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From Intoxication to Addiction: Neurobiological Substrates for Hubris? Paul Fletcher pcf22@cam.ac.uk Bernard Wolfe Health Neuroscience Fund The Intoxication of Power: From Neurosciences to Hubris in Healthcare and Public Life. Royal Society of Medicine October 2012
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Speculations on the neurobiology of hubris syndrome Impaired risk appraisal Inability to foresee undesirable outcomes Dangerous decision-making (with ensuing harm). Highly unlikely to be localisable to a single region or neurotransmitter system
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From Intoxication to Addiction: Neurobiological Substrates for Hubris?
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What do we mean by addiction? Drug addiction – a chronic relapsing state characterised by: –Compulsion to seek/take drugs –Loss of control –Emergence of a negative emotional state Latterly, research focus has shifted from the acute effects (the high and the come-down) to addiction as an evolving condition characterised by neuroadaptation Koob and Volkow, Neuropsychopharmacology, 2010
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Withdrawal/ Negative affect Preoccupation/ anticipation (Craving) Binge/Intoxication Impulsive (arousal/excitement) Drug Pleasure Compulsive (anxiety/stress) Drug Relief (+)ve(-)ve Goal-directed behaviours Habitual behaviours
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From Intoxication to Addiction: Neurobiological Substrates for Hubris?
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Interim summary We have two syndromes that entail impaired risk appraisal inability to foresee undesirable outcomes dangerous decision-making (with consequent harm) And for one (addiction) we have a sophisticated, though incomplete, understanding of the endophenotype and neurobiological basis. Does the addiction model help us to understand Hubris Syndrome?
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Summary… Hubris Addiction Poor Decisions Impaired risk appraisal Incorrigbility Low self-esteem Guilt Anxiety Depression Habitual behaviours -Stimulus-driven -Narrowed repertoire -Devoid of goals
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further thoughts – dopamine function in an uncertain world.
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A few simple principles… Successful interaction with our environment entails accurate predictions Prediction-based actions are rapid and efficient We must therefore be sensitive to (sometimes) subtle environmental regularities
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Prediction error – a key signal in learning ΔV = α β (λ – ΣV) Fiorillo et al
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Brain marker for PE-dependent learning Fletcher et al Nature Neurosci, 2001 Turner et al Cereb Cortex, 2004 Corlett et al Neuron, 2004 Murray et al, Molecular Psych, 2007; Corlett et al, Arch Gen Psych 2006; Brain 2007
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Prior knowledge Current input Prediction Error Update signal
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What happens when uncertainty is great? Prior knowledge Current input Prediction Error Update signal
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Prior knowledge Prediction Error Update signal Stress Personality Intoxication Arousal Current input
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From Intoxication to Addiction: Neurobiological Substrates for Hubris?
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