Food choice in rats (Rattus norvegicus): the effect of exposure to a poisoned conspecific

Three experiments were conducted to examine the effects of exposure to a poisoned conspecific on subsequent food aversion in rats. In Experiment 1A, rats that had been aversively conditioned to a cocoa-flavored food were exposed to a poisoned conspecific that had eaten the same food. On the subsequent choice test, the animals increased their aversion to that food. These results were reconfirmed in Experiment 1B, in which a cinnamon-flavored food was used as the stimulus. In Experiment 2, subjects were first exposed to a poisoned conspecific and then conditioned to the food which the conspecific had eaten. On the test, they showed no sign of increased aversion to that food.     

味觉厌恶性条件反射与条件反射性免疫抑制的研究

以环磷酰胺的注射为非条件刺激（ＵＣＳ）,糖精水的摄入为条件刺激（ＣＳ）,并以血白细胞和淋巴细胞数量及脾淋巴细胞的转化反应为免疫指标,糖精水的饮用量为行为指标,通过改变条件刺激与非条件刺激结合的次数来观察条件反射性厌恶行为与条件反射性免疫抑制的反应。结果表明不管是一次性的还是两次性的ＣＳ－ＵＣＳ结合训练都能使动物明显地建立起味觉厌恶性条件反射,然而条件反射性免疫抑制只在两次性ＣＳ－ＵＣＳ结合训练后才     

Ambiguity seeking in multi-attribute decisions: Effects of optimism and message framing

This paper investigates the influence of message framing and personality variables on preferences over ambiguity in the context of multi-attribute decision scenarios. Undergraduate subjects responded to scenarios in which one of two medical treatments was associated with ambiguous probabilities of treatment effects. Probabilities were either positively or negatively framed. Subjects indicated their degree of preference for one treatment over the other. Subjects' optimism, trait anxiety, health locus of control, need for cognitive structure, and current mood were measured. In two separate studies, subjects preferred ambiguity when probabilities were positively framed, and were neutral toward ambiguity when probabilities were negatively framed. Also, in both studies the preference for ambiguity in positively framed scenarios was greater for more optimistic subjects. The unexpected finding of ambiguity seeking may be associated with the use of different decision strategies in multi-attribute versus single-attribute decisions.     

Gender differences in optimism,loss aversion and attitudes towards risk

Systematic differences in the attitudes of men and women towards risk is well established. In this paper, we investigate the joint role of two prominent psychological characteristics in explaining this difference. Our starting point is that risk assessments can be thought of, in general terms, to combine beliefs about the probability of negative outcomes occurring with a subjective valuation of how painful that negative outcome would be. Exploiting large-scale panel data from the United Kingdom, we find that gender differences in financial optimism and financial loss aversion – the stronger psychological response to monetary losses than monetary gains – explain a substantial proportion of the parallel gender difference in willingness to take risks. This result prevails even after controlling for the Big Five personality traits, suggesting that the prominent psychological characteristics capture different aspects of behaviour than the Big Five.     

Expertise Shapes Multimodal Imagery for Wine

Although taste and smell seem hard to imagine, some people nevertheless report vivid imagery in these sensory modalities. We investigate whether experts are better able to imagine smells and tastes because they have learned the ability, or whether they are better imaginers in the first place, and so become experts. To test this, we first compared a group of wine experts to yoked novices using a battery of questionnaires. We show for the first time that experts report greater vividness of wine imagery, with no difference in vividness across sensory modalities. In contrast, novices had more vivid color imagery than taste or odor imagery for wines. Experts and novices did not differ on other vividness of imagery measures, suggesting a domain-specific effect of expertise. Critically, in a second study, we followed a group of students commencing a wine course and a group of matched control participants. Students and controls did not differ before the course, but after the wine course students reported more vivid wine imagery. We provide evidence that expertise improves imagery, exemplifying the extent of plasticity of cognition underlying the chemical senses.     

Contextual framing of loss impacts harm avoidance during risky spatial decisions

Although the same decision to act can occur in multiple contexts, how these contexts differentially influence behavior is not well understood. In this paper, we investigate whether contextual framing affects individuals' behavior in spatial decision making. Although previous research suggests that individuals' judgments are sensitive to contextual (and particularly moral) factors of a scenario, no work has addressed whether this effect extends to spatial decisions. To investigate the impact of context on perceptual sensorimotor behavior, we superimposed two moral dilemmas (which we call help and harm) on a spatial decision-making paradigm. The basic task required participants select a target area while avoiding an overlapping nontarget area. Although the visuospatial task was constant, the moral context was changed when participants had to execute either a drone missile strike on enemies in the harm context or deliver ammunition to allies in the help context. Participants more strongly avoided losses in the harm context, reflected by a greater selection bias away from the nontarget (i.e., allies) on drone strike trials. These findings suggest that the contextual framing of a subjective perceived loss on a spatial decision can drive avoidant motor execution behavior.     

Distinguishing indeterminate belief from “risk-averse” preferences

I focus my discussion on the well-known Ellsberg paradox. I find good normative reasons for incorporating non-precise belief, as represented by sets of probabilities, in an Ellsberg decision model. This amounts to forgoing the completeness axiom of expected utility theory. Provided that probability sets are interpreted as genuinely indeterminate belief (as opposed to “imprecise” belief), such a model can moreover make the “Ellsberg choices” rationally permissible. Without some further element to the story, however, the model does not explain how an agent may come to have unique preferences for each of the Ellsberg options. Levi (1986, Hard choices: Decision making under unresolved conflict. Cambridge, New York: Cambridge University Press) holds that the extra element amounts to innocuous secondary “risk” or security considerations that are used to break ties when more than one option is rationally permissible. While I think a lexical choice rule of this kind is very plausible, I argue that it involves a greater break with xpected utility theory than mere violation of the ordering axiom.     

Testing alternative explanations of phantom decoy effects

Phantom decoys are alternatives that asymmetrically dominate a targeted alternative and yet lead to increased selection of the target when the decoy is declared to be unavailable. This effect is difficult to explain within most standard theoretical accounts of decoy effects. The current experiments tested between three explanations of this effect: (1) the relative advantage model based on loss aversion, (2) similarity substitution, and (3) range weighting. In Experiment 1, participants were presented trinary choice sets, with half of the sets containing a phantom decoy in one of five possible locations within the attribute space. Phantom decoy effects were robust across all decoy locations but one, and the pattern of effects most closely corresponded to predictions of the relative advantage model. Experiment 2 used a within‐subjects manipulation of the five phantom decoy locations. The overall pattern of effects most closely corresponded to predictions from the relative advantage model, as did the pattern for the group of participants who exhibited the strongest phantom decoy effects. Copyright © 2007 John Wiley & Sons, Ltd.     

A systematic review of algorithm aversion in augmented decision making

Despite abundant literature theorizing societal implications of algorithmic decision making, relatively little is known about the conditions that lead to the acceptance or rejection of algorithmically generated insights by individual users of decision aids. More specifically, recent findings of algorithm aversion—the reluctance of human forecasters to use superior but imperfect algorithms—raise questions about whether joint human-algorithm decision making is feasible in practice. In this paper, we systematically review the topic of algorithm aversion as it appears in 61 peer-reviewed articles between 1950 and 2018 and follow its conceptual trail across disciplines. We categorize and report on the proposed causes and solutions of algorithm aversion in five themes: expectations and expertise, decision autonomy, incentivization, cognitive compatibility, and divergent rationalities. Although each of the presented themes addresses distinct features of an algorithmic decision aid, human users of the decision aid, and/or the decision making environment, apparent interdependencies are highlighted. We conclude that resolving algorithm aversion requires an updated research program with an emphasis on theory integration. We provide a number of empirical questions that can be immediately carried forth by the behavioral decision making community.     

The Unbearable Uncertainty Paradox

People can be risk seeking and risk averse, but people can also be uncertainty averse: in other words, if risk is at least the possibility of an unwanted affect, then it is not only the unwanted effect that they want to avoid, it can also be the uncertainty inherent in the possibility that they wish to avoid. This uncertainty aversion can even lead to a state where someone prefers a certain outcome at all costs, even when it is the worst case. This gives rise to the following paradox: the worst case seems to be more acceptable than the state where there is still a chance that it will not materialize. We can call this the Unbearable Uncertainty Paradox. This essay provides a first conceptual sketch of this phenomenon that seems to be widespread but nevertheless does not appear to have been identified before, either by philosophers or by psychologists.