W2: Conditioning and Brain Mechanisms Flashcards
Operant conditioning
rewards and punishments increase or decrease the likelihood of an individual repeating an action in the future
Positive reinforcement (O.C)
activation of reward pathways => increasing probability of behaviour
Negative reinforcement (O.C)
increases probability of behaviour my removing discomfort
Punishment
decreases the probability as we avoid punishment
People still engage in addictive behaviour although there is punishment because
of contiguity => time interval between behaviour and punishment is long, while reinforcement (high) is immediate
Classical conditioning
- unconditioned response = reflex elicited by a stimulus
- unconditioned stimulus
- neutral stimulus = it doesn’t initially elicit a response
- conditioned stimulus = a new stimulus that paired with UCS will elicit response
- conditioned response
Extinction (C.C)
repeatedly presenting the CS alone until the CS stops to elicit a CR
Abstinent drug users may experience
conditioned drug responses to people, places -> prevent relapse by change of environment
Categories of conditioned responses
- Drug-opposite CRs
- Conditioned withdrawal
- Conditioned Tolerance
- Drug-like conditioned responses
Drug Opposite CRs
- repetitive use of the same drug can produce CRs that are opposite to the direct effects
- can mimic withdrawal symptoms
- can cause relapse in abstinent people
Conditioned withdrawal
experience withdrawal symptoms through cues in their environment that remind of drug
Conditioned tolerance
- reduction of drug effect with repeated administration
- through conditioned responses
- might cause overdose when in new environment
Drug like conditioned responses
-suggestion that the body’s reaction to the drug rather than the drug’s effects is conditioned
= needle freaking
Social learning theory
the environment can affect use but we also influence environment = reciprocal determinism
Key principles of social learning theory
- modelling
- past learning doesn’t completely determine what we do next
- reinforcement and punishment are indirect factors of learning
- expectation of reinforcement or punishment can be as powerful as actual
Self-efficacy
- degree to which one feels competent to perform
- prob of someone quitting smoking depends on how much he depends he will
Self-efficacy types important for prevention
resistance
harm-reduction
self-efficacy types important for treatment and relapse prevention
action
coping
recovery
Dual System Theory
- people have poor access to the functioning of their own cognitive processes
- rather than reporting on which processes occurred, people tend to come up with guess explanations
cognitive decoupling
people think hypothetically about the world
cognitive misers
we tend to avoid effortful thinking whenever possible
Automatic cognitive processing system 1
- outside of conscious awareness
- cant be examined directly by individual
- rapid
- environmentally triggered
- produces responses in absence of system 2
- contextualizes info
Controlled Cognitive processing S2
- investing attention
- conscious monitoring
- dependent on system 1 input
- reciprocal effects on the contents of system 1
Tiffany’s Craving Model
- dependence as form of automatic behaviour
- development of drug-use representations in memory by mental schemas
- efortless and habitual over time
Two components of craving (Tiff)
Automatic Craving
Controled Craving
Automated Craving
activation of drug-use representations in memory which lead to drug use
Controlled craving
intense feeling of wanting and needing something
Controlled craving only occurs when
an obstacle prevents the aims of the automatic process from being achieved
Attentional biases increase
the motivation to seek out and use substances because we pay attention to things that matter to us
Modified stroop tasks showed that
attentional biases are identified when participant takes longer to respond to the colour of alcohol words compared to neutral words
Franken’s model of drug craving
-hypervigilance for drug stimuli => increased dopaminergic activity in the reward pathway => driver of attentional bias
Houben and Wiers found positive associations with
alcohol were related to alcohol consumption, but only among those who scored poorly on response inhibition tasks
Many drugs of dependence selectively impair
controlled processing in acute situations of use, while automatic processing seems almost unaffected => behaviour likely to be guided by previously learned patterns of behaviour
3 failures in reasoning Toplak (gambling)
- Overriding system 1
- Incomplete system 1 outputs (failure to express emotional reactions)
- Missing mental software (not enough or false knowledge)
Common routes of administration
oral injection inhalation application to skin through mucous membranes
Speed of effect also guides choice, since the fastest route is
injalation and injection
- medium via mucous membranes
- slowest is oral
The sooner the effect
the more reinforcing
A slower rise guarantees an effect for
a longer time
Degree to which the drug will be dissolved in membrane lipids (of cells)
determines success
The greater proportion of ionised molecules in the drug, the
slower the rate of movement of the drug across membrane
Diffusion of drug
the greater the difference in drug concentration on each side of the membrane, the more rapid the movement
Drug distribution
during the drugs journey to the brain, some of it might leave the blood stream and be metabolised, leaving less of the drug to reach the brain
Drug excretion
elimination of the drugs and its metabolites via expired air, bodily fluids, kidneys
Metabolism occur at a greater rate when
concentration of drug in the body is higher and then gradually slows down when drug is eliminated
Excerption
some drugs (alcohol) metabolise at constant rate and require a particular enzyme, which is limited
Agonist
- drugs that binds to the receptor and turns neutron on
- intensity of drug effect is associated with the number of receptors that are occupied by the agonist and activated
Antagonist
- binds to the receptors and prevents agonists from binding=>won’t switch it on
- sometimes used to treat dependence
Monoamines
-NT associated with cognition, emotions and behaviour
Most important monoamines for understanding addictive behaviours are
Dopamine
Serotonin
Noradrenaline
Dopamine
- euphoria
- motivation
- arousal
- reinforcement
- reward through signaling cascades
Serotonin
- stabilizes mood
- well being
- happiness
Noradrenaline
help body respond to stress and mobilises for action
Types of Drug Tolerance
Neuroadaptation
Cross-tolerance
Metabolic tolerance
Cellular tolerance
Neuroadaptation
homeostasis in the brain - steady effect
Cross-tolerance
tolerance to one drug will lead to tolerance in other drugs of the same class
Metabolic tolerance
- pharmacokinetic
- speed at which the body metabolises the drug increases over time => toxicity
Cellular tolerance
- pharmacodynamics
- consequence of changes in number of receptors and their functions + alterations to the responsiveness of post-synaptic neurons
Withdrawal syndrome
- opposite of the drug’s effects
- can cause seeking of negative reinforcement by taking the drug again
Half life of a drug
the time it takes for the amount of a drug’s active substance in your body to reduce by half
The shorter the half life
the more intense the withdrawal syndrome
Psychological drug dependence is characterised by
compulsion and craving
Physical drug dependence is characterised by
the experience of a physical withdrawal syndrome
Traditional view on adolescence
as a period of development associated with progressively greater efficiency of cognitive capacities, which is dependent on the maturation of the PFC
During adolescence, there is a bias by
functionally mature subcortical relative to less mature cortical circuitry -> imbalance in reliance of systems
The mechanisms that explain changes in risk taking behaviour and impulsivity can be related to
frontostriatal circuitry and functional strengthening of connections
Triadic model explains that
motivated behaviour has 3 neural circuits
-casey and jones
The systems of the triadic model
- Approach system: ventral striatum (rewarding cues)
- Avoidance system: amygdala
- Regulatory system: PFC
Motivation can modulate cognitive control by
reward
and capacity to exert control (challenged upon appetitive cues)
Sensitivity to rewards and incentives peaks during
adolescence (presence of peers is a risk)
The circuit that undergoes most change during adolescence is
the fontrostriatal circuit
During adolescence, the receptors that are at peak in density are
dopamine D1 and D2 in the striatum
Changes in dopamine-rich circuitry relates to
sensitivity to reward
The difference in development of striatal regions and the PFC is that
the stratal regions develop sooner while the PFC undergoes delayed maturation
Positive association between ventral stratum activity to large reward and
the likelihood of engaging in risky behaviour
In boys, the impulsivity rating is inversely correlated to
vmPFC volume
Exaggerated ventral striatal plays role in
level of excitement because it is a representation of appetitive cues in the absence of a mature cognitive control response
Substance reinforce the
mesolimbic dopamine transmission with acute activations of neurons in frontolimbic circuitry rich in dopamine, including the ventral striatum
In alcohol dependent adolescents it is observed
smaller frontal and hippocampal volumes, altered white matter microstructure, poorer memory
Hippocampal volume and age of first use
possitive association
Hippocampal volume and duration
negative association
The energy model of self regulation
self reg is a resource that can run out
Gailliot measured blood glucose level before and after self-control activities and found
- reduction in blood glucose after task
- reduced level of glucose => poorer performance
Personality states
transient characteristics
Personality traits
vary very little over time and situations
Trait theories of personality
identify core traits to categorise individuals
Tri-dimensional theory of addictive behaviour Cloninger
3 traits that predispose individuals towards dependence:
novelty seeking
harm avoidance
reward dependence
Sensation/novelty seeking predicts
addictive behaviour especially in early stages
Third variable cause
particular traits could seem to cause addictive behaviour, but in fact they do so only indirectly (to cope with smth)
Rational choice theory
addictive behaviours are rational to the extent that they are directed towards maximising benefits for the individual
Problem of the rational choice theory is that it
doesn’t distinguish between those who use and want to, and those who use but want to stop
Rational choice theory conceptualised addictive behaviour at level of
groups not individuals, therefore increasing the costs of substances should reduce use
Instrumental rationality
tend to make choices that lead them to achieving their goals in most efficient way
Epistemically rationality
evaluate contents of their mind to ensure that what they know are consistent with the reality
Incentive-sensitization theory
persistent use of drugs leads to alteration in the dopaminergic reward system
Incentive salience
cue becomes associated with positive reward
Most drugs excite this reward systems, leading to
disproportionate increase in incentive sensitisation of drug related cues => compulsion to use drugs
Drug wanting
attribution of incentive salience to drug stimuli => stronger urge
Drug liking
separate neural pathways in the brain and refers to the anticipating hedonic effects of the drug
Incentive sensitisation theory lacks
evidence from human studies
Problem of incentive sensitisation theory
craving not often associated with use or relapse
Inhibitory dysregulation theory
addictive behaviour as a problem of compulsive behaviour
-impairment in ACC and OFC (inhibitory control)
Incentive motivation (Franken)
cognitive and affective state triggered by stimuli associated with the perception of unconditioned stimuli
Drug related stimuli can elicit
classically conditioned responses both physiological (dopamine) as subjective (craving)
Psychological approaches
- craving as a continuous measurable state that can also be present in non-addicted subjects
- in the past= homeostatic dysregulation theory (drug needed to establish homeostasis after withdrawal)
- incentive motivational framework (conditioned appetite)
- attentional system as major role in emotional system (reward/punishment salience)
To prepare for an action, we need
attention
motivation
emotion
2 categories of attention
- non-specific general state of arousal
2. selective (processing of relevant stimuli and inhibition of less relevant)
Selective attention can be
- voluntary (actively searching, top-down)
- involuntary (novel stimuli)
Limited capacity mechanism
the more attention focused on a secondary stimulus, the less cognitive capacity available for primary task
In the emotional stroop task,
reaction times of colour naming are slower on words with an emotional content
Attentional bias for drug cues
because positively valenced stimuli -> making drugs to have attention grabbing properties
Processing of appetitive info has an effect on
cortical measures of attention such as ERP and EMG
The present view explains that craving itself isn’t responsible for the disruption of a secondary task, but rather
the accompanied attentional bias for drug-related stimuli
Preconscious processing
presentation of emotional info can influence behaviour unconsciously
Neurobiological approaches
- incentive sensitisation theory => drugs enhance the mesolimbic dopamine transmission => attribute incentive salience to the perception of events associated
- dopamine antagonist as a way to help addicts (animal studies) => reduce appetitive approach motivation towards rewards
- dopamine triggers attention towards conditioned incentives => dopamine antagonist modulate selective attention and craving
When general selective attention is increased by dopamine antagonists, then
automatic processes are consequently decreased and attention for drug cues will be reduces
ACC is involved in
selective attention
Metabolism in superior cingulate is increased by
dopamine agonists and decreased by dopamine antagonists
NA and ACC are a part of a corticostriatal circuit involved in
stimulus reward learning
The dopamine system of the corticostriatal circuit consists of
ACC
amygdala
NA
The dopamine corticostriatal circuit has a role in
integrating attentional functioning
signaling reward
The integration model
attentional bias and craving are able to modulate each other
Attentional bias contributes to addictive behaviour in 3 ways
1- automatic selection process = detect drug cues
2- attention related cognitive process = if cue detected, it is automatically processed and difficult to shift attention
3- limited capacity of attention = subsequent failure in processing competitive cues
Integration model stresses the need to
incorporate the extinction of automatic responses in the extinction processes
