Lecture 6 Goal Directed Behaviour Flashcards
What is Dickson’s (1985) goal devaluation paradigm?
Rats are trained with typical reinforcement
The reward is then de-valued by:
1- feeding the rat full so they don’t want the reward
2- Giving it an anaesthetic so that they feel nauseous when they eat
If the rats press the lever still: habitual behaviour
If they don’t press the lever: it is to do with knowing and wanting the reward.
What did Dickson (1985) find about the transfer or outcome sensitive behaviour to habitual behaviour?
Depends on amount of training
100 experiences pressing lever - press lever 4 times a min (no devaluation) this halfs when devalued
500 experiences pressing lever - carry on pressing lever at same rate when devalued: SHOWS HABITUAL, NOT REWARD DRIVEN
What is the neural basis of habitual and goal driven behaviour?
Motor areas send an action bid to the striatum which has a go or a no go pathway
What is the go/no go pathway based on?
Reward prediction from dopamine areas of the brain
Context: whether there has/ hasn’t been reward from this area before
What are the three basic decision making loops?
Motivational/ emotional
Executive/ associative
Motor/ sensorimotor
What does the ventral striatum do?
responsible for reward signals, carries out decision making about how rewarding something is going to be.
What does the caudate nucleus do?
Gets info from the frontal cortex, motor cortex and memory areas of the brain like the hippocampus. \
Memory helps inform decision
Decision making here is outcome sensitive
What does the putamen do?
Decides what action should occur next based on what action has just occurred. Good for action chunking and smooth sequences of movement.
What does decision making in the limbic loop do?
Concerns how to feel/ predict reward to particular cases of stimuli
What does decision making in the associative loop do?
Links previous memories together
What does decision making in the sensorimotor loop do?
Concerns movements that follow one another in a sequence, signalled by specific cues
When does behaviour become habitual?
When there is a transfer of control between the caudate and putamen loops
What was they hypothesis of Yin & Knowlton 2016 & Thorn et al 2010?
Maybe action outcome sensitive behaviour is controlled through the caudate and flow of action sequence could be controlled by putamen.
What did Yin & Knowlton 2016 and Thorn et al 2010 do?
- Used single cell recording : from dorsolateral striatum (putamen in humans)
- Rats learn that high tone means chocolate milk on left/right
- Cell initially active throughout the whole task, particularly at reward sites
- As habit forms: task bracketing pattern (most activity at the start of task and right at end has been chunked and it is recognising beginning and end of task)
- Habit imprinted- Dorsal medial striatum (caudate in humans) active at decision making point, decreases as habit settles.
What happens if you lesion the dorsolateral striatum ?
Prevents behaviour becoming habitual
How does the DSM diagnose addiction?
Must have 2 or more of 11 criteria over 12 months at least
What is addiction?
Compulsive behaviour can be defined as the maladaptive persistence of responding despite adverse consequences (Everitt & Robins 2016)
What are drugs of abuse linked to?
Liking (opiates) and wanting (cocaine/ alcohol/ marijuana)
What is the physical dependence theory of addiction?
Go back to the drug to avoid the aversive effects of withdrawal
But: this is insufficient because relapse is common after full detox
How does positive incentive theory of addiction work? (A)
Incentive- sensitisation
Drugs, such as opiates, alcohol, marijuana and cocaine stimulate dopamine pathways that promote wanting and learning
Drug contexts and stimulus promote dopamine release, becoming predictive of reward- can also be internal cues e.g. memories.
What did Kuhn & Gallinat 2011 find?
Meta- analysis: found that smokers, alcoholics and cocaine users have much bigger reward prediction response than controls
How does positive incentive theory of addiction work (B)?
Transfer from outcome sensitive behaviour to habitual behaviour for drug rewards
Overtraining for drug ‘reward’ leads to habitual responding in devalued paradigm
Rats given cocaine burst with lever
- short training: stop pressing lever
- Long training: keep pressing lever
What has research shown about compulsive drug taking?
Deroche-Gamonet et al 2004
- After overtraining in cocaine taking task, 17% of rats persisted in seeking cocaine despite footshock.
How many people become addicted to drugs?
about 20-30% from a pool of recreational users (Everitt & Robbins 2016)
What research has there been into individual differences in susceptibility to addiction ?
Ersche et al 2013
- Studied non-addictive relatives on impulsivity and sensation seeking traits
- IMPULSIVITY: found that addicted users scored highest, then relatives, then controls
- SENSATION SEEKING: found that addicted and recreational users were higher, then relatives and controls scored very similar.
