Psychobiology Flashcards
1
Q
What is neuropsychology?
A
a method of exploring the brain - shows the consequences of damage to specific areas.
2
Q
What is PET imaging?
A
Position emission tomography - detects radiation and brain activity (glucose levels).
3
Q
What is MRI imaging?
A
Magnetic resonance imaging - measures blood oxygenation changes - measure of neuronal activity
4
Q
What is the CNS?
A
Nerves that make up the spinal cord and brain.
5
Q
What is the PNS?
A
What is left over from the CNS - responsible for providing us with inputs/outputs.
6
Q
What is the PNS made up of?
A
The autonomic nervous system and the somatic nervous system.
7
Q
What is the ANS made up of?
A
Two branches: the sympathetic and parasympathetic.
8
Q
What are sympathetic nerves responsible for?
A
Fight or flight - e.g. speeding up heart rate - bring the body to an aroused state.
9
Q
What are parasympathetic nerves responsible for?
A
Rest and digest - e.g. lower heart rate - return the body to its resting state.
10
Q
What is the somatic nervous system responsible for?
A
Handles inputs from the external world by functioning via the spinal cord. Inputs come from the dorsal root and leave to affect muscles via the ventral root.
11
Q
What do the ventricles contain?
A
Cerebrospinal fluid (CSF)
12
Q
What is CSF?
A
A liquid produced from ependymal cells which bathes the brain, protecting it from injury - circulates between membranes, along large blood vessels and through the ventricles.
13
Q
What are neurones?
A
Information transmitting cells which transmit and process information using electrical signals
14
Q
What are neurones made up of?
A
Dendrites, which receive info
Soma, which integrate inputs
Axons - axon hillock, myelin sheath and axon terminal
15
Q
What the types of glia?
A
Astrocytes, oligodendrocytes and microglia
16
Q
What is the role of astrocytes?
A
Wrap processes around and communicate with neurones and contact blood vessels.
17
Q
What is the role of oligodendrocytes?
A
Wrap myelin sheath around axons.
18
Q
What is the role of microglia?
A
The brains resident immune system - remove damage and infection.
19
Q
What is Ohm’s law?
A
current = (potential x conductance)
or
(potential / resistance)
20
Q
What creates the concentration gradient?
A
Ion channels in the membrane allow potassium ions to flow outside of the cell, making the inside more negative which then attracts more potassium ions inside the cell - equilibrium maintained by a Na+ / K+ pump.
21
Q
What is an action potential?
A
A wave of transient depolarisation that travels down the axon.
22
Q
What are the steps of an action potential?
A
1) When neurotransmitters bind to receptors they depolarise the neurone (+)
2) A threshold of -55mV has to be reached for an AP to go ahead
3) Depolarisation occurs due to Na+ channels opening and the shutting of K+ channels (+)
4) Then the neurone is repolarised due to the Na+ channels closing and the K+ channels opening (-)
5) The neurone is then hyper-polarised as K+ continues to leave the cell, causing the inside to become very negative.
6) Then the neurone returns to its resting state of -70mV.
23
Q
What is an absolute refractory period?
A
When all sodium channels are inactivated, enforcing one way transmission. The neurone is unable to respond to another stimulus.
24
Q
What is a relative refractory period?
A
When some sodium channels are inactivated and only a very strong stimulus can reopen them to produce an action potential.
25
What is saltatory conduction?
When the action potential travels through gaps in the myelin sheath (Nodes of Ranvier).
26
What happens at the presynaptic cell?
An AP arrives, depolarising the terminal. this releases calcium which activates the release of neurotransmitters into the synapse. Then the neurotransmitter binds to receptors on the postsynaptic membrane, producing either an excitatory or inhibitory response.
27
What happens to produce an excitatory response?
Depolarisation of dendrites due to ions flowing through glutamate receptors generates an excitatory post synaptic response (EPSP) which increases the likelihood of an AP occurring.
28
What is temporal summation?
Lots of EPSP's are needed to reach the threshold for an AP.
29
What is spatial summation?
The activation of lots of synapses produces enough EPSP's at the same time to summate and reach the threshold for an AP.
30
What produces an inhibitory response?
GABA, an inhibitory neurotransmitter, opens chloride channels which allows negative charge into the cell, generating an inhibitory post synaptic potential (IPSP), hyper-polarising the membrane.
31
What is tolerance?
When you take a drug in repeated, identical doses the effects diminish.
32
What is sensitisation?
Repeated exposure to a drug makes the effects stronger.
33
What is addiction?
Compulsive use: which leads to a loss of control over a form of behaviour pleasurable to most people - suggests a separation between wanting and liking.
34
What are the effects of cocaine?
It blocks dopamine transporters, increasing the levels of dopamine at the synapse.
35
What are the effects of amphetamine?
Amphetamine is transported into the presynaptic terminal and displaces dopamine from its vesicles, releasing it into the synapse, and then reduces its reuptake.
36
What does cannabis do?
It mimics the effects of endocannabinoids.
37
What is a full agonist?
Produces maximal stimulation at higher doses - high efficacy and affinity.
38
What is a partial agonist?
Produces a small effect than a full agonist but can reduce its effects. High affinity and a lower efficacy.
39
What is an antagonist?
Reduces the effects of agonists. Has high affinity and low efficacy.
40
What is anxiety?
A feeling or fear or dread, usually in situations where there is no reasonable external cause. Or clinical anxiety which interferes with other activities.
41
What are rods and cones?
Specialised cells that hyper-polarise when light falls on them, depolarising retinal ganglion cells, producing an action potential.
42
How is information projected in the eyes?
Information from the nasal side of the retina is sent to the opposite side of the brain - projected contra-laterally.
Information from the temporal side of the retina remains on the same side of the brain - projected ipsilaterally.
43
How do muscle contractions occur?
Acetylcholine released at muscle end plate and binds to nicotinic receptors, opening sodium channels. This depolarises the muscle membrane which releases calcium ions, triggering the muscle fibres to contract.
44
What are individual differences in response to stress?
People have one of two gene variants of an enzyme important in degrading dopamine - either Met (which leads to higher dopamine levels due to lower COMT activity) or Val. Individuals with Met may be more prone to greater stress and worry whereas those with Val are at a greater vulnerability to psychosis.
45
What is the faster, neutrally mediated response to stress?
Stresser activates brain circuits in the amygdala and hypothalamus, which activates the sympathetic NS, stimulating the medulla of the adrenal gland, which releases epinephrine which activates the endocrine glands, releasing adrenaline. If the parasympathetic NS is active acetylcholine is released.
46
What is the slower, hormonally mediated response to stress?
The stressor causes the hypothalamus to release CRH into the pituitary gland, releasing ACTH which acts on the adrenal gland cortex, which releases cortisol which activates the boys cells, endocrine glands and the brain.
47
What are emotions used for?
- To co-ordinate responses to environmental challenges.
- Act as a basis for social communication
- Support conscious evaluation of a situation
48
What is folk psychology (in emotion)?
Intuitions tell us when something is frightening, which makes us fearful, which is expressed through facial expressions, followed by experiencing a stress response.
49
What is the James - Lange theory?
Suggests that emotions follow a physiological response to a stimulus.
50
What is Damasio's somatic marker hypothesis?
Suggest that feelings are able to influence decision making - shown in the IOWA gambling task.
51
What is Schacter and Singers cognitive arousal theory?
Physiological arousal enhances any emotion induced at the same time. Emotion generated either by cognition alone or with arousal.
52
What is Zajonc's affective primacy theory
Pre-exposure to stimuli produces an increased liking for it - single exposure can change responses to a stimuli.
53
How can opioids modify liking?
An opioid agonist enhances hedonic responses to sweet but suppressed aversive responses to bitter.
54
What is learning?
A relatively permanent change in behaviour as a result of experience.
55
What is non-associative learning?
Learning that stimuli exist in the world - through repeated exposure.
56
What is associative learning?
Learning associations between stimuli or between actions and stimuli.
57
What is habituation?
The learned suppression of a response to a repeated stimuli.
58
What is a unconditioned stimulus?
Produces a response (UCR) without learning
59
What is a conditioned stimulus?
Stimulus that elicits a response (CR) through learning
60
What is acquisition?
The reinforcement of an UCR by an UCS.
61
What is extinction?
When there is no reinforcement the associations between stimuli fade - less responses produced.
62
What is spontaneous recovery?
After a period of extinction the CS is reintroduced which increases the likelihood of the response returning.
63
What is reacquisition?
When the CS is reinforced again the response is acquired again.
64
What is generalisation?
If you learn to respond to a certain stimulus if a similar one is displayed then a response will be produced.
65
What is discrimination?
If you learn to respond to a specific stimulus, you will only respond to that to gain rewards.
66
What are Thorndike's laws of learning?
- law of effect: behaviour that leads to a positive outcome more likely to reoccur.
- law of exercise: connections between responses and outcomes are strengthened by repetition.
- law of readiness: learning is motivated by an internal state.
67
What is operant (instrumental) conditioning?
Associations between a response and outcome - based on positive/negative consequences.
68
What are schedules of reinforcement?
- continuous: each response is reinforced
- partial: behaviour is reinforced sometimes
- ratio schedule: reinforcement given after after nth response - fixed or variable
- interval schedule: reinforcement given after certain amounts of time - fixed or variable.
69
What is declarative memory?
Semantic and episodic information
70
What is non-declarative memory?
procedural memory, skill learning, conditioning and non-associative learning.
71
What is the principle of equipotentiality?
All cortical regions can mediate learning equally - no particular area is essential for memory
72
What is the principle of mass action?
Ability to learn is proportional to the amount of cortex available
73
What is long term potentiation?
High frequency of the chemical synapse produces an increase in synaptic strength.
74
How is body temperature reduced?
Blood vessels dilate and sweat glands secrete.
75
How is body temperature increased?
Blood vessels constrict and sweat glands are closed.
76
What is osmometric thirst?
Changes in concentration - water loss causes salt concentration to increase.
77
What is hypovolemic thirst?
Changes in overall volume - loss of extracellular fluid levels can induce thirst. Measured by the kidneys and the heart.
78
How do the kidneys measure changes in volume?
Changes in volume trigger the release of renin from the kidneys which converts angiotensinogen into angiotensin (stimulates kidneys to conserve water)
79
How does the heart measure changes in volume?
The atria contain baroreceptors that detect stretch and measure the volume of blood. This information is sent to the nucleus of the solitary tract and median pre optic area which encourages drinking.
80
How is energy used?
Basal metabolism (maintain body heat etc.), digestion of food and active behavioural processes.
81
What are some sources of energy?
Carbohydrates, amino acids, lipids and vitamins + minerals.
82
What is the glucostatic set point theory?
Eating is controlled by deviations from a hypothetical blood glucose set point - as levels drop, need for food is triggered.
83
What is the lipostatic theory?
Eating is controlled by a hypothetical body fat set point.
84
What is the lateral hypothalamus?
The hunger centre - damage causes a decrease in feeding.
85
What is the ventromedial hypothalamus?
The satiety centre - damage increases feeding.
86
What are the roles of ghrelin and orexin?
They are peptide hormones secreted in the gut and they increase hunger and feeding behaviour
87
What are the roles of cholecystokinin and polypeptide YY?
CCK - a hormone that inhibits feeding
| PPY - a hormone that inhibits feeding
88
What is leptin?
Satiety signal - reduces feeding.
| A leptin deficiency is associated with obesity.
89
What are some direct benefits of group living?
- lower probability of being killed by predators
- better at finding food
- improved competitive ability
- improved success at rearing young
90
What are some costs of group living?
- increased chances of being detected by predators
- higher risk of parasitism
- resources have to be shared
- reproductive suppression for subordinates
91
What is altruism?
Behaviour that benefits the recipient at some cost to the donor.
92
What is inclusive fitness?
The total fitness an individual gains, by breeding and helping close relatives to breed.
93
What is Hamilton's rule?
B/C > 1/r
B= benefit to recipient
C= cost to donor
r= coefficient of relatedness
94
What is reciprocal altruism?
The benefit to the recipient has to be greater than the cost to the donor - and when the act is reciprocated both pp's gain.
95
What occurs in individual contests?
Assessment of resource holding potential (fighting ability) - are they likely to win the competition?
96
What occurs in group contests?
The probability of the approach is predicted by the ration of number of defenders to the number of intruders.
97
What is intra-sexual competition?
Competition between members of the same sex over mates (e.g. male-male competition)
98
What is inter-sexual competition?
Choice by members of one sex for particular mating partners of the opposite sex
99
What are two forms of intra-sexual competition?
Direct combat (larger males selected) and sperm competition (male successful in fertilising egg is selected)
100
What are factors involved in inter-sexual choice?
```
Good genes (females choose males with characteristics that indicate high genetic quality)
Attractive sons (females choose highly attractive males so they have attractive sons who will be chosen by females)
Sensory exploitation (females choose males as their characteristics exploit their sensory systems)
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101
What is sexual dimorphism?
The sex with the higher potential reproductive rates competes for the sex with the lower potential reproductive rates.
102
What are sexual displays?
Information transferred via signals which brings sexes together for mating.
103
What is referential signalling?
Using signals to denote external objects and events.
| e.g. vervet monkey alarm calls denote predator types
104
What is response urgency signalling?
Different signals for different levels of urgency.
| Whistle for high urgency predation threat and chitter chat for low urgency (Californian ground squirrel)
105
What language abilities do animals have?
Animals can attach acoustic labels to objects and events (semantics).
106
What is social organisation?
How animals interact with and space themselves in relation to other individuals of the same species.
107
What is a mating system?
The way individuals obtain and bond with mates
108
What is solitary living?
Sexes live apart and come together to mate.
109
What is a monogamous family unit?
Long term pair - males and females defend territory together.
110
What is polyandry?
Where several males are bonded to one female.
111
What is polygyny?
Where there are multiple females per male.
112
What determines rank and dominance?
In primates females often inherit the dominance rank directly below their mother.
In chimpanzees, males stay in the group, so dominant mothers have dominant sons.
