Biopsychology Flashcards
(125 cards)
1
Q
What is the nervous system?
A
Consists of the CNS and the PNS
2
Q
What is the central nervous system?
A
Consists of the brain and the spinal cord and is the origin of all complex commands and decisions
3
Q
What is the brain’s outer layer called?
A
The cerebral cortex
4
Q
What is the peripheral nervous system?
A
It transmits messages, via neurons, to the CNS from the outside world and transmits messages from the CNS to muscles and glands in the body
5
Q
What 2 systems can the PNS be divided into?
A
- Somatic nervous system
- Autonomic nervous system
6
Q
What is the somatic nervous system?
A
- Transmits information from receptor cells in the sense organs to the CNS
- It also receives information from the CNS that directs muscles to act
7
Q
What is the autonomic nervous system?
A
- Transmits information to and from the internal bodily organs
- It is ‘autonomic’ as the system operates involuntarily
- Governs the vital body functions
8
Q
What 2 systems can the autonomic nervous system be divided into?
A
- Sympathetic
- Parasympathetic
9
Q
What does antagonistic mean?
A
Work in opposition
10
Q
Which nervous system is responsible for the ‘fight or flight’ response?
A
Sympathetic nervous system
11
Q
What actions is the sympathetic nervous system responsible for?
A
- Slows digestion
- Inhibits saliva production
- Increases heart rate
- Stimulates glucose production
- Stimulates urination
- Dilates pupils
- Dilates bronchi
12
Q
What actions is the parasympathetic nervous system responsible for?
A
- Increases digestion
- Increases saliva production
- Decreases heart rate
- Stimulates bile production
- Inhibits urination
- Constricts pupils
- Constricts bronchi
13
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 target organs in the body.
14
Q
What is a gland?
A
An organ in the body that synthesises substances such as hormones
15
Q
What are hormones?
A
- Chemical substances that circulate in the bloodstream and only affect target organs.
- They are produced in large quantities but disappear quickly
- Their effects are very powerful.
16
Q
What is adrenaline?
A
A hormone produced by the adrenal glands which is part of the human body’s immediate stress response system
17
Q
What does adrenaline do?
A
Adrenaline has a strong effect on the cells of the cardiovascular system:
- Stimulating the heart rate
- Contracting blood vessels
- Dilating air passages
18
Q
What is the normal resting state of the autonomic nervous system?
A
Parasympathetic state
19
Q
What is the ‘rest and digest response’?
A
The parasympathetic system acts as a ‘brake’ and reduces the activities of the body that were increased by the actions of the sympathetic branch during the ‘flight or flight’ response
20
Q
What is a neuron?
A
Nerve cells that process and transmit messages through electrical and chemical signals.
21
Q
What are sensory neurons?
A
- These carry messages from the PNS to the CNS
- They have long dendrites and short axons.
22
Q
What are relay neurons?
A
- These connect the sensory neurons to the motor or other relay neurons
- They have short dendrites and short axons.
23
Q
What are motor neurons?
A
- These connect the CNS to the effectors such as muscles and glands
- They have short dendrites and long axons.
24
Q
What is the nucleus?
A
The control centre of a cell, which contains the cell’s chromosomal DNA
25
What is a dendrite?
Receives the nerve impulse or signal from adjacent neurons
26
What is an axon?
Where the electrical signals pass along
27
What is a myelin sheath?
Insulates and protects the axon from external influences that might affect the transmission of the nerve impulse down the axon.
28
What are nodes of ranvier?
These speed up the transmission of the impulse by forcing it to ‘jump’.
29
What are terminal buttons?
Send signals to an adjacent cell
30
What is action potential?
- An action potential occurs when a neuron sends information down an axon, away from the cell body
- The action potential is an explosion of electrical activity - this means that some event (a stimulus) causes the resting potential to move forward.
31
How does a relfex arc work?
- Stimulus detected by the PNS conveyed along a sensory neuron
- Reaches the CNS where it connects with a relay neuron
- Message transferred to a motor neuron
- Message carried to an effector
32
Does a relfex arc involve the brain?
No
33
What does StoRM mean?
Sensory to Relay Motor
34
What can StoRM be used to remember?
How a reflex arc works
35
What is synaptic transmission?
The process by which neighbouring neurons communicate with each other by sending chemical messages across the gap (the synaptic cleft) that separates them.
36
What is a neurotransmitter?
Chemicals that are released from a synaptic vesicle into the synapse by neurons
37
What is excitation?
- When a neurotransmitter, such as adrenaline, increases the positive charge of the postsynaptic neuron.
- This increases the likelihood that the neuron will fire and pass on the electrical impulse.
38
What is inhibition?
- When a neurotransmitter makes the charge of the postsynaptic neuron more negative.
- This decreases the likelihood that the neuron will fire and pass on the electrical impulse.
39
What does normal brain function depend upon?
A regulated balance between excitatory and inhibitory influences
40
What is localisation of function?
The theory that different areas of the brain are responsible for different behaviours, processes or activities.
41
What is the motor area?
A region of the frontal lobe involved in regulating movement
42
What is the somatosensory?
An area of the parietal lobe that processes sensory information such as touch
43
What is the visual area?
A part of the optical lobe that receives and processes visual information.
44
What is the auditory area?
Located in the temporal lobe and concerned with the analysis of speech-based information
45
What is Broca's area?
An area of the frontal lobe of the brain in the left hemisphere (in most people) responsible for speech production
46
What is Wernicke's Area?
An area of the temporal lobe (encircling the auditory cortex) in the left hemisphere (in most people) responsible for language comprehension
47
How many hemispheres are there in the brain?
2 - Left and right
48
What are the 3 concentric layers of the brain?
- The Central Core
- The Limbic System
- The Cerebrum
49
What is the central core?
- Regulates homeostasis
- Regulates the endocrine system
- Includes the hypothalamus
50
What is the limbic system?
- Controls our emotions
- Around the central core, interconnected with the hypothalamus
- Contains the hippocampus
51
What is the cerebrum?
- Regulates our higher intellectual processes
- It has an outermost layer known as the cerebral cortex
- Made up of the left and right hemispheres which are connected by a bundle of fibres called the corpus callosum
52
What is each hemisphere divided into?
- The Frontal Lobe
- The Parietal Lobe
- The Temporal Lobe
- The Occipital Lobe
53
What is the frontal lobe?
The location for awareness of what we are doing within our environment (our consciousness)
54
What is the parietal lobe?
Location for sensory and motor movements
55
What is the temporal lobe?
Location for the auditory ability and memory acquisition
56
What is the occipital lobe?
Location of vision
57
What is hemispheric lateralisation?
The idea that the 2 hemispheres of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other, as in the example of language
58
What is split brain research?
- A series of studies which began in the 1960s (and are still ongoing) involving epileptic patients who had experienced a surgical separation of the hemispheres of the brain.
- This allowed researchers to investigate the extent to which brain function is lateralised.
59
What is the corpus callosum?
- A bundle of nerve fibres which joins the two hemispheres of the brain
60
What is commissurotomy?
The division of the 2 hemispheres by surgery
61
How do the 2 hemispheres of the brain communicate?
Through the corpus callosum
62
What is the left hemisphere responsible for?
- Language centre of the brain
- Controls the right side of the body
- Receives information from the right visual field
63
What is the right hemisphere responsible for?
- Focuses on visuospatial tasks
- Controls the left side of the body
- Receives information from the left visual field
64
What was Sperry's Split Brain Experiment?
- A quasi experiment
- 11 participants
- Sperry’s participants were epileptics who could not be treated with drugs. They has already had their corpus callosums split
65
What was the procedure of Sperry's Split Brain Experiment?
- The participant gazes at a fixation point on an upright translucent screen
- Slides are projected either side of the fixation point (into one visual field or the other) at a rate of one picture per 1/10 second
- Tactile tasks (tasks with objects) were carried out with the participant’s hands underneath a screen so the participants themselves couldn’t see what they were doing. They had to use ‘feel’ only
66
What were the variations of Sperry's Split Brain Experiment?
- Recognition by touch
- Drawings
- Composite words
- Face Recognition
- 2 objects placed in each hand then hidden for retrieval in a pile of items
67
What are the strengths of Sperry's Split Brain Experiment?
- Supports the lateralisation of the brain. The 2 hemispheres are functionally different
- Procedure was standardised and controlled
- Unique - allowing him to test a number of functions
68
What are the limitations of Sperry's Split Brain Experiment?
- Pucetti - hemispheres are dual in all brains (dualism). We have split minds. These differences are just exaggerated in Sperry’s split brain patients
- Limited sample - all epileptics and only 11 = Poor generalisability
- Lateralisation and functions are not as clear cut - some functions can be shared by different areas of the brain through constant communication e.g. during functional recovery
69
What is plasticity?
This describes the brain’s tendency to change and adapt (functionally and physically) as a result of experience and new learning
70
What is functional recovery?
A form of plasticity following damage through trauma, the brain’s ability to redistribute or transfer functions usually performed by a damaged area(s) to other, undamaged area(s).
71
What is synaptic pruning?
As we age, rarely used connections are deleted and frequently used connections are strengthened
72
What did Gopnick et al discover about synaptic connections during infancy?
- The brain experiences a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 at age 2-3 years
- This equates to about twice as many as there are in the adult brain.
73
What did Maguire et al study?
- Studied the brains of London taxi drivers using an MRI and found significantly more volume of grey matter in the posterior hippocampus than in a matched control group
- 16 right-handed male London taxi drivers participated; all had been driving for more than 1.5 years
- 'The Knowledge' test alters the structure of the taxi driver's brains
74
What are the strengths of Maguire et al's study?
- Real life application - ecological validity/external
| - Good evidence to support brain plasticity
75
What are the weaknesses of Maguire et al's study?
- Lack of generalisability due to a specific target group
| - No women involved
76
Which study is similar to that of Maguire et al's?
Draganski et al (2006)
- Scanned the brains of a group of German medical students 3 months before and right after an important exam
- Compared the scans to scans of students who were not studying for an exam. The students who were studying for an exam showed learning-induced changes in the parietal cortex and posterior hippocampus, regions known to be involved in memory retrieval and learning.
77
What is functional recovery?
- After injury, trauma (stroke) unaffected areas of the brain are able to adapt and compensate for damaged areas
- Healthy brain areas may take over functions of those that are damaged
78
What is spontaneous recovery?
Neuroscientists say that healthy brain areas may take over functions of those that are damaged very quickly
79
What are the 3 different ways the brain can attempt recovery?
- Axonal sprouting
- Reformation of blood vessels
- Recruitment of homologous areas
80
What is axonal sprouting?
The growth of new nerve endings which connect with each other undamaged nerve cells to form a new neuronal pathways
81
What is the recruitment of homologous areas?
Recruitment of homologous (similar) areas on the opposite side of the brain to perform specific tasks.
82
Give an example of the recruitment of homologous areas?
If Broca’s areas was damaged on the left side of the brain, the right-sided equivalent would carry out it’s functions. After a period of time, functionally may then shift back to the left side.
83
What is the reformation of blood vessels?
The blood vessels are reformed to ensure the brain functions in affected areas
84
What is fMRI?
- Measures rain activity while a person is performing a task
- fMRI works by detecting the changes in blood oxygenation and flow that occurs as a result of neural (brain) activity in specific parts of the brain.
- When a brain area is more active it consumes more oxygen and to meet this increased demand, blood flow is directed to the active area
- Produces 3D images
85
What are the strengths of fMRI?
- Does not rely on the use of radiation.
- Virtually risk-free, non-invasive and straightforward to use.
- High spatial resolution, depicts detail by the millimeter and provides clear picture of how brain activity is localised.
86
What are the weaknesses of fMRI?
- Expensive
- Only capture clear image if the person stays perfectly still, so not great for children
- Poor temporal resolution due to 5 second time lag.
- Only measure blood flow in the brain and cannot hone in on the activity of individual neurons.
- Difficult to tell exactly what kind of brain activity is being represented on screen.
87
What is electroencephalogram (EEG)?
- Measures electrical activity within the brain via electrodes that are fixed to an individual’s scalp using a skull cap
- The scan recording represents the brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity
88
What are the strengths of EEG?
- Invaluable in the diagnosis of conditions such as epilepsy
- Contributed to our understanding of the stages involved in sleep
- Unlike fMRI, EEG technology has extremely high temporal resolution.
- Can accurately detect activity at a resolution of a single millisecond
- Painless and safe
89
What are the weaknesses of EEG?
- Not useful for pinpointing the exact source of neural activity
- Does not allow researchers to distinguish between activities originating in different but adjacent locations
90
What are Event-related Potentials (ERPs)?
The brain’s electrophysiological response to a specific sensory, cognitive or motor event can be isolated through statistical analysis of EEG data.
91
What are post-mortem examinations?
The brain is analysed after death to determine whether certain observed behaviours during the patient’s lifetime can be linked to abnormalities in the brain.
92
What are the strengths of post-mortem examinations?
- Evidence was vital in providing a foundation for early understanding of key processes in the brain - no technology like fMRIs.
- Improve medical knowledge and help generate hypotheses for further study
93
What are the weaknesses of post-mortem examinations?
- Causation is an issue as damage may not be linked to deficits
- Ethical issues, unless they are a donor, patients cannot give informed consent
94
What are the different ways of investigating the brain?
- fMRI
- EEG
- ERPs
- Post-mortem examinations
95
What are circadian rhythms?
Biological rhythms that occur over a 24 hour cycle.
96
What are biological rhythms?
Patterns of changes in body activity over cyclical periods
97
Give 2 examples of circadian rhythms.
- Sleep/wake cycle
| - Core body temperature
98
What are ultradian rhythms?
Biological rhythms that occur more than one cycle in 24 hours
99
What are infradian rhythms?
Biological rhythms that occur less than one cycle in 24 hours
100
What are endogenous pacemakers?
Internal body clocks that regulate biological rhythms
101
Give 2 examples of an endogenous pacemaker.
- Body temperature
| - The influence of the suprachiasmatic nucleus (SCN) on the sleep/wake cycle
102
What are exogenous zeitgebers?
External cues that influence our biological rhythms
103
Give 2 examples of an exogenous zeitgeber.
- Light
| - Meal times
104
What is the sleep/wake cycle?
The brain’s circadian clock regulates:
- Sleeping
- Feeding patterns
- Alertness
- Core body temperature
- Brain wave activity
- Hormone production
- Regulation of glucose and insulin levels
- Urine production
- Cell regeneration
105
What determines the sleep/wake cycle?
- Endogenous pacemakers
| - Exogenous zeitgebers
106
What was Siffre's Cave Study?
- Spent several extended periods underground to study the effects on his own biological rhythms
- His ‘free-running’ biological rhythm settled down to one that was beyond the usual 24 hour cycle (around 25 hours), an Ultradian Rhythm, though he did continue to fall asleep and wake up on a regular schedule
107
What did Aschoff and Wever do?
- Convinced a group of participants to spend 4 weeks in a WW2 bunker deprived of natural light.
- All but 1 of the participants (whose sleep/wake cycle extended to 29 hours) displayed a circadian rhythm between 24 & 25 hours.
- Suggests that our ‘natural’ sleep/wake cycle may be slightly longer than 24 hours but that it is entertained by exogenous zeitgebers associated with our 24-hour day such as the number of daylight hours and typical meal times etc.
108
What are the strengths and weaknesses of sleep/wake cycle studies?
- Practical application to why night shift workers have limited concentration and why accidents are more likely to happen
- Research into circadian rhythms has revealed that there are certain peak times during the day and night when drugs are more likely to be at their most effective. This has led to the development of guidelines to do with the timing of drug dosing for a whole range of medicines
- Small samples - lack of generalisability
- Lack of control - cannot generalise
- Individual differences
109
Give 2 examples of an infradian rhythm.
- Menstruation
| - Seasonal affective disorder
110
Give an example of an ultradian rhythm.
Stages of sleep
111
What is the menstrual cycle?
- Infradian rhythm, approx 28 days to complete
| - Endogenous system
112
What did McClintock do?
- 29 women with a history of irregular periods
- Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles
- Shared with the other 20 women
- 68% of women experienced changes to their cycle which brought them closer to the cycle of their ‘odour donor’.
- Menstrual cycles may synchronise as a result of the influence of female pheromones
113
What is seasonal affective disorder (SAD)?
- Symptoms are triggered during the winter months when the number of daylight hours becomes shorter.
- Persistent low mood alongside a general lack of activity and interest life
- Infradian rhythm (circannual)
- Also considered a circadian rhythm as the experience of SAD may be due to the disruption of the sleep/wake cycle and this can be attributed to prolonged periods of daily darkness during winter
114
How many stages of sleep are there?
5
115
What are stages 1&2 of sleep?
- Light sleep where the person may be easily woken
- At the beginning of sleep, brainwave pattern start to become slower and more rhythmic (alpha waves), becoming even slower as sleep becomes deeper (theta waves)
116
What are stages 3&4 of sleep?
- Involve delta waves which are slower still and have a greater amplitude than earlier wave patterns
- This is deep sleep or slow wave sleep (deep sleep) and it is difficult to rouse someone at this point
117
What is stage 5 of sleep?
- REM sleep
- The body is paralysed, yet brain activity speeds up significantly in a manner that resembles the awake brain
- REM stands for rapid eye movement to denote the fast, jerky activity of the eyes under the eyelids at this point
- Research has suggested that REM activity during sleep is highly correlated with the experience of dreaming.
118
What is one criticism of infradian rhythms (McClintick's work)?
- Questionable validity
- Schank argued that if there would too many females cycling together within a social group, this would produce too much competition for the highest quality males so it would be most the adaptive evolutionary strategy to avoid synchrony
119
How long is 1 sleep cycle?
90 mins
120
What is the sleep/wake cycle?
A daily cycle of biological activity based on a 24-hour period (circadian rhythm) that is influenced by regular variations in the environment
121
What is the role of the suprachiasmatic nucleus (SCN)?
- Obtains information on light from the optic nerve, even when our eyes are shut. Light penetrates the eyelids, and special photoreceptors in the eyes pick up light signals and carry them to the SCN
- Influential in maintaining circadian rhythms such as the sleep/wake cycle
122
What did Patricia DeCoursey et al do?
- Destroyed the SCN connections in the brains of 40 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
123
What is the role of melatonin in the sleep/wake cycle?
- During the night, the pineal gland increases production of melatonin
- Induces sleep
- Is inhibited during periods of wakefulness
- Melatonin has also been suggested as a causal factor in seasonal affective disorder.
124
Give 2 examples of social cues affecting the sleep/wake cycle.
- Mealtimes
| - Bedtimes
125
What did Klein and Wegmann do?
- Found that the circadian rhythms of air travellers adjusted more quickly if they went outside more at their destination
- This was thought to be because they were exposed to the social cues of their new time zone, which acted as a zeitgeber
- Research has suggested that adapting to local times for eating and sleeping (rather than responding to one’s own feelings of hunger and fatigue), is an effective way of intraining circadian rhythms and beating jet lag when travelling long distances
