NON‐RELATIVE REASONS AND HUMEAN THOUGHT: IF WHAT IS A REASON FOR YOU IS A REASON FOR ME,WHERE DOES THAT LEAVE THE HUMEAN?

Abstract: A variety of strategies have been used to oppose the influential Humean thesis that all of an agent's reasons for action are provided by the agent's current wants. Among these strategies is the attempt to show that it is a conceptual truth that reasons for action are non‐relative. I introduce the notion of a basic reason‐giving consideration and show that the non‐relativity thesis can be understood as a corollary of the more fundamental thesis that basic reason‐giving considerations are generalizable. I then consider the relationship between the generalizability thesis and the Humean thesis that all of an agent's reasons for action are provided by the agent's current wants. I argue that, contrary to a common assumption, there is a subtle and clearly motivated version of the Humean thesis that does not deny, and so is not threatened by, the generalizability thesis.     

Limits to preference and the sensitivity of choice to rate and amount of food

Studies of choice holding food‐amount ratio constant while varying food‐rate ratio within sessions showed that local changes in preference depend on relative amount of food. The present study investigated whether sensitivity of choice to food‐rate ratio and sensitivity to food‐amount ratio are independent of one another when food‐rate ratios are varied across sessions and food‐amount ratios are varied within sessions. Food deliveries for rats’ presses on the left and right levers were scheduled according to three different food‐rate ratios of 1:1, 9:1, and 1:9; each food‐rate ratio lasted for 106 sessions and was arranged independently of seven food‐amount ratios (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, and 1:7 food pellets) occurring within sessions in random sequence. Each amount ratio lasted for 10 food deliveries and was separated from another by a 60‐s blackout. Sensitivity to rate ratio was high (1.0) across food deliveries. Sensitivity to amount ratio was low when food rates were equal across alternatives, but was high when rate ratio and amount ratio opposed one another. When rate ratio and amount ratio went in the same direction, choice ratio reached an elevenfold limit which reduced sensitivity to approximately zero. We conclude that three factors affect sensitivity to amount: (1) the limit to preference, (2) the equal effect on preference of amounts greater than four pellets, and (3) the absence of differential effects of switches in amount in the equal‐rates (1:1) condition. Taken together, these findings indicate that rate and amount only sometimes combine independently as additive variables to determine preference when amount ratios vary frequently within sessions.     

Effects of signaling on temporal control of behavior in response‐initiated fixed intervals

Behavior and events distributed in time can serve as markers that signal delays to future events. The majority of timing research has focused on how behavior changes as the time to some event, usually food availability, decreases. The primary objective of the two experiments presented here was to assess how behavior changes as time passes between two time markers when the first time marker was manipulated but the second, food delivery, was held constant. Pigeons were exposed to fixed‐interval, response‐initiated fixed‐interval, and signaled response‐initiated fixed‐interval 15‐ and 30‐s schedules of reinforcement. In Experiment 1, first‐response latencies were systematically shorter in the signaled response‐initiated schedules than response‐initiated schedules, suggesting that the first response was a more effective time marker when it was signaled. In Experiment 2, responding in no‐food (i.e. “peak”) trials indicated that timing accuracy was equivalent in the three schedule types. Compared to fixed interval schedules, timing precision was reduced in the signaled response‐initiated schedules and was lowest in response‐initiated schedules. Results from Experiments 1 and 2 coupled with previous research suggest that the overall “informativeness” of a time marker relative to other events and behaviors in the environment may determine its efficacy.     

Fetal Risks,Relative Risks,and Relatives' Risks

Several factors related to fetal risk render it more or less acceptable in justifying constraints on the behavior of pregnant women. Risk is an unavoidable part of pregnancy and childbirth, one that women must balance against other vital personal and family interests. Two particular issues relate to the fairness of claims that pregnant women are never entitled to put their fetuses at risk: relative risks and relatives' risks. The former have been used—often spuriously—to advance arguments against activities, such as home birth, that may incur risk; the latter implicate the nature of relationships in determining the acceptability of coercing or precluding activities. Motivated reasoning by clinicians and judges leads to inaccurate risk assessments, and judgments based on false claims to objectivity. Such judgments undermine the moral and legal standing of pregnant women and do not advance the interests of fetuses, pregnant women, families, or states.     

论开展亲属活体供肾移植的风险与对策

肾脏移植是救治终末期肾功能衰竭的最佳手段。亲属活体捐献肾脏是扩大供肾来源的有效手段。当前国内开展亲属肾移植存在伦理、法律和健康风险,主要来自供体和医疗两方面。为防范风险,医务人员应严格审查供受者的血缘关系,签署完整规范的法律文书,进行全面细致的术前评估,制定完善的手术方案。     

Blocking in Rapid Finger Tapping: The Role of Variability in Proximodistal Coordination

In rapid finger tapping, occasional intertap intervals of about twice the normal length or even longer, called blockings, can be observed. Skilled rapid tapping requires that flexor and extensor activity be timed so that they coincide with certain phases of the finger movement. In the present study, the hypothesis examined was that blockings are associated with a deviation from the proper timing relations between the more proximal signals (electromyographic [EMG] bursts) and the more distal signal (position-time curve of the finger). Participants (N = 8) performed up-and-down tapping. Blockings were compared with the preceding normal tapping cycles; a temporal forward shift of the flexor burst in the time interval between two kinematic landmarks—the lifting of the finger and the reversal of the movement—was found consistently in the blockings The phase shift of the flexor burst relative to the kinematic landmarks did not develop gradually in the course of the tapping cycles that preceded the blocking but was an abrupt deviation, which suggests that blockings occur with an increased likelihood as the extremes of the normal variability of the phase relation are approached.     

语言对知觉的影响—— 来自颜色范畴知觉研究的证据

介绍了近年来语言和颜色范畴知觉关系研究的新进展, 特别是颜色范畴知觉效应的偏侧化、婴幼儿颜色范畴知觉的特点等。同时指出了今后需要进一步研究的问题, 如颜色范畴知觉效应偏侧化与语言的关系、右脑语言优势者颜色范畴知觉的特点、颜色加工脑区和语言加工脑区之间的关系以及婴幼儿颜色范畴知觉特点的追踪研究等。     

A tuned-trace theory of interval-timing dynamics

Animals on interval schedules of reinforcement can rapidly adjust a temporal dependent variable, such as wait time, to changes in the prevailing interreinforcement interval. We describe data on the effects of impulse, step, sine-cyclic, and variable-interval schedules and show that they can be explained by a tuned-trace timing model with a one-back threshold-setting rule. The model can also explain steady-state timing properties such as proportional and Weber law timing and the effects of reinforcement magnitude. The model assumes that food reinforcers and other time markers have a decaying effect (trace) with properties that can be derived from the rate-sensitive property of habituation (the multiple-time-scale model). In timing experiments, response threshold is determined by the trace value at the time of the most recent reinforcement. The model provides a partial account for the learning of multiple intervals, but does not account for scalloping and other postpause features of responding on interval schedules and has some problems with square-wave schedules.     

Social comparison processes in the experience of personal relative deprivation

Drawing on social comparison and equity theories, we investigated the role that perceived similarity of a comparison target plays in how resentful people feel about their relative financial status. In Study 1, participants tended to choose a comparison target who was better off, and they selected a target they perceived to be more similar than dissimilar along dimensions that surrounded their financial outcomes. In Study 1, perceived relative disadvantage was positively associated with resentment regardless of the perceived similarity of the comparison target. The results of Studies 2 to 5b clarified these findings by showing that being both similar and dissimilar to a target can cause resentment depending on the context. Using hypothetical and real social comparisons, we found that people are more dissatisfied with their financial outcomes when their comparative targets have the same background qualifications (i.e., are similar) but are financially better off (Studies 2, 3b, 4, and 5b). However, we also found that when the comparative financial contexts were similar (i.e., equal affluence), participants were more dissatisfied when their target for comparison had lower qualifications (i.e., was dissimilar; Studies 2, 3a, 4, and 5a). In all cases, perceptions of unfairness mediated the effects of social comparison on financial dissatisfaction. Taken together, these studies address some of the ambiguities around what it means to be similar to a target in the context of social comparisons of affluence, and they underscore the importance of perceived unfairness in the link between social comparison and resentment with one's financial status.     

亲子间科技干扰与青少年网络人际关系成瘾：有调节的中介模型

对1353名高中生进行问卷调查,探究亲子间科技干扰与青少年网络人际关系成瘾之间的关系,相对剥夺感的中介作用及内在觉知的调节作用,结果表明：（1）亲子间科技干扰正向预测青少年网络人际关系成瘾;（2）相对剥夺感是亲子间科技干扰与网络人际关系成瘾之间的中介变量;（3）亲子间科技干扰与网络人际关系成瘾的间接效应前半段受到内在觉知的调节。因此,亲子间科技干扰和网络人际关系成瘾之间存在有调节的中介效应。