Psychobiology Flashcards
1
Q
Brains job
A
-takes in info from outside world, perform computations/processes it and produces effects/outputs/behaviours
2
Q
Peripheral nervous system
A
- Automatic:CNS -> motor neurone -> internal environment -> sensory neutron -> CNS
- Somatic: CNS -> motor -> external env. -> sensory -> CNS
- sensory neurones: input from skin, output to spinal cord
- motor neurones: input from brain, output to muscles
- parasympathetic system: rest or digest, conserve energy, slows HR
- sympathetic system: fight or flight, rapid involuntary response to danger/stressful situations, raise HR
3
Q
Brain regions/brain slicing
A
Anterior: in front of Posterior: behind Superior: above Inferior: below Medial: towards midline Lateral: towards side Coronal Sagittal Horizontal
4
Q
Brain structures
A
Brain stem: midbrain, pons, medulla
Forebrain: central hemisphere, diencephalon (thalamus, hypothalamus)
Cerebellum
Spinal cord
5
Q
Cerebellum
A
Layered organised structure
Involved in refining movements and thoughts
6
Q
Diencephalon
A
Bilateral structure
Thalamus: information hub, relays info from widespread brain areas
Hypothalamus: regulates homeostatic processes, connects to pituitary gland
7
Q
Cerebrum
sub cortical structures
A
Hippocampus
Basal ganglia
Amygdala
Olfactory bulb
8
Q
Hippocampus
A
Inputs: mid brain, cortex, projection nuclei
Outputs: cortex, amygdala, thalamus, ventral striatum
Computations: associative learning, spatial memory
9
Q
Basal ganglia
A
Inputs: cortex, hippocampus, substantia nigra
Outputs: thalamus, substantia nigra
Computations: coordinating movement and motivated behaviour
10
Q
Amygdala
A
Inputs: cortex, hippocampus, thalamus, brainstem
Output: cortex, basal ganglia, hypothalamus, brain stem
Computations: emotional learning
11
Q
Ventricles
A
Contain cerebrospinal fluid, produced from ependymal cells lining ventricles
Circulated around brain, meninges, blood vessels and small extracellular space around neurones
Clears brain of unwanted products
12
Q
Blood supply in brain
A
Specialised blood supply that’s self regulated
Brains highly vascularised
Functional MRI measures increase in oxygenated blood flow
13
Q
Brain cell types
A
Neurones Glia: Astrocytes Oligodendrocytes Microglia
14
Q
Neurones
A
Information transmitting brain cell
Transmit and process info using electrical signals
Made up of dendrites, soma, myelin sheath, axon terminal
Different shapes indicate different functions
15
Q
Glia
A
Astrocytes: wrap processes around neurones, supportive roles
Oligodendrocytes: wrap myelin sheath around axon to insulate
Microglia: resident immune cell, survey brain for infection and damage, destroy/eat damage or infection
16
Q
Labelling cell types
A
-fill with dye by inserting an electrode and allowing dye to diffuse in
-label with antibodies which attach to proteins specific to cell
Genetically modify mice to express fluorescent protein that expresses specific proteins
17
Q
Electricity and corpses
A
Galvanic process
Electricity applied to corpse face, muscles contorted
Electricity applied to corpse body result in hand being raised and clenched
18
Q
Electricity
A
-flow of charged particles
-current only flows through material that conducts electricity
Ohms law:
-current = potential x conductance
-current = potential / resistance
-potential: voltage difference, stored electrical energy
19
Q
Concentration gradient across axon membrane
A
Outside of membrane there is more positive ions eg Na+, Cl+, Ca+
Inside membrane is K+, and negatively charged proteins
Electrochemical gradient created and maintained by Na+/K+ ATPase, pumps 3 Na+ out and 2 K+ in
Membrane potential is set by electrochemical gradient and permeability of membrane to ions
20
Q
resting potential
A
outside cell is more sodium and little potassium
inside cell is more potassium, little sodium
electrochemical gradient as there is more positive ions on outside of cell
ATPase pump manages resting potential, pumps out 3 sodium ions, and in 2 potassium ions
21
Q
action potential is a …
A
wave of transient depolarisation that travels down axon
measured using voltmeter
22
Q
key concepts about ion channels
A
- holes in membrane
- allow ions to pass into and out of cell
- selective ions
- opened by different stimuli
- ions flow down electrochemical gradients
23
Q
action potentials:
convey …
generated by …
occur when …
A
- convey fast signals from one place to another
- generated by changes in membrane permeability (opening and closing of voltage gated channels)
- self regenerating
- only occur if reach threshold
24
Q
action potential events
A
- threshold reached
- depolarisation of membrane (sodium channels opened)
- repolarisation of membrane (sodium channels close, potassium channels open)
- hyperpolarisation as voltage-gated potassium channels still open
25
all or nothing principles
-for action potential to occur voltage inside membrane must reach that of threshold otherwise no actin potential
26
action potential propagation
- same size all along
- as move along, depolarises next section of membrane and opens up the next voltage gated sodium channels
- if enough channels open, reach threshold potential and action potential propagates along
27
absolute refractory periods
all sodium channels inactivated
| one-way transmission
28
relative refractory period
some sodium channels inactivated
| only strong stimuli can re-open channels and generate action potential
29
saltatory conduction
- only in myelinated axons
- action potential jumps from node of ranvier to the next
- depolarisation only occurs at node of ranvier
- faster and more efficient than unmyelinated actions
30
synapse events
- action potential arrives at pre synaptic cell, opens calcium voltage gated channels
- influx of calcium causes vesicles containing neurotransmitters to fuse with membrane and release them into synaptic cleft
- neurotransmitters bind to post synaptic ligand-gated channels
- ligand gated channels open and sodium ions diffuse into post synaptic neurone
- depolarisation creating new impulse
31
excitatory and inhibitory action potentials
excitatory: makes action potential more likely to happen by allowing positive charged ions to diffuse into post-synaptic neuron
inhibitory: makes action potentials less likely to happen by allowing negatively charged ions to diffuse into post-synaptic neuron
32
excitation in post-synaptic membrane
- depolarisation of dendrites
- glutamate binds to AMPA receptor causing it to open allowing sodium ions to diffuse through
- generates excitatory post synaptic potential
33
summation
- temporal summation: many action potentials from one neuron, increases the amount of neurotransmitter in synaptic cleft
- spatial summation: many neurons active at same time, combine to reach threshold
34
post synaptic membrane inhibition
- GABA is main inhibitory neurotransmitter in brain
- opens chloride channels allowing negative charge into cell, hyperpolarising membrane making ti harder to reach threshold
- generates inhibitory post-synaptic potential
35
anxiety: clinical aspects
- feeling of fear or dread
- psychiatric literature: term anxiety used in situations where there is 'no reasonable' external cause fro anxiety and fear
- clinical anxiety refers to anxiety that's 'pathologically' interfering with other activities and priorities
- symptoms: fear (panic/phobia), worry (anxious misery, apprehensive expectations, obsessions)
36
drug treatments of anxiety
- alcohol (self medicated)
- barbiturates, mepobromate: low therapeutic index, induces tolerance and dependence
- benzodiazepine: anxiolytic effect, induce dependence
- selective seratonin reuptake inhibitors: first line pharmacological treatment, delayed onset of action
37
expectations of psychopharmacological treatments
- disease centred: suggests drug restores normal function
- symptom centred: suggests drug produces specific change in aspects of mood, motivation, cognition and makes condition less disabling
38
GABA synapse and benzodiazepine
- GABA binds to receptor causing chloride ion pore to open, inhibiting action potential
- GABA receptor: separate binding sites for alcohol, barbiturates and benzodiazepine
- benzodiazepine enhances effect of GABA
- benzodiazepine sensitive receptors are selectively expressed in specific brain areas such as hippocampus and amygdala (mouse brain)
39
GABA receptor subtypes
- made up of 5 subunits, each coded for by different genes
- variety in structure alters sensitivity to benzodiazepine
- GABA a receptor is ionotrophic (ligand gated channel)
- GABA b receptor is metobotrophic (g protein coupled receptor)
40
fear and amygdala
fear conditioning
-tone played creates small increase in blood pressure and brief startle response
-tone preceded by mild footshock, larger increase in blood pressure and freeze response
-tone elicits increase in blood pressure and freezing
-condition process greatly reduced in rats with damage to amygdala
PET imaging
-subjects given stroop test with fear related words
-fear related words produce greater activation of amygdala (suggest structure involved with processing linguistic coded threat stimuli)
41
fear circuit
-output from amygdala can modulate aspects of fear including processing fear stimuli, hormonal changes and autonomic symptoms
42
noradrenaline and fear circuits
- peripheral stress hormone and central neurotransmitter
- hindbrain contains noradrenergic cell bodies that project forwards to cortex and subcortical structures eg amygdala
- selective chemogentic stimulation of cell bodies delays extinction of simple response in rats
- effect blocked by propanolol, noradrenergic beta receptor antagonist
43
worry circuits
- complex neural loops run between cortex, striatrum and thalamus
- responsible for modulation of motor output and cognition
- dorsolateral prefrontal cortex important in worry and anxiety
44
benzodiazepine and modulation
- may modulate GABA-ergic inputs to amygdala
| - may modulate GABA-ergic inputs in CSTC worry loop
45
overlap of anxiety and depression
- many of the same symptoms present in anxiety and depression
- overlap in drugs that are effective at treating anxiety and depression
46
non-benzodiazepine anxiolytics
- selective seratonin reuptake inhibitors: enhance sertonergic inhibition in the amygdala
- buspirane: serotonergic drug with different mechanism
- modulators of voltage gated calcium channels: reduce excitatory glutamate transmission
- noradrenergic antagonists: reduces inputs taht enhance vigilance in hippocampus and amygdala
47
recreational drugs
varied groups of compounds:
- nicotine, alcohol, hallucinogens, cannabis, psychostimulants, opiates
- widespread use in human cultures
- use frequently associated with addiction, tolerance, dependence and withdrawal
48
addictive behaviour
definition: "loss of control over form of behaviour pleasurable to most" "excessive appetite"
- suggests separation of liking and wanting; basis of some psychological theories of addiction
49
drugs and their neurotransmitter receptors
nicotine -> subtype of acetylcholine receptor
alcohol -> modulates GABA receptors, opioid receptors
opiates -> opioid receptors
MDMA -> seratonin 2A receptors and seratonin transporter
cocaine -> dopamine receptor
amphetamine -> releases dopamine
barbiturates -> modulate GABA a receptor
cannabis -> cannabinoid CB1 receptor
50
recreationally used drugs are likely to ...
interact with specific neurotransmission systems, often by mimicking a natural neurotransmitter
51
place preference task
- one compartment associated with drug administration (morphine or control)
- other compartment had no association
- rat moves freely between
- transgenic mouse without opioid receptors fail to learn task
- normal mouse shows preference for morphine compartment
52
cocaine
obtained from leaves of coca shrub
blocks dopamine transporter
-increase levels at synapse
-local anaesthetic resemblances lidocaine
53
amphetamine
- first synthesised in 1887
- psychotrophic effects not discovered until 1920
- clinical uses eg narcolepsy
- used recreationally at higher doses
- widely used as decongestant
- enhances dopamine release, reduces reuptake
54
psychostimulants and dopamine receptor
- dopamine is released into synaptic cleft, taken up by transporter, reincorporated into vesicles by vesicular monoamine transporter
- cocaine and amphetamine block dopamine transporters preventing reuptake
- amphetamine stimulates release of dopamine by displacing vesicles
55
cannabis: components, mechanisms and mimics
components:
-∆9-tetrahydrocannabidol (THC) (major psychoactive component)
-cannabidiol (diff pharmacological properties)
-canabigerol (precursor with own activity)
mechanisms:
-CB1 mostly CNS
-CB2 mosty peripheral
-TRPV1 capsacin acts here also
mimics:
endogenous neurotransmitters: anadamide, 2-arachidonoglycerol
56
synthetic cannabinoids
- originated from work of huffman
- ∆9-THC high affinity, low efficacy, partial agonsit
- full agonist, max stimulation, high efficacy
- partial agonist, smaller effect at larger doses, compete with full agonist and reduce effect-moderate efficacy
- antagonist, negligible effect, by competition at receptor reduce effect of partial and full agonists
57
dopamine and reward
- many abused drugs lead to activation of brain dopamine systems
- natural rewards such as palatable food, may also lead to activation of same systems
58
cocaine craving and brain receptors
- neutral or cocaine associated images rate their craving, craving significant when seeing cocaine associated images
- blood flow to prefrontal cortex and medial temporal lobe increased
- activation of ventral striatum and other structures of basal ganglia
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mesolimbic dopamine system activation
- activated by range of natural rewards even those with cognitive elements
- imaging study and laughter activated motor areas and other cortical areas
60
treating drug addiction
- substitute one drug for another thats less rewarding
- block effects of drug with antagonist or partial agonist
- naltrexone helpful is reducing heavy drinking
- variety of behavioural strategies
61
psychoactive drugs
acts to alter mood, thought or behaviour, used to manage neuropsychological illness and/or is abused
62
Analysing visual scene
- cornea and lens focus inverted image on retina
- specialised cells in refine transducer physical energy of light into depolarisation of retinal ganglion cells resulting in action potentials in optic nerve
- retinal circuitry is complex, rod and cones hyperpolarised by light and have resting potential closer to 0mV
63
Optic nerve projects to lateral geniculate nucleus
- optic nerve fibres from nasal half of retina cross midline, projecting contralaterally but those from temporal half of retina project ipsilaterally and do not cross at optic chiasm
- animals with laterally places eyes have minimal crossing over
- damage to optic nerve on right side lead to loss vision of eye
- damage to optic tract on right side lead loss peripheral vision
64
Dorsal and ventral stream
Dorsal stream goes to posterior parietal cortex
Ventral stream goes to inferior temporal cortex
Identifying an object and remembering where it came from
Projections from brainstem to cortex are important in maintaining attention and arousal-like processes
65
Moving the eyes
-making a saccade (rapid movement of eye between fixation points)
supplementary area is rostral to motor cortex (involved in planning of movement)
-frontal eye fields have role in voluntary control of gaze distribution
66
How a Saccade occurs
Critical structures : caudate nucleus, putamen, globes pallidus, substantia nigra
- substantia nigra cells firing away until there’s a pause where cells in caudate and superior colliculus fire
- the disinhibition of superior colliculus by pause of firing of cells within substantia nigra leads to saccade
67
Cortico striato thalamo cortical loops
- Motor loop and oculomotor loop both have additional cortical output to brainstem motor control areas
- three further loops connect cortical area involved in cognition and emotion with basal ganglia
68
Parts of motor loop
Cortical input: motor, premotor, somatosensory cortex
Striatum: putamen
Pallidum: lateral globes pallidus, internal segment
Thalamus: ventral lateral and ventral anterior nuclei
69
Parts of oculomotor loop
Cortical input: posterior parietal, prefrontal cortex
Striatum: caudate (body)
Pallidum: globes pallidus, internal segment, pars reticulata (sub nig)
Thalamus: mediodorsal and ventral anterior nuclei
70
Function of basal ganglia in relation to motor control
Initiation and termination of actions
Selection of actions
Relating actions to reward or reinforce value
71
Penfields ‘motor homunculus’
map of brain involved with motor processing- electrical stimulation of human motor cortex
Area lies at back of frontal cortex, adjacent to central sulcus
Some areas such as for hand movement are larger
72
Muscle contraction
- acetylcholine released at muscle end plate, bonds to nicotine receptors opening sodium channels
- muscle membrane depolarises close to end plate and depolarisation is transmitted along membrane
- depolarisation and sodium influx releases stored calcium ions within muscle and directly triggers contraction of muscle fibre
73
Motor unit
Consist of motor neurone and set of muscle fibres in which it innervates
Muscle contraction involves mix of recruitment and rate coding (increasing degree of contraction of motor unit by firing frequency of motor neurone)
74
Effects of TMS during reaching task
- low amplitude transcortical magnetic stimulation to motor cortical hand region during reach sequence, disrupts neuronal firing
- muscle involved in grasp become more sensitive in late stages
75
Processing taste
-taste buds in tongue contain cells with receptors for salt, sour, sweet, bitter, Unami
-project to hindbrain thalamus
-then project to cortical areas including insula
-brain contains ‘reward’ system that brings you back for more
-taste, texture, smell contribute to rewarding properties and stimulate reward system
Key structures:
-central tegmentum, nucleus accumbens
76
hypothalamo-pituitary axis
- pituitary gland embedded into bone in mouth and hangs from stork just eblow brain
- anterior in outgrowth of primitive gut, releases hormones into its own blood supply
- posterior is formed from brain tissue, release hormones into blood stream
77
components of physiological/hormone response to stress
- CRH - corticotrophin releasing hormone
- ACTH - peptide hormone
- Glucocorticoids - steroid
- adrenalin, noradrenalin - monoamines
78
normones, neurotransmitters and receptors
- steroids can directly penetrate cell membrane and act on intracellular receptors
- standard mechanism is bind to surface reeptors which stimulate intracellular production of secondary messenger
79
fast, neurally mediated response to stress
- stressor activates circuits in amygdala, hypothalamus and brain stem
- hypothalamus send neural message through spian cord
- sympatetic dividsion is activated, stimulates medulla of adrenal gland
- adrenal medulla release epinephrine into circulatory system
- epinephrine activate body cells in endocrine glands and brain
- monoamines lead to mobilisation of metabloic resources and shifts in blood circulation to facilitate vigorous activity
80
slow, hormonally mediated response to stress
- hypothalamus release CRH into pituitary gland
- pituitary gland release ACTH whihc act on cortex of adrenal gland
- adrenal cortex release cortisol into circulatory system
- cortisol activate body cells, endocrine gladns and brain
- enhance ability to use fats and proteins in metabolism
- inability to produce glucocorticoids greatly increases vulnerability to stress
81
stress and responses to painful stimuli
- acute stressors induce an 'analgesic' effect -involves suppression of incoming 'noiceptive' information
- process involves release of endogenous opioid peptides and monoamines
- different types of stress activate different mechanisms
82
stress and feeding
Cottone
- not receiving expected reward is stressful and reduces consumption of normal food
- effect can be reversed by treatment with CRH receptor antagonist, associated with increased levels in amygdala
Bryce & Floresco
- stress/CRF modulates choice in decision making task
- stress reduces high reward choice, CRF antagonism abolishes the difference
83
effects of chronic stress
- chronic exposure may be assocated with loss of usual feedback control by cortisol on production and release of CRH and ACTH, cortisol levels remain high
- changed hippocampal function and structure which is associated with depression
84
stress and immune function
- glucocorticoid release leads to suppression of inflammation and immune responses
- tissue damage leads to increased release or cytokines
- cytokines act as CNS receptors to produce beahvioural effects
- these feelings promote rest and recovery and enhance biological fitness
85
individual difference in response to stress
- enzyme catechol-o-methyl-transferase (COMT) important in dopamine degradation
- gene variants MET and VAL influence the enzyme activity
- dopamine levels play important role in regulating activity in CSTC loops
- MET variants may prone to greater stress responses
- VAL variants need greater activation of CSTC loops
86
james - lange theory of emotional responses
stimulus -> physiological response -> sense response -> emotional feelings
87
'folk' psychology theory of emotional responses
stimulus -> evaluate -> emotional response -> physiological response
88
objections to james lange theory
Cannon & Bard
- disconnection of viscera from brain does not disturb emotional experience
- viscera are poorly innervated and viscera changes too slow to be direct source of emotional experiences
89
Damasio somatic marker hypothesis
-feelings arent at conscious level but can guide or influence decision making
90
2 factor theory/origin of emotional response
- arousal was manipulated by administration of adrenalin
| - physiological arousal enhanced emotion that was induced
91
Schacter & Singer 1962
adrenalin
- two groups given adrenalin
- one told theyd get increased heart rate
- others told nothing
- entered room with actor who acted euphoric or angry
- when asked to report on feelings those in group 2 had feelings that matched the actor
92
Zajonc's Affective Primacy theory
stimulus -> unconscious affect -> feeling
- idea preconscious processing can be important determinant of emotional responses
- exposure effect in which pre exposed to patterns or stimuli produces increased liking for those stimuli
93
classifying emotions
- approaches vary in extent to which they accept that there number of primal emotions
- social constructionist approach suggest emotional responses are constructed to give meaning to world
94
limbic system
cingulate cortex, hypothalamus, amygdala, mammillothalamic tract anterior thalamus
95
Papez circuit
emotion circuit
cortex->mammilary body-> anterior thalamic nuclei -> gyrus cinguli
- lesions to temporal lobes lead to inappropriate oral behaviour, hypersexuality
- electrical stimulation in hypothalamic sites could ellicit attack, defense or flight
96
effects of localised electrical stimulation of hypothalamus
stimulation of anterior produces 'sham rage' but stimulus of lateral hypothalamus produced directed rage
97
Somatic marker experiment
IOWA gambling task
- damage to prefrontal cortex or amygdala impaired acquisition of task and no anticipatory SCRs
- on simple aversive classical conditioning task VMF and amygdala damage produce different effects on skin conductance
98
fear conditioning in rats
- rat learn relationship between specific conditioned stimulus and unconditioned stimulus in context
- amygdala lesion abolish specific CS contextual conditioning whereas hippocampal lesion effects are confined to context
99
anatomy of fear
LA-inputs from auditory thalamus and cortex, somatosensory thalamus and cortex
CE-outputs projecting to central grey in midbrain to laterla and paraventricular nuclei of hypothalamus
100
Panksepps emotional arousal systems
fear: central and lateral amygdala, medial hypothalamus and glutamate
panic: anterior cingulate, preoptic area, dorsal thalamus, opiods, glutamate
rage: medial amygdala, bed nucleus of stria teminalis, medial and perifomical hypothalamic, glutamate
seeking: nucelus accumbens, mesolimbic and mesocortical outputs
lust: preoptic hypothalamus, steriods, vasopressin, oxytocin
101
seeking, wanting and liking
seeking system is similiar to wanting or incentive motivation processes
anatomically based on medial forebrain bundle where self stimulation originally identified
liking is modified by opioids in nucleus accumbens
102
what is learning
- relatively permanent change in behaviour that occur as result of experience
- doesnt include reflexes, taxes or instincts
103
limitation of innate responses
stimulus must be physcially present in environment
little opportunity to modify result
modification on evolutionary (phylogenetic) tiem scale not individual time scale
104
functions of learning and memory
- non associative learning
- associative learning
- habituation
105
classical (respondent) conditioning
- unconditioned stimulus produces unconditioned response
- neutral stimulus produces no salivation stimulus
- unconditioned stimulus repeatedly presented after neutral response
- nuetral stimulus alone produces conditioned response
- neutral stimulus becomes conditioned stimulus
106
principles of respondent conditioning
- acquisition when CS-US reinforcement
- reinforcement of CS by US
- extinction
- spontaneous recovery
- reacquisition
- generalisation
- discrimination
107
relevance of respondent conditioning
extends mechanism of behavioural adaptation beyond simple reflexes
ontogenci 'adaptation'
ubiquitous and preserved
laws of classical conditioning shape emotional life
108
pavlov corticol model of learning and memory
when connection between CS and US is conditioned, area of cortex activated bby CS becomes physically connected with activatd US
109
thorndikes laws of learning
law of effect: behaviour that leads to positive outcome more likely to occur in future
law of exercise: connections between responses and outcomes are strengthened by repetition
law of readiness:learning is motivated by internal state
110
instrumental/operant conditioning
- behaviour changes the environment
- behaviour is goal directed
- form associations between behaviour and consequence (positive or negative)
- behaviours shaped by schedules of reinforcement
111
skinners operant behaviourism
- reinforcer: stimulus/event increases likelihood of preceding behaviour to occur
- positive reinforcer: stimulus produced by behaviour that increases likelihood of preceding behvaiour to occur
- negative reinforcer: stimulus eliminated by behaviour that increases likelihood of preceding behaviour to occur
punishment: neg event/stimulus that decrease likelihood of preceding behaviour to occur
omission: elimination of positive reinforcer decreases likelihood of preceding behaviour
112
schedules of reinforcemnt
continuous: each behavioural response is reinforced
partial: behaviour reinforced only part of time
ratio schedules (fixed or variable): reinforcement given after every nth response
interval schedules (fixed or variable): reinforcement given after certain amount of time
113
nn
nn
114
principles of associative learning
- learning through reinforcement
- association by continguity: co-occurrence in space and time
- arbitrariness: any stimulus any response
- passive organism: learning happens to organism
115
taxonomies of memory
-non associative learning: habituation or sensitization
-associative learning: respondent or operant conditioning
-declarative/explicit: smeantic or episodic
non declarative/implicit: procedural or skill learning
116
principle of equipotentiality and mass action
all cortical regions can mediate learning equally
ability to learn is proportional to amount of cortex available
117
brain regions involved in learning
hippocampus: declarative and spatial memories
cerebellum: procedural memories
amygdala: emotional memories, pavlovian associations
frontal cortex: short term memory, working memory
118
cellular basis of memory storage
- neurogenesis occur between olfactory bub, hippocampal formation and neocortex
- new synapses could be generated to store new memories
- new synapses anatomically connected
- upon activation synapses are 'strengthened' and incorporated into memory network
119
Hebbian learning and memory
Snails siphon:
- stimulated, snail withdraw gills for protection
- stimulus activated receptions in siphon, which directy or indirectly activates motor neuron which withdraws gills
- when repeated stimulation, stimulation lead to decrease in neurotransmitter released into synpase and motor neuron
120
3 ways body uses energy
-basal metabolism: 55% of energy to maintain body temp and resting functions
digestion fo food: 33% energy used to break down macromolecules into micromolecules
active behavioural processes:12-13% energy usage fro behaviours other than rest
-remaining energy stored as energy reserves
121
sources of energy
carbs: converted to glucose, stored as glycogens in muscles and liver
amino acids: proteins, converted to glucose
lipids:long term storage
vitimins and minerals
122
homestasis and drive reduction
- set point: physiological parameter
- error detector: compares actual state against set state
- error correction mechanism: neg feedback
123
food and homestasis
set points:
glucostatic-eating is controlled by deviations from hypothetical blood glucose
lipostatic-eating controlled by hypothetical body fat set point
124
dual centre hypothesis
- feeding dedicated areas: corpus callosum, hippocampus, cortex, ventromedial, arcute nucelus, ventromedial hypothalamus, lateral hypothalamus
- lesions to VMH increase feeding and weight as its satiety centre
- lesions of LH decrease feeding and weight as its hunger centre
125
Ghrelin and orexin
- peptide hormones secreted in gut from adipose tissue and hypothalamus
- ghrelin increases hunger and promotes fat storage
- orexin regulates arousal
126
cholecystokinin and leptin
- cholecystokinin is released in intestines in response to fat, stimulates enzyme secretion
- leptin is produced by adipose tissue and binds to receptors in ventromdeial nucelus of hypothalamus, it decreases appetite
127
appetite as motivational system
- appetite is neg feedback system based on competitions between hunger and satiety signals
- dedicated drives signal indicating the need for nutrients: hormones an dlateral hypothalamus
- dedicated drives signal related to food ingestion: ventral medial hypothalamus an dhormones
128
drive reduction theory
thorndike and hull
law of readiness: learning is motivated by internal state
proposed that reinforcer supports learning as alleviates internal state of derivation
emphasis on homeostasis: imbalance create arousal that initiates reaction to decrease arousal
129
components of homeostatic system
system variable: variable controlled by systems
set point: desired level of variable
sensor: mechanism for measuring variable
effector system: behavioural/physiological mechanism to change variable and restore homeostasis
principle: number of physiological variables that must be maintained within narrow limits
130
regulation of body temperature
cells in pre-optic area oh hypothalamus sense brain temp
thermal sensors throughout periphery
hypothalamus controls physiological and behavioural responses to regulate temperature
131
thirst and homeostasis
- direct water loss occurs primarily from extracellular compartment
- intracellular and intravascular fluid volume and composition msut be pet in precise limits
132
osmometric thirst
- extracellular fluid consist of water and salts
- water loss causes salt conc to increase
- increase in salts create osmotic imbalance between extra and intra cellular compartments, water leaves intra by osmosis
- drinking is directly proportional to additional salt load
- changes in osmolarity are monitored by cells in organum vasculosum
133
hypovolemic thirst
loss of extracellular fluid levels can induce thrist in absene of osmotic changes
thirst stimulus arises from 2 systems whihc measure blood pressure: kidneys and heart
134
angiotensin and drinking
- hypovolemia causes release of enzyme renin from kidneys
- renin converts blood born molecules into angiotensin
- angiotensin stimulates pituitary gland and kidneys to release hormone to conserve water
- increase blood pressure by vasoconstriction
- stimulate drinking by binding to receptors in subfornical organ
135
atrial baroreceptor
- atria of heart contain neurons that detect stretch of arterial wall
- volume of return blood is detected by baroreceptors
- info is sent to nucleu of solitary tract and then onto medial preoptic area
136
learning effects in eating
step 1: pavlovian conditioning
step 2: satiate with free feeding
step 3: back to conditioned stimulus and it produces over eating
137
measuring taste hedonics in humans and rats
- influence of pleasure
- dopamine levels related to pleasure so increase when eating sweet things but decrease when eating bitter things
- gene mutation that increases dopamine activity makes mice want more sucrose without changing their liking for it
- liking is mediated by opiod and GABA systems
- nucleus accumbens, hypothalamus, amygdala
138
limbic system
- frontal cortex, hippocampus, amygdala and nucleus accumbens alter hypothalamic processes to influence motivation and emotion
- connections between limbic system and hypothalamus integrate homeostatic and non-homeostatic mechanisms infeeding, drinking and temp reg.
139
paul ekman basic emotions in facial expressions
```
anger
fear
disgust
surprise
happiness
sadness
fear and sadness
```
140
what are the additions to the 6 basic emotions
jealousy
guilt
embarrassment
141
jaak panksepp 4 basic emotional system
fear
seeking
panic
rage
142
basic emotions definition
intense but short lived affective responses to an event which is associated with specific body change
143
evolutionary emotion definiton
- specialised modes of operation shaped by natural selection to adjust physiological, psychological and behavioural parameters
- increase capacity to respond adaptively to threats and opportunities characteristic of specific situations
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key function of emotion signalling
- facilitate social cohesion and reduce uncertainty
- used as signals
- crucial in decision making
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evolutionary origin of smile
- threatening vocalisations in dominance displays involve bringing corners of mouth forward to lengthen vocal tract an dlower resonances
- non threatening vocalisations used in display of submission draw lips back into smile
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lateralisation in processing of emotions
right hemisphere advantage, shift to left hemisphere when processing pro vs anti social expressions
- anti social expressions processed in right hemisphere
- where look with left gaze we process more negative emotions
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parallels in lateralisation in animals
sheep, horses, humans and chimps use left visual field more than right for detecting negative emotion cues
-horses better at matching owners voice to sight when owner in right visual field
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approaches to studying social behaviour
mechanistic: understand mechanism by which trait achieved
ontogenetic: factors influencing development of trait
functional: understanding fitness consequences of trait
evolutionary: unravel history of trait
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ideas on why humans are social
- selfish, solitary and aggressive but enter social contract to curb their naturally selfish instincts
- group living benefits individuals so that behaviours which facilitate group living are favoured
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darwins theory of evolution
- continual competition between individuals for resources in a population and some individuals contribute more offspring to next gen
- provided offspring resemble parents, traits of individuals that leave more offspring will increase in frequency over time
- evolutionary fitness
- produces evolutionary change due to individual survival and reproduction
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what is evolutionary fitness
contribution of individual gene to gene pool in next generation
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benefits of group living for prey
- lower probability of being killed by predators
- better at finding and capturing food
- improved competitive ability
- improved success at rearing own young
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costs of group living for prey
- increased chance of being detected by predator
- higher risk of parasitism
- resources must be shared
- increased risk of reproductive suppression for subordinates
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what happens when benefits of group lviing outweigh the costs
can be direct selection on individuals to live in groups
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indirect benefits of group living
- inclusive fitness: total fitness that an individual gains, by breeding itself and by helping close relatives breed
- increase own fitness by helping relatives to breed as share genes
- kin selection: process by which characteristics are favoured due to beneficial effects on survival of close relatives
- reciprocated altruism: provided benefit of altruistic act is greater than costs of donor and must be reciprocated at later date
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what is altruistic behaviour
behaviour that increases evolutionary fitness of recipient at some cost to the donor
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communication as basis of social behaviour
- adapted signals to mediate relationships and sat in contact with others
- mechanism that allows for social behaviour
- transmit info on identity of signaller to receiver
- allow different ranked individuals to communicate without fighting
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relating social systems to mating and sexual selection
mating system: affected by system parental care and defensibility of females
sexual selection: affected by relative importance of physical or behavioural traits in determining success of breeding
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sexual selection
process by wihc secondary sexual traits become elaborated because they increase ability to gain mates
generated by two processes: intrasexual competition and intersexual competition
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what is intra sexual competition
competition between members of same sex about a mate
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what in inter sexual competition
choice/preference by members of one sex for particular mating partners
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key forms of intra sexual competition
direct combat: males with large body size and weaponry selected
sperm competition: ales whose sperm successful in fertilising eggs selected
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key parameters of inter sexual choice
good genes: males chosen based on characteristics that indicate high genetic quality and high viability for offspring
attractive sons: choose highly attractive males so have more attractive sons that will be chosen by females in next gen
sensory exploitation: choose males that exploit their innate sensory biases
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sexual dimorphism
where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs such as males usually larger, extravagant displays and more developed weaponry
-individual with higher potential reproductive rate competes for sex with lower potential reproductive rate
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sexual displays
bring sexes together for mating and influecne outcome of intrasexual competiton and intersexual choice
information transferred via signals that may be visual, acoustic or olfactory
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displays and intra sexual competition
- opponents are rarely equally matched, differ in ability to acquire or defend resource (resource holding potential)
- evolutionary models have shown that where fighting is costly, individuals monitor RHP of opponent to judge if have likely chance of winning
- red deer: roaring rate and parallel walking, 50% of challenges result in fights
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displays and inter sexual choice
- displays function to attract mating partners of opposite sex
- provide a means of choosing a mate -
- provides the 'best' mate available at that current time
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cognition
mental process concerned with acquisition and manipulation of knowledge including perception and thinking
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referential signalling
use of signals to functionally denote external objects and events
response urgency-different signals for high urgency threat or low urgency threat
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language ability in animals
attach acoustic labels to objects and events (semantic)
| label social relationships in some species
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Dasser 1988
labelling social relationships
-jave monkeys (female)
-shwon slides of members of socail group and trained to distinguish between mother-offspring pairs and rewarded for successful pairings
-shown slides of additional unseen pairs
-high success rate despite diverse exemplars of age/sex/class
-
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knowledge of third party relationships
- knowledge of dominance between other individuals has fitness benefits, able to assess potential allies
- baboons know vocal interactions between dominants and subordinates
- male bonnet macaques use info about thrid party relationships when recruit support, choose allies that outrank themselves AND opponents
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tactical deception
- short term tactics where elements from honest counterpart in repertoire used in deceptive act
- concealment, distraction, creating image, manipulation of target with social tool, deflection of target to fall guy and counter deception
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theory of mind
hare 2000 - chimps
- attribute a visual perspective to others
- appear to know what other individuals have and have not seen
- recall what conspecific has and hasnt seen in immediate past
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theory of mind
santos - monkeys
appear to know hwat others can and cannot hear
when human competitor looking at them, stole grapes from noisy and silent containers
when competitor look away, preferentially stole from silent container
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theory of mind
krupenye - apes
pass false belief test
understanding hallmark of human theory of mind
-shown through anticipatory looking
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theory of mind
crockford - chimps
aware of ignorance and knowledge in others
| more likely to make alarm call in response to snake when unaware group members than aware group members
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theory of mind
dally, emery, clayton - birds
preferentially store food in distant sites when watched by another jay, but used near and distant whne observer view blocked
items stored in observer view where moved multiple times
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theory of mind
hare, miklosi, call - dogs
perform better than primates at using human social cues to find hidden food, ability is present in puppies
highly sensitive to attentional states in humans
due to associative learning or mental state understanding is unknown
