Research on preference reversals has demonstrated a disproportionate influence of outcome probability on choices between monetary gambles. The aim was to investigate the hypothesis that this is a prominence effect originally demonstrated for riskless choice. Another aim was to test the structure compatibility hypothesis as an explanation of the effect. The hypothesis implies that probability should be the prominent attribute when compared with value attributes both in a choice and a preference–rating procedure. In Experiment 1, two groups of undergraduates were presented with medical treatments described by two value attributes (effectiveness and pain-relief). All participants performed both a matching task and made preference ratings. In the latter task, outcome probabilities were added to the descriptions of the medical treatments for one of the groups. In line with the hypothesis, this reduced the prominence effect on the preference ratings observed for effectiveness. In Experiment 2, a matching task was used to demonstrate that probability was considered more important by a group of participating undergraduates than the value attributes. Furthermore, in both choices and preference ratings the expected prominence effect was found for probability.
Adenylyl cyclase type-5 (AC5) is preferentially expressed in the dorsal striatum. Recently, we reported that AC5 knockout (KO) mice preferred food pellets carrying an olfactory cue produced by AC5 KO mice during food consumption (AC5 KO pellets) over food pellets that had been taken by wildtype (WT) mice. In the present study, we demonstrated that whisker trimming on the right side of the face but not the left in AC5 KO mice blocked the behavioral preference for AC5 KO pellets. Conversely, whisker trimming on the right but not the left in WT mice induced a behavioral preference for AC5 KO pellets. Mice lacking D2 dopamine receptor (D2 KO mice) also showed a behavioral preference for AC5 KO pellets. In D2 mice, whisker trimming on the right side of the face but not the left blocked a behavioral preference for AC5 KO food pellets. AC5 KO mice had increased level of phospho-CaMKIIα in the dorsal striatum, and WT mice with whiskers cut on either side also showed increased p-CaMKIIα level in the dorsal striatum. The siRNA-mediated inhibition of CaMKIIα in the dorsal striatum in either the right or the left hemisphere in AC5 KO mice and D2 KO mice blocked the behavioral preference for AC5 KO pellets. However, behavioral changes induced by this inhibition on each side showed asymmetrical time courses. These results suggest that an unconditioned behavioral preference for specific food pellets can be switched on or off based on the balance of states of neural activity in the dorsal striatum regulated by a signaling pathway centered on AC5 and D2 and the sensory inputs of whiskers from the right side of the face.
This paper analyzes a fully funded social security system under the assumption that agents face temptation issues. Agents are required to save through individually managed Personal Security Accounts without, and with mandatory annuitization. When the analysis is restricted to CRRA preferences our results are congruent with the literature in indicating that the complete elimination of social security is among the reform scenarios that maximize welfare. However, when self control preferences are introduced, and as the intensity of self control becomes progressively more severe the "social security elimination" scenario loses ground very rapidly. In fact, in the case of relatively severe temptation the elimination of social security becomes the least desirable alternative. Under the light of the above findings, any reform proposal regarding the social security system should consider departures from standard preferences to preference specifications suitable for dealing with preference reversals.
We present a new theory of decision under uncertainty: third-generation prospect theory (PT3). This retains the predictive power of previous versions of prospect theory, but extends that theory by allowing reference points to be uncertain while decision weights are specified in a rank-dependent way. We show that PT3 preferences respect a state-conditional form of stochastic dominance. The theory predicts the observed tendency for willingness-to-accept valuations of lotteries to be greater than willingness-to-pay valuations. When PT3 is made operational by using simple functional forms with parameter values derived from existing experimental evidence, it predicts observed patterns of the preference reversal phenomenon.
Environmental conditions can dramatically influence the behavioral and neurochemical effects of drugs of abuse. For example, stress increases the reinforcing effects of drugs and plays an important role in determining the vulnerability to develop drug addiction. On the other hand, positive conditions, such as environmental enrichment, can reduce the reinforcing effects of psychostimulants and may provide protection against the development of drug addiction. However, whether environmental enrichment can be used to “treat” drug addiction has not been investigated. In this study, we first exposed mice to drugs and induced addiction-related behaviors and only afterward exposed them to enriched environments. We found that 30 days of environmental enrichment completely eliminates behavioral sensitization and conditioned place preference to cocaine. In addition, housing mice in enriched environments after the development of conditioned place preference prevents cocaine-induced reinstatement of conditioned place preference and reduces activation of the brain circuitry involved in cocaine-induced reinstatement. Altogether, these results demonstrate that environmental enrichment can eliminate already established addiction-related behaviors in mice and suggest that environmental stimulation may be a fundamental factor in facilitating abstinence and preventing relapse to cocaine addiction.