Nicotine addiction II Lee Hogarth

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Nicotine addiction IILee Hogarth
Lectures available at http//www.psychology.notti
ngham.ac.uk/staff/lch/C81ADD/
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Smoking cues motivate drug seeking/taking
Shiffman (1996) tested this by asking smokers who
had just quit smoking to record on a palm-top,
the situations in which they lapsed to smoking.
Almost 100 of lapses occurred in situations in
which cigarettes were available and smoking was
allowed. These data suggests situational cues f
or drug availability/acceptability play a
critical role in maintaining drug use in addicts
who would otherwise quit. The question is, how
do drug cues motivate drug seeking/taking
behaviour.
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How do smoking cues motivate drug seeking
behaviour?
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Pavlovian conditioning (Pavlov 1927)
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Pavlovian conditioning (Pavlov 1927)
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1. Stimulus-response habit
According to habit theory, drug induced dopamine
activity reinforces the synaptic connection
between drug cues present at the time, and the
drug seeking response that produced the drug. As
a consequence of this change in synaptic
strength, drug cues elicit the drug seeking
response directly. This model envisages the add
ict as a machine, automaton, robot, or zombie, in
that the addicts behaviour is controlled by
external cues without thought for the
consequences of behaviour.
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Critique of habit theory - craving
Relapse and drug use often accompanied by an urge
or craving to smoke. Here, the addicts engages
a mental image of the drug, which incorporates
the perceived appetitive value of the drug, the
stimulus characteristics of the drugs, and
circumstances under which the drug might be
obtained, and the behaviour that is required to
obtain the drug. Indeed, most addicts report th
at their drug seeking behaviour is undertaken
intentionally, that is, with a mental image of
the drug driving their behaviour.
Habit theory is at odds with this apparent role
of conscious (albeit compulsive) decision making
in the control of drug seeking behaviour.
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Cognitive model of drug use (Tiffany 1990)
Tiffany was interested in the relationship
between questionnaire reports of cigarette
craving (I desire a cigarette right now) and
actual smoking behaviour. If drug seeking was int
entional, one would expect a perfect correlation
between craving a drug use behaviour. But in
fact, in meta analysis of studies that have
looked at this relationship, showed that the
correlation is far from perfect.
Consequently, Tiffany proposed that addictive
behaviour is sometimes intentional (i.e.
controlled by a mental image or craving for the
drug) and sometimes controlled automatically by
external drug related cues in the same sense as a
stimulus-response habit. Thus, drug users can swi
tch between and intentional and automatic mode of
control.
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Devaluation Dickinson (1985)
The devaluation procedure was developed to
demonstrate the transition from intentional
control to behavioural autonomy with practice.
Rats are first learned a lever press response for
food pellets. Then, in a separate environment, th
ey were given the opportunity to consume the food
to satiation (to reduce the value of the food).
Finally, rats were given the opportunity to press
the food lever in extinction. Rats showed reduced
lever pressing, indicating that this behaviour
was controlled by a representation of the current
value of the outcome of that behaviour (i.e. the
rat has knowledge of the consequences of its
behaviour). By contrast, after extensive training
lever pressing became insensitive to
devaluation, suggesting this behaviour has come
under the control of a stimulus-response habit
(i.e. had become automatic).
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Habit learning is quicker for drug vs. natural
reward (Dickinson 2002)
Rats learned to press one lever for sucrose and
one lever for alcohol. Then, one of these rewards
was devalued by pairing with lithium chloride
induced sickness. Finally, rats were given the op
portunity to press the two levers in extinction.
If these two actions are controlled by an
expectation of new low value of the rewards, then
rats should reduce lever pressing for these
rewards. In fact, whereas lever pressing for sucr
ose was decreased, lever pressing for alcohol was
not. Conclusion After the same level of training
, whereas food seeking was still controlled by an
expectation of the consequences of this
behaviour, alcohol seeking had come under the
control of a habit, that is, the behaviour was
controlled by the external stimulus of the
alcohol lever automatically, without engaging an
expectation of the consequences of this behaviour.
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2. Incentive salienceRobinson and Berridge (2003)
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Incentive salience theoryRobinson and Berridge
(2003)
Incentive salience theory is an elaboration of
habit theory, which proposes that through
Pavlovian conditioning, drug cues acquire the
capacity to capture attention, which engages
thought about the drug and drug use, which in
turn causes drug users to initiate drug
seeking/taking.
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Attentional bias for drug cues

• Stroop task (e.g. Gross et al. 1993)
• 2. Interference with simple target detection
  (e.g. Sayette and Hufford 1994)
  
• 3. Change detection (e.g. Jones et al. 2002).
• 5. Dot probe task (e.g. Ehrman et al. 2002).
• 6. Eye tracking (e.g. Rosse et al. 1993).

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Correlations between attentional bias and
treatment outcome
Greater Stroop attentional bias is associated
with poorer treatment outcome in addicts of
various drugs 1. Waters (2003) Smoking 2
. Cox (2002, 2007) Alcohol 3. Marissen (2006)
Heroin 4. Carpenter (2006) Cocaine
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3. Expectancy theoryDickinson (1987)
It is axiomatic that Pavlovian stimuli only
elicit conditioned responses if they elicit a
representation or expectation of the outcome.
This is true for both human conditioning in
general (Lovibond and Shanks 2002)
and drug conditioning in particular (Hogarth et
al 2006).
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Expectancy in drug conditioning
Schedule AX AY BX- BY-
Hogarth L, Dickinson A, Hutton SB, Elbers N, Duka
T (2006). Psychopharmacology 185 495-504
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Expectancy in drug conditioning
Hogarth L, Dickinson A, Hutton SB, Elbers N, Duka
T (2006). Psychopharmacology 185 495-504
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Expectancy and drug taking
Schedule AX AY BX- BY-
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ConclusionThis lecture started with the
question of how drug cues motivate drug seeking
behaviour. We have considered three major
options (all of which interact in a complex
motivational system)1. Stimulus-response habit
learning where drug cues automatically elicit
drug seeking through the reinforcement of a
stimulus-response neural connection.2.
Incentive salience Where drug cues capture
attention, which engages thought about drug use,
and which in turn motivates drug seeking.3.
Goal-directed learning where the drug cues
engage a mental representation or expectation of
the drug, which drives drug seeking behaviour.