A Model of the Initial Stages of Drug Abuse: From Reinforcement Learning to Social Contagion

2011 ◽  
pp. 185-201
Author(s):  
Gilly Koritzky ◽  
Adi Luria ◽  
Eldad Yechiam
2019 ◽  
Vol 29 ◽  
Author(s):  
Kenneth S. Kendler ◽  
Henrik Ohlsson ◽  
Alexis C. Edwards ◽  
Jan Sundquist ◽  
Kristina Sundquist

Abstract Aims Can drug abuse (DA) be transmitted psychologically between adult siblings consistent with a social contagion model? Methods We followed Swedish sibling pairs born in 1932–1990 until one of them, sibling1 (S1), had a first DA registration. We then examined, using Cox regression, the hazard rate for a first registration for DA in sibling2 (S2) within 3 years of a first DA registration in S1 as a function of their geographical proximity. We examined 153 294 informative pairs. To control for familial confounding, we repeated these analyses in sibships containing multiple pairs, comparing risk in different siblings with their proximity to S1. DA was recorded in medical, criminal or pharmacy registries. Results The best-fit model predicted risk for DA in S2 as a function of the log of kilometres between S1 and S2 with parameter estimates (±95% confidence intervals) of 0.94 (0.92; 0.95). Prediction of DA included effects of cohabitation and an interaction of proximity and time since S1 registration with stronger effects of proximity early in the follow-up period. Proximity effects were stronger for smaller S1–S2 age differences and for same- v. opposite-sex pairs. Sibship analyses confirmed sibling-pair results. Conclusions Consistent with a social contagion model, the probability of transmission of a first registration for DA in sibling pairs is related to their geographical proximity and similarity in age and sex. Such effects for DA are time-dependent and include cohabitation effects. These results illustrate the complexity of the familial aggregation of DA and support efforts to reduce their contagious spread within families in adulthood.


2021 ◽  
Vol 17 (1) ◽  
pp. e1008552
Author(s):  
Rani Moran ◽  
Mehdi Keramati ◽  
Raymond J. Dolan

Dual-reinforcement learning theory proposes behaviour is under the tutelage of a retrospective, value-caching, model-free (MF) system and a prospective-planning, model-based (MB), system. This architecture raises a question as to the degree to which, when devising a plan, a MB controller takes account of influences from its MF counterpart. We present evidence that such a sophisticated self-reflective MB planner incorporates an anticipation of the influences its own MF-proclivities exerts on the execution of its planned future actions. Using a novel bandit task, wherein subjects were periodically allowed to design their environment, we show that reward-assignments were constructed in a manner consistent with a MB system taking account of its MF propensities. Thus, in the task participants assigned higher rewards to bandits that were momentarily associated with stronger MF tendencies. Our findings have implications for a range of decision making domains that includes drug abuse, pre-commitment, and the tension between short and long-term decision horizons in economics.


2006 ◽  
Vol 40 (10) ◽  
pp. 28
Author(s):  
JOHN R. BELL
Keyword(s):  

2007 ◽  
Vol 40 (22) ◽  
pp. 22-23
Author(s):  
SHARON WORCESTER
Keyword(s):  

2011 ◽  
Vol 44 (8) ◽  
pp. 62
Author(s):  
KERRI WACHTER
Keyword(s):  

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