Iowa gambling task

The Iowa gambling task (IGT) is a psychological task thought to simulate real-life decision making. It was introduced by Antoine Bechara, Antonio Damasio, Hanna Damásio and Steven Anderson,[1] then researchers at the University of Iowa. It has been brought to popular attention by António Damásio (proponent of the Somatic markers hypothesis) in his best-selling book Descartes' Error.[2]

The task was originally presented simply as the Gambling Task, or the "OGT". Later, it has been referred to as the Iowa Gambling Task and, less frequently, as Bechara's Gambling Task.[3] The Iowa Gambling Task is widely used in research of cognition and emotion. A recent review listed more than 400 papers that made use of this paradigm.[4]

Task structure

Participants are presented with 4 virtual decks of cards on a computer screen. They are told that each time they choose a card they will win some game money. Every so often, however, choosing a card causes them to lose some money. The goal of the game is to win as much money as possible. The decks differ from each other in the number of trials over which the losses are distributed. Thus, some decks are "bad decks", and other decks are "good decks", because some will lead to losses over the long run, and others will lead to gains.

Screen shot of the Iowa Gambling Task

Common findings

Most healthy participants sample cards from each deck, and after about 40 or 50 selections are fairly good at sticking to the good decks. Patients with orbitofrontal cortex (OFC) dysfunction, however, continue to persevere with the bad decks, sometimes even though they know that they are losing money overall. Concurrent measurement of galvanic skin response shows that healthy participants show a "stress" reaction to hovering over the bad decks after only 10 trials, long before conscious sensation that the decks are bad.[5] By contrast, patients with amygdala lesions never develop this physiological reaction to impending punishment. In another test, patients with ventromedial prefrontal cortex (VM) dysfunction were shown to choose outcomes that yield high immediate gains in spite of higher losses in the future.[6] Bechara and his colleagues explain these findings in terms of the somatic marker hypothesis.

The Iowa gambling task is currently being used by a number of research groups using fMRI to investigate which brain regions are activated by the task in healthy volunteers[7] as well as clinical groups with conditions such as schizophrenia and obsessive compulsive disorder.

Critiques of the Iowa Gambling Task

Although the IGT has achieved prominence, it is not without its critics. Criticisms have been raised over both its design and its interpretation. Published critiques include:

References

  1. Bechara, A., Damásio, A. R., Damásio, H., Anderson, S. W. (1994). "Insensitivity to future consequences following damage to human prefrontal cortex". Cognition. 50 (1–3): 7–15. doi:10.1016/0010-0277(94)90018-3. PMID 8039375.
  2. Damásio, António R. (2008) [1994]. Descartes' Error: Emotion, Reason and the Human Brain. Random House. ISBN 978-1-4070-7206-7. Descartes' Error
  3. Busemeyer JR, Stout JC (2002). "A contribution of cognitive decision models to clinical assessment: Decomposing performance on the Bechara gambling task". Psychologicasl Assessment. 14 (3): 253–262. doi:10.1037/1040-3590.14.3.253.
  4. 1 2 Dunn BD, Dalgleish T, Lawrence AD (2006). "The somatic marker hypothesis: a critical evaluation". Neurosci Biobehav Rev. 30 (2): 239–71. doi:10.1016/j.neubiorev.2005.07.001. PMID 16197997.
  5. Bechara A, Damasio H, Tranel D, Damasio AR (1997). "Deciding advantageously before knowing the advantageous strategy". Science. 275 (5304): 1293–5. doi:10.1126/science.275.5304.1293. PMID 9036851.
  6. Bechara A, Damasio H, Tranel D, Damasio AR (2000). "Characterization of the decision-making deficit of patients with ventromedial prefrontal cortex lesions". Brain. 123 (11): 2189–2202. doi:10.1093/brain/123.11.2189. PMID 11050020.
  7. Fukui H, Murai T, Fukuyama H, Hayashi T, Hanakawa T (2005). "Functional activity related to risk anticipation during performance of the Iowa Gambling Task". NeuroImage. 24 (1): 253–9. doi:10.1016/j.neuroimage.2004.08.028. PMID 15588617.
  8. Lin CH, Chiu YC, Lee PL, Hsieh JC (2007). "Is deck B a disadvantageous deck in the Iowa Gambling Task?". Behav Brain Funct. 3: 16. doi:10.1186/1744-9081-3-16. PMC 1839101Freely accessible. PMID 17362508.
  9. Chiu, Yao-Chu; Lin, Ching-Hung (August 2007). "Is deck C an advantageous deck in the Iowa Gambling Task?". Behavioral and Brain Functions. 3 (1): 37. doi:10.1186/1744-9081-3-37. PMID 17683599.
  10. Chiu, Yao-Chu; Lin, Ching-Hung; Huang, Jong-Tsun; Lin, Shuyeu; Lee, Po-Lei; Hsieh, Jen-Chuen (March 2008). "Immediate gain is long-term loss: Are there foresighted decision makers in the Iowa Gambling Task?". Behavioral and Brain Functions. 4 (1): 13. doi:10.1186/1744-9081-4-13. PMID 18353176.
  11. Richard L. Peterson (9 July 2007). Inside the Investor's Brain: The Power of Mind Over Money. Wiley. ISBN 978-0-470-06737-6.
  12. http://www.fooledbyrandomness.com/

External links

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