Biopsychology Flashcards
(114 cards)
1
Q
What is the role of the nervous system?
A
To communicate messages through networks of nerve cells in our brain and body called neurons.
2
Q
What are the two divisions of the nervous system?
A
Central and peripheral
3
Q
What is the role of the Central Nervous System?
A
Uses the brain and spinal cord to receive, process and store information and then directs the actions of the body.
4
Q
What is the role of the Peripheral Nervous System?
A
Acts as a two-way communication highway to the CNS. It sends sensory messages picked up from the environment to the CNS and transmits messages from the CNS to the muscles and glands.
5
Q
What are the two divisions of the PNS?
A
Somatic nervous system and Autonomic nervous system.
6
Q
What is the role of the Somatic nervous system?
A
Controls voluntary muscle movement and receives information from sensory receptors.
7
Q
What is the role of the Autonomic nervous system?
A
Controls automatic, vital functions in the body, such as breathing, heart rate and digestion.
8
Q
What are the two divisions of the Autonomic nervous system?
A
Sympathetic nervous system and Parasympathetic nervous system.
9
Q
What is the role of the Sympathetic nervous system?
A
Prepares the body for ‘fight or flight’ response.
Increases heart rate, increases breathing rate, dilates pupils, inhibits digestion and inhibits saliva production.
10
Q
What is the role of the Parasympathetic nervous system?
A
Restores the body to ‘normal resting’ state after fight or flight response.
Decreases heart rate, decreases breathing rate, constricts pupils, stimulates digestion and stimulates saliva production.
11
Q
What is a neuron?
A
A nerve cell that is the basic building block of the nervous system. They communicate through electrical and chemical messages to enable us to move, think, feel and direct organs.
12
Q
What is the function of the nucleus?
A
The control centre of the neuron which contains DNA.
13
Q
What is the function of the dendrites?
A
Receives signals from other neurons.
14
Q
What is the function of the Node of Ranvier?
A
Speeds up transmission by making them jump.
15
Q
What is the function of the axon?
A
Conducts electrical impulses away from the neuron’s cell body.
16
Q
What is the function of the axon terminal?
A
Makes connections with other dendrites of other neurons or muscle (effector).
17
Q
What is the function of Schwann cells?
A
Produce the myelin sheath.
18
Q
What is the function of myelin sheath?
A
Fatty layer that insulates the neuron and speeds up electrical impulses.
19
Q
What is action potential?
A
An electrical signal that passes along the neuron. It only travels in one direction, from the dendrites, along the axon to the axon terminal.
20
Q
What are the three types of neuron?
A
Sensory neuron
Relay neuron
Motor neuron
21
Q
What is the role of the sensory neuron?
A
Carries messages from the Peripheral nervous system to the Central nervous system. Receives a message from the stimulus.
Long dendrites and short axons.
22
Q
What is the role of the relay neuron?
A
Connects the sensory neurons to the motor neurons or other relay neurons. These are only found in the CNS.
Short dendrites and short axons.
23
Q
What is the role of the motor neuron?
A
Connects the CNS to effectors such as muscles and glands to bring about an action.
Short dendrites and long axons.
24
Q
What is the process of a reflex arc?
A
Stimulus. Pain receptor stimulated. Signal sent along sensory neuron. Signal passed along relay neuron. Signal sent along motor neuron. Effector muscle contracts.
25
What is the endocrine system?
A communication system in the body responsible for vital functions. It is made up of glands in the body that produce and release hormones into the bloodstream.
26
What is a gland?
An organ in the body that secretes a particular hormone for use in the body.
27
What is a hormone?
Chemicals that affect the activity of a part of the body.
28
What hormone does the hypothalamus produce and what is its function?
Anti-diuretic hormone
| Regulates homeostasis
29
What hormone does the pituitary gland produce and what is its function?
ACTH - adrenocorticotropic
| Starts the process of the fight or flight response by controlling the release of hormones.
30
What hormone does the adrenal cortex produce and what is its function?
Cortisol
| Stimulates the release of glucose to provide the body with a burst of energy during the fight or flight response.
31
What hormone does the adrenal medulla produce and what is its function?
Adrenaline
| Triggers physiological changes in the body needed for the fight or flight response.
32
What hormone does the pineal produce and what is its function?
Melatonin
| Controls cycle of sleep and wake, and acts to make us sleepy.
33
What hormone does the thyroid produce and what is its function?
Thyroxine
| Affects heart rate and metabolic rate which affects long-term growth rates.
34
What hormones do the ovaries produce and what are its functions?
Oestrogen and progesterone
Regulates the female reproductive cycle. Oestrogen builds the lining of the uterus and progesterone maintains the lining of the uterus.
35
What hormones does the testes produce and what is its function?
Testosterone
| Develops the male reproductive tissues and increases muscle and bone mass.
36
What changes does adrenaline make to the body during fight or flight response?
Faster heart rate to pump blood faster around the body.
Dilates air passages in the lungs so more oxygen is more available.
Reduces the digestive activity including salivation.
Pupils dilate to allow more light into the eye.
37
What changes does cortisol make to the body during fight or flight response?
A quick burst of energy
Heightened memory function
A burst of increases immunity
Reduced sensitivity of pain
38
What is a synapse?
The junction between an axon terminal of one neuron and the dendrite of another neuron.
39
What is a neurotransmitter?
A chemical released at a synapse.
Excitatory neurotransmitters increase the chance the neuron will fire. This happens by increasing the positive charge at the post synaptic neuron.
Inhibitory neurotransmitters decrease the chance the neuron will fire by decreasing the charge at the post synaptic neuron.
40
What is the synaptic transmission process?
An action potential travels down dendrites, along the axon to the axon terminals.
The action potential causes the synaptic vesicles to fuse with the cell membrane and release the contents of the neurotransmitters to diffuse across the synaptic cleft. The electrical signal is transferred into a chemical message.
The neurotransmitters bind with the receptors on the dendrites of the receiving neuron and pass on the meassge.
41
What is summation?
Whether there are more excitatory or inhibitory neurotransmitters. If there are more excitatory, the signal will transmit and start an action potential in the next neuron. If there are more inhibitory, the post synaptic neuron will not fire.
42
What are the areas of the left hemisphere of the brain?
- Cerebral cortex
- Corpus callosum
- Limbic system
- Brain stem
- Cerebellum
43
What is the cerebral cortex?
Outer layer of the cerebrum, covers the hemispheres of the brain.
Folds increase the surface area.
Home to 'higher' functions - reasoning, language, morals.
Appears grey because of cell bodies 'grey-matter'.
44
What is the corpus callosum?
Bundles of millions of connective fibres (axons) join the left and right hemispheres of the cerebrum. These axons form the 'white matter' of the brain.
45
What is the limbic system?
Includes amygdala, hypothalamus, hippocampus and other areas.
Involved in many of our emotions and motivations, particularly those that are related to survival such as fear, anger and sexual behaviour.
46
What is the brain stem?
Controls heart, breathing, involuntary actions.
47
What is the cerebellum?
Responsible for motor actions such as balance, posture and smooth movement.
48
What is the holistic theory of brain function?
The theory that the brain works as one, with no area more or less responsible for any function.
This is no longer an accepted theory - we have very good evidence of localisation of function - that certain functions take place in specific areas of the brain.
However, the brain's remarkable ability to recover from trauma and its plasticity tell us that functioning is not necessarily always limited to a specific area of the brain.
49
What is localisation?
The theory that specific areas of the brain are associated with particular physical and psychological functions.
50
What is lateralisation?
One hemisphere of the brain being responsible for particular physical and psychological functions.
51
How is sensory processing and motor control housed?
Contralaterally (opposite side)
So damage to the left hemisphere will affect the right side of the body. Also, language for most people is based only in the left hemisphere.
The cerebrum is made up of the left and right hemispheres connected by the corpus callosum.
52
What are the 4 lobes of the left hemisphere?
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
53
What are the 4 cortexes of the hemispheres of the brain?
- Motor cortex
- Somatosensory cortex
- Visual cortex
- Auditory cortex
54
What is the motor cortex?
- Found in the frontal lobe
- Responsible for controlling voluntary movements
- Damage to this area results in impaired movements
55
What is the somatosensory cortex?
- Found in the parietal lobe
| - Responds to heat, cold, touch, pain and our sense of body movement
56
What is the visual cortex?
- Found in the occipital lobe
- Vision
- Damage can cause partial or total blindness
57
What is the auditory cortex?
- Found in the temporal lobe
- Complex processing of sounds happens here
- Also Meyer (2010) found that this area is activated when watching a silent film, for example seeing a door banging
58
What is the difference between the left and right hemispheres of the brain?
Language areas are only found in the left side of the brain.
| But each hemisphere has each lobe and specialised cortexes.
59
What is Broca's area?
- Found in the frontal lobe
| - Responsible for converting thought into speech
60
What is Wernicke's area?
- Found in the temporal lobe
| - Plays an important role in understanding other people's speech and for producing speech which makes sense
61
What would damage to either Broca's area or Wernicke's area create?
- Result in aphasia - inability or impaired ability to understand or produce speech.
- Broca's aphasia (aka productive aphasia) may make speech stilted, based mainly on using nouns, no connective words. It is effortful but lacks richness.
- Wernicke's aphasia (aka receptive aphasia or fluent aphasia) speech is effortless but flows easily but the meaning of words is lost.
62
How did the physicians Broca and Wernicke study patients?
Performed post-mortems to study localisation.
Impairment + visible injury = localisation
63
Who was Phineas Gage?
Had an iron rod shot through his brain and lived for 12 more years.
He became challenging, impatient and rude; reportedly 'not Gage'.
His frontal loves were damaged - we now know that this area is associated with impulse control and mood regulation.
64
What evidence is there for localisation?
Petersen et al
- Brain scans of people doing a listening task and a reading task
- Wernicke's area was more active during a listening task and Broca's was more active during a reading task.
- Supports localisation of function
Tulving et al
- Carried out brain scans (PET) to show images of the brain while participants recalled different types of memories
- They located different sections of the pre-frontal cortex for (left) semantic and (right) episodic memories
65
What neurosurgical evidence for localisation is there?
From 1950s onwards brutal and imprecise lobotomies were performed as treatments.
The frontal loves were servered form the brain with devastating effects, including personality changes and losing the 'self'.
This supports localisation of function.
66
What evidence is there for holistic brain function?
Lashley (1950)
Removed parts of the cortex (10-50%) in rats who were learning a maze.
He found that maze learning was not housed in a particular part of the cortex - this 'higher level' task was distributed across the brain.
This argues against localisation.
However, the research is done on rats, they are different species who don't have the same cognitive abilities as humans, so can't be generalised to humans.
67
How is vision processed in the brain?
- Vision from left of the nose is the left visual field
- This is picked up from both eyes
- This information crosses to the right hemisphere of the brain and is processed in the right visual cortex
- Vice verse for the right visual field
68
Why does separating the hemispheres control epilepsy?
Cutting the corpus callosum means seizures are contained in one hemisphere and cannot spread to the whole brain.
This is done when no other treatments work and is known as 'hemispheric deconnection' or 'split brain'.
69
How did Sperry examine certain functions specialised in the two hemispheres?
- 11 patients had undergone a split brain operation as a treatment for epilepsy + a control group
- Natural experiment
- The procedure was designed to make it possible to get information into one hemisphere only, so that communication, perception and memory of each hemisphere could be tested
- A tachistoscope was used
- The patient focused on a dot in the middle of the screen
- Word/s flashed for 1/10 of a second so information only went to one hemisphere
- On table under screen and out of sight, items could be handled in the tactile tests
70
What would participants say of the word tree was projected to the right of the central dot?
Tree because the information in the right visual field goes to the left hemisphere and the area for speech production (Broca's area) is in the left hemisphere.
If they use their right hand they can draw or find the object because the hand is contralaterally controlled by the same hemisphere. With the left hand, they cannot.
71
What was the tactile task participants did?
Participants simply had an object placed in their left or right hand and were then asked to find it from an assortment of objects without looking.
If participants used the same hand to find the object they could; if they used the opposite hand they could not.
OR they were asked to select the object which matched a word on the tachistoscope screen; again they could only find the object that the same field had seen.
72
What are the summary findings of split brain research?
When visual information is presented to the left visual field (and so right hemisphere) participants are not able to describe it and may say they saw nothing.
However, when information is presented to the right visual field (so left hemisphere) the participant can say what they saw.
This shows that language production is lateralised only to the left hemisphere.
The words flashing task shows that each hemisphere has a separate understanding and separate memory in a split brain patient.
73
Why is Sperry's split-brain research useful?
Because it tells us that speech production is housed only in the left hemisphere - so we already knew this was primarily in the LH but not the extent of the specialisation.
It also tells us the importance of the corpus callosum + its role in whole brain communication.
74
What aspects of Sperry's methodology made the research valid?
Participants stared at a central dot, information was flashed to one VF for 1/10 second so information only went into one hemisphere.
75
What aspects made Sperry's methodology reliable?
Standardised equipment and tasks used for all participants. So it is replicable.
Relatively objective questions with clear right and wrong answers, which increase reliability.
76
What are the problems with Sperry's sample?
Participants had differing degrees of surgery, differing levels of medication prior to the operation, and differing time periods since their operation.
These are problematic because the participant's capabilities could have varied and affected the results. Ideally they would have screen + gathered very similar participants.
77
Sperry's sample only had 11 participants in the 'experimental' condition. Why is this a problem?
Because it is unlikely to be representative of people with split brains therefore it may not be generalisable to all split-brain patients.
78
Sperry's control group did not have epilepsy or the associated medication history. Why is this a problem?
Because these could have acted as confounding variables and affected the split brain patient's capabilities; acting like another IV.
79
What is plasticity?
The capacity of the brain to change.
80
What are the two primary condition neuroplasticity occurs in?
- During normal brain development and learning
| - Functional recovery (compensate for lost function or to maximise remaining function in the event of brain injury)
81
What is neurogenesis?
Formation of new neurons; most of this happens before we are born but a little continues into adulthood especially in the hippocampus.
82
What is synaptogenesis?
Formation of new synapses; happens as we learn, particularly when making long term memories.
83
What is synaptic pruning?
Getting rid of unneeded synapses; peaks between 3 and 16 years of age but continues into adulthood.
84
Why is Maguire's study of London taxi drivers evidence of brain plasticity?
The longer they had been taxi driving, the greater the volume of they grey matter in the back of their hippocampi.
85
What research was done on newborn kittens?
One eye was sewn shut in newborn kittens.
The brain reorganised itself so that the parts of the visual cortex that should have received information from the shut eye processed information from the remaining eye instead.
86
What case study shows functional recovery?
Jodie Miller
Aged 3 she had her right hemisphere removed to treat severe seizures.
10 days later she could walk out of the hospital.
This is functional recovery (and plasticity).
87
What is negative plasticity?
Refers to the negative effects on brain plasticity.
For example, phantom-limb syndrome is the sensation that a severed limb still exists. It can be very painful.
It is thought to be a result of somatosensory cortex reorganisation following trauma.
88
What is functional recovery?
Brain trauma either through internal injury (stroke) or from a motorbike accident, results in damage and death to neurons, glial cells and blood vessels.
The brain may be able to adapt to this injury; this is a form of brain plasticity called functional recovery.
89
What is neural reorganisation?
Healthy brain areas may take over the functioning of damaged or missing parts of the brain.
Either areas alongside or a similar area in the other hemisphere.
90
What is involved in neural regeneration?
- Axonal sprouting
| - Reformation of blood vessels
91
What is axonal sprouting?
Healthy neurons will grow fine nerve endings which connect with other undamaged neurons to form new neural pathways.
92
What is reformation of blood vessels?
Blood vessels may change structure or function to assist with recovery, particularly the response to swelling and inflammation.
93
What is cognitive reserve?
The plasticity effect of all that education means the brain is better equipped to reorganise post-trauma.
Schneider et al found that the longer a person with brain injury had spent in education, the greater chance they would have of a disability-free recovery.
94
Why does age of injury matter?
Degree of recovery is negatively correlated with age; on average younger people who suffer brain injury are able to regain much greater functioning than older people.
95
What are the applications to functional recovery?
Understanding functional recovery has contributed to neuro-rehabilitation following stroke and other injury.
Intervention is needed to restore functioning. The first six months is crucial.
Current research involves looking at whether stem cells or drugs can be used to assist with neuro-rehabilitation.
96
What are the 5 ways of studying the brain?
- EEG (ElectroEncephaloGram)
- ERP (Event Related Potentials)
- Post mortem
- fMRI (functional Magnetic Resonance Imaging)
- PET (Positron Emission Tomography)
97
What is an EEG?
- Electrical activity ("brain waves") in the brain are recorded using electrodes placed on the scalp
- The EEG records the electric impulses (action potentials) as neurons fire
- Show patterns of activity which can be used diagnostically in epilepsy or to study mirror neurons or sleep for example
- Each electrode produces its own reading so some vague localisation may be visible
98
What are examples of EEGs?
Mirror neuron research used to show areas that are active both when doing and watching a task.
This led to the broken mirror theory of autism.
Diagnostic tool in epilepsy treatment + research and sleep research.
99
What are the strengths of EEGs?
- Measuring electrical activity from the brain is useful because the brain uses electrical impulses to operate.
- Application to diagnosis of epilepsy and studying stages of sleep.
- High temporal resolution (a millisecond).
- Non invasive and risk-free.
100
What is the weakness of EEGs?
It can identify a general area of activity, but it cannot pinpoint specific areas of neuronal activity, so it may be less useful than other methods.
101
What is ERP?
- Uses EEG equipment
- ERPs are the measurement of small potential changes in the EEG signal immediately after the presentation of a sensory stimulus (event)
- This makes it possible to record specific brain responses to sensory, motor, cognitive and other mental events
- Show patterns of activity
- These can be linked to specific processes such as attention and perception
102
What are the strengths of ERPs?
- A form of EEG so shares the positives
| - Provide more specific data on neural processes and allow for comparison of different ERPs and EEG.
103
What is the weakness of ERPs?
Can be difficult to use; background noise and other stimuli must be completely eliminated.
104
What is post mortem?
- Dissection and examination of the brain after death
- May involve observation of the gross structure of the brain, or the examination of slides of thin slices of the brain for microscope study; this is known as histology
105
What are the strengths of post mortem?
- Historically very important
| - Allows detailed study of structure which may be used to generate hypotheses for further studies on living brains
106
What are the weaknesses of post mortem?
- Limited as it is structural rather than functional information
- It is impossible to be sure about cause and effect (Broca's patient Tan may have had speech problems because of a less obvious area of damage)
- Ethics - issue of informed consent obtained from brain damage patients before death eg. HM's brain was studied in post mortem
107
What are the examples of post mortem?
HM - thousands of slices were taken from his brain
Kitten's visual cortex were studied after having one eye sewn shut
Tan - post mortem allowed identification of Broca's area
108
What is fMRI?
- Functioning magnetic resonance imaging
- Measures blood flow = more oxygen = more activity in that part of the brain
- Detects radio wave changes
- Measurements are taken as the person performs a certain task, therefore functional
- Allows for study of localisation of function
109
What are the strengths of fMRI?
- Very high spatial resolution to 3 cubic mm or less, becoming more precise all the time
- Non invasive and virtually risk-free
- Compared to PET, it is safer as it does not use radiation
110
What are the weaknesses of fMRI?
- The person must remain completely still for accurate results
- Temporal resolution is poor - there is a 5 second time lag between the firing of a neuron and screen image
- Measures blood flow not neuronal activity so exactly what sort of brain activity is represented is hard to know
111
What is PET?
- Positron Emission Tomography
- Radioactive isotope attached to glucose molecules; can be tracked in the brain
- More glucose (more radiation = more activity)
112
What are the strengths of PET?
- Small movements do not affect the accuracy of PET scans, a clear advantage over fMRI scanning
- So for example someone could read out words or answer questions while being PET scanned
113
What are the weaknesses of PET scans?
- PET scans are less precise than fMRI: 5-10 cubic millimetres compared to fMRI 3 cubic millimetres
- PET scanning is much more expensive (special machines and isotopes) than fMRI
- Invasive
- Radioactive isotopes are used, these can be given only a few times before it is unsafe to do so
114
What are the examples of where PET scans were used?
Adrian Raine: PET scans of pre-frontal cortex + amygdala in murderers compared to controls
Tulving: located episodic LTM - right PFC, semantic LTM - left PFC
