Effects of Tryptophan Depletion on the Performance of an Iterated Prisoner's Dilemma Game in Healthy Adults
by
Wood RM, Rilling JK, Sanfey AG, Bhagwagar Z, Rogers RD.
1University Department of Psychiatry,
University of Oxford, Oxford, UK.
Neuropsychopharmacology. 2006 Jan 11;

ABSTRACT

S Adaptive social behavior often necessitates choosing to cooperate with others for long-term gains at the expense of noncooperative behaviors giving larger immediate gains. Although little is know about the neural substrates that support cooperative over noncooperative behaviors, recent research has shown that mutually cooperative behavior in the context of a mixed-motive game, the Prisoner's Dilemma (PD), is associated with increased neural activity within reinforcement circuitry. Other research attests to a role for serotonin in the modulation of social behavior and in reward processing. In this study, we used a within-subject, crossover, double-blind design to investigate performance of an iterated, sequential PD game for monetary reward by healthy human adult participants following ingestion of an amino-acid drink that either did (T+) or did not (T-) contain l-tryptophan. Tryptophan depletion produced significant reductions in the level of cooperation shown by participants when playing the game on the first, but not the second, study days. This effect was accompanied by a significantly diminished probability of cooperative responding given previous mutually cooperative behavior. These data suggest that serotonin plays a significant role in the acquisition of socially cooperative behavior in human adult participants, and suggest novel hypotheses concerning the serotonergic modulation of reward information in socially cooperative behavior in both health and psychiatric illness.

SSRIs
Suicide
Serotonin
Dopamine
Melancholia
Noradrenaline
SSRI spectrum
SSRI mechanisms
Future anxiolytics
Serotonin research
21C antidepressants
Serotonin and psychedelics
SNaRIs, NaSSAs, and NaRIs
Serotonin and romantic lovers
Neuropharmacology of serotonin
The monoamine theory of depression
Fluoxetine (Prozac): 10th Anniversary
Serotonin and the genetics of depression

Refs
and further reading

HOME
HedWeb
Nootropics
cocaine.wiki
Future Opioids
BLTC Research
MDMA/Ecstasy
Superhapiness?
Utopian Surgery?
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
Critique of Huxley's Brave New World

The Good Drug Guide
The Responsible Parent's Guide
To Healthy Mood Boosters For All The Family