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1.
Blue jays (Cyanocitta cristata) responded to projected black-and-white silhouettes of cherry leaves that were either undamaged or were damaged by either cryptic caterpillars that disguise leaf damage due to their feeding or by noncryptic caterpillars that do not disguise leaf damage due to their feeding. Pecks to the key on which the images were projected were reinforced only if interresponse times fell within specified temporal boundaries. These boundaries were different in the presence of the two types of leaf damage. Following training with one exemplar of each damage type, the jays correctly categorized novel instances of both types. They categorized novel undamaged leaves as if they were examples of leaves showing damage by cryptic caterpillars. Results suggest that the jays can readily discriminate and generalize to new members of a polymorphous stimulus class. The results suggest that techniques for the study of concept formation in animals can be applied to an animal’s ability to categorize stimuli that are involved in a potential prey-predator relationship.  相似文献   

2.
In the present study, we investigated the impact of a word-problem intervention in retention and acquisition of knowledge after the intervention ended. We based analyses upon Grade 4 students experiencing mathematics difficulty (average age at pretest = 8.77) who received one of two variants of a word-problem intervention (with [n = 111] vs. without [n = 110] embedded pre-algebraic reasoning instruction) and students within a business-as-usual condition (BaU [n = 127]) separately. Findings revealed that students who received the intervention not only tended to retain less, but they also showed more active knowledge acquisition after the intervention ended. Furthermore, word-problem intervention altered the contributions of some prior knowledge and skills on both retention and acquisition.  相似文献   

3.
The performances of adult and aged macaque monkeys were compared on several tasks requiring acquisition and retention of concurrent object discriminations. Cross-sectional and longitudinal comparisons between 11-year-old and over-20-year-old animals were conducted on the acquisition of several 16-problem concurrent tasks, and after 2 weeks, retention by the different age groups was also evaluated. Although the retention tests indicated no age-related impairment, acquisition tests showed that aged animals made reliably more errors-to-criterion than did adult animals. The relative contributions of intersession and intrasession improvement and preference phenomena were considered and contrasted to some previously reported age-specific outcomes. Although the present results affirmed the contention that old animals were selectively impaired on intersession task requirements, some earlier interpretations of preference effects were questioned. Old animals did not show a potentiation of specific object preferences; rather, they tended to be nonsystematic in maintaining their selection of initially preferred objects. Concurrent discrimination was indicated to be a behavioral measure that is, under appropriate circumstances, selectively sensitive to aging and may offer an appropriate comparative model of information-processing characteristics.  相似文献   

4.
Ten rhesus monkeys were trained on five tasks, each of which consisted of eight concurrently presented object discrimination problems. Sequences of presentation were devised to allow one, two, or three new tasks to intervene between acquisition and retention tests or to provide a 30-day period of no testing. Equivalent and proficient performances were obtained in all retention tests, and no relationship was observed between retention and the initial preference characteristics of various objects. Object pReferences did produce significant influences upon acquisition, but these effects were not as pronounced in early tasks as in later ones. An additional retention test provided support for the contention that monkeys do not necessarily process information about specific object pair discriminations. Rather, they appeared to retain a list of previously rewarded objects even when object pairings were different from those provided during acquisition. Concurrent discriminations involving many distinct objects were resistant to interference and independent of preference characteristics over long retention periods.  相似文献   

5.
Trial-by-trial acquisition of the CER was measured in a number of groups with different CSs. Analysis of the acquisition curves for individual animals revealed that, for the majority of animals, CS-US associations developed in a stepwise rather than a gradual fashion. In some cases, with the most effective CS, conditioning occurred with one CS-US pairing.  相似文献   

6.
This article introduces a new model of Pavlovian conditioning, attention as an acquisition and performance variable (AAPV), which, like several other so-called attentional models, emphasizes the role of variation of cue salience, together with associative strength, in accounting for conditioning phenomena. AAPV is primarily (but not exclusively) a performance-focused model in that it assumes not only that both the saliences and associative strengths of cue representations change during acquisition, but also that they are both influential at the time of test in determining responding. Different weights are given to the representations’ associative strengths according to the representations’ respective saliences at test. The model also treats the representation of a stimulus that is directly activated by presentation of that stimulus as distinct from the representation of the same stimulus that is activated by presenting a companion of the stimulus. Additionally, extinction is viewed as resulting from a decrease in the salience of the cue’s representation, rather than a decrease in associative strength. Simulations of several Pavlovian phenomena are presented in order to illustrate the model and assess its robustness.  相似文献   

7.
This study investigated the effects of problem-based learning (PBL) on knowledge acquisition and knowledge retention in a controlled experiment in a lab setting. Eighty-eight first-year psychology students were randomly assigned to either a PBL condition, a lecture condition, or a self-study condition. All participants had the opportunity to study the same text. Their knowledge acquisition was tested on both an immediate post-test and a delayed post-test, one week later. The results showed beneficial effects for the PBL group on the immediate and the delayed test compared to the lecture group. There were no differences between knowledge acquisition scores for the self-study condition and either of the other conditions. Moreover, no differences on knowledge retention were shown, because the decline in performance over time was equal in all conditions. In conclusion, the present study provides experimentally based evidence of the disadvantageous effects of instruction through lectures compared to PBL.  相似文献   

8.
Cebus monkeys explored a small T-maze for 5 min, and their preference for the striped or black arm of the maze was assessed. On the next day, the experimental animals were placed into the nonpreferred arm for a 1-min period (exposure to the CS), removed from the T-maze for a 30-min delay interval, and then returned to the startbox of the maze, where they received a food reward (UCS). One control group (CS only) received the placement experience but was not rewarded after the 30-min period. A second control group (noncontingent UCS) received the reward in the startbox but not the placement experience. A second preference test showed that the experimental, but not the control, animals reversed their original preference, now showing a preference for the arm associated with reward. A retention test given 4 months after three such training-test trials revealed considerable retention of the preferences exhibited by the experimental and CS-only control subjects.  相似文献   

9.
10.
The purpose of this study was to explore the influence of reading comprehension on the acquisition of word meanings from context and to compare it to the effects of local context characteristics, such as proximity and directness of context clues. The study also examined the effects of prior topic and enabling concept knowledge. Sixth-grade students were pretested on their knowledge of target vocabulary from two expository passages appropriate for their grade and reading level. The students were then familiarized with selected main concepts from one passage and, subsequently, read both experimental passages. Half of the target words appeared in an informative context, while the rest appeared in an less-informative context. A comprehension test and a vocabulary posttest followed the reading of each passage. Hierarchical Regression analyses indicated that reading comprehension level and prior main concept knowledge facilitated vocabulary learning from context. In comparison, the effect of presence or absence of informative context clues was not significant. These findings, underline the need for a reconceptualization of context to take into account the mental representation that readers construct in addition to the printed text that surrounds an unfamiliar word.  相似文献   

11.
EightCebus albifrons monkeys received 25 sessions of discriminative operant conditioning of the skin conductance response (SCR), with colored lights as discriminative stimuli and with Sidman avoidance (SS-40 sec, RS-40 sec) scheduled during one light and response-contingent shock during the other, Discriminative stimulus segments were separated by 30-sec periods of time-out from shocks and lights, Two extinction sessions were run 3 months after training, Almost from the beginning of conditioning, the monkeys made significantly more unelicited skin conductance responses in the avoidance periods than in punishment, The monkeys’ heart rates also increased significantly, but there was no difference between avoidance and punishment, SCR frequency during extinction continued to differentiate significantly between avoidance and punishment, and there was a significant increase in this differentiation from the last conditioning session to the first extinction session, but the difference then reduced in the second session, The results indicated that monkey’s SCRs are influenced by instrumental reinforcement contingencies somewhat in the same fashion as those of humans.  相似文献   

12.
An experiment was carried out to compare the time course of the acquisition of two basic spelling mechanisms in Spanish, a shallow system, and French, a deep system. The first was lexical. It relies on the orthographic lexicon, a hypothetical structure containing the orthographic representations of words accessible for word spelling. To evaluate its contribution the participants were asked to spell words of high and low frequency containing phonemes which can take different graphemic values. The second mechanism relies on sub-lexical processes. Its contribution was evaluated asking the participants to spell words containing consistent phoneme-to-grapheme translation pairs which were identical in Spanish and French. Two contrasting predictions were considered, one derived from the Orthographic Depth Hypothesis (ODH, Frost, 2005) and the other from the Self-Teaching Hypothesis (STH, Share, 2004). According to the ODH, the orthographic lexicon should develop more rapidly in French than in Spanish because Spanish spellers can rely on phoneme-to-grapheme translation mechanisms to spell most words, meaning that they do not need to resort to the orthographic lexicon. In contrast, the STH suggests that effective identification of a word gradually generates its orthographic representation. The results revealed that both spelling mechanisms develop far faster in Spanish than in French. The fact that word frequency effects appeared earlier in Spanish than in French, indicating that the orthographic lexicon incorporates words more rapidly in a shallow than in a deep system, is clearly incompatible with the ODH and easier to handle in the context of the STH.  相似文献   

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14.
Twenty domestic Muscovy ducks were trained to traverse a runway for food reward. Subjects were then randomly assigned to treatments. In one treatment, subjects received six nonrewarded trials followed by six rewarded trials every day for 12 days; and, in the other treatment, subjects received six rewarded trials followed by six nonrewarded trials every day for 12 days. These successive acquisition and extinction (SAE) treatments were selected because different extinction rates on the nonrewarded trials are expected on the bases of previous research performed with rats. Analyses of variance revealed the former treatment yielded significantly greater resistance to extinction than did the latter treatment. It was concluded that ducklings performed similarly to rats in the above SAE situation.  相似文献   

15.
The purpose of this study was to compare the effects of two methods of instruction designed to teach preservice elementary teachers to acquire and retain integrated science process skills. In one section instruction was provided by the teacher, whereas in the other section, instruction was provided by written self-paced self-instructional materials. Results indicated that the self-instructional method was significantly more effective than the teacher-directed method. Both treatments produced long-lasting retention effects.  相似文献   

16.
This study examined the effect of imagery interventions for the presentation of novel science vocabulary to fifth grade learners. Eighty-nine students from two schools in Long Island participated in this study and were randomly assigned to four different instructional interventions: a Picture Presentation method, in which a word was paired with a picture; an Image Creation??No Picture method, in which the participants were told to create an image of the word and draw it on paper; an Image Creation??Picture method, in which the students were presented with the picture and then told to draw it; and a Word Only method, which involved the simple verbal presentation of the word. Results demonstrated that students in the imagery intervention groups (Picture Presentation, Image Creation??No Picture, and Image Creation??Picture) scored higher on the outcome measures at both immediate and delayed recall. It was also shown that the deeper the students processed the ??to be learned?? vocabulary words, the higher they scored on the outcome measures. Based on the mean outcome measure scores at both time points, students in the Image Creation??Picture intervention scored the highest, followed by the students in the Image Creation??No Picture intervention, those in the Picture Presentation intervention, and finally the Word Only intervention students. Such a study has implications as to the most effective way to integrate science and literacy and successfully present novel concepts in the classroom.  相似文献   

17.
An established, captive colony of 74 rhesus monkeys (Macaca mulatta) was group-tested on a simultaneous visual discrimination problem and three reversals of the initial discrimination. The task incorporated important aspects of rhesus foraging behavior. Although other studies of communal groups of nonhuman primates have reported rapid learning, subjects in the present study showed no evidence of one-trial acquisition of the initial problem or of rapid learning-set formation across the reversal series. Instead, mean and individual performance, on all variables measured, improved gradually, both within and across series. Subjects appeared to “learn how to learn,” consistent with findings of traditional studies of individual discrimination learning. Our finding of gradual learning in group-living animals argues that the source of rapid learning in previous reports is not attributable to social influence or ecological relevance, but may reflect specific procedural or species differences between studies.  相似文献   

18.
Young toads,Xenopus laevis, were trained for dark avoidance in a passive avoidance paradigm using electric shock in a fully automatic training and recording procedure. Dark avoidance was acquired within approximately 30 min and was retained on retesting 24 h later. Comparison of the performance of the toads during training and during retesting was used as an indicator for saving or reinforced retention. Control experiments demonstrated that changes in behavior were due to learning and not to nonassociative effects such as pseudoconditioning, increased sensitization to shock, or acquaintance with the testing apparatus.  相似文献   

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ABSTRACT

Massive open online courses (MOOCs) are usually six to ten weeks long. Participation tends to decrease as the courses progress, leading to low completion rates. This led to the question: Could shorter MOOCs contribute to learners’ engagement, retention and success? This paper compares two versions of Study Skills MOOC, which shared the same content but were delivered in different length formats. One was deployed as a single six-week course and the other as two three-week blocks. In total, 617 people registered for the two versions. Data sources included learning analytics, surveys and the Spanish version of the General Self-Efficacy Scale. Both versions of the Study Skills MOOC resulted in increased participants’ self-efficacy. However, learners enrolled in the version composed of two three-week blocks were also more engaged with course content, other students and the facilitators. Their retention and completion rates were higher than those in the longer version of the course. Reasons linked to goal proximity, motivation, interactions and social modelling are discussed  相似文献   

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