Biopsych Flashcards
(131 cards)
1
Q
\What is the nervous system?
A
- A specialised network of cells in the human body and is our primary internal communication system
- Divided into the central nervous system and the peripheral nervous system
2
Q
What is the role 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 is the Central Nervous System?
A
- Made up of the brain and spinal cord
- The origin of all complex commands and decisions
4
Q
What is the brain?
A
- The centre of all conscious awareness
- Cerebral cortex is the outer layer of the brain + distinguishes human mental functions from those of animals
5
Q
What is the spinal cord?
A
- An extension of the brain
- Responsible for reflex actions
- Passes messages to and from the brain and connects nerves to the PNS
6
Q
What is the Peripheral Nervous System?
A
- Transmits messages via millions of neurons to and from the central nervous system
- Subdivided into autonomic and somatic nervous system
7
Q
What is the Autonomic Nervous System?
A
- Governs vital functions in the body such as breathing, heart rate and stress responses (involuntary effect)
- Subdivided into sympathetic and parasympathetic nervous system
8
Q
What is the Sympathetic Nervous System?
A
Activates internal organs and increases bodily activities
9
Q
What is the Parasympathetic Nervous System?
A
Relaxes internal organs and decreases bodily activities
10
Q
What is the Somatic Nervous System?
A
- Transmits information from receptor cells in the sense organs to the CNS
- Receives information from the CNS that direct muscles to act voluntary
11
Q
What is the endocrine system?
A
- One of the body’s major information systems that instructs glands to release hormones directly into the blood stream
- These hormones are carried towards target organs in the body
12
Q
What is a gland?
A
An organ in the body that syntheses substances such as hormones
13
Q
What is a hormone?
A
- Chemical substances that circulate in the bloodstream and only affect target organs
- Produced in large quantities but disappear quickly
- Effects are very powerful
14
Q
What is the pituitary gland?
A
- Release lots of hormones
- Master gland: hormones released control and stimulate the release of hormones from the other glands in the endocrine system
15
Q
What is the pineal gland?
A
- Melatonin is released
- Responsible for important biological rhythms
16
Q
What is the thyroid gland?
A
- Thyroxine is released
- Responsible for regulating metabolism
17
Q
What are testes?
A
- Releases testosterone
- Responsible for the development of male sex characteristics during puberty
- Promotes muscle growth
18
Q
What are the ovaries?
A
- Releases oestrogen
- Controls the regulation of the female reproductive system including pregnancy and the menstrual cycle
19
Q
What is the adrenal gland?
A
- Releases adrenaline
- Responsible for the flight or fight response: stimulates heart rate, contracts blood vessels and dilates air passages
20
Q
What is the pancreas?
A
- Releases insulin
- Allows the body to use glucose from carbohydrates in food for energy or store energy for future use
- Helps keep blood sugar levels stable
21
Q
Fight or Flight Response
A
- The way an animal responds when stressed
- Body body becomes physiologically aroused in readiness to fight an aggressor or flee
- Reflexive: occurs without conscious awareness
22
Q
What is a neuron?
A
- Basic building blocks of the nervous system
- Nerve cells that process and transmit messages through electrical and chemical signals
23
Q
What is adrenaline?
A
- A hormone produced by the adrenal glands (part of the body’s stress response system
- Has a strong effect on the cardiovascular system (stimulates the heart rate, contracting blood vessels and dilating air passages
24
Q
What are sensory neurons?
A
- Carry nerve impulses from sensory receptors to the spinal cord and brain (PNS to the CNS)
- Receptors of sensory neurons are located on/near the body’s surface
- Short axon
- Long dendrites
25
What are relay neurons?
- Allow sensory and motor neurons to communicate with eachother
- Most common type of neuron in the CNS
- Located in the brain, spinal cord and visual system
- Short axon
- Short dendrite
26
What are motor neurons?
- Carry nerve impulses from the spinal cord and brain to the effectors from the CNS to the PNS
- Its axons are directly or indirectly linked to muscles
- Long axon
- Short dendrites
27
What is the cell body?
- Factory of the neuron
- Consists of the nucleus and produces all proteins a neuron needs in order to function
28
What is the nucleus?
Contains the genetic material within the neuron
29
What are dendrites?
- Branch like features protrude from the cell body
- Carry nerve impulses from neighbouring neurons towards the cell body
30
What are axons?
- Carries the electrical impulse from the cell body, down to the length of the neuron
- Covered in myelin sheath
31
What is the myelin sheath?
- Fatty layer surrounding and protecting the axon
- Helps speed up electrical transmission of the impulse
32
What are the nodes of ranvier?
- Gaps between the myelin sheath
- Speeds up the transmission of the impulse, forcing it to jump across the gaps along the axon
33
What are terminal buttons?
- Located at the end of the axon
- Communicate with the next neuron that is on the other side of the synaptic cleft
34
What is synaptic transmission?
Process in which neighbouring neurons communicate with eachother by sending chemical messages across the synaptic cleft then separates them
35
What are neurotransmitters?
- Brain chemicals released from synaptic vesicles that relay signals across the synapse of one neuron to another
- Can perform an inhibitory or excitatory function
36
What is excitation?
- When a neurotransmitter (e.g. adrenaline increase the positive charge of the postsynaptic neuron)
- Increases the likelihood the neuron will fire + pass on the electrical impulse
37
What is inhibition?
- When a neurotransmitter e.g. serotonin makes the charge of postsynaptic neuron more negative
- Decrease the likelihood of the neuron passing on an electrical signal
38
What is a synapse?
- Junction between two neurons
- Includes the presynaptic neuron, synaptic cleft and postsynaptic receptor site
39
What is the synaptic cleft?
The space between the pre and postsynaptic neuron
40
What are vesicles?
Small sacs at the end of a presynaptic neuron that contain neurotransmitters that will be released into a synapse
41
What is the presynaptic neuron?
The transmitting neuron, before the synaptic cleft
42
What is the postsynaptic neuron?
A neuron receiving the information at the synapse
43
What is the postsynaptic receptor site?
- A receptor on the postsynaptic neuron
- A neurotransmitter locks into a specific receptor on the postsynaptic neuron, triggering an electrical impulse in the postsynaptic neuron
44
What impact do drugs have on synaptic transmission?
- Increase amount of neurotransmitter - block reuptake channels
- Decrease amount of neurotransmitter - clock the receptors
45
What are the 4 ways of studying the brain?
- fMRIs
- EEGs
- ERPs
- Post Mortems
46
What are fMRIs?
- Detects changes in blood oxygenation and flow that indicate increase neural activity
- Asked to do a task and it's observed where brain activity is
- As the brain area is more active, it consumes more oxygen and blood flow is therefore directed to the active area (haemodynamic response)
- Produces activation maps showing which parts of the brain are involved in particular mental processes (imp. for localisation of function
47
What are the advantages of using fMRIs?
- Non invasive - doesn't rely on the use of radiation and is safe and therefore an appropriate method to study the brain
- High spatial resolution - Shows detail by the millimetre and therefore provides a clear picture of how brain activity is localised
48
What are the disadvantages of using fMRIs?
- fMRIs are expensive - Expensive compared to other techniques and can only capture an image if the persons stays still, limiting the appropriateness of fMRIs
- fMRIs have poor temporal resolution - 5 second lag between initial neural activity and image so doesn't represent moment to moment brain activity
49
What are EEGs?
- Records changes in electrical activity using electrodes attached to the scalp
- Scan recording shows brain wave patterns generated from the action of millions of neurons, providing an account of the brain activity
- Often used as a diagnostic tool as unusual arrhythmic patterns may indicate neurological abnormalities
50
What are the advantages of using EEGs?
- EEGs are invaluable in diagnosing conditions - e.g. identifying epilepsy and understanding the stages of sleep, making them an appropriate way to measure brain activity
- EEGs have high temporal resolution - detect brain activity as a resolution of a single millisecond, making it able to represent moment to moment bran activity
51
What are the disadvantages of using EEGs?
- EEG info is received from many neurons - they produce a generalised signal from thousands of neurons, making it difficult to know the exact source of neural activity - cannot therefore distinguish different but adjacent neurons
- EEGs do not provide a clear picture of brain activity - only monitor electrical activity in outer layers of the brain, therefore cannot reveal electrical activity in deeper brain sites
52
What are ERPs?
- Records changes in electrical activity using electrodes attached to the scalp but uses a specific stimulus (sensory, cognitive or motor) to see where the activity is
- Using a statistical averaging technique, all extraneous brain activity from the original EEG recording is filtered out, leaving the responses related to the stimulus
- Many forms of ERP are related to cognitive processes
53
What are the advantages of using ERPs?
- ERPs uses a specific measurement of neural processes - more specific that what can be achieved using raw EEG data making it a better method of investigating the brain
- ERPs have a high temporal resolution - can detect brain activity as a resolution of a single millisecond, making it more able to represent moment to moment brain activity
54
What are the disadvantages of using ERPs?
- Lacks standardisation in methodology between studies - makes it difficult to confirm findings in studies including ERPs and therefore the reliability of the info regarding the brain's function and structure is lowered
- ERPs have background noise which must be eliminated - limits the appropriateness of the method for studying the brain
55
What are post mortems?
- Examine abnormalities in the structure of the brain which try to explain psychological abnormalities people have before death
- May involve a comparison with a neurotypical brain to ascertain the extent of the difference
56
What are the advantages of using post mortems?
- PMs provide the foundation of understanding the brain - Broca and Wernicke both relied on PM studies, showing that they have improved medical knowledge and helped generate hypotheses for further study
- PMs allow for in-depth study of the brain - Detailed examinations + measurements of deep brain structures (e.g. hypothalamus) that are not measurable by brain scans can occur, providing us with knowledge of the brain that can't be gained from less invasive options
57
What are the disadvantages of using post mortems?
- Causation may be an issue - observed damage in the brain may not be linked to deficits under review but some other related to trauma or decay, limiting its appropriateness
- Unethical - before death, patients need to give informed consent but there's a reason psychologists wanted to investigate their brains in the first place, meaning they may not be able to provide consent e.g. HM
58
Localisation of function - What happened to Phineas Gage?
- Had an iron pole through his left cheek, passing behind the left eye, making most of this left frontal lobe
- Survived the damage but left a mark on his personality - became rude and quick tempered
- Landmark case in science - change in temperament suggested the frontal lobe is responsible for regulating the mood
59
What did the localisation of function theory argue?
- Argued that specific areas of the brain are associated with particular physical and psychological functions
- Damage to these areas can cause consequences for behaviour
60
What is the cerebral cortex?
- Brain is separated in two hemispheres and is surrounded by the cerebral cortex which is 3mm thick and covers the inner parts of the brain
- The cortex of both hemispheres is subdivided into four lobes which are named after the bones beneath which they lie
61
What are the 4 lobes within the cortex?
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
62
What is the motor cortex?
- Location: at the back of the frontal lobe
- Role: control voluntary movement in the contralateral side of the body
- Damage: loss of fine movements
63
Where is the motor cortex located?
At the back of the frontal lobe
64
What is the role of the motor cortex?
Controls voluntary movement in the contralateral side of the body
65
Damage to the motor cortex can cause what?
Loss of fine movements
66
What is the somatosensory cortex?
- Location: at the front of the parietal lobe
- Role: represents sensory info from the skin (touch, heat, pressure) / the sensitive an area, the more space it takes up in the somatosensory cortex
- Damage: loss of senses
67
Where is the somatosensory cortex located?
At the front of the parietal lobe
68
What is the role of the somatosensory cortex?
Represents sensory info from the skin (touch, heat pressure) / the more sensitive an area, the more space it takes up in the somatosensory cortex
69
Damage to the somatosensory cortex can cause what?
Loss of senses
70
What is the visual cortex?
- Location: in the occipital lobe
- Role: Info from the right visual cortex is sent to the left visual cortex and vice versa
- Damage: Loss of specific areas of the visual field
71
Where is the visual cortex located?
In the occipital lobe
72
What is the role of the visual cortex?
Info from the right visual field is sent to the left visual field and vice versa
73
Damage to the visual cortex can cause what?
Loss of specific areas of the visual field
74
What is the auditory cortex?
- Location: in the temporal lobe
- Role: analyses speech based information
- Damage: partial hearing loss
75
Where is the auditory cortex located?
In the temporal lobe
76
What is the role of the auditory cortex?
Analyses speech based information
77
Damage to the auditory cortex can cause what?
Partial hearing loss
78
What is Wernicke's area?
- Location: in the left temporal lobe
- Role: responsible for language comprehension
- Damage: producing nonsense words i.e. they can speak fluently but the words are meaningless to them
78
Where is Wernicke's area located?
In the left temporal lobe
79
What is the role of Wernicke's area?
Responsible for language comprehension
80
Damage to Wernicke's area can cause what?
Producing nonsense words i.e. they can speak fluently, but the words are meaningless to them
81
What is Broca's area?
Small area of the left frontal lobe
82
Where is Broca's area located?
Small area of the left frontal lobe
83
What is the role of Broca's area?
Responsible for speech production
84
Damage to Broca's area can cause what?
Slow speech that lacks fluency
85
Which hemisphere is Wernicke and Broca's area located?
In the left hemisphere
86
What are the names of the different cortexes (and areas)?
- Motor cortex
- Somatosensory cortex
- Visual cortex
- Auditory cortex
- Wernicke's area
- Broca's area
87
What is plasticity?
- The brain's tendency to change and adapt as a result of experience and new learning
- Infancy - brain experiences a growth in the number of synaptic connections, peaking at 15,000 at 2-3 years old
- Synaptic pruning - rarely used connections are deleted and frequently used connections are strengthened
88
What is synaptic pruning?
When rarely used connections are deleted and frequently used connections are strengthened as humans age
89
Plasticity and functional recovery: Maguire's study
- Studied the brains of London taxi drivers + found more volume of grey matter in the posterior hippocampus than in the control group
- PH's associated with the development of spatial + navigation skills
- "The Knowledge Test" - assesses recall of city streets // altered structure of brains, the longer in the job, the more pronounced the structural difference
90
Plasticity and functional recovery: Kuhn's study
- Control compared to video game group who played Super Mario for 30mins a day for 2 months
- Increase of grey matter in numerous brain areas for the video game group (brain areas associated with spatial navigation, working memory + motor performance
- Increase not found in the control group, demonstrating plasticity within the brain
91
Plasticity and functional recovery - Mediation: Lazar's study
- Used MRI scans to show how experienced mediators had a thicker cortex than non-mediators, in areas relating to attention
- The cortex is associated with higher level functions e.g. thought, emotion and reasoning
92
What is functional recovery?
- A form of plasticity, following damage through trauma
- Where the brain is able to redistribute/transfer functions usually performed by a damaged area to other undamaged areas
93
What happens during functional recovery?
- Brain learns how to compensate for the area that has lost the function
- Process can occur quickly (spontaneous recovery) + slow down after several weeks + may go to rehabilitation therapy to further recovery
- Brain reorganises itself by forming new synaptic connections close to the area of damage
- Secondary neural pathways that wouldn't typically be able to carry out certain functions are activated to enable functioning to continue
94
What structural changes can occur during functional recovery?
- Axonal sprouting
- Reformation of blood vessels
- Recruitment of homologous areas on the opposite side of the brain to perform specific tasks
95
What is axonal sprouting?
The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
96
What factors affect functional recovery?
- How much people want to recover
- How tired people are
- How stressed people are
- How much alcohol/drugs people are having
- Age - younger individuals recover more quickly
- Gender - women recover more quickly
97
What is hemispheric lateralisation?
- The idea that the two hemispheres of the brain are functionally different
- Some mental processes in the brain are mainly specialised to the left or right hemisphere
- Left hemisphere dominant in language and speech
- Right hemisphere dominant in recognising faces
98
What does damage to the brain during hemispheric lateralisation mean?
- We can assess which mental processes are mainly done by one hemisphere
- As damage to a particular hemisphere means people will not be able to do that task
99
What is the corpus callosum?
- A broad band of fibres that joins the two hemispheres of the brain, allowing communication to occur
- Cutting this has allowed brain lateralisation to be investigated
100
Visual fields and hemispheres
- Info from the left visual field is processed by the right hemisphere and vice versa
- Language is lateralised to the left hemisphere
- Right hand side of the body is controlled by the left hemisphere and vice versa
- Cutting of the corpus callosum means info cannot be passed between hemispheres
101
Split brain research: Sperry - Procedure
- Investigated hemispheric lateralisation
- Individual focuses on a central dot allowing info to be presented to the left visual field (processed by the right hemisphere) and vice versa
- Means info can only be processed by one hemisphere + we can see what functions are controlled by each hemisphere
102
Split brain research findings: Describing what you see
- Left hemisphere (which has language centres) is responsible for speech and language
- Image shown in right visual field, patient could describe what was being seen
- Image shown in left visual field, they couldn't due to lack of lang. centres
- If patient draws image presented in visual field, they let left hemisphere in on the secret + word can be said
103
Split brain research findings: Recognition by touch
- Unable to say what was seen in the left visual field as info is processed by the right hemisphere (no lang.)
- Using their left hand, they can pick out a matching object to the word shown
- Means they're able to identify the word that was shown in the left visual field in another way
104
Split brain research findings: Recognising faces
- Right hemisphere is for recognising faces
- When asked to match a face from a series of other faces, picture processed by RH was consistently selected, while pic in the LH was ignored
- When a composite pic made up of two halves of a face was selected, LH dominated verbal description + RH dominated in terms of a matching picture
105
What are biological rhythms?
- Cyclical changes in the way biological systems behave
- Have evolved as the environment humans + other organisms live has cyclical changes
106
What are biological rhythms controlled by?
- Endogenous pacemakers
- Exogenous zeitgebers
107
What are endogenous pacemakers?
Internal body clock that regulate biological rhythms e.g. the influence of SCN on the sleep/wake cycle
108
What are exogenous zeitgebers?
External cues that may impact/entrain biological rhythms e.g. influence of light on the sleep/wake cycle
109
What is a circadian rhythm?
- Cycle that lasts for 24hrs
- Rhythms optimise an organism's bodily functions + behaviour to best meet the demands of the sleep/wake cycle
- Rhythm is regulated by an internal systems e.g. release of hormones, metabolic rate + body temperature
110
What is the sleep/wake cycle?
- Light + dark provide signals about when we should be awake/asleep // s/w cycle dips and rises at different times
- Strongest sleep drive = 2-4am + 1-3pm
- Homeostasis also controls the need to sleep
- Factors combine, allowing individuals to sleep during the night + be awake during the day
111
Hormone production as a circadian rhythm
- Melatonin is produced and is released from the pineal gland
- Peaks during the hours of darkness
- Encourages feelings of sleep through activating synapses
112
Indicator of the sleep wake cycle: body temperature
- Lowest at 4am and highest at 6 pm
- Temperature rises during the last hrs of sleep (feel alert in the morning)
113
Sleep/wake cycle research: Siffre's study
Aim: Studied the effects of exogeneous zeitgebers on his biological rhythms
Procedure: Deprived of natural light + sound w/ minimal food + drink (absence of ex. cues altered his BR)
Findings: resurfaced 2 months after being in the Southern Alp cave + believed it was a month earlier than it actually was // his BR settled to one that was beyond the 24hrs + fell asleep and woke up on a regular schedule
114
Sleep/wake cycle research: Aschoff and Weaver
- Group sent 4 wks in a WW2 bunker deprived of natural light
- All but one displayed a circadian rhythm of 24-25hrs // anomalous had their cycle extended to 29hrs
- Suggests the natural sleep/wake cycles may be longer than 24 hrs but EZs entrain the human circadian rhythm to 24hrs
115
Endogenous pacemakers
- Internal body clocks that regulate our biological rhythms
- Impacted by the environment e.g. making individual sleep when there's little light
- Function without cues from the environment about what the body should be doing, but alters the circadian rhythm
- Must be constantly reset so human bodies are in synchrony with the outside world
116
Endogenous pacemakers: SCN and the pineal gland
- Located in the hypothalamus in each hemisphere of the brain
- Influential in maintaining circadian rhythms
- Regulated by light from the environment + receives info about light even when the eyes are closed
- Passes info on day lengths + light to the pineal gland
- PG produces melatonin in the night, inducing sleep by inhibiting the brain mechanisms that promote wakefulness
117
Exogenous zeitgebers
- External cues that impact or entrain biological rhythms e.g. effect of light on the sleep/wake cycle
- Set human body clocks thorough entrainment (synchronisation of the body to the environment)
118
What is entrainment?
Synchronisation of the body to the environment
119
Exogenous zeitgebers: light
- Resets the SCN
- Affects hormone secretion + blood circulation
120
Exogenous zeitgebers: light - Campbell and Murphy's study
- 15 participants were woken at various times + a light pad shone at the back of their knees
- Researchers produced a deviation in the participants' usual sleep/wake cycle, was up to 3hrs in some cases
- Suggests light is a powerful EZ that influences brains + bodies as it can be detected by skin receptor sites on the body, even when the same info is not received by the eyes
121
What are examples of exogenous zeitgebers?
- Light
- Social cues
122
Exogenous zeitgebers: social cues
Schedules imposed on us by society + are key influences on our sleep/wake cycle
- Entrainment of the body following jet lag is quicker when people eat and sleep when the local culture do
123
What are infradian rhythms?
- Infradian rhythms are rhythms that have a duration greater than 24 hours
- E.g. female menstrual cycle
124
Infradian rhythms: The menstrual cycle
- Refers to the time between the first day of a woman's period, when the lining is shed, to the day before her next period
- Rising levels of oestrogen cause the ovary to develop an egg and release (ovulation)
- Post-ovulation: progesterone levels increase, helping the womb line to grow thicker, reading the body for pregnancy
- If pregnancy doesn't occur, the egg is absorbed into the body ], the womb lining comes away and leaves the body
125
Infradian rhythms: Seasonal Affective Disorder
- Depressive disorder which has a seasonal pattern of onset
- Symptoms: low mood and lack of activity + interest in life
- Called a circannual rhythm (yearly cycle)
- Melatonin is the cause of SAD - pineal gland secretes melatonin until morning when there's an increase in light
- Lack of light in the winter = secretion process continues for longer
126
What are ultradian rhythms?
- Ultradian rhythms are biological rhythms that last less than 24 hrs
- Means there's more than one cycle within the 24hr period e.g. sleep cycle and the wake cycle
127
Stages 1 and 2 of the sleep cycle
- Light sleep where the person can be easily woken
- Start of sleep: brainwave activity become slower and more rhythmic (alpha waves) + become even slower as sleep becomes deeper (theta waves)
128
Stages 3 and 4 of the sleep cycle
- Involve delta waves which are slower still and have a greater change than earlier wave patterns
- This is deep sleep + is difficult to rouse someone at this point
129
Stage 5 of the sleep cycle
- REM sleep
- Body is paralysed yet brain activity speeds up significantly in a manner that resembles the awake brain
- Rapid eye movement describes the fact activity of the eyes under the eyelids
- REM activity during sleep is highly correlated with the experience of dreaming
130
Basic Rest Activity Cycles
- 90 min cycle that is found during sleep continues during the day
- We move progressively from a state of alertness into a state of physiological fatigue
- Human mind can focus for 90mins and then the body begins to run out of resources, resulting in loss of concentration
