irrational economic decision making in schizophrenia
DESCRIPTION
Kyongsik Yun, Yang Tae Kim, Jaeseung Jeong. “Irrational Economic Decision-Making in Schizophrenia: Evidence from the Ultimatum Game”, Korean Neuropsychiatric Association. Seoul, Korea, October 23 – 24, Oral PresentationTRANSCRIPT
Irrational Economic Decision Making in Schizophrenia:
Evidence from the Ultimatum GameEvidence from the Ultimatum GameKorean Neuropsychiatric Association
2008.10.23, 03:25p.m.
Kyongsik Yun, Ph.D. CandidateKyongsik Yun, Ph.D. CandidateBio and Brain Engineering
Questions to be asked• Is the Ultimatum game behavior of schizophrenia
different from that of normal controls?
• Does time frequency analysis of EEGs show impaired decision making in schizophrenia?
• Does phase synchronization of EEGs show impaired decision making in schizophrenia?
2
3
What are the temporal dynamics of social interaction?
proposer responder
4
What are the temporal dynamics of social interaction?
proposer responder
1. Make an offer: 9:1(send emotional cue)(send emotional cue)Reward anticipation (NAcc)
5
What are the temporal dynamics of social interaction?
proposer responder
1. Make an offer: 9:1(send emotional cue) 2. Conflict btwn emotion & cognition
ACC, Ins, dlPFC activation (interaction)
responder
(send emotional cue)Reward anticipation (NAcc)
ACC, Ins, dlPFC activation (interaction)
6
What are the temporal dynamics of social interaction?
proposer responder
1. Make an offer: 9:1(send emotional cue) 2. Conflict btwn emotion & cognition
ACC, Ins, dlPFC activation (interaction)
responderresponder
(send emotional cue)Reward anticipation (NAcc)
ACC, Ins, dlPFC activation (interaction)3. Make a decision (reject: Ins)
7
What are the temporal dynamics of social interaction?
proposer responder
1. Make an offer: 9:1(send emotional cue) 2. Conflict btwn emotion & cognition
ACC, Ins, dlPFC activation (interaction)
responderresponderproposer
(send emotional cue)Reward anticipation (NAcc)
ACC, Ins, dlPFC activation (interaction)
4. Reward prediction error
3. Make a decision (reject: Ins)
8
Previous studies:
emotion vs. cognition
Sanfey et al. Science, 2003 9
What are the neural mechanisms of human decision making in the context of emotion and cognition?
Anterior dlPFC Anterior insula
dlPFC
ACC10
Time line for a single round of the Ultimatum Game
Subject decides
6 sec 6 sec 6 sec x sec 6 sec
+ He gets $9You get $1 Accept Reject He gets $0
You get $0
x: Time continues until the subject decides.
RevealFixation
RevealPartner
RevealOffer
RevealOptions
RevealOutcome
11
Behavioral results from the Ultimatum Game
80
100
Schizophrenic
Control
20
40
60
Ac
cep
tan
ce r
ate
s (
%)
*
5:5 7:3 8:2 9:1
0
Offer
These are the offer acceptance rates averaged over all trials. Each of schizophrenia patients and normal controls saw three $5:$5 offers, two $7:$3 offers, two $8:$2 offers, and three $9:$1 offers from human partners (10 offers in total). 12
No difference between schizophrenia and controls was found in total earnings and reaction times.
13
Group average of induced spectral power for all electrodesschizo
Overall power is decreased in schizo.Especially when accepting the offer -> fairness valuation deficiency
normal
14
Topography of event related spectral power for each condition
Schizo accept
Normal accept
Schizo reject
-800~400ms
Normal reject
-400~0ms 0~400ms 400~800ms
SD
15
Group average of time series of event related spectral power for all electrodes and each decision in gamma
frequency range (30~50Hz)schizo
Lower overall power in schizo.Power change is not stable -> meaning?? regional communication is impaired.
normal
16
Phase synchronization analysis
Lachaux et al. 1999 17
schizo
Long range
Group average of phase synchrony for all electrodes
normal
Long range synchronization and communication is impaired in schizoEspecially when accepting the offer -> fairness valuation deficiency
18
Summary• Is the Ultimatum game behavior of schizophrenia
different from that of normal controls?– Yes. Abnormally accept. – Fairness valuation deficiency? Or economically rational?– Fairness valuation deficiency? Or economically rational?
• Does time frequency analysis of EEGs show impaired decision making in schizophrenia?– Yes. Lower overall power amplitude. – Especially when accepting the offer -> fairness valuation deficiency
• Does phase synchronization of EEGs show impaired decision making in schizophrenia?– Yes. Lower phase synchrony.– Especially when accepting the offer -> fairness valuation deficiency
19
Acknowledgments
• Jaeseung Jeong, Ph.D.• Jaeseung Jeong, Ph.D.– Advisor, Brain Dynamics Lab, KAIST,
• Dongil Chung– Ph.D. candidate, Brain Dynamics Lab, KAIST
Yang Tae Kim, M.D.• Yang Tae Kim, M.D.– Bugok National Hospital
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