Impulsivity and SelfControl

1
Impulsivity and Self-Control
John Monterosso1, George Ainslie2, Edythe
London1 1 UCLA, Dept of Psychiatry2 Coatesville
VA Medical Center
"To cease smoking is the easiest thing I ever
did. I ought to know because I've done it a
thousand times." - Mark Twain
2
Plan

• Summarize the intrapersonal bargaining account
  of willpower
• Present fMRI data from 3 studies
• Methamphetamine addicts and controls performing a
  delay discounting task
• Signal change in the ventral striatum of normal
  participants winning money varying in amount and
  delay
• Craving smokers voluntarily abstaining from
  available access to cigarette smoke
• 12-step and recovery from addiction

3
How do people say no?
4
Local Vs Global framing of the contingencies

• Are you hammering a nail or building a house?
• Are you having fun, or undermining the life you
  want?

5
How do you move from local to global?

• Picoeconomic/ Bargaining answer -
• You come to see specific behaviors (local) as
  predictive of what your own behavior will be
  within the larger category of behaviors (global).
  

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Bargaining account of self-control
Times Now and Future Alternatives Dirty Vs
Clean
Dirty Now and Dirty Future (DD) Dirty Now and
Clean Future (DC) Clean Now and Dirty Future
(CD) Clean Now and Clean Future (CC)
Ranking

• DC
• CC
• DD
• CD

Ranking

• DC
• CC
• DD
• CD

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Tomorrow, Tomorrow!
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Future behavior is uncertain
Ranking

• DC
• CC
• DD
• CD

If my estimate of what my future behavior will be
is (sufficiently) informed by present choice then
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A thought experiment on willpower

• Would the smoker trying to quit resist todays
  temptation if
• She knew she was destined to relapse for good
  tomorrow?
• She knew she would not smoke at all starting
  tomorrow?

Willpower requires there to seem to be more in
the balance than what is literally at stake.
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Internal feedback between behavior and expectation
Expectation of future choices
Current Preference
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(No Transcript)
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Delay Discounting in MA Abusers and Controls

• Administer a delay discounting task outside the
  scanner.
• Estimated a discount function for each
  individual.
• Administer delay discounting task in the scanner
  with three block-types No Choice, Hard Choices,
  Easy Choices.

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(K.04)
No Choice
27 Today
Hard Choice
27 Today
50 in 21 days
Easy Choice
27 Today
259 in 21 days
27 Today
29 in 21 days
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MA discounted more steeply
Geometric mean k-value for MA abusers .045
(Indifferent between 20 today and 47 in 1
month)
Geometric mean k-value for control subjects .013
(Indifferent between 20 today and 28 in 1
month)
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(No Transcript)
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Task Related Activity (Choice - No Choice)
VLPFC
AC/SMA
DLPFC
IPS
(Human Brain Mapping, 2007)
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(No Transcript)
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(Human Brain Mapping, 2007)
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Conclusions

• Meth addicts exhibit steep delay discounting
• Differences in Meth and control discount rates do
  not appear to require robust signal change in
  Beta regions
• Meth addicts did differ from controls in
  frontoparietal activity as a function of decision
  difficulty

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Anomalies of human discounting data

• Inconsistent across domains
• Far more variable than other species tested
• Negative discounting for pain and some pleasure

Conceived contingencies are not limited to what
is explicitly at stake Tom
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(No Transcript)
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Non-choice based discounting

• Would it be different?
• Would it be less domain specific?
• Would we see differences in drug users relative
  to controls?

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Signal change in nucleus accumbens during
anticipation of reward
Knutsen et at., 2003
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Estimating Delay Discounting from fMRI signal
change (NOT ACTUAL DATA!)
100 In 1 month
Vi
Vd
56 In 1 month
DK1
37 In 1 month
30 In 1 month
25 Today
Signal increase
27 In 1 month
26 In 1 month
25.50 In 1 month
25.25 In 1 month
K.00016
K.0004
K.001
K.0025
K.006
K.016
K.041
K.1
25
10
20
30
Today
In 1 week
In 2 weeks
26
10
20
30
Today
In 1 week
In 2 weeks
27
10
20
30
Today
In 1 week
In 2 weeks
Red
28
10
20
30
Today
In 1 week
In 2 weeks
Red
29
10
20
30
Today
.29
.07
.04
In 1 week
.14
.07
In 2 weeks
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Pilot Study Design

• 10 healthy participants
• Outside the scanner subjects made choices between
  all 36 pairs
• During fMRI subjects completed 12 trials at each
  of the 9 amount-delay combinations.
• So far we just looked at signal change in the
  ventral striatum during anticipation.
• Treated as ordinal data

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Later larger gt 10 Now
N 10 normal healthy college students
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Later larger gt 20 Now
N 10 normal healthy college students
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Non-choice based discounting

• Would it be different?
• Would it be less domain specific?
• Would we see differences in drug users relative
  to controls?

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(No Transcript)
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Smoking Self-ControlChallenge
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Would you like to smoke right now?
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Smoke Unavailable
Valve is closed 20 sec
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Smoke available, but try not to
Valve is open 20 sec
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Successful Self-Control - Unavailable
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(No Transcript)
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When people recover from addiction

• They may talk of a spiritual awakening
• If they got help, gt90 chance 12-step
• They may talk of having hit rock bottom
• They will likely experience quitting as a
  struggle to gain control over their life.

?
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12-Step

• Free
• Arguably more effective then alternative
  therapies.

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Crits-Christoff, 1999
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Weiss et al, 2003
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Intertemporal bargaining and 12-Steps

• Self-control requires there to be more seen in
  the balance then just one.
• Anything that makes a choice unique undermines
  its status as precedent, making smaller sooner
  more compelling.
• Underconfidence in future self should produce
  choice of smaller sooner.
• Overconfidence in future self should produce
  choice of smaller sooner.
• Bright lines facilitate self-control

You cannot use in moderation
Strict
Emphasis on the process.
Every day one day closer to next relapse.
Permanent
Smoke in Future
Abstain in Future
DC
DD
Abstinence, not moderation
Smoke Now

• DC
• CC
• DD
• CD

CC
CD
Abstain Now
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THANKS

• George Ainslie, MD
• Edythe London, PhD
• Traci Mann, PhD
• Steve Engel, PhD
• Andrew Ward, PhD
• Xochitl Cordova
• Sara Cathcart

Funding from NIDA TRDRP