Impulsivity and Cognitive Distortions in …...‘Close only counts in horseshoes and hand grenades’ Horseshoes Game of skill Near-misses provide indication of skill acquisition,

Impulsivity and Cognitive Distortions in Pathological Gambling

Dr Luke Clark

Department of Experimental Psychology

University of Cambridge, U.K.

The Psychology of Gambling

1. How do we explain the prevalence of gambling if people understand that ‘the house always wins’?

2. How does gamble become dysfunctional (addictive?) in a minority?

Cognitive distortions during

gambling

Brain mechanisms of decision-making and

reward processing

Emotional / physiological

responses in the body

The Cognitive Approach to Gambling

• Gamblers experience distorted processing of probability and randomness, such that they over-estimate their chances of winning

• Distortions elevated in problem gamblers

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Gamblers Controls

Tota

l Sco

re

Gambling-Related Cognitions Scale

• Two basic types: 1) Sequential predictions based

on independence of turns 2) Mistaken appraisals of skill

due to perceived personal control

Clark (2010 Proc Roy Soc B), Michalczuk et al (2011)

The ‘Gambler’s Fallacy’ in Simulated Roulette

Simple task: • Guess RED or BLACK • Then, rate your

confidence

Black, Black, Black, Black “RED!” (i.e. negative recency)

Studer & Clark (in prep)

Choose red after Choose red after

The ‘Gambler’s Fallacy’ in Simulated Roulette

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% s

ame

as p

revi

ous

outc

ome

Consecutive Reds / Blacks

Confidence after Loss Loss Confidence after Loss Loss Loss Loss

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Short (1,2) Long (4,5) %

Cho

ice

of P

revi

ous

Outcome Run Length

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Short (1,2) Long (4,5)

Z(Co

nfid

ence

Rat

ing)

Losing Streak

Near-Misses

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468

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1214

15% 30% 45%

Near-Miss Frequency

Tria

ls in

Ext

inct

ion

“A special kind of failure to reach a goal, one that comes close to being successful” (Reid 1986)

Kassinove & Schare 2001

Near-Misses in a Simulated Slot Machine

Selection - Anticipation - Outcome

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NearMiss FullMiss

Z s

core

of

rati

ng

"Continue to play?" "Pleased with outcome?"

Subjective Differences between Near-Misses and Full-Misses

Clark et al (2009 Neuron)

Arousal Responses to Wins and Near-Misses

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1 2 3 4 5 6 SCR

Cha

nge

from

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elin

e (lo

g +

1)

Time post-outcome (2s bins)

Participant - WINS

All Non-Wins

-0.004

-0.002

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0.012

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SCR

Cha

nge

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elin

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g +

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Time post-outcome (2s bins)

Participant - NEAR

Participant - FULL

Clark et al (2011 Journal of Gambling Studies)

fMRI Responses to Wins and Near-Misses

P<.05 FWE Dopaminergic

Midbrain Anterior

Insula Ventral Striatum mPFC

WINNING OUTCOMES minus ALL NON-WIN OUTCOMES

NEAR-MISS OUTCOMES minus FULL-MISS OUTCOMES

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B

P<.001 uncorr Clark et al (2009 Neuron)

Gambling Severity predicts Near-Miss Activity in Midbrain

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Per

cen

t Si

gnal

Ch

ange

SOGS

re-smoothed at 4mm

Chase & Clark (2010 J Neurosci)

‘Close only counts in horseshoes and hand grenades’

Horseshoes

Game of skill

Near-misses provide indication of skill acquisition, and thus likelihood of future success

Should be valued by brain reward system

Fruit machine

Game of chance

Near-misses provide no indication of future success

Should be ignored by brain

Griffiths (1993), Reid (1986)

• Gambling distortions can be elicited in healthy individuals in a laboratory environment (Gambler’s Fallacy, effects of near-misses)

• Near-miss outcomes are experienced as unpleasant but invigorate gambling behaviour

• Wins and near-misses are associated with phasic changes in peripheral arousal

• At a neural level, near-misses trigger anomalous activation in components of the brain reward system: VS, insula, vmPFC.

• The size of these near-miss responses predicts susceptibility to gambling distortions in healthy volunteers (insula) and severity of gambling involvement in regular gamblers (midbrain)

• No evidence for changes in (baseline) dopamine D2 receptors in PG, but correlations with impulsivity

Conclusions

Acknowledgements University of Cambridge

Andrew Lawrence

Rosanna Michalczuk

Henry Chase

Mike Aitken

Barbara Sahakian

Trevor Robbins

Barney Dunn (MRC CBU)

Funding support:

Medical Research Council

MRC – Wellcome Trust Behavioural and Clinical Neuroscience Institute

Economic and Social Research Council

Responsibility in Gambling Trust (now RGF)

Imperial College, London

Henrietta Bowden-Jones

Paul Stokes

Anne Lingford-Hughes

Kit Wu

Robert Rogers (Oxford)

Antonio Verdejo (U Granada)