Addiction Flashcards
What is addiction?
A chronic disease characterized by drug seeking and use that is compulsive, or difficult to control, despite harmful consequences.
Due to the brain changes cause it is considered a ‘relapsing’ disease, b.c. people relapse into addiction often.
Both classical and instrumental conditioning are relevant to addiction.
Instrumental (operant) conditioning
A response followed by a reward is more likely to be repeaded. E.g. I press lever I get food.
Explains how patterns of behaviour are reinforced or trained.
Habitual behaviour
A habit is a pattern of behaviour acquired by frequent repetition, it is often unconscious. It is a behaviour that we engage in, prompted by cues, and without a particular conscious desire to achieve the outcome that the behaviour will produce.
Why can be drug taking seen as goal directed?
Operant learning explains it, the drug taking (behaviour) is reinforced by the effect of the drug (consequence/goal).
Drug seeking is, therefore, seen as intentional b.c. we are aware of the contingency (! the sequence and time between US and CS) and we take the drug in the anticipation of the outcome. The effects of drugs reward taking them.
Conditioned compensatory responses
It is physiological; that is cues in the environment can prompt a physiological response that prepares the body for a drug. Conditioned compensatory responses map onto the body’s physiological homeostatic response.
A bit different than UR, it occurs in the anticipation of it.
It alwats mimics body’s beta resposne
Extinction
A process of reducing the association between the behaviour (e.g. pressing the lever) and the outcome (e.g. getting food).
Pairing behaviour with no outcome
Blocking
Blocked stimulus is not learned about. When CS1 is paired with US and association is learned, then we show CS1 + CS2 and US and then CS2 on its own, no US is expected bc the learning of CS2 - US association was blocked. –> When CS1 + CS2 were being show US there was no error or surpise that US followed becasue CS1 was alredy predicting it.
Alpha response
Initial physiological response that is positive. The first peak. The euphoric and pleasurable part, makes you feel less pain and decreases frequency and depth of breathing.
Beta response
Follows alpha process and aims to return to hedonic level of 0. The system ‘overshoots’ creating a negative hedonic state before returning to 0 (equilibrium).
The counteraction to get back to homeostasis, feeling ‘down’, increases pain sensitivity and increaesed the frequency and depth of breathing.
CR is always beta response
Tolerance
The high that the person feels compared to the high they felt when first taking the drug is reduced.
The development of conditioned compensatory responses suggest development of tolerance (Siegel et al., 2000).
Withdrawl
Present when the drug is removed when you have conditioned compensatory responses.
Outcome devaluation
Reduce the value of the outcome.
Can be done by pairing with sth bad or giving so much of it the animals gets bored.
If devalued outcome is still seemed he behaviour is habitual.
Pavlovian to Instrumental Transfer (PIT) (Colwill and Rescorla, 1988).
There are classical and instrumental conditionins acquires independently. CS is associated with a reward.
You have classical conditioning of CS being paired with US e.g. see light (CS) press lever which will give food (US)
But also it lears the associateion that lever gived food (instrumental conditioning).
In PIT, positively valued Pavlovian cues promote instrumental responses and approach (more frequent behaviour to get drug).
Pavlovian conditioned cues can thus bias instrumental behaviour towards drug seeking and intake in both drug abusers and animals trained to self-administer drugs.
Schultz (1999)
3 function of rewards
- Make us what to do more of make us feel good (e.g. eat food)
- Rewards work as positive reinforcers. We are drawn to pleasure= dopamine
We have reward-driven learning; on the discrepancy or “error” between the prediction of reward and its actual occurrence. [same as error driven learning] - Reward result in hedonia (subjective feeling of pleasure); hard to measure in rats
Schultz (1999) Dopamine experiments rats
Showed that dopamine is essential for learning.
- Surpise bc no anticipation of reward and it occured= spike in dopamine neurons.
- Spike after CS but not reward.
- Spike after CS and depression when reward should have occured.
ALSO
- ‘blocked’ stimulus followed by no reward did not trigger depression in dopamine activity
- Reward following the blocking stimulus casued dopmine spike again = reward was not expected.
Schultz (1999)
3 function of rewards
- Make us what to do more of make us feel good (e.g. eat food)
- Rewards work as positive reinforcers. We are drawn to pleasure= dopamine
We have reward-driven learning; on the discrepancy or “error” between the prediction of reward and its actual occurrence. [same as error driven learning] - Reward result in hedonia (subjective feeling of pleasure); hard to measure in rats
Schultz (1999) Dopamine experiments rats
Showed that dopamine is essential for learning.
- Surpise bc no anticipation of reward and it occured= spike in dopamine neurons.
- Spike after CS but not reward.
- Spike after CS and depression when reward should have occured.
ALSO
- ‘blocked’ stimulus followed by no reward did not trigger depression in dopamine activity
- Reward following the blocking stimulus casued dopmine spike again = reward was not expected.
Why can be drug taking seen as goal directed?
Operant learning explains it, the drug taking (behaviour) is reinforced by the effect of the drug (consequence/goal).
Drug seeking is, therefore, seen as intentional b.c. we are aware of the contingency (! the sequence and time between US and CS) and we take the drug in the anticipation of the outcome. The effects of drugs reward taking them.
Olmstead et al., 2001 study
Rats, drug-taking is goal-drected
Cocaine seeking by rats as a goal directed behaviour.
- Rats traind a chain of steps needed to get the reward.
- Press ‘seeking lever’ to get acess to ‘taking level’.
- Press ‘taking lever’ to get intravenous cocaine.
- Extinction of the association of ‘taking level’ and drugs. Rats can press it without seeking level BUT it doesn’t give them cocaine.
- Seeking response tested. Rats get access to S lever again (it takes them to T lever).
- After extinction there is a reduction in seeking behaviour. They didn’t want to press it when they knew taking lever is not giving them drugs.
==> Shows that drug-seeking is goal directed behaviour
Issue with gola directed explanation of drug taking?
After some time drugs start having detrimental effects on a person, so why do people keep taking them of the goal is not so good?
Can be because of dopamine.
Can be becasue of conditioned compensatory responses
Dopmaine reason for drug taking
Surges of dopamine in the reward circuit cause the reinforcement of pleasurable but unhealthy behaviours like taking drugs, leading people to repeat the behaviour again and again.
The more drugs you take you brain looses ability of reward circuit to respond to them–> the high is not as good when compared to the first time taking the drug (tolerance) = need more drugs to get the same high and less ablity to get pleasure from other things
Schultz (1999) Dopamine experiments rats
Showed that dopamine is essential for learning.
- Surpise bc no anticipation of reward and it occured= spike in dopamine neurons.
- Spike after CS but not reward.
- Spike after CS and depression when reward should have occured.
ALSO
- ‘blocked’ stimulus followed by no reward did not trigger depression in dopamine activity
- Reward following the blocking stimulus casued dopmine spike again = reward was not expected.
S-O-R learning by Balleine et al.
Opposite suggestion that what Hull says (we see S, it evoked R, not care about O ! O is not incluced in Hulls model, so how can it tell us anything about it?)
-In S-O-R the S predicts the drug outcome O and this elicits R that produse O.
S–> O
I want O so I do R.
BUT the value of O does not play a role, becasue its a habit
Habit theory for drug taking
Argues that drug seeking is elicited automatically by drug associated stimuli, without engaging an expectation of the consequences of this behaviour.
Hull’s veiw on drug taking
According to Hull we learn the association between (S) environmental stimulus which predicts drug and (R) the morotoric response sequence which gives assess to the drug.
So when we see S this elicits behaviour R with an insensitivity to the outcome.
S-O-R learning by Balleine et al.
Opposite suggestion that what Hull says (we see S, it evoked R, not care about O ! O is not incluced in Hulls model, so how can it tell us anything about it?)
-In S-O-R the S predicts the drug outcome O and this elicits R that produse O.
S–> O
I want O so I do R.
BUT the value of O does not play a role, becasue its a habit
Exposure is not enough
Not all people who take illicit drugs get addicted to them (Belin et al., 2016).
Perhaps it’s due to individual differences (Hogarth).
Anthony et al., (1994) stat from 8000 interviewed people- 16% had treid cocaine, only 3% was addicted.
Possible individual differences
- Differences in reward systems
- Incentive Sensitization: wanting
- Stimulus control: incentive salience of the stimuli (sign and goal tracking)
Differences in reward systems as an explanation for why only some people become addicted
Volkow et al. (2009)
- Difference in the dopmaine response
- People who described methylphenidate drug as pleasant < lower levels of D2 DA dopamine receptors vs ppl who said it was not pleasant.
- Other studies show higher levels of D2 DA receptors significantly reduced alcohol intake in animals previously trained to self-administer alcohol. (potentially protecting agains alcoholism by modulating frontal circuits involved in inhibition)
People with ADHD are at higher risk of substance abuse disorder
- Depressed dopamine activity in specific brain regions of adults with ADHD compared to controls
- Depressed DA phenotype was associated with higher scores on self-reports of methylphenidate liking
Incentive sensitisation
Is a process through which we might “learn” the value of an outcome.
Outcome might not have a fixed value, its value can be defined by previous experiences.
As the value of the outcome changes, the rate of learning with that outcome should change- RW model.
Premack principle
An animal will do one behaviour to get the opportunity to engage in a preferred behaviour. Learning is reinforced when the instrumental act allows access to a preferred behaviour.
A water depreived rat will drink more than it runs.
A water not depreived rat runs more than it drinks.
Incentive salience
Through conditioning, different components of the task becoming a ‘wanted’ stimulus
Some researchers argue that acquisition of incentive salience might contribute to drug addiction, making the drug-associated stimuli more salient.
Zener (1937!!)
Individual differences in classical conditioning with dogs (same as Pavlov)
- Observed that after training, some dogs responded with an initial glance at the bell, followed by a fixed interest in the food bowl, while other dogs approached the bell. –> Sign tracking (interest in bell)
- –> Goal tracking (interest in food)
Replicated on rats (Flagel et al., 2009) and humans (Garofalo & di Pellegrino, 2015).
Sign vs goal trackers
Sign-trackers have been suggested to be more susceptible to addiction than goal-trackers because they are more likely to be motivated to seek drugs in the presence of drug-related stimuli (Robinson, Yager, Cogan & Saunders, 2014).
BUT
it is not 1-0 thing, a person doesn’t have to be just a sign or goal tracker
