Rats with perirhinal cortex lesions were compared with sham controls on a conditional discrimination in which saccharin was paired with LiCl in context 1, but paired with saline in context 2. Perirhinal-lesioned rats were slightly slower to acquire the discrimination but reached control levels by the end of acquisition. Both groups showed transfer to familiar tap water, consuming less in contex...

The present study was designed to evaluate the effects of bulbectomy and acute administration of anxiolytic drugs (diazepam, 10 mg/kg; chlordiazepoxide, 10 mg/kg) on the behavior of both sham-operated and olfactory bulbectomized rats in two tests predictive of anxiolytic activity: plus-maze test and Vogel's conflict test. We investigated also the effect of flumazenil (10 mg/kg), a benzodiazepin...

Nicotine from smoking tobacco produces one of the most common forms of addictive behavior and has major societal and health consequences. It is known that nicotine triggers tobacco addiction by activating nicotine acetylcholine receptors (nAChRs) in the midbrain dopaminergic reward system, primarily via the ventral tegmental area. Heterogeneity of cell populations in the region has made it diff...

Risk aversion is a fundamental concept in economics used to explain agents' behavior under uncertainty. Risk aversion in auctions has been justified through the many uncertainties faced by bidders and through the large value of bids relative to bidders' assets. In first-price auctions, risk aversion renders more aggress­ sive bidding, while bidding in ascending auc­ tions is not affected, leadi...

In this paper we propose the inÞmum of the Arrow-Pratt index of absolute risk aversion as a measure of global risk aversion of a utility function. We then show that, for any given arbitrary pair of distributions, there exists a threshold level of global risk aversion such that all increasing concave utility functions with at least as much global risk aversion would rank the two distributions in...

BACKGROUND Emerging data from younger and middle-aged persons suggest that cognitive ability is negatively associated with risk aversion, but this association has not been studied among older persons who are at high risk of experiencing loss of cognitive function. METHODS Using data from 369 community-dwelling older persons without dementia from the Rush Memory and Aging Project, an ongoing l...

We consider a formal approach to comparative risk aversion and applies it to intertemporal choice models. This allows us to ask whether standard classes of utility functions, such as those inspired by Kihlstrom and Mirman (1974), Selden (1978), Epstein and Zin (1989) and Quiggin (1982) are well-ordered in terms of risk aversion. Moreover, opting for this model-free approach allows us to establi...

When attempting to draw a ball of a specified color either from an urn containing 50 red balls and 50 black balls or from an urn containing an unknown ratio of 100 red and black balls, a majority of decision makers prefer the known-risk urn, and this ambiguity aversion effect violates expected utility theory. In an experimental investigation of the effect of urn size on ambiguity aversion, 149 ...

We consider a formal approach to comparative risk aversion and applies it to intertemporal choice models. This allows us to ask whether standard classes of utility functions, such as those inspired by Kihlstrom and Mirman (1974), Selden (1978), Epstein and Zin (1989) and Quiggin (1982) are well-ordered in terms of risk aversion. Moreover, opting for this model-free approach allows us to establi...