Using the simultaneous protocol to study equivalence class formation: the facilitating effects of nodal number and size of previously established equivalence classes

The emergence of equivalence classes in college students is unlikely when all baseline relations are trained concurrently and all probes for emergent relations are then introduced concurrently (the simultaneous protocol). This experiment showed how the number of nodes and the size of previously established equivalence classes enhanced the emergence of new equivalence classes under the simultaneous protocol. First, one-node three-, five-, or seven-member classes or three-node five- or seven-member classes were established with college students. A sixth group received no pretraining. Then, the simultaneous protocol was used to establish new three-node five-member equivalence classes with all students. The speed and variability with which the baseline relations were established in the simultaneous protocol were inverse functions of number of nodes in the previously established classes, but not of their size. The percentage of subjects who showed the emergence of new equivalence classes under the simultaneous protocol was a direct function of number of nodes and size of pretrained classes. The additional time spent for pretraining greatly reduced the total training time needed to produce individuals who showed the emergence of classes under the simultaneous protocol. The total time saved was a direct function of number of nodes and number of stimuli in the pretrained classes.     

Effects of food-pellet size on rate,latency, and topography of autoshaped key pecks and gapes in pigeons.

Four pigeons responded under autoshaping contingencies in which different conditional stimuli (red or green keylights) were associated with unconditional stimuli of different magnitudes (large or small food pellets) over successive trials within a session. Both topography (beak opening or gape) and strength (rates and latencies of key pecks and gapes) of responding during the conditional stimuli depended on the magnitude of the correlated unconditional stimulus. Key-peck and gape rates were higher and latencies were shorter in large-pellet trials than in small-pellet trials. Gape amplitudes varied directly with pellet size, although conditional and unconditional gapes were larger than either pellet. These findings were replicated when the key colors were presented either on one or two keys and after reversals of the color-size correlations. Because the unconditional stimulus was varied through pellet size, magnitude was not confounded with food-access duration or quality. These results demonstrate the effects of the magnitude of the unconditional stimulus, in that rates and latencies of both key pecks (which are directed movements toward the key) and gapes (which are independent of the bird''s position and key properties) varied with pellet size. Gape measures were unique in that two dimensions (response strength and topography) of a single response class varied simultaneously with magnitude.     

Some conditions affecting the choice to cooperate or compete

Three experiments investigated conditions affecting the choice to cooperate or compete. Experiment I compared the effects first of an individual activity, then of a competitive task as an alternative to cooperation. For both comparisons, subjects could earn more by cooperating. Choice of competition, but not individual activity, was found to depend on the task choice contingencies. Competition predominated when both subjects could compete if either or both chose competition. Previously competitive pairs cooperated when both subjects could cooperate if either or both chose cooperation. Experiment II investigated the effects of differences in magnitude of the reinforcers for cooperating or competing. Choice between the two alternatives was manipulated in all pairs by varying reinforcer difference. Competition was chosen over cooperation only within the limits within which competition was potentially profitable. Experiment III replicated the findings of Experiment II using triads. Subjects in triads, however, were more likely to withdraw from the experiment. Thus, the data for pairs and triads suggest an orderly relation between reinforcer difference for cooperating or competing and task choice. Motivation of subjects to maximize relative gain by competing can be overridden by moderate reinforcer differences favoring cooperation.     

认知行为实验研究中最佳素材容量的选择与确定：多元概化理论应用

心理学实验首先必须保证结果的有效性和可靠性。实验素材容量是影响实验结果的关键因素之一。本文的目的是通过运用多元概化理论分析几个典型认知行为实验的素材容量对实验结果精度的影响, 从而探讨最佳的实验素材容量的确定问题。研究结果发现, 在IAT测验上, 相容与不相容任务的素材容量为50时最佳, 可靠性指数为0.92; 在图-词干扰范式中, 素材容量以48时为最佳, 可靠性指数为0.95; 对线索提示范式, 50%有效提示中, 有效与无效提示最佳素材容量为35, 可靠性指数是0.97。研究表明, 多元概化理论可以很好地用于确定认知行为实验中素材的最佳容量。     

阅读中疲劳、心理负荷因素对瞳孔大小的调节作用

以大学生为被试,探讨文本阅读过程中,疲劳和心理负荷因素对瞳孔大小的调节作用。实验一主要检验文本阅读中的疲劳效应;实验二分析不同文本加工水平者的瞳孔变化差异,以探讨疲劳和心理加工对瞳孔变化的作用。结果表明：在文本阅读中,疲劳会使瞳孔缩小,心理负荷增大会使瞳孔放大,一定的心理负荷可以起到维持瞳孔大小不变的作用;疲劳和心理负荷因素对瞳孔大小的调节存在颉颃效应。     

Clues for dominance in female chamois: Age,weight, or horn size?

A study of social interactions among female Apennine chamois Rupicapra pyrenaica ornata was made in Abruzzo National Park, central Italy, between 1981 and 1982. A linear hierarchy among females was observed, rank order being highly correlated with age, weight, and horn size. An analysis of which physical clues are used by females to assess dominance suggests that body weight may be the most important attribute. The percentages of threats and dominance displays decrease beyond 7–8 years of age when females usually start to lose weight, whereas horns keep growing throughout life. Furthermore, the greater effect of weight compared to that of horn size on the rank/age correlation supports our conclusion.     

Set size,assertion form,thematic content and sampling in the selection task

Participants attempted to solve a modified version of Wason's (1966) selection task. Variables were: (1) sizes of the sets referenced by a specified assertion, (2) form of the assertion (conditional or categorical), (3) thematic content of the assertion (letters and numbers or makes and owners of taxicabs), and (4) the need for sampling or not. In Experiment 1, participants were given enough information to determine the truth or falsity of the specified assertion with certainty; in Experiment 2, they had to rely on sampling and could not determine the assertion's truth or falsity with certainty. Performance was better in Experiment 1 than in Experiment 2, but in both cases much better than what is typically obtained with the conventional selection task. The results support the hypothesis that performance of the selection task is sensitive to the sizes of the sets involved, add credence to the conclusion that framing the task in a thematically meaningful way can facilitate performance, and demonstrate that facilitation does not require deontic reasoning or a well-known convention being involved. The relationship between expressed confidence and level of performance is consistent with other studies showing the former to be a good predictor of the latter.     

Heterogeneity Coefficients for Mahalanobis' D as a Multivariate Effect Size

The Mahalanobis distance D is the multivariate generalization of Cohen's d and can be used as a standardized effect size for multivariate differences between groups. An important issue in the interpretation of D is heterogeneity, that is, the extent to which contributions to the overall effect size are concentrated in a small subset of variables rather than evenly distributed across the whole set. Here I present two heterogeneity coefficients for D based on the Gini coefficient, a well-known index of inequality among values of a distribution. I discuss the properties and limitations of the two coefficients and illustrate their use by reanalyzing some published findings from studies of gender differences.     

What’s wrong with human extinction?

Abstract

This paper explores what could be wrong with the fact of human extinction. I first present four reasons why we might consider human extinction to be wrong: (1) it would prevent millions of people from being born; (2) it would mean the loss of rational life and civilization; (3) it would cause existing people to suffer pain or death; (4) it would involve various psychological traumas. I argue that looking at the question from a contractualist perspective, only reasons (3) and (4) are admissible. I then consider what implications this limitation on reasons has for the wrongfulness of various forms of human extinction.     

Measuring perceived ceiling height in a visual comparison task

When judging interior space, a dark ceiling is judged to be lower than a light ceiling. The method of metric judgments (e.g., on a centimetre scale) that has typically been used in such tasks may reflect a genuine perceptual effect or it may reflect a cognitively mediated impression. We employed a height-matching method in which perceived ceiling height had to be matched with an adjustable pillar, thus obtaining psychometric functions that allowed for an estimation of the point of subjective equality (PSE) and the difference limen (DL). The height-matching method developed in this paper allows for a direct visual match and does not require metric judgment. It has the added advantage of providing superior precision. Experiment 1 used ceiling heights between 2.90?m and 3.00?m. The PSE proved sensitive to slight changes in perceived ceiling height. The DL was about 3% of the physical ceiling height. Experiment 2 found similar results for lower (2.30?m to 2.50?m) and higher (3.30?m to 3.50?m) ceilings. In Experiment 3, we additionally varied ceiling lightness (light grey vs. dark grey). The height matches showed that the light ceiling appeared significantly higher than the darker ceiling. We therefore attribute the influence of ceiling lightness on perceived ceiling height to a direct perceptual rather than a cognitive effect.