A PARADIGM FOR OPERANT CONDITIONING IN BLOW FLIES (PHORMIA TERRAE NOVAE ROBINEAU‐DESVOIDY, 1830)

An operant conditioning situation for the blow fly (Protophormia terrae novae) is described. Individual flies are trained to enter and reenter a hole as the operant response. Only a few sessions of contingent reinforcement are required to increase response rates. When the response is no longer followed by food, the rate of entering the hole decreases. Control procedures revealed that rate of responding is not a simple overall result of feeding or of aging. The flies entered into the hole only if the response was required to obtain the food.     

A Bayesian-optimal principle for learner-friendly adaptation in learning games

Adaptive learning games should provide opportunities for the student to learn as well as motivate playing until goals have been reached. In this paper, we give a mathematically rigorous treatment of the problem in the framework of Bayesian decision theory. To quantify the opportunities for learning, we assume that the learning tasks that yield the most information about the current skills of the student, while being desirable for measurement in their own right, would also be among those that are efficient for learning. Indeed, optimization of the expected information gain appears to naturally avoid tasks that are exceedingly demanding or exceedingly easy as their results are predictable and thus uninformative. Still, tasks that are efficient for learning may be experienced as too challenging, and the resulting failures can lower motivation. Therefore, in addition to quantifying the expected informational benefit for learning of any prospective task to be presented next, we also model the expected motivational cost of its presentation, measured simply as the estimated probability of failure in our example model. We propose a “learner-friendly” adaptation algorithm that chooses the learning tasks by optimizing the expected benefit divided by the expected cost. We apply this algorithm to a Rasch-like student model implemented within a real-world application and present initial results of a pilot experiment.     

Implicit learning of social predictions

Humans exchange a range of nonverbal social signals in every interaction. It is an open question whether people use these signals, consciously or unconsciously, to guide social behavior. This experiment directly tested whether participants could learn to predict another person’s behavior using nonverbal cues in a single interaction, and whether explicit knowledge of the cue-outcome relationship was necessary for successful prediction. Participants played a computerized game of rock-paper-scissors against an avatar they believed was another participant. Sometimes the avatar generated a predictive facial cue before the play. On these trials, participants’ win-frequency increased over time, even if they did not acquire explicit knowledge of the predictive cue. The degree to which participants could predict the avatar (wins on cued trials) related to their self-reported liking of the avatar. These findings demonstrate the importance of implicit associative learning mechanisms in guiding social behavior on a moment-to-moment basis during interaction.     

Learned preference for a hedonically negative flavor is observed after pairings with positive post-ingestion consequences rather than with a palatable flavor

In two experiments, thirsty rats consumed a compound of sucrose and a non-preferred flavor. In Experiment 1, a conditioned preference was observed in the experimental group when animals were tested both thirsty and hungry, but not when they were tested just thirsty. Animals in the control group, which experienced the flavor and the sucrose unpaired, never showed a preference. Experiment 2 replicated the absence of a preference in the experimental group when rats were tested thirsty, but provided evidence that a flavor-taste association had been formed during training. After conditioning, sucrose was paired with LiCl in group Dev whereas it was unpaired in group NonDev. The sucrose devaluation produced a decrease in CS preference in group Dev, and an increment in group NonDev. Taken together, these results show that preference for a non-preferred flavor can be readily observed after pairings with the positive consequences of the US (calories or absence of an expected illness) rather than with a palatable flavor.     

Song recognition in zebra finches: Are there sensitive periods for song memorization?

Male zebra finches learn to sing songs that they hear between 25 and 65 days of age, the sensitive period for song learning. In this experiment, male and female zebra finches were exposed to zebra finch songs either before (n = 9) or during (n = 4) the sensitive period. Following song exposure, recognition memory for the songs was assessed with an operant discrimination between familiar and novel songs. Zebra finches that were exposed to songs between 22 and 30 days of age discriminated between familiar and novel songs; zebra finches exposed to songs from 9 to 17 days of age did not. Failure to memorize songs heard prior to the sensitive period may contribute to the exclusion of those songs from the repertoire of songbirds.     

Distributed recognition of natural songs by European starlings

Individual vocal recognition behaviors in songbirds provide an excellent framework for the investigation of comparative psychological and neurobiological mechanisms that support the perception and cognition of complex acoustic communication signals. To this end, the complex songs of European starlings have been studied extensively. Yet, several basic parameters of starling individual vocal recognition have not been assessed. Here we investigate the temporal extent of song information acquired by starlings during vocal recognition learning. We trained two groups of starlings using standard operant conditioning techniques to recognize several songs from two conspecific male singers. In the first experiment we tested their ability to maintain accurate recognition when presented with (1) random sequences of 1–12 motifs (stereotyped song components) drawn from the training songs, and (2) 0.1–12-s excerpts of continuous song drawn from the training songs. We found that song recognition improved monotonically as more vocal material is provided. In the second experiment, we systematically substituted continuous, varying length regions of white noise for portions of the training songs and again examined recognition accuracy. Recognition remained above chance levels for all noise substitutions tested (up to 91% of the training stimulus) although all but the smallest substitutions led to some decrement in song recognition. Overall, above chance recognition could be obtained with surprisingly few motifs, short excerpts of song, and in the absence of large portions of the training songs. These results suggest that starlings acquire a representation of song during individual vocal recognition learning that is robust to perturbations and distributed broadly over large portions of these complex acoustic sequences.     

Chronic passive exposure to aggression escalates aggressiveness of rat observers

Previous studies have documented that exposure to aggression increases aggressiveness of human witnesses. However, the question of whether passive exposure to aggression can exclusively cause a risk of aggressive inclination for observers through a learning process, rather than mimicry effect, has not been readily addressed in the clinical literature. This study aimed to investigate this question by using a simple animal model to test the behavioral effect of chronic passive exposure to aggression. Our results indicate that observer rats that had been passively exposed to aggression for 10 min per day for 23 consecutive days exhibited more aggressive behavior than controls or those groups undergoing a single exposure to passive aggression. Furthermore, aggression levels in the group of 23‐day chronic exposure to aggression lasted 16 days after the recovery from exposure to aggression. These data suggest that the development of aggression in this model occurred through a learning process because only chronic exposure to aggression resulted in this behavioral outcome in the long run. Aggr. Behav. 36:54–66, 2010. © 2009 Wiley‐Liss, Inc.     

大学生学习动机问卷的初步编制

本研究结合开放式问卷所获资料,在文献研究的基础上建构了大学生学习动机的维度,编制了大学生学习动机问卷,并将之施测于427名大学生。问卷的因素分析结果表明：（1）大学生学习动机归并为求知兴趣、能力追求、声誉获取和利他取向四个维度;（2）自编大学生学习动机问卷的信度和效度指标均达到了心理测量学要求。     

Retrieval of names in face and object naming in an interference study

Two experiments using the interference paradigm are reported. In the first experiment, the participants spoke aloud the names of celebrities and the names of objects when presented with pictures while hearing distractors. In the case of proper names, we replicated the data obtained by Izaute and Bonin (2001) using the interference paradigm with a proper name written naming task. In the case of common names, the results replicated those obtained by Shriefers, Meyer, and Levelt (1990). In the second experiment, the participants produced the names of celebrities when presented with their faces while hearing distractors that were either proper names associated with the celebrities (associate condition), that belonged to a different professional category (different condition), or that corresponded to the proper names of the celebrities (identical condition). For negative SOAs, “associate” distractors were found to increase latencies compared to the “different category” condition. The implications of the findings for proper name retrieval are briefly discussed.