Spatial configuration and list learning of proximally cued arms by rats in the enclosed four-arm radial maze

In an enclosed four-arm radial maze, after sampling three experimenter-selected baited arms (thestudy segment) and following rotation of the maze, rats had to find the fourth baited arm among all four unblocked arms (test segment). The rats learned this task with two sets of arm cues, objects at arms’ entrances and full arm inserts, each maintained in a fixed configuration. When we changed the configuration of one set of arms to itsmirror image and that of the other set to a moremixed variation by switching opposite and adjacent cued arms, the rats’ accuracy was similarly disrupted (Experiment 1). In Experiment 2, the same rats rapidly recovered their high search accuracy on four new configurations recombined from pairs of adjacent arms and pairs of opposite cued arms from the previous final two configurations. Their test segment search accuracy, however, was again disrupted when these configurations were varied either only over trials’ study segments or only over trials’ test segments. In Experiment 3, however, these rats attained accuracy as high on two sets of cued arms with constantly changing configurations as on two sets with constant configurations. Thus, the rats were able to separately represent four different spatially stable configurations, and then they could learn to represent two of these configurations as lists of spatially irrelevant items. We discuss these findings in terms of association theory and parallel map theory (Jacobs & Schenk, 2003).     

Central-place foraging by rats on the radial maze: The effects of patch size,food distribution,and travel time

Rats foraged on a four-arm radial maze with one, two, three, and four food items (0.65.g pieces of cheese) placed on different arms (patches) of the maze. In two experiments, the hypothesis was tested that rats should carry food to the center of the maze more often when a patch contains one food item than when it contains multiple food items. Support for this prediction was found when the tendency to carry initial items encountered in patches was compared among the different sized patches. However, a further observation failed to support the hypothesis: Food carrying declined from first to last item encountered in multiple-item patches with clustered food items. Experiment 1 revealed that food carrying was reduced when travel time was increased by barriers placed at arm entrances. Both Experiments 1 and 2 indicated that the tendency for rats to carry food to the center of the radial maze increased as the distance of food encountered on an arm increased from the center. In both experiments, some rats dealt with the problem of multiple items by resorting to multiple-item loading, and some rats carried food items from the end of an arm to a point on the arm nearer the center for consumption.     

Evidence for a shift in the choice criterion of rats in a 12-arm radial maze

Rats were trained in a standard 12-arm radial maze task. Following training, each trial consisted of a sequence of 2, 4, 6, 8, or 10 choices, followed by a 15-min delay, which then was followed by a choice between a single arm and a response manipulandum mounted in the center of the maze. An arm visit was reinforced if the arm had not been visited prior to the delay, whereas a manipulandum response was reinforced if the arm had been visited. It was found that rats are relatively more likely to reject arms by responding to the manipulandum following a delay occurring late in the choice sequence. This indicates that the choice criterion used by rats in the radial maze becomes more strict as the choice sequence progresses. Such a process provides an alternative explanation for some of the data recently reported by Cook, Brown, and Riley (1985).     

Spatial memory and the performance of rats and pigeons in the radial-arm maze

The resource-distribution hypothesis states that the ability of an animal to remember the spatial location of past events is related to the typical distribution of food resources for the species. It appears to predict that Norway rats would perform better than domestic pigeons in tasks requiring spatial event memory. Pigeons, tested in an eight-arm radial maze, exhibited no more than half of the memory capacity observed in rats in the same apparatus and may not have used spatial memory at all. The results were interpreted as supporting the hypothesis.     

Response cost and time-place discrimination by rats in maze tasks

Time-place discrimination has been shown reliably in several avian and insect species, but only occasionally in rats and fish. In the present experiments, we explored the effects of response cost on time-place discrimination by rats. In the first experiment, we increased the cost of making a choice and the cost of recovering from a wrong choice in two types of maze, a radial arm and a vertical maze. In the radial arm maze, we found only general place preference, whereas in the vertical maze, we obtained evidence of time-place discrimination. In the second experiment, we found that the proportion of rats showing time-place discrimination increased with the height and, therefore, the response cost of the vertical maze. These results suggest that rats do not automatically store and/or retrieve the time and place of reward events but that response cost is an important trigger for time-place discrimination.     

Reversal of spatial discrimination learning in a water maze by previously undernourished rats

The development of the hippocampus in rats may be vulnerable to undernutrition during the fetal and suckling periods. Hence the behavioral effects of early growth restriction may resemble those of hippocampal lesions. This suggestion was investigated by testing previously undernourished rats for reversal learning, an ability badly affected in hippocampectomized rats. Developing rats were undernourished by feeding their mothers a restricted quantity of a good quality diet during pregnancy and lactation. All rats were fed ad lib from weaning. Reversal of spatial discrimination learning was tested in adult animals using a water T-maze. Previously undernourished rats learned the initial spatial discrimination more quickly than controls. However, there was no effect of early treatment on serial reversal learning in Experiment I or on performance of a single reversal after prolonged initial training in Experiment II.     

Testing optimal foraging theory on the radial maze: The role of learning in patch sampling

A four-arm radial maze containing 10 feeders in each arm (patch) was used to study patch sampling in rats. In each of three experiments, rats foraged for 30 sessions. On each session, two randomly chosen patches were baited with food and the remaining two patches were empty. In Experiment 1, the number of baited feeders in baited patches (6) was varied from 1–10 over five groups of subjects. Mean visits to empty patches was an inverse function of 6, as predicted by an optimal foraging model. In Experiments 2 and 3, rats’ ability to discriminate between baited and empty patches was examined when food in baited patches was placed in fixed locations, either in clumps (Experiment 2) or distributed throughout the patch (Experiment 3). Rats in fixed-food-location conditions reliably visited fewer feeders in empty patches than did rats in randomly changing control groups. Examination of within-patch foraging patterns indicated that rats in fixed-food-location groups selectively sampled potentially baited locations and abandoned the patch if food was not found. It is suggested that processes of patch discrimination were responsible for these effects.     

Pretest cuing after forgetting of a food-motivated maze task in rats: Synergistic action of context and reinforcement

It is now well known in animal studies that spontaneous forgetting, as well as performance decrements resulting from other sources, can be alleviated by means of pretest treatments. Several previous experiments have shown that reliable forgetting is observed after a 25-day training-to-test interval on a relatively complex maze. This forgetting can be alleviated by pretest exposure to background stimuli in the experimental room. The effects of this treatment can be modulated by varying either the duration of the treatment or the length of the cuing-test interval. The purpose of the experiment presented here was twofold: (1) to demonstrate the multidimensionality of memories in our paradigm by comparing the effects of different reminder treatments, namely pretest access to the reinforcer and contextual cuing, and (2) to test the general hypothesis, formulated by Spear (1978, p. 418), that “the elicitation and retrieval of the target attribute of a memory depend on the arousal of a sufficientnumber or kind of the remaining attributes of this memory.” The data showed that pretest food reinforcement had no significant effect on retention performance; that pretest contextual cuing did, in some precise conditions, alleviate forgetting; and that some combinations of context and reinforcement had what amounted to a synergistic action on retention performance.     

Spatial pattern learning in rats: Conditional control by two patterns

Rats searched for food hidden on top of poles in a 4 × 4 matrix of poles. Before each trial, the location of the four baited poles was unpredictable. However, the poles were always baited in one of two spatial patterns, either a square or a line. The food hidden on the four baited poles was one of two types, and the food type determined the identity of the pattern. Thus, once one baited pole was discovered, the food type provided a cue for the spatial pattern in which the remaining food was hidden. The results showed that rats learned the two spatial patterns in which the food was hidden and used the conditional cue to determine which pattern was relevant on individual trials, thereby increasing the efficiency of spatial search.     

Retroactive interference in rat radial maze performance: The role of point of delay interpolation and the similarity and amount of interpolated material

The conditions necessary for producing retroactive interference (RI) were examined in a 12-arm radial maze. Rats were first given either three or nine forced choices in a to-be-remembered maze. During a 2-h delay, they received one or two trials in a second 12-arm maze, located either in a different room or the same room as the to-be-remembered maze. During the postdelay memory test, RI from the interference trials was produced only when nine choices had been made in the to-be-remembered maze and two interference trials had been conducted during the delay interval. RI was not found when only three forced choices had to be retained or after a single interference trial. The similarity between the interpolated and to-be-remembered mazes had no effect on choice accuracy. It was concluded that two conditions are required for the production of RI in the radial maze. First, a “large amount” of information should be resident in working memory. Second, a substantial number of interpolated trials or choices must be made during the delay.     

The development and piloting of a training web site for health and safety enforcement officers

This paper evaluates the development and piloting of a training web site for Local Authority (LA) based health and safety enforcement officers and reviews the technique of knowledge elicitation as a means of informing training content. The research was part of a project funded by the Health and Safety Executive (HSE) to investigate the application of emerging technologies for enforcement officer training. A web site was developed to provide work-based training in the field of accident investigation, using a group knowledge elicitation technique. Evaluation of eight key aspects of the training was carried out to determine the acceptability and utility of the web site for health and safety inspector training. The majority of the respondents believed that the training was realistic and that the embedded discussion facility had the potential to improve consistency of enforcement. Whilst many of the participants reported that this exercise was their first exposure to the Internet and some experienced minor difficulties using the technology, most found training via the Internet easy to use, an enjoyable experience and one they would like to repeat.     

Effects of goal relations on self-regulated learning in multiple goal pursuits: performance, the self-regulatory process, and task enjoyment

The purpose of this study was to investigate the effects of goal relations on self-regulation in the pursuit of multiple goals, focusing on self-regulated performance, the self-regulatory process, and task enjoyment. The effect of multiple goal relations on self-regulation was explored in a set of three studies. Goal relations were divided into two categories: facilitating goal relations and conflicting goal relations. A facilitating goal relation is a relationship in which the pursuit of a focal goal enhances the attainment of an additional goal, whereas a conflicting goal relation is a relationship in which the pursuit of a focal goal generates conflicts with additional goal pursuits. Specifically, Study 1 tested the general hypothesis that conflicting goals decrease self-regulatory performance, task enjoyment, and the adaptive self-regulatory process, whereas facilitating goals increase them during the performance of the focal goal task. Studies 2A and 2B tested how the extent of facilitating or conflicting relations between goals affects self-regulatory performance, the self-regulatory process, and task enjoyment during the pursuit of the focal goal. The findings of the three studies were consistent with the authors?? hypothesis that facilitating goal relations increase self-regulatory performance and the self-regulatory process, whereas conflicting goal relations decrease them. The author also discuss the implications for self-regulation, intrinsic motivation, and classroom organization.     

用有限元法分析径向磁性联轴器的力矩特性

从电磁场的基本理论出发,建立了径向磁性联轴器的有限元数学模型,利用磁场的周期性条件来压缩求解区域范围,使计算大为简化。分析了环间转角、磁极数、磁环尺寸、磁环间距等因素对联轴器传动力矩的影响,并总结了径向磁性联轴器力矩特性的变化规律。     

Spatial matching and nonmatching in male and female Wistar rats: Effects of delay-interval duration

Male and female Wistar rats were trained in a delayed matching-to-position procedure in which one of the two levers (sample) was presented. Pressing this lever resulted in its retraction and began a delay interval of random variable duration, which terminated with the occurrence of the first nose poke in the pellet retrieval unit after the delay interval had expired. Both levers were then inserted into the chamber, and food became available when the subject pressed the lever that had previously been pressed (matching response). When the subject failed to make a matching response, time out (5 sec) was presented. In the next experimental condition, nonmatching was reinforced. Males and females required an equal number of trials to attain 80% accuracy during three consecutive sessions under matching and nonmatching conditions. Response accuracy decreased as the delay interval increased, during both conditions. Differences between the sexes were not observed, suggesting that memory functions in male and female rats may only differ when other behavioral differences between the sexes are allowed to interfere with the assessment of memory functioning.     

Spatial Contiguity and Spatial Split-Attention Effects in Multimedia Learning Environments: a Meta-Analysis

Spatial split-attention effects have been noted in the research literature, where, under split-attention conditions, integrating text and diagrams has been shown to be effective. From this literature grew the spatial contiguity principle (or spatial contiguity effect), which states that people learn more when related words and pictures are displayed spatially near one another. Research has shown both effects to influence learning; however, little is known about the conditions in which integrated designs are most effective. This meta-analysis examines the influence of integrated designs across numerous moderator variables in order to improve our understanding of under which conditions integrated designs influence learning. A random effects meta-analysis of 58 independent comparisons (n?=?2426) produced an overall effect size of g?=?0.63 (p?<?0.001). Moderator analyses indicated that integrated designs have benefited learning across many intervention-related and context-related moderator variables. Practical and theoretical implications of the findings are provided.     

Spatial interaction between cage and test environments: Position preferences of young isolated and pair-housed rats

This study further investigates the relationship between cage size and activity in the open field. Male hooded rats were housed at weaning either individually or in pairs in small, medium, or large cages and observed after 15 days in an apparatus providing a choice between three environments of identical construction and dimensions to the different home cages. Three experimental conditions were employed. Both isolated and pair-housed rats were tested alone in the unfamiliar apparatus and some isolated rats were first habituated to the apparatus. Time spent in each size apparatus component was recorded. The results failed to explain earlier findings of a positive relationship between open-field behavior and cage size in isolated rats, in terms of spatial preference. Isolated component preferences were inversely related to cage size, while pair-housed preferences were positively related to cage size. Component preference was not related to component area or perimeter distance. The implications of this spatial behavior for exploration and emotionality theories are discussed.     

Searching for cochlear implant information on the internet maze: implications for parents and professionals

The present study has three purposes: (a) to determine who disseminates information on cochlear implants on the Web; (b) to describe a representative sample of Web sites that disseminate information on cochlear implants, with a focus on the content topics and their relevance to parents of deaf children; and (c) to discuss the practical issues of Web-based information and its implications for professionals working with parents of deaf children. Using the terms cochlear implants and children, the first 10 sites generated by the four most popular search engines (Google, Yahoo, Microsoft's MSN, and America Online) at two points in time were selected for analysis, resulting in a sample of 31 Web sites. The majority of Web sites represented medically oriented academic departments and government organizations, although a wide variety of other sources containing information about cochlear implants were also located. Qualitative analysis revealed that the content tended to fall into eight categories; however, the important issues of educational concerns, habilitation following surgery, and communication methods were either addressed minimally or neglected completely. Using analytical tools that had been developed to evaluate user friendliness in other domains, each Web site was assessed for its stability, service/design features and ease of use. In general, wide variability was noted across the Web sites for each of these factors. The strong recommendation is made that professionals understand and enhance their knowledge of both the advantages and limitations of incorporating the new technology into their work with parents.     

Overshadowing and blocking between landmark learning and shape learning: the importance of sex differences

Rats were trained in a triangular-shaped pool to find a hidden platform that maintained a constant relationship with two sources of information, an individual landmark and one part of the pool with a distinctive shape. In Experiment 1, shape learning overshadowed landmark learning but landmark learning did not overshadow shape learning in males, while landmark learning overshadowed shape learning but shape learning did not overshadow landmark learning in females. In Experiment 2, rats were pretrained either with the single landmark relevant or with the shape relevant, in the absence of the alternative cue. Final test trials, without the platform, revealed reciprocal blocking only in females; in males, shape learning blocked landmark learning, but not viceversa (Experiment 2a). In Experiment 2b, male rats received a longer pretraining with the single landmark relevant, and now landmark learning blocked shape learning. The results thus confirm the claim that males and females partially use different types of spatial information when solving spatial tasks. These results also agree with the suggestion that shape learning interacts with landmark learning in much the same way as does learning about any pair of stimuli in a Pavlovian conditioning experiment.     

Effects of maze geometry and experience on exploratory behavior in the rat

Rats were exposed twice in a rotated sequence to a series of six mazes, consisting of hexagonal alleys, balanced for different alley length and structural complexity. Locomotor activity increased with alley length and decreased with structural complexity of the mazes. Locomotion became less stereotyped with increased experience, showing an increasing number of turns, less constant velocity, loss of the initial preference for outward leading alleys and weakening of the forward tendency at reentry from side alleys into hexagonal alleys. In contrast to these qualitative changes of locomotion, the amount of activity remained almost unchanged throughout the experiment. The results suggest that these increases in locomotion complexity depend upon complex interactions between experience and stimulus content of the mazes.     

Students' achievement goal orientations and their behavioral and emotional engagement: Co-examining the role of perceived school goal structures and parent goals during adolescence

The role of perceived school goal structures and parent goals in predicting adolescents' goal orientations and their behavioral and emotional engagement in the classroom was examined in the present study. Surveys were given to a sample of 271 seventh- and ninth-grade students. Path analyses showed that (a) perceived school mastery goal structures and parent mastery goals predicted student mastery goal orientation, perceived school and parent performance goals predicted student performance-avoidance goal orientation, whereas performance-approach orientation was only predicted by perceived parent performance goals; (b) perceived school and parent mastery goals predicted behavioral but not emotional engagement directly as well as indirectly through the mediation of student mastery goal orientation; (c) behavioral and emotional engagement were predicted by student mastery goal orientation. Results are discussed in relation to current theory and their implications for promoting adaptive patterns of learning in the school and the family context.