information to the contralateral hemisphere? Where does this occur?

A
  • The nasal retina
  • This occurs at the optic chiasm
76
Q

Which part of the retina does not send information to the contralateral hemisphere, and where is it sent?

A

Information from the temporal retina does not cross to the contralateral hemisphere, and instead is sent to the ipsilateral hemisphere (same side).

77
Q

At which point is visual information combined, and which structure is involved?

A

Once the information reaches the cortex, it is shared across hemispheres via the corpus callosum.

78
Q

Where does the right visual field project information to?

A

To the nasal retina of the right eye and then the temporal retina of the left eye.

79
Q

What happens to visual information if the corpus callosum is severed?

A

Each hemisphere will only have information from the contralateral visual field (from the temporal retina).

80
Q

Which hemisphere is language largely processed in?

A

Left

81
Q

Which hemisphere are faces and facial emotion processed in?

A

Right

82
Q

Split-brain research

A

Surgery for intractable epilepsy involved severing the corpus callosum to prevent the spread of electrical discharge - this is known as a commissurotomy, preventing communication between the 2 hemispheres.

83
Q

Sperry (1968) - split-brain research - method

A

He used a divided field task, in which patients would look ahead at a dot located centrally on a screen, and then visual information would be presented to the left or right visual field for 0.1 seconds. Underneath the screen was a table, in which participants could feel, but not see objects.

84
Q

Sperry (1968) - split-brain research - why was the visual information presented so briefly?

A

So that participants could not orient their head to the stimulus, which would then mean that both hemispheres would receive the information.

85
Q

Sperry (1968) - split-brain research - what happened when visual information was presented to the right visual field, and why?

A

Subjects could correctly recall the information, because language is processed in the contralateral left visual hemisphere.

86
Q

Sperry (1968) - split-brain research - what would happen when visual information was presented to the left visual field, and why?

A

Patients would report not seeing any information, because the stimulus was processed by the contralateral right hemisphere, which does not have access to verbal information, without the input of the left hemisphere.

87
Q

Sperry (1968) - split-brain research - what happened when participants were asked to recognise objects presented to the left visual field by touch?

A

Participants were able to identify the objects by touch with their left hand, because the right hemisphere was able to process spatial information.

88
Q

Sperry (1968) - split-brain research - what happened when 2 words were presented simultaneously?

A

The patient could write the word on the left with their left hand (right hemisphere is superior for drawing), and say the word on the right (left hemisphere is superior for language).

89
Q

Sperry (1968) - split-brain research - what happened when shown composite faces (composed of a male and female face), and why? (x3)

A
  • The participant would say ‘man’ but the left hand would select the woman.
  • The right hemisphere is dominant for recognising faces.
  • The left hemisphere has superior verbal description and the right is superior to matching a face to a picture.
90
Q

What conclusions can we make from work on split-brain patients? (x3)

A
  • Discovered a number of differences between the 2 hemispheres (e.g left - speech and language, right - visual-spatial processing and facial recognition).
  • Has not shown that the brain is organised into discrete regions with specific sections responsible for different tasks.
  • It suggests that the connectivity between the different regions is as important as the operation of the different parts.
91
Q

What does plasticity mean with regard to the brain?

A

The brain can change and adapt over time as a result of experience and new learning.

92
Q

How as the view on plasticity changed? (x2)

A
  • It was originally thought that changes were restricted to the developing brain within childhood, and that the adult brain, having moved beyond a critical period would remain fixed and static in terms of function and structure.
  • Research has since demonstrated that the brain continues to create new neural pathways and alter existing ones in response to changing experiences.
93
Q

How does infant development demonstrate plasticity?

A
  • During infancy the brain experiences growth in the number of synaptic connections it has, peaking at around 15,000 per neuron at age 2-3 (Gopnick et al. 1999).
  • This is twice as many connections per neuron as in the adults brain.
94
Q

What is synaptic pruning?

A

As we age, connections that are rarely used deleted and frequency used connections are strengthened.

95
Q

What is functional recovery?

A

A form of plasticity where, following damage from trauma, the brain is able to redistribute functions normally performed by damaged areas, to other unmanaged areas.

96
Q

Give 4 examples of how when environments are enriched or impoverished, it is reflected in brain plasticity

A
  • Romanian orphans suffered conditions of neglect and understimulation. PET scans of their brains showed hypometabolism in their temporal lobes, indicating lack of neural development.
  • Davidson et al (2004) found that Tiebetan monks had increased gamma waves (coordinate neural activity) when meditating. This showing long term changes.
  • Rosenweig et al (1972) found that brains of enriched rats were different from impoverished rats; the neurons were larger, and the cerebral cortex heavier and thicker.
  • Boyke et al (2008) found that there is a natural decline in cognitive functioning with age. Boyke found that60 year olds had increased grey matter in the visual cortex when learning to juggle. It decreased when they stopped.
97
Q

Maguire (2000) - Aim

A

The posterior hippocampus is associated with spatial and navigational skills.
Maguire was interested in whether the participants with extensive experience in the use of navigational skills would show increased brain volume within this region.

98
Q

Maguire (2000) - Method (x3)

A
  • 16 male right-handed taxi drivers were compared to 50 healthy right-handed males who were not taxi drivers.
  • The taxi drivers have to undergo extensive navigational training, known as ‘The Knowledge’ in order to become a licensed taxi driver.
  • Using MRI, the volume of hippocampus was compared between groups.
99
Q

Maguire (2000) - Results

A

Taxi drivers showed an increase in volume of the posterior hippocampus, compared to healthy volunteers, and smaller anterior hippocampus.

100
Q

Maguire (2000) - Why is a straightforward interpretation of these findings complicated?

A

The results are correlational, so the association could be spurious (relationship is caused by a third variable that is not accounted for).
Correlation is not causation, and can be the simple result of chance.

101
Q

Maguire (2000) - What might be an alternative explanation?

A

It is possible the causality could be in the opposite direction: that is, those with strong navigational skills, and therefore have a larger posterior hippocampus, are more likely to seek employment i positions which utilise these skills, such as taxi drivers.

102
Q

Name 2 other studies that are consistent with the findings of Maguire

A
  • Draganski et al (2006) imaged the brains of medical students 3 months before and after their final exams. Learning-induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex, presumably as a result of studying for their exams.
  • Mechelli et al (2004) found a larger parietal cortex in the brains of people who were bilingual compared to matched monolingual controls.
103
Q

How does functional recovery suggest plasticity? (x3)

A
  • Following injury or trauma (such as a stroke), unaffected areas of the brain are often able to adapt and compensate for those areas that are damaged.
  • Recovery is more likely at a younger age, where the potential for plasticity is greater.
  • The functional recovery that may occur in the brain after trauma is another example of neuroplasticity.
104
Q

How does neural reorganisation support plasticity? (x2)

A
  • Healthy brain areas may take over the functions of those areas that are damaged, destroyed or ever missing (neural reorganisation).
  • Neuroscientists suggest that this process can occur quickly after trauma (spontaneous recovery) and then slow down after several weeks or months. At this point the individual may need rehabilitative therapy.
105
Q

How can neural reorganisation occur?

A

Through the recruitment of homologous areas, when a homologous (similar) are of the brain on the opposite side is used to perform a specific task.

106
Q

How might secondary neural pathways be involved in functional recovery?

A

Secondary neural pathways, that would not typically be used to carry out certain functions, are activated or ‘unmasked’ to enable functioning to continue, often in the same ways as before.

107
Q

Name 3 structural changes related to plasticity

A
  • Axonal sprouting: Growth of new nerve ending which connects with other unmanaged nerve cells to form new neural pathways.
  • Reformation of blood vessels.
  • Denervation super-sensitivity: Axons become more responsive to compensate for the loss of adjacent neurons.
108
Q

Name 4 methods of studying the brain

A
  • Functional magnetic resonance imaging (fMRI)
  • Electroencephalograms (EEGs)
  • Event-related potentials (ERPs)
  • Post-mortem examinations
109
Q

Spatial resolution

A

Refers to the smallest feature (or measurement) that a scanner can detect.
Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy.

110
Q

Temporal resolution

A

Refers to the accuracy of the scanner in relation to time or how quickly the scanner can detect changes in brain activity.

111
Q

How does fMRI work? (x6)

A
  • fMRI measures changes since blood oxygenation in the brain when a person performs a task.
  • It works on the assumption that an active brain area consumes more oxygen.
  • Energy requires glucose and oxygen.
  • Oxygen is carried in the blood attached to haemoglobin released for use by neurons (deoxygenation).
  • Oxygenated and deoxygenated blood have different magnetic properties, and this difference is detected by the fMRI scanner.
  • fMRI produce dynamic 3D images that are activation maps, showing which parts of the brain are using larger amounts of oxygen, and are therefore more active.
112
Q

What are the strengths of fMRI?

A
  • Non-invasive (unlike PET which requires radiation).
  • Good spatial resolution (accurate with 1-2mm).
113
Q

What are the limitations of fMRI? (x5)

A
  • Poor temporal resolution as there is around a 5 second time lag between image and neuron firing.
  • Indirect way to measure brain activity - difficult to establish causation as it only measures blood flow, not neuronal activity.
  • The person must stay perfectly still (stimulus-correlated motion (in-sync with the task)), which is especially problematic.
  • Expensive.
  • Not suitable for those with MRI-contraindications.
114
Q

How is EEG measured?

A

EEGs measure electrical activity within the brain via electrodes that are fixed on the scalp, usually using a skull cap.
It works on the assumption that information is processed in the brain as electrical activity in the form of action potentials.

115
Q

What is the basis for the EEG signal? (x2)

A
  • Small electrical charges are detected by the electrodes and graphed over a period of time, indicating the level of activity.
  • The waves are measured in amplitude (vertical dimension) and frequency (horizontal dimension).
116
Q

What are the 4 types of EEG waves?

A
  • Alpha
  • Beta
  • Theta
  • Delta
117
Q

EEG waves - alpha (x4)

A
  • Frequency range of around 8-13 waves per second
  • They are typically witnessed in people who are awake, with their eyes open or closed, often in a relaxed state
  • Most visible in the occipital lobes of the brain (area responsible for vision)
  • Most alpha activity tends to be higher in amplitude on the dominant side of the brain in most people
118
Q

EEG waves - beta (x4)

A
  • Frequency greater than 13 per second, the usual range being from 13 to about 30Hz
  • Typically seen in people who are awake, with their eyes either opened or closed and are often viewed in the frontal lobes (where conscious thought and movement occurs)
  • Low amplitude and varying frequencies
  • Most often associated with active thinking
119
Q

EEG waves - theta (x3)

A
  • Frequency of around 4-7 waves per second
  • These waves are also known as slow activity, typically occurring during sleep, meditation and in younger children
  • If there is an excess of theta activity in older children and adults, this could represent abnormal activity and could relate to drowsiness
120
Q

EEG waves - delta (x3)

A
  • Frequency of up to 4Hz, and so are the slowest waves
  • Highest in amplitude, so have the strongest intensity
  • Most commonly witnessed during slow wave sleep and infants under the age of 1 year old
121
Q

How are EEGs used?

A

EEGs are often used by clinicians as a diagnostic tool because unusual arrhythmic patterns of activity (no particular rhythm) may indicate neurological abnormalities such as epilepsy, tumours, or disorders of sleep.

122
Q

What are the advantages of EEG? (x3)

A
  • It has contributed to much of the understanding of sleep
  • High temporal resolution (can detect brain activity at one millisecond)
  • Important in the diagnosis of conditions such as epilepsy
123
Q

What are the limitations of EEG? (x2)

A
  • Produces very generalised information, so not useful for pinpointing neural activity
  • EEGs do not allow researchers to distinguish between activity originating in different but adjacent locations of the brain
124
Q

What are ERPs? (x3)

A
  • ERPs are a way to isolating specific neural responses associated with sensory, cognitive and motor events
  • These are of interest to cognitive neuroscientists
  • ERPs work by using statistical averaging techniques, that filter out extraneous brain activity from the original EEG recording, leaving only the responses that relate to say, the presentation of a specific stimulus or performance of a specific task
  • Event-related potentials remain; types of brainwave that are triggered by particular events
125
Q

What are the advantages of ERPs? (x4)

A

(ERPs partly address the limitations of EEGs)
- ERPs bring much more specificity to the measurement of neural processes than could be achieved using raw EEG data
- As ERPs are derived from EEG measurements, they have excellent temporal resolution, especially when compared to fMRIs
- The excellent temporal resolution of ERPs has led to their widespread use in the measurement of cognitive functions and deficits
- Researchers have been able to identify many different types of ERP and describe the precise role of these in cognitive functioning, including parts of working memory

126
Q

What are the limitations of ERPs? (x2)

A
  • Critics have pointed to a lack of standardisation in ERP methodology between different studies, making it difficult to confirm findings
  • In order to establish pure data in ERP studies, background noise and extraneous material must be completely eliminated, which is not always easy to do
127
Q

How is post-mortem data used in psychology research? (x5)

A
  • This is a technique that involves the analysis of a person’s brain following their death
  • In psychological research, those whose brains are subject to a post-mortem are likely to be those who have a rare disorder and have experienced unusual deficits in mental processes or behaviour during their lifetime
  • Areas of damage within the brain are examined after death as a means of establishing the likely cause of the affliction the person suffered
  • This may also involve comparison with a neurotypical (healthy) brain in order to see the extent of the difference
128
Q

What are the advantages of post-mortem research? (x3)

A
  • Post-mortem evidence was vital in providing a foundation for early understanding of key processes in the brain
  • Both Broca and Wernicke relied on PM studies in establishing links between language, brain and behaviour decades before neuroimaging began
  • PM studies improve medical knowledge and help generate hypotheses for further study
129
Q

What are the limitations of post-mortem research? (x3)

A
  • Causation is an issue within these investigations
  • Observed damage to the brain may not be linked to the defects under review but to some other unrelated trauma or decay
  • PM studies raise ethical issues of consent from the patient before death (patients may not be able to provide informed consent, for example in the case of HM who lost his ability to form memories and was not able to provide such consent; nevertheless PM research has been carried out on his brain)
130
Q

What are biological rhythms?

A

Cyclical patterns within biological systems.
They are a series of bodily functions regulated by your internal clock.
They control cycles like sleep and wakefulness, body temperature, hormone secretion etc.

131
Q

Circadian rhythms

A

A circadian rhythm is a natural oscillation that repeats roughly every 24 hours.
Circadian rhythms can refer to any process that originates within an organism and responds to the environment.

132
Q

Infradian rhythms

A

Infradian rhythms last longer than 24 hours and can be weekly, monthly or annually.
A monthly infradian rhythm is the female menstrual cycle.

133
Q

Ultradian rhythms

A

Ultradian rhythms last fewer than 24 hours and can be found in the pattern of human sleep.

134
Q

Endogenous pacemakers

A

Internal body clocks that regulate our sleep-wake cycle and other bodily processes.
They are controlled by our body’s natural rhythms and are responsible for maintaining our internal body clock.

135
Q

Exogenous zeitgebers

A

External environmental cues that can help regulate our internal body clock.
They include factors such as light, temperature and social cues.

136
Q

Why have humans likely evolved a 24-hour cycle?

A

The most important exogenous zeitgeber is light, which is responsible for resetting the body clock each day, keeping it on a 24-hour cycle.

137
Q

What is the relationship between endogenous pacemakers and exogenous zeitgebers?

A

All living organisms are subject to biological rhythms which are governed by endogenous pacemakers and entrained by exogenous zeitgebers.

138
Q

What is the biological basis for the sleep-wake cycle? - What does the SCN do? (x4)

A
  • The suprachiasmatic nucleus (SCN) is a major endogenous pacemaker in mammals that controls the sleep-wake cycle (‘master clock’).
  • It is in the hypothalamus, where the optic nerves from the eyes cross over.
  • It gets stimulated by light that penetrates our closed eyelids and the SCN (tiny bundle of nerve cells) then regulates our sleep-wake cycle.
  • The SCN passes the information on day length and light that it receives to the pineal gland (a pea-like structure in the brain just behind the hypothalamus).
139
Q

What role does the pineal gland play?

A

During the night, the pineal gland increases the production of melatonin, which induces sleep.

140
Q

What is the role of melatonin?

A
  • Melatonin is a hormone that your brain produces in response to darkness.
  • It helps with the timing of your circadian rhythms (24-hour internal clock) and with sleep.
  • Sunlight in the morning stops the production of melatonin, increasing the production of cortisol which increases wakefulness.
  • Research suggests that melatonin plays other important roles in the body beyond sleep.
141
Q

What is the role of homeostasis? (x4)

A
  • The tendency of the human body to seek balance, equilibrium, and stability.
  • The role of homeostasis is to maintain the established internal environment without being overcome by external stimuli that exist to disrupt the balance.
  • When an individual has been awake for a long time, homeostasis tells the body that there is a need for sleep because of energy consumption.
  • The homeostatic drive for sleep increases through the day, reaching its maximum in the late evening (when most people fall asleep).
142
Q

Describe another circadian rhythm other than sleep (x3 points)

A
  • Body temperature
  • It is at its lowest (36°C) at 4:30am, and at its highest (38°C) at around 6pm.
  • Sleep occurs when the core temperature begins to drop, and body temperature starts to rise during the last few hours of sleep, promoting a feeling of alertness in the morning.
  • Temperature also drops slightly between 2pm and 4pm, which explains why many people feel sleepy in the early afternoon.
143
Q

Michel Siffre (1975) - aim

A

To find out what would happen to a person’s circadian rhythms if they are cut off from all zeitgebers (such as light, dark and an awareness of time), and how this would affect reliance on endogenous pacemaker to tell them when to eat and sleep.

144
Q

Michel Siffre (1975) - method (x4)

A
  • The only participant was Siffre himself.
  • He spent 179 days and nights in an underground cave with no lights, clocks or radios to give him any indication of what time it was.
  • His only influence was his internal body clock, which has ‘free run’ to do what felt natural.
  • His only link to the outside world was a telephone where he could keep in touch, a video camera that monitored him, and wires attached to his body that monitored how he was functioning.
145
Q

Michel Siffre (1975) - findings

A
  • At first, Siffre’s sleep-wake patterns were very irregular.
  • After a while, they settled into a 25-hour pattern rather than 24 hours, which is the time a human considers to be a full day and therefore how long a sleep-wake cycle should last.
146
Q

Michel Siffre (1975) - conclusion

A
  • Circadian rhythms are mainly controlled by endogenous pacemakers rather than exogenous zeitgebers, but that exogenous zeitgebers do have a significant influence.
  • Siffre concluded that humans do have a natural sleep-wake cycle, but without the influence of exogenous zeitgebers it naturally settles into a 25-hour pattern, so an hour longer than what people would experience normally.
147
Q

Strengths of Michel Siffre (1975)’s study (x3)

A
  • Gives validation to the idea that humans’ sleep-wake cycles are regulated by endogenous pacemakers.
  • The study lasted a long time, and so Siffre’s rhythms were allowed to settle into a natural pattern.
  • Similar studies carried out with rats have also found that sleep-wake cycle increases, which supports the findings.
148
Q

Limitations of Michel Siffre (1975)’s study (x4)

A
  • The sample size was just one person, and so the findings aren’t reliable.
  • A cave is not where humans would naturally go to sleep, and so the study lacks ecological validity.
  • It has been suggested that other factors, such as loneliness, may have affected Siffre’s sleep-wake cycle.
  • Researcher bias (Siffre was both the researcher and the participant).
149
Q

Evidence other than Siffre for evidence of extended sleep-wake cycle in the absence of external light (x2)

A
  • Aschoff and Wever (1976) convinced participants to spend 4 weeks in a WW2 bunker deprived of light. All but 1 participant displayed a circadian rhythm of 24-25 hours. The other extended to 29 hours.
  • Folkard conducted a study of circadian rhythms similar to Siffre, in a cave. This time, they had a clock to enforce strict bed and waking times. What participants didn’t know was that the researchers sped up the clock so that their days were only 22 hours instead of 24. Only 1 participant was able to comfortably adjust to the new regime.
150
Q

How can the sleep-wake cycle become desynchronised? (X2)

A
  • Jet lag. The internal clock is not synchronised with the daytime-nighttime rhythm at the place of arrival. Jet lag can cause insomnia, fatigue, irritability and poor concentration.
  • Shift work (i.e working during the night and sleeping during the day) can cause desynchronisation in the circadian rhythm, which in turn leads to negative health effects.
151
Q

Ralph (1990)’s study on sleep-wake cycle in hamsters (x4)

A
  • Took the SCN out of genetically abnormal hamsters with a circadian cycle of 20 hours and then transplanted them into hamster foetuses with the usual 24-hour cycle, and their cycles shortened to 20 hours when they were born.
  • Their brains were then transplanted with SCN cells from 24-hour cycle hamsters, and within a week their cycles had adopted this new 24-hour cycle.
  • When cells from the SCN were removed from the hamsters, the 24-hour cycle of neural activity persisted in the isolated cells.
  • This suggests that circadian rhythms are primarily controlled by evolutionary-determined, biological structures that exert a strong influence on us to maintain normal sleep-waking patterns.
152
Q

Experimental biological evidence for sleep-wake cycles existing outside the body

A
  • Yamazaki (2001) found that isolated lungs and livers, and other tissues grown in a lab, still persist in showing circadian rhythms.
  • This suggests that cells are capable of maintaining a circadian rhythm even when they are not under the control of any brain structures and that most bodily cells are tuned in to following a daily circadian rhythm.
153
Q

How do Inuits in the Arctic Circle support the role of an endogenous drive of the sleep-wake cycle?

A
  • Inuit Indians who live in the Arctic Circle inhabit an environment that has hardly any darkness in summer and hardly any light in winter.
  • If the sleep-waking cycle has primarily controlled exogenous zeitgebers they would tend to sleep a huge amount in winter and hardly at all in summer.
  • However, they maintain a fairly regular pattern of sleeping and waking all year round.
154
Q

Give an example of an infradian rhythm, with details (x3)

A
  • The female menstrual cycle is one example of an infradian rhythm as it is governed by monthly changes in hormone levels which regulate ovulation (a cycle which lasts longer than 24 hours).
  • The cycle starts the first day of a woman’s period (when the womb lining is shed), and finished the day before her next period.
  • The cycle is between 24 and 35 days (28 days is most common).
155
Q

What is the role of oestrogen in the menstrual cycle?

A

Rising levels of oestrogen cause the ovary to develop and release an egg (ovulation).

156
Q

What is the role of progesterone in the menstrual cycle?

A

Progesterone helps the womb lining to grow thicker in preparation for implantation of the embryo.
If pregnancy does not occur, the egg is absorbed into the body and the womb lining comes away and leaves the body (menstrual flow).

157
Q

McClintock & Stern (1998) - aim

A

To investigate whether the menstrual cycle is influenced by pheromonal secretions from other women.
Although the menstrual cycle is an endogenous system, evidence suggests that it might be influenced by exogenous factors, such as the cycles of other women.

158
Q

McClintock & Stern (1998) - sample

A

29 female university students, not taking birth control pills.

159
Q

McClintock & Stern (1998) - design

A

Quasi experiment with independent measures.

160
Q

McClintock & Stern (1998) - method (x2)

A
  • 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 (for at least 8 hours).
  • The other 20 participants were exposed to the pheromones and their menstrual cycles were monitored.
161
Q

McClintock & Stern (1998) - results (x3)

A
  • When the experimental group inhaled secretions from women who were about to ovulate, their menstrual cycles became shorter.
  • When they inhaled secretions from women who had just ovulated, their menstrual cycles became longer.
  • McClintock found that 68% of women experienced changes to their cycle.
162
Q

Seasonal Affective Disorder (SAD) (x3)

A
  • SAD is a depressive disorder which has a seasonal pattern of onset, and is described and diagnosed as a mental disorder in DSM-5.
  • As with other forms of depression, the main symptoms of SAD are persistent low mood alongside a general lack of activity and interest in life.
  • SAD is often referred to as ‘the winter blues’, as the symptoms are triggered during the winter months when the number of daylight hours becomes shorter.
163
Q

What biological rhythm does SAD follow?

A

SAD is a particular type of infradian rhythm called a circannual rhythm, as it is subject to a yearly cycle.

164
Q

What is a potential mechanism for SAD?

A
  • It is believed that the hormone melatonin is implicated in the cause of SAD.
  • During the night, the pineal gland secretes melatonin until dawn when there is an increase in light.
  • During winter, the lack of light in the morning means that the secretion process continues for longer.
  • This is thought to have a knock-on effect on the production of serotonin in the brain - the neurotransmitter that is linked to depression.
165
Q

What is a common treatment for SAD? (x3)

A
  • Talking therapies (such as CBT)
  • Medication (such as antidepressants)
  • Light therapy
166
Q

How many sleep stages are there?

A

5

167
Q

Over what time frequency do the sleep stages repeat?

A

They span approximately 90 minutes and repeat throughout sleep.

168
Q

Describe stages 1 and 2 of the sleep cycle

A
  • Stages 1 and 2 are light sleep, where the person may be easily woken.
  • At the beginning of sleep, brain wave patterns start to become slower and more rhythmic (alpha and theta waves).
169
Q

Describe stages 3, 4 and 5 of the sleep cycle

A
  • Stages 3 and 4 involve delta waves, which are slower still and have greater amplitude than earlier wave patterns.
  • This is deep sleep of slow wave sleep (SWS), and it is difficult to wake someone at this point.
  • In stage 5, REM sleep is when the body is paralysed yet brain activity speeds up significantly in a manner that resembles the awake brain.
  • REM stands for rapid eye movement, and it is the stage that is associated with dreaming.
170
Q

Dement & Kleitman (1957) - aim

A

To investigate the relationship between eye movements in REM and non-REM sleep.

171
Q

Dement & Kleitman (1957) - procedure (x5)

A
  • They monitored the sleep patterns of 9 adult participants in a sleep lab, between 6-17 nights.
  • The brain activity was recorded on an EEG.
  • They all consumed no caffeine or alcohol as a control.
  • IV: whether they were woken from REM / NREM.
  • DV: whether they could recall a dream and if so, the detail.
172
Q

Dement & Kleitman (1957) - findings (x3)

A
  • More dreams were recalled from REM than NREM sleep (152:11).
  • Participants could accurately estimate dream duration.
  • Participants’ eye movements were strongly related to dream content (e.g one participant mentioned looking up and down a ladder (vertical), and another said about watching a tomato fight (horizontal)).
173
Q

Dement & Kleitman (1957) - conclusion (x3)

A
  • REM activity during sleep was highly correlated with the experience of dreaming.
  • Brain activity varied according to how vivid dreams were.
  • Participants woken during dreaming reported very accurate recall of their dreams.
174
Q

3 limitations of Dement & Kleitman (1957)’s study

A
  • Low ecological validity because participants are in an extreme artificial environment (e.g sleeping wired up to an EEG machine, being restricted from caffeine and alcohol).
  • Potential demand characteristics because dream recalls May not have been entirely true due to pepople feeling annoyed, wanting to get back to sleep quickly, being embarrassed etc.
  • Lack of generalisability as there were only 9 participants (7 male and 2 female), from the USA.
175
Q

Randy Gardner (1965)

A
  • Randy Gardner remained awake for 264 hours (11 days).
  • While he experienced numerous problems such as blurred vision and disorganised speech, he coped rather well with the massive sleep loss.
  • After this experience, Randy slept for just 15 hours and over several nights he recovered only 25% of his lost sleep.
  • He recovered 70% of stage 4 sleep, 50% of his REM sleep, and very little of the other stages.
  • These results highlight the large degree of flexibility in terms of the different stages within the sleep cycle and the variable nature of this ultradian rhythm.

Psychology (14 decks)

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