大学生的自我差异与价值偏好

基于以往对自我透视和价值偏好的研究,本研究提出自我差异是引发价值偏好出现分离的原因之一。两项研究对这一假设进行了检验。结果发现：相对于害怕的可能自我,大学生在期望可能自我上体验到更大的差异;在可能自我差异激活后,理想主义价值在个体的价值系统中占据主导地位,而在当前自我差异激活后,实用主义价值占据主导地位;当下目标和当前自我同时启动时,与当下目标未启动时,两组个体对价值偏好无显著差异。     

“If only I had” versus “If only I had not”: Mental deletions,mental additions,and perceptions of meaning in life events

ABSTRACT

The present research investigated the relationship between meaning perceptions and the structure of counterfactual thoughts. In Study 1, participants reflected on how turning points in their lives could have turned out otherwise. Those who were instructed to engage in subtractive (e.g. If only I had not done X…”) counterfactual thinking (SCT) about those turning points subsequently reported higher meaning perceptions than did those who engaged in additive (e.g. ‘If only I had done X…’) counterfactual thinking (ACT). In Study 2, participants who reflected upon life events from the perspective of understanding the past (versus preparing for the future) tended to engage in more SCT than ACT. Finally, in Study 3, participants engaged in more SCT than ACT about life events whose meaning was perceived as certain (as opposed to uncertain) – presumably to maintain their pre-existing sense of meaning. Implications for the study of counterfactual thinking and meaning are discussed.     

The associated nontargets effect: Evidence of nontarget processing at and beyond the level of letter recognition

In four visual search tasks participants were asked to make a target response if either of two targets was present and to make a nontarget response if neither target was present. Some target-absent displays included only nontarget stimuli or features that never occurred in the same displays as targets, whereas other target-absent displays included nontarget stimuli or features that did sometimes occur with targets. Nontarget responses were reliably faster in the former case than in the latter. This “associated nontargets effect” indicates that nontargets are not simply classified as nontargets but in addition are discriminated from one another. Current visual search models may underestimate the degree to which nontargets are processed during search.     

The effects of morphine on the production and discrimination of interresponse times

Recent experiments suggest that the effects of drugs of abuse on the discrimination of the passage of time may differ for experimenter-imposed and subject-produced events. The current experiment examined this suggestion by determining the effects of morphine on the discrimination of interresponse times (IRTs). Pigeons pecked a center key on a random-interval 20-s schedule of matching-to-sample trials. Once the interval had timed out, a choice trial randomly followed either a short (2- to 3-s) or long (6- to 9-s) IRT on the center key. Pecking the side key lit one color produced food after a short IRT, and pecking the side key lit the other color produced food after a long IRT. Two experimental phases differed in the functional role of the different key colors. Under control conditions, the IRT distributions had two modes, one at the lower bound of the short category and a smaller one at the lower bound of the long category. Pigeons accurately categorized the duration of the IRTs: One key color was pecked following short IRTs and the other key color was pecked following long IRTs. Morphine flattened the IRT distribution and reduced the accuracy of categorizing IRTs. Categorization of long IRTs was particularly disrupted. Morphine did not produce overestimation of time as assessed by the production or categorization of IRTs. These results are similar to those obtained previously for the effects of morphine on the discrimination of the duration of experimenter-imposed events.     

Distant Causation in <Emphasis Type="Italic">C</Emphasis>+

The action language C+ of Giunchiglia, Lee, Lifschitz, McCain and Turner is a high-level, logical formalism for the representation of domains involving action and change. However, one cannot directly express relationships which hold between states more than one time-step distant, or even say that one action determines another at the next time. We present C+_timed, a generalization of C+ which removes these limitations. As for C+, translations to the language of causal theories are given. We also define a new kind of transition system called a ‘run system’ to provide a graphical semantics. Finally, we show how domains involving prohibition and permission can be modelled, by incorporating the ideas of another extension of C+.     

Representation and Reasoning about Evolutions of the World in the Context of Reasoning about Actions

The first step in reasoning about actions and change involves reasoning about how the world would evolve if a certain action is executed in a certain state. Most research on this assumes the evolution to be only a single step and focus on formulating the transition function that defines changes between states due to actions. In this paper we consider cases where the evolution is more than just a single change between one state and another. This is manifested when the execution of an action may trigger execution of other actions, or when multiple agents act on the environment following certain strategies.