The Cognitive Neuroscience of Addiction

Question 1

What is an addiction?

Answer 1

Intense cravings for desired substance and severe withdrawals when taken away

Question 2

What is the effect of cocaine?

Answer 2

Reduced volume of frontal lobe, strokes and seizures

Question 3

What is the effect of heroin?

Answer 3

Grey matter reduction, brain hypoxia, cerebral edema, stroke etc

Question 4

What is alcoholism closely linked to?

Answer 4

Wernicke-Korsakoff syndrome

Question 5

What is Wernicke-Korsakoff syndrome?

Answer 5

End stage of general brain shrinkage, characterised by anterograde amnesia (general forgetting)

Question 6

What is the greatest cause of addiction?

Answer 6

Individual variability in susceptibility to addiction

Question 7

What do associative learning theories of addiction say it is?

Answer 7

Conditioning

Question 8

How does relapse take place?

Answer 8

Re-exposure to the cue (smoking) after attempted extinction procedures

Question 9

How was the conditioned compensatory response investigated?

Answer 9

• Dogs injected with adrenaline
• HR increased
• Researchers noticed the HR increase was getting smaller after each injection
• Tolerance increasing

Question 10

What else did they find out about the CCR?

Answer 10

Actual drug not needed

Question 11

How can conditioning g show drug addiction?

Answer 11

UCS (HR increase - adrenaline) + CS (Contextual cues e.g. syringe) –> UR (Reduced HR)

CS (Cues) –> CR (Reduced HR)

Question 12

How can heroin and a CCR lead to an overdose?

Answer 12

• Reduced HR from heroin, organism compensated by increasing HR
• In absence, effect of drug is stronger
• Lack of CCR to heroin means the effect is stronger

Question 13

What is the CCR a form of?

Answer 13

Tolerance

Question 14

How are the effects of tolerance complex?

Answer 14

• Can be a form of homeostatic protection to reduce harmful effects
• Can also lead to overdose if contextual cues are absent

Question 15

What causes a craving?

Answer 15

Withdrawal symptoms

Question 16

What has research with rats shown?

Answer 16

Animals prepared to work hard to receive stimulation of nucleus accumbens

Question 17

What did Wise discover?

Answer 17

Anhedonia hypothesis

Question 18

What is the anhedonia hypothesis?

Answer 18

Dopaminergic synapses convey ‘goodness’ (e.g. food)

Question 19

How was Wise’s Dopamine and reinforcement experiment carried out?

Answer 19

• Rats trained to press lever to obtain food, then split into 3 groups
• G1 - lever pressing reinforced by food
• G2 - no longer reinforced - rats stop pressing lever
• G3 - given dopamine antagonist and reinforcement continued

Question 20

What was the result of Wise’s experiement?

Answer 20

3rd group showed similar disengagement as group 2 despite continued reinforcement

Question 21

What was commonly found among long term drug users?

Answer 21

Drug taking overtime results in less euphoria - reduction in ‘high’ but craving increases

Question 22

What is the incentive salience theory?

Answer 22

Dopaminergic circuit involving NA and VTA is not so much responsible for pleasure obtained but motivation to obtain

Question 23

What else does the IST theory propose?

Answer 23

Addicts become sensitised to drugs because their use affects the motivation related dopaminergic synapses in their brain

Question 24

What is Comorbidity?

Answer 24

The probability of a diagnosis of drug or alcohol dependence increasing with the severity of a mental illness

Question 25

How can drug use cause mental illness and vice versa?

Answer 25

Drug use –> neurotoxicity –> MHP
MHP –> self-medication –> Drug use

Question 26

Why do people use drugs to cope?

Answer 26

Self medication due to comorbidity