Stimulus discriminability in free-operant and discrete-trial detection procedures.

Six pigeons were trained to discriminate different light intensities in four experimental procedures. Experiment 1 compared stimulus discriminability in a yes-no signal-detection task with discriminability measures obtained from two free-operant procedures. Discriminability estimates were significantly lower in the detection procedure. Experiment 2 showed this lowered discriminability to be a function of the delay between stimulus presentation and the availability of the choice-response keys in the standard detection task. In addition, reinforcement sensitivity was lowest when correct choice responses were intermittently, rather than continuously, reinforced.     

Effects of cocaine and d-amphetamine on the repeated acquisition and performance of conditional discriminations.

The acute and chronic effects of cocaine and d-amphetamine on food-reinforced behavior were investigated in pigeons responding on a two-component multiple schedule. In one component, the behavioral task consisted of the same chain of conditional discriminations each session (performance). In the other component, the chain of conditional discriminations was changed from session to session (learning). In comparison to control sessions, both acute cocaine and d-amphetamine increased errors in each component of the multiple schedule. Responding in the learning component, however, was generally disrupted at lower doses than those that affected responding in the performance component. At high doses, both drugs produced pauses in responding in each component in three of the four subjects. Pausing engendered by d-amphetamine was approximately twice as long as that under cocaine. Upon chronic administration, both the pausing and error-increasing effects of each drug diminished. Drug-induced changes in timeout responding, however, did not decrease during chronic administration. Redeterminations of the d-amphetamine dose-effect curves following chronic cocaine administration suggested the existence of cross-tolerance between cocaine and d-amphetamine. Both the acute and chronic data are consistent with the view that conditions of stimulus control may modulate the behavioral effects of drugs.     

Reinforcement magnitude and the inhibiting effect of reinforcement

In a two-key concurrent variable-interval schedule (using pigeons), if the reinforcement frequency for one response is held constant while that for the other is increased, the rate of response on the constant key decreases. The immediate reinforcement for key pecking can usually be conceptualized as the change from a condition in which the key light is on and the food hopper light is off to one in which the key light is off and the hopper light is on. The prechange condition is associated with a delay to food of one-half the average interreinforcement interval in effect during this condition. The postchange condition is associated with a delay to food of about .5 seconds. The programming of additional reinforcement results in a decrease in the delay to food associated with the prechange stimulus condition, and thus a decrease in the value of the improvement that results from the change. This would appear to be analogous to a decrease in the amount of reinforcement, and thus sufficient explanation for the decrease in the rate of the response.     

Positive contrast, negative induction, and inhibitory stimulus control in the rat

In Experiment I, 24 rats were trained on a multiple variable-interval variable-interval schedule with a doorlight and white noise serving as component cues. Two groups were then shifted to a multiple extinction variable-interval schedule, and a third group was maintained on the multiple variable-interval variable-interval schedule. The multiple extinction variable-interval condition produced positive contrast when either the light or noise signalled extinction, and both of these cues acquired inhibitory stimulus control as measured by a combined cue test. In Experiment II, the multiple variable-interval variable-interval condition was shifted to multiple extinction variable-interval for one group, to multiple variable-time variable-interval for a second group, and was unchanged for the third group. The two experimental conditions produced identical patterns of response-rate reduction in the altered component, but the multiple extinction variable-interval condition produced positive contrast, whereas the multiple variable-time variable-interval condition did not. Subsequent combined cue and resistance to reinforcement tests revealed that the cue signalling extinction acquired stronger inhibitory stimulus control than the cue signalling variable time.     

Dimensional stimulus control following brief wavelength training

Pigeons with extensive training pecking a key illuminated by a white line then had brief training with the key illuminated by 555 nanometers. This was immediately followed by a wavelength generalization test in extinction. Dimensional stimulus control about the training wavelength increased with the duration and number of reinforcements given on variable-interval 30-sec and variable-interval 10-sec schedules in Experiment I. In Experiment II, dimensional stimulus control was obtained after only 4 min of wavelength training from birds with prior and independent discrimination training. Experiment III provided groups equated in number of reinforcers with groups in Experiment I and two 8-min duration groups. Analyses, which included results from both Experiments I and III, showed that dimensional stimulus control increased: (a) more rapidly as a function of the duration of variable-interval 10-sec than variable-interval 30-sec reinforcement; (b) at the same rate across variable-interval reinforcement schedules, as a function of the number of reinforcers available during brief wavelength training.     

4岁幼儿线条偏好实验研究

本研究采用对偶比较法,对4岁幼儿进行6类常见线条的偏好调查研究,得出以下结果:4岁幼儿线条偏好的顺序依次是:漩涡线、曲线、弧形线、波浪线、折线、直线;男生和女生对线条的偏好没有明显差异;4岁幼儿对不同方向的漩涡线的偏好有明显差异,对不同方向的直线、波浪线、折线、曲线和弧形线的偏好没有明显差异。     

The distinction between positive and negative reinforcement: use with care

It is customary in behavior analysis to distinguish between positive and negative reinforcement in terms of whether the reinforcing event involves onset or offset of a stimulus. In a previous article (Baron & Galizio, 2005), we concluded that a distinction of these terms is not only ambiguous but has little if any functional significance. Here, we respond to commentaries by a group of distinguished behavior analysts about the issues we raised. Although several of the commentators argued for preservation of the distinction, we remain unconvinced that its benefits outweigh its weaknesses. Because this distinction is so deeply embedded in the language of behavior analysis, we hardly expect that it will be abandoned. However, we hope that the terms positive and negative reinforcement will be used with circumspection and with full knowledge of the confusion they can engender.     

Back to the Consideration of Future Consequences Scale: Time to Reconsider?

Abstract

The Consideration of Future Consequences (CFC) Scale is a measure of the extent to which individuals consider and are influenced by the distant outcomes of current behavior. In this study, the authors conducted factor analysis to investigate the factor structure of the 12-item CFC Scale. The authors found evidence for a multiple factor solution including one completely present-oriented factor consisting of all 7 present-oriented items, and one or two future-oriented factors consisting of the remaining future-oriented items. Further evidence indicated that the present-oriented factor and the 12-item CFC Scale perform similarly in terms of internal consistency and convergent validity. The structure and content of the future-oriented factor(s) is unclear. From the findings, the authors raise questions regarding the construct validity of the CFC Scale, the interpretation of its results, and the usefulness of the CFC scale in its current form in applied research.     

STROOP效应及其反转：无意识和意识知觉

该研究基于Stroop效应确立了意识知觉和无意识知觉间的质的差异,刺激特性(呈现时间)的改变和注意的改变引起了非常类似的行为上的质差模式,二者在决定意识时存在着补偿作用。当色词短暂呈现而被无意识知觉时,被试在对靶颜色进行命名时不能利用色词提供的预期信息,从而反应时出现典型的Stroop效应;而通过增强刺激特性或提高注意水平可以使色词被有意识知觉。从而出现了Stroop效应的反转。