Pigeons can discriminate locations presented in pictures

The present experiments were designed to teach pigeons to discriminate two locations represented by color photographs. Two sets of photographs were taken at two distinctive locations on a university campus. These sets represented several standpoints at each location. For the true-discrimination group, pictures from the two locations were differentially associated with reward; for the pseudodiscrimination group, half of the views from each location were arbitrarily but consistently associated with reward. The former group acquired the discrimination much more rapidly. These birds also showed good transfer to new views from the standpoints used in training and to a new standpoint at each location not used in training. In a second experiment, another group of pigeons could terminate any training trial by pecking an “advance” key. Three of 4 subjects used this option to reduce the duration of trials in which pictures from the negative location were presented. These data suggest that pigeons can integrate views shown in pictures into a “concept” of a location. The method used here may be the experimental analogue of a common, natural process by which animals learn to identify locations.     

记忆训练对改善少年、青年和老年人认知功能的作用

本工作采用“位置法”(method of loci)对24例少年、24例青年和22例老年被试进行了记忆训练研究。以毕生发展的观点比较认知训练对改善不同年龄人记忆的作用,进而探讨发展的认知功能储备能量的年龄差异和训练的迁移效应。结果表明认知干预措施可在一定程度上改善老年人的记忆,同时也显示了在发展的储能和对图形的迁移效应方面,老年人明显不如青、少年,而青年与少年则彼此相近。     

Science and politics: Dangerous liaisons

In contrast to the opinion of numerous authors (e.g. R. Rudner, P. Kitcher, L. R. Graham, M. Dummett, N. Chomsky, R. Lewontin, etc.) it is argued here that the formation of opinion in science should be greatly insulated from political considerations. Special attention is devoted to the view that methodological standards for evaluation of scientific theories ought to vary according to the envisaged political uses of these theories.I wish to thank the Alexander von Humboldt Foundation for having supported the work on this paper.     

Visually guided catching and tracking skills in pigeons: A preliminary analysis

Research on reaching, tracking, and catching in the pigeon has been hampered by limitations of technology. A new system was developed in which the target was a small rectangle presented on a video display terminal and the pecking response was detected with touch technology. The target moved up and down vertically with sinusoidal velocity. A coincidence between the location of the pigeon's beak and the cursor produced reinforcement. The pigeon pecked ahead and behind the target, but most pecks occurred behind the target so the dominant tracking strategy was lagging. The pigeon was adept at “catching” the target at many locations throughout the trajectory. Transfer of motor learning was tested on probe trials during which the trajectory changed from vertical to horizontal. On transfer trials the pigeons' dominant pattern of pecking immediately shifted from vertical to horizontal. The motor skill displayed by the pigeons was flexible and adaptive, suggesting that the pigeons had learned to track the cursor.     

Determination of a behavioral transfer function: White-noise analysis of session-to-session response-ratio dynamics on concurrent VI VI schedules

Six pigeons were exposed to concurrent variable-interval schedules in which the programmed reinforcer ratios changed from session to session according to a pseudorandom binary sequence. This procedure corresponded to the stochastic identification paradigm (“white-noise experiment”) of systems theory and enabled the relation between log response ratios in the current session and log reinforcer ratios in all previous sessions to be determined. Such dynamic relations are called linear transfer functions. Both nonparametric and parametric representations of these, in the form of “impulse-response functions,” were determined for each bird. The session-to-session response ratios resulting from the session-to-session pseudorandom binary variations in reinforcer ratios were well predicted by the impulse-response functions identified for each pigeon. The impulse-response functions were well fitted by a second-order dynamic model involving only two parameters: a time constant and a gain. The mean time constant was 0.67 sessions, implying that the effects of abrupt changes in log reinforcer ratios should be 96% complete within about five sessions. The mean gain was 0.53, which was surprisingly low inasmuch as it should equal the sensitivity to reinforcement ratio observed under steady-state conditions. The same six pigeons were subjected to a similar experiment 10 months following the first. Despite individual differences in impulse-response functions between birds within each experiment, the impulse-response functions determined from the two experiments were essentially the same.     

Discriminated interresponse times: role of autoshaped responses.

When discriminated interresponse-time (IRT) procedures have been used to assess preference relations among temporally extended operants, deviations from matching have been obtained. Using a yoked-control procedure, the present study found that key pecking in a discriminated IRT procedure has two sources of strength--that arising from the response-reinforcer contingency that is explicitly arranged, and that arising from a stimulus-reinforcer contingency that is a by-product of the explicitly arranged contingency. The key pecking of all lead birds, and that of 3 of the 4 birds exposed to a yoked autoshaping procedure, was controlled by the keylight that signaled the lead birds' criterion IRTs. Because stimulus control of key pecking by the keylight, whether autoshaped or discriminative, fosters deviations from matching, the discriminated IRT procedure does not provide an appropriate basis for conclusions about preference relations among IRTs.     

Transfer of matching-to-figure samples in the pigeon

Three pigeons were trained on a modified six-key matching-to-sample procedure. The third peck on the figure-sample key (which presented a bird, hand, face, beetle, rabbit, fish, flower, or red hue, as the sample) lighted only one comparison key. Every three additional pecks on the sample lighted another comparison key, up to a maximum of five keys. Pecks on keys of matching figures produced grain. Pecks on nonmatching keys (mismatches) turned off all lights on the comparison keys and repeated the trial. Three figures were used during acquisition. The birds learned to peck each sample until the matching comparison stimulus appeared on one of three comparison stimulus keys, and then to peck that key. Later, five novel stimuli, employed as both sample and comparison stimuli, and two additional matching keys were added. Each bird showed matching transfer to the novel samples. The data suggest that the birds may have learned the concept of figure matching rather than a series of two-component chains or discrete five-key discriminations.     

“‘WE' AND ‘THEY'”: WHY MUST WE ENGAGE IN CROSS-CULTURAL CONVERSATION?

This article contains the principal ideas that I presented in four different sessions at the IRAS 2022 conference, on the theme “‘We' and ‘They’: Cross-Cultural Conversation on Identity.” Focusing on the central topic, the article begins with (i) the contents of my opening lecture; followed by (ii) a broad outline of the concerns discussed in my book, Cross-Cultural Conversation: A New Way of Learning, intertwined with glimpses of the intellectual journey that led me to CCC, delivered in the Book-discussion session; (iii) a summary of the main ideas about the importance of meeting of religions today, which formed the background for the CCC Panel discussion on religion, where I was in conversation with spokespersons of five world religions; and (iv) my comments on how science–religion dialogue can help promote a sense for human solidarity by combining knowledge with wisdom, in the concluding session.