Waiting in pigeons: the effects of daily intercalation on temporal discrimination.

Pigeons trained on cyclic-interval schedules adjust their postfood pause from interval to interval within each experimental session. But on regular fixed-interval schedules, many sessions at a given parameter value are usually necessary before the typical fixed-interval "scallop" appears. In the first case, temporal control appears to act from one interfood interval to the next; in the second, it appears to act over hundreds of interfood intervals. The present experiments look at the intermediate case: daily variation in schedule parameters. In Experiments 1 and 2 we show that pauses proportional to interfood interval develop on short-valued response-initiated-delay schedules when parameters are changed daily, that additional experience under this regimen leads to little further improvement, and that pauses usually change as soon as the schedule parameter is changed. Experiment 3 demonstrates identical waiting behavior on fixed-interval and response-initiated-delay schedules when the food delays are short (less than 20 s) and conditions are changed daily. In Experiment 4 we show that daily intercalation prevents temporal control when interfood intervals are longer (25 to 60 s). The results of Experiment 5 suggest that downshifts in interfood interval produce more rapid waiting-time adjustments than upshifts. These and other results suggest that the effects of short interfood intervals seem to be more persistent than those of long intervals.     

3─6岁儿童层级类概念发展的实验研究

以３－６岁儿童为被试,以７个常见物体种类的图片为实验材料,按概念水平（基本类概念及上级类概念）以及选择图与目标图的感知相似程度（高、中、低）将实验材料分为四种类型,对３－６岁儿童层级类概念的发展过程进行了研究。结果表明：（１）３岁幼儿已能按基本类概念标准进行正确的种类匹配;对于上级类概念,３－５岁儿童的匹配能力尚较差,６岁基本达到掌握水平。（２）实验材料的感知相似程度对３－５岁儿童的上级类概念匹配操作有显著性影响,６岁儿童才摆脱了这种制约作用。     

3─6岁儿童层级类概念发展的实验研究

以３－６岁儿童为被试,以７个常见物体种类的图片为实验材料,按概念水平（基本类概念及上级类概念）以及选择图与目标图的感知相似程度（高、中、低）将实验材料分为四种类型,对３－６岁儿童层级类概念的发展过程进行了研究。结果表明：（１）３岁幼儿已能按基本类概念标准进行正确的种类匹配;对于上级类概念,３－５岁儿童的匹配能力尚较差,６岁基本达到掌握水平。（２）实验材料的感知相似程度对３－５岁儿童的上级类概念匹配操作有显著性影响,６岁儿童才摆脱了这种制约作用。     

字符的知觉表征及其启动

实验以英文单词,汉字和图片为材料,采用速示补笔测验测量了大脑左右半球的启动效应。结果是,如果学习与测验的字体和大小不变,则视觉启动右半球高于左半球。其他材料不产生这种效应。这表明,至少有一个分离的系统对构成启动的汉字的视觉表征进行编码,此系统在右半球表征形状特异形状特异信息更有效;对字符抽象特征的表征,两半球无显著差异,速示补笔测量的是前语义水平的知觉表征,是一种知觉（数据驱动）内隐记忆测验。     

Pure timing in temporal differentiation

Temporal control appears to depend on whether the critical durations are those of stimuli or those of responses. Stimulus timing (temporal discrimination) supports Weber's law, whereas response timing (temporal differentiation) indicates decreasing relative sensitivity with longer time intervals. The two types of procedure also yield different conclusions in scaling experiments designed to study the functional midpoint of two or more durations (temporal bisection procedures). In addition, the fractional-exponent power relation between emitted and required duration usually found with animals in differentiation experiments conflicts with deductions from formal analyses. The experiment reported here derived from considering differentiation arrangements as schedules of reinforcement. When analyzed from this perspective, the procedures are tandem schedules involving a required pause followed by a response, and it is the pause alone that involves temporal control. A choice procedure separated timing from responding, and enabled observations of pause timing in isolation. Pure temporal control in differentiation consisted of linear overestimation of the standard duration, and Weber's law described sensitivity. These results indicate that the two problems, the fractional-exponent power relations and the apparently different nature of sensitivity in differentiation and discrimination, disappear when temporal control is observed alone in differentiation.     

Introspection during visual search

Recent advances in the field of metacognition have shown that human participants are introspectively aware of many different cognitive states, such as confidence in a decision. Here we set out to expand the range of experimental introspection by asking whether participants could access, through pure mental monitoring, the nature of the cognitive processes that underlie two visual search tasks: an effortless “pop-out” search, and a difficult, effortful, conjunction search. To this aim, in addition to traditional first order performance measures, we instructed participants to give, on a trial-by-trial basis, an estimate of the number of items scanned before a decision was reached. By controlling response times and eye movements, we assessed the contribution of self-observation of behavior in these subjective estimates. Results showed that introspection is a flexible mechanism and that pure mental monitoring of cognitive processes is possible in elementary tasks.     

Synchrony and emotion in children and adults

This study examined both the development of synchronisation activities and the way emotion affects these activities in children and adults. Children aged from 3 to 8 years, as well as adults, performed a spontaneous motor tempo (SMT) task and a synchronisation task with a 500‐millisecond and 700‐millisecond inter‐stimulus interval (ISI), followed by a continuation task, in both an emotion‐free and an emotional context (High‐Arousal, Low‐Arousal, and Neutral). The results showed that the SMT was faster and more variable in the younger children. In addition, the younger children found it more difficult to slow down their tapping rate in synchrony with the 700‐millisecond ISI, with the result that they quickly returned to their internal tempo in the continuation phase. In contrast, the 8‐year‐olds' synchronisation performance was close to that of the adults. However, despite developmental changes in synchronisation skills, all the participants produced faster tempi in both the SMT and the synchronisation task for the High‐Arousal emotion than for the other emotions. This suggests that emotions induce an automatic distortion of motor timing as has also been observed for the perception of time.     

Effects of harsh parenting and positive parenting practices on youth aggressive behavior: The moderating role of early pubertal timing

Prior research indicates that early pubertal timing is associated with aggressive behavior, particularly in the context of adversity as postulated in the contextual amplification hypothesis. However, few studies have examined harsh parenting as the context for the effect of early pubertal timing. Even fewer studies have tested the interactive effect of early pubertal timing and positive parenting on aggressive behavior. In this study, we tested the proposition that early pubertal timing, contrary to the general conception of it as a vulnerability, indexed susceptibility, and thus early maturing individuals were affected more by their environment in a “for better and for worse” manner. The sample consisted of 411 community‐recruited youth aged 11–12 years (51% boys, 80% African Americans). Participants reported Tanner Stages of pubertal development, aggressive behavior and harsh parenting practice of their parents. Puberty scores were standardized with groups of the same age, sex, and ethnicity, and those that scored the top one‐third were defined as early maturing individuals. Parents reported youth's aggressive behavior and their parenting practices towards the youth, including harsh parenting and positive parenting. Early pubertal timing significantly moderated the relationship between harsh/positive parenting and aggressive behavior. Specifically, harsh parenting was positively associated with aggressive behavior to a larger degree among early maturing individuals than among on‐time/late‐maturing individuals. Positive parenting was inversely associated with aggressive behavior but only among early maturing individuals. This study is the first to document support for early pubertal timing as susceptibility to the environmental influences in relation to aggressive behavior. Theoretical and intervention implications are discussed.