Reproduction memory of two-event sequences in pigeons

Six pigeons were trained to reproduce two-event sequences in an experiment that employed a discrete-trial procedure that required subjects to peck one of four possible sample sequences (left-left, left-right, right-right, right-left) signaled on a given trial by the successive illumination of response keys. Following a retention interval (0.1 to 30 seconds), a reinforcer was delivered if a subject reproduced the prior sample sequence during a test condition in which both left and right keys were illuminated. The pigeons readily reproduced the orders in which they had just seen and pecked two illuminated keys. Reproduction accuracy declined as the retention interval was increased. Homogeneous sequences (left-left, right-right) were reproduced with greater accuracy than heterogeneous sequences.     

Behavioral variability and frequency-dependent selection.

In Experiment 1, two conditions were compared: (a) a variability schedule in which food reinforcement was delivered for the fourth peck in a sequence that differed from the preceding N four-peck sequences, with the value of N continuously adjusted to maintain reinforcement probability approximately constant; and (b) a control condition in which the variability constraint was dropped but reinforcement probability remained constant. Pigeons responded approximately randomly under the variability schedule but showed strong stereotyped behavior under the control condition. Experiments 2 and 3 tested the idea that variability is the outcome of a type of frequency-dependent selection, namely differential reinforcement of infrequent behavior patterns. The results showed that pigeons alternate when frequency-dependent selection is applied to single pecks because alternation is an easy-to-learn stable pattern that satisfies the frequency-dependent condition. Nevertheless, 2 of 4 pigeons showed random behavior when frequency-dependent selection was applied to two pecks, even though double alternation is a permissible and stable stereotype under these conditions. It appears that random behavior results when pigeons are unable to acquire the stable stereotyped behavior under a given frequency-dependent schedule.     

Immediate reinforcement in delayed reward learning in pigeons

Pigeons were trained on simultaneous red-green discrimination procedures with delayed reward and sequences of stimuli during the delay. In Experiment 1, three stimuli appeared during the 60-second intervals between the correct responses and reward, and the incorrect responses and nonreward. The stimulus that immediately followed a correct response also preceded nonreward, and the stimulus that followed an incorrect response preceded reward. These stimuli were 10 or .33 second in duration for different groups. Stimuli during the remainder of the delay interval differed following correct and incorrect responses. Group 10 initially persisted in the nonrewarded choice, but shifted to a preponderance of rewarded responses after further training. Group .33 rapidly acquired the correct response. Similar results were obtained in Experiment 2 where delay intervals consisted of opposite sequences of two stimuli of equal duration and total delays were 6, 20, or 60 seconds. Early in training, generalization of differential conditioned-reinforcing properties from the conditions preceding reward and nonreward to postchoice conditions had a greater effect relative to backchaining than it did later. It was concluded that delayed-reward learning is best analyzed in terms of the conditioned-reinforcing value of the patterns of cues that follow immediately after rewarded and nonrewarded responses.     

Response of female cuttlefish Sepia officinalis (Cephalopoda) to mirrors and conspecifics: evidence for signaling in female cuttlefish

Cuttlefish have a large repertoire of body patterns that are used for camouflage and interspecific signaling. Intraspecific signaling by male cuttlefish has been well documented but studies on signaling by females are lacking. We found that females displayed a newly described body pattern termed Splotch toward their mirror image and female conspecifics, but not to males, prey or inanimate objects. Female cuttlefish may use the Splotch body pattern as an intraspecific signal, possibly to reduce agonistic interactions. The ability of females to produce a consistent body pattern in response to conspecifics and mirrors suggests that they can recognize same-sex conspecifics using visual cues, despite the lack of sexual dimorphism visible to human observers. Electronic Supplementary Material Supplementary material is available for this article at and is accesible for authorized users.     

故事阅读中句子加工时间与理解的研究

被试是３０名大学生,实验材料为两个双情节故事。实验采用计算机按键计时的方式进行,每个故事一句一句地呈现在计算机屏幕上,每读完一句就按一下空格键,读完一个故事就马上回忆。实验结果表明：阅读时间呈现出一种递减模式,回忆量呈现出一种波浪模式,而且回忆量不受阅读时间的影响。     

中美成年人和老年人数学能力发展的比较研究

采用一套心理计量测验考察中美两国青老年被试在算术能力、知觉速度及空间方位能力方面的操作是否有国家间和年龄组间差异,不同领域之间是否有不同的能力模式。测验结果表明：在知觉速度和空间方位测验上,中美青年组的操作成绩均明显超过老年组;在算术能力测验上,中国青年组的成绩仍超过老年组,但美国青老年组间则无明显差异;中国青年组在算术能力测验上成绩优于美国同龄组,在其它两个测验上则无明显差异;在所有能力测验上中美老年组的成绩都无明显差异;总的模式表明,美国青年的算术能力呈逐代下降趋势,中国儿童和青年的算术能力远远超过美国同龄人的状况可能只是个近期的现象。     

Pigeons' discrimination of paintings by Monet and Picasso

Pigeons successfully learned to discriminate color slides of paintings by Monet and Picasso. Following this training, they discriminated novel paintings by Monet and Picasso that had never been presented during the discrimination training. Furthermore, they showed generalization from Monet's to Cezanne's and Renoir's paintings or from Picasso's to Braque's and Matisse's paintings. These results suggest that pigeons' behavior can be controlled by complex visual stimuli in ways that suggest categorization. Upside-down images of Monet's paintings disrupted the discrimination, whereas inverted images of Picasso's did not. This result may indicate that the pigeons' behavior was controlled by objects depicted in impressionists' paintings but was not controlled by objects in cubists' paintings.     

动作的创造性操作与原型效应

对各种不同动作操作水平的被试,进行动作操作图式的操作实验。结果发现：１．经过系列动作的学习,可以形成动作原型。２．动作原型对于动作操作有影响作用,这种原型效应明显地表现在动作的创造性操作上。３．动作操作水平与动作原型效应有密切关系,动作原型效应,在操作水平高的人的动作操作上,表现最为明显。４．动作原型效应受背景条件所制约。