Attenuated and enhanced neophobia in the taste-aversion “delay of reinforcement” effect

Learning & Behavior - Rats were made ill immediately or 6 h after drinking either familiar tap water or a novel .1% saccharin solution. Control animals were given sham treatments immediately...     

Stimulus selection in discriminative taste-aversion learning in the rat

In three experiments, rats were presented compound solutions consisting of a common element, saccharin, mixed with one of two different flavor elements, cinnamon and wintergreen. Rats in the experimental groups consistently received a toxicosis-inducing injection following one compound solution but not following the other compound solution. Rats in the control groups received toxicosis-inducing injections half the time following each of the compound solutions. After training in each experiment, there were tests for conditioning to the saccharin alone. The experimental groups drank significantly more than the control groups, indicating that the aversion to the partially reinforced saccharin in isolation was less when the different flavor cues were more highly correlated with reinforcement. In Experiment III, there was also a test for conditioning to the cinnamon or wintergreen flavor alone. The experimental group drank significantly less of the continuously reinforced flavor than the control group did of the partially reinforced flavor. These results are similar to those reported within more traditional conditioning paradigms.     

Socially mediated attenuation of taste-aversion learning in Norway rats: Preventing development of “food phobias”

After interacting with rat demonstrators that had eaten a novel, palatable diet, many observer rats exhibited either attenuation or total blockade of their subsequent acquisition of a lithium-chloride-induced aversion to that diet. In natural circumstances, such social attenuation of aversion learning could prevent new recruits to a population (weanlings or recent immigrants) from learning maladaptive aversions (“food phobias”) to tainted or spoiled samples of normally safe foods that others of their social group were eating.     

Exteroceptive cues in taste-aversion learning,no artifact: Reply to Holder

Holder (1988) has raised several objections to our work on the role of exteroceptive contextual stimuli in taste-aversion learning by rats. Our main conclusion from that work is that tongue-tactile stimuli from the drinking spout constitute the likely basis for findings of contextual bottle control over learned taste aversions. Holder suggests that our results are confounded by taste cues from the fluid containers. We refute this suggestion by presenting data from two experiments showing contextual bottle control, even though potential taste cues from the drinking bottles were eliminated. We also point to the fact that some of Holder’s criticisms are based on misreadings of our various reports.     

Rethinking the flipped learning pre-class: Its influence on the success of flipped learning and related factors

Flipped learning (FL) has had a substantial impact on higher education worldwide, prompting active dialog among educational researchers and practitioners. It is widely accepted that the value of FL lies in enabling in-depth, learner-centered learning experiences by offloading content delivery onto pre-class online learning. The in-class component is thus generally considered more critical, even though both pre-class and in-class elements are indispensable components of FL and practitioners are faced with the issue of under-prepared learners. In this study, we examine the significance of pre-class learning as a gateway to the intended benefits of FL. We aim to investigate the extent to which FL pre-class learning influences overall FL success and what other factors affect FL pre-class learning to ascertain the implications of designing and implementing FL pre-class learning. A college life science course was designed and implemented with the FL model for a semester, from which data were collected and statistically analyzed. The results indicate that the influence of pre-class learning on final FL success is significant and strong. Regarding the modality of pre-class learning materials, learners demonstrated higher levels of performance in the weeks with video materials than during those with reading materials. Among several learner factors, self-direction was found to significantly influence pre-class learning performance and perceived learning readiness. The role of FL pre-class learning to attain the intended value of FL is discussed, and theoretical and practical design implications are suggested.     

Positive correlation between pre- and postconditioning saccharin intake in taste-aversion learning

Data from 36 groups of rats from a total of 12 taste-aversion (saccharin+lithium chloride) experiments were analyzed for (1) individual differences of absolute saccharin (sacc) intake on the first (conditioning) and second (test) presentations, and (2) the correlation between intakes on the two presentations. Large individual differences and strong positive correlations were found for sacc+LiCl, sacc+NaCl, sacc?LiCl unpaired, and “different context” conditions. In addition to raising doubts about the use of absolute saccharin intake as a measure of taste-aversion learning, these results support the view that an associative (taste-nausea) component is superimposed on a neophobic avoidance of the novel taste stimulus.     

论自我效能感对数学学习的影响

根据自我效能理论，从数学学习的增生阶段、融会贯通阶段及学习的动机，自我调节、自我监控等方面阐述了自我效能感对数学学习过程的影响，并提出了一些提高学生自我效能感的方法。     

Should taste-aversion learning experiments control duration or volume of drinking on the training day?

It has been reported that increases in volume drunk of a solution, prior to poisoning, lead to greater learned aversions. However, this effect may be due totally or partially to differences in time spent drinking rather than to amount drunk. When duration of drinking is held constant, rats differ spontaneously in how much of a solution they drink. In 29 experimental groups, varying in procedural details, the correlation between amount drunk on the training day and percent preference for the solution on the test day (the opposite of aversion) was positive in 16 cases, negative in 13, and usually low. Regardless of whether volume drunk affects taste-aversion learning under some conditions, evidently it is sufficient to control duration of drinking rather than volume, since the spontaneously occurring variations in volume have only slight, if any, effects on the individual differences in learned aversion.     

Poison-induced neophobia in rats: Role of stimulus generalization of conditioned taste aversions

Rats repeatedly injected with lithium chloride were subsequently tested drinking novel and familiar solutions of both casein hydrolysate and vinegar. Injections in the absence of edibles result in only a small, and sometimes not reliable, increased avoidance of the novel casein and vinegar solutions. In contrast, if subjects acquired an aversion to saccharin as a result of the lithium injections, this learned aversion generalized to casein hydrolysate, with the generalization greatly enhanced by novelty of the casein flavor. However, the saccharin aversions did not generalize to the novel vinegar solution nearly as much as to the novel casein flavor. These results suggest that previous observations of poison-induced neophobia were probably in part a result of the stimulus generalization of conditioned taste aversions and that in addition to test stimulus novelty some other factor, such as stimulus salience or similarity to the conditioned aversive flavor, is also involved in the generalization of learned taste aversions.     

Effects of pretraining on conditioning-enhanced neophobia: Evidence for separable mechanisms of neophobia and aversion conditioning

In two experiments, rats (n = 228) received pretraining access to a distinctive novel flavor (saline) followed by aversion conditioning to a different novel conditioned stimulus (CS) (saccharin). Then the rats were tested for aversion to the CS (saccharin) or for conditioning-enhanced neophobia to a third novel flavor (casein hydrolysate). Pretraining access to a distinctive novel flavor that differed from the CS reliably reduced the magnitude of conditioning-enhanced neophobia to casein, but did not reliably affect conditioned aversion effects to the CS. Pretraining access to the CS reduced aversion effects to the CS and reduced postconditioning neophobia to casein to the performance level shown by ingestion-toxin controls. Results were consistent with the view (Braveman & Jarvis, 1978) that conditioned aversion and neophobia may be independent phenomena with separable underlying mechanisms.     

Feature-negative effect in rats’ discrimination learning in the runway

In two experiments, rats were trained on a successive go/no-go discrimination problem in the runway in which the positive (S+) and negative (S?) discriminanda were differentiated by the presence or absence of a distinctive feature. The feature in Experiment 1 was a series of flashing lights over the runway. In Experiment 2, the feature was a pretrial reinforcement (Phase 1), or pretrial reinforcement versus pretrial nonreinforcement (Phase 2). The feature signaled S+ trials in feature-positive (FP) groups and S? trials in feature-negative (FN) groups. The original discrimination was reversed in Phase 2 of both experiments. With the exception of the pretrial nonreinforcement groups in Experiment 2, there was an asymmetry in discrimination learning in both phases of both experiments favoring superior discrimination learning by FN subjects over FP subjects, a feature-negative effect. Implications of the results for an information processing account of asymmetries in learning feature discriminations are discussed.     

Improving the quality of student learning: the influence of learning context and student approaches to learning on learning outcomes

Previous studies of the relationship between perceptions and/or evaluations of the learning environment and approaches to study have either not included measures of students' learning outcomes, or have included quantitative differences and not qualitative differences in learning outcomes. The studies reported in this paper focus on the relationship between qualitative differences in learning outcomes, perceptions/evaluations of the learning environment and approaches to study. The results support previous research in identifying relationships between perceptions/evaluations of the learning environment and approach to study and between approach to study and the quality of the learning outcomes. The second of the two studies reported also identifies a relationship between perceptions, approaches and the quality of the outcomes. The results suggest that perceived environments which encourage deep approaches are more likely to facilitate higher quality learning than environments designed to discourage surface approaches.     

Reflective practicum in higher education: the influence of the learning environment on the quality of learning

Sustaining students in becoming reflective practitioners is considered as a valued outcome of higher education. The paper aims to evaluate the impact of the learning environment conditions inspired by Schön’s theory of reflective practicum, by discussing a case study of a master’s degree class. The learning environment was designed to sustain reflective practice and meaningful engagement through professional practice simulation, problem-based learning and reflective writing. Unlike much of the research into reflective learning, the quality of learning was evaluated by assessing the use of reflective practice in students’ weekly journaling, rather than measuring students’ satisfaction or perceptions of effectiveness. Two hundred and six journal entries of 23 students were assessed and used in a quantitative analysis based on a linear mixed-effects model. Findings indicated that the reflective practicum has an incremental effect on students’ reflective practices and that reflective practice is dynamic and sensitive to specific learning environment conditions. In conclusion, students’ co-responsibility of the learning environment allowed by the professional practice simulation appears to foster meaningful and reflective learning. Conversely, conditions that stimulate only cognitive engagement have little impact or even inhibit reflective practices. Practical implications of the use of reflective journal are discussed.     

Dissociation of patterned alternation learning and the partial reinforcement extinction effect in preweanling rats

Sprague-Dawley rat pups aged 14 or 18 days were trained on a patterned (single) alternation schedule with either an 8- or a 105-sec intertriai interval (ITI). At the 8-sec ITI, alternation learning was obtained at both ages, but the older age group learned more rapidly. There was no evidence of response alternation at the 105-sec ITI at either age. Continuously reinforced (CRF) and partially reinforced (PRF) groups trained and extinguished along with the patterned alternation (PA) group at the 105-sec ITI showed a robust partial reinforcement extinction effect (PREE) at both ages. Moreover, there was no difference in the rate of extinction of the PRF and PA groups at either age (i.e., no effect of N-length). A PREE can therefore be obtained in infant rats under conditions that apparently preclude the formation of sequential associations. The implications of this finding for the ontogeny of instrumental learning and extinction are discussed.     

Knowledge, the disciplines, and learning in the Digital Age

ICTs (Information and Communication Technologies) are now widely used in schools: However, despite predictions, they have not revolutionized teaching and learning. Why is this? Does it matter? Should we care? This paper outline seeks to answer such questions and why we should care. School ICTs are informed by a range of different, and often conflicting ideas, with the result that student work is often “digital busywork”. The article argues that if ICTS are to play a useful role in helping us to re-develop our schools for the Knowledge Age, we need to re-examine some of our old ideas about knowledge. In particular, we need to re-examine the place and purpose of the traditional disciplinary knowledge that is the basis of the current curriculum.     

The effect of nonnutritive satiation on the learning of a flavor preference by rats

On each day of training in Experiment 1, hungry rats were given one flavored saccharin solution followed by a differently flavored saccharin solution. The rats drank more of the first flavor during training, but preferred the second flavor in a subsequent choice test. In Experiment 2, the two flavored saccharin solutions were provided on alternate days, with one flavor being preceded by nothing and the other flavor by plain saccharin. The rats drank more of the flavor preceded by nothing during training, but preferred the other flavor in a subsequent choice test. These results suggest that a state of nonnutritive satiation can reinforce a flavor preference.     

Making inquiry-based science learning visible: the influence of CVS and cognitive skills on content knowledge learning in guided inquiry

ABSTRACT

Many science curricula and standards emphasise that students should learn both scientific knowledge and the skills associated with the construction of this knowledge. One way to achieve this goal is to use inquiry-learning activities that embed the use of science process skills. We investigated the influence of scientific reasoning skills (i.e. conceptual and procedural knowledge of the control-of-variables strategy) on students’ conceptual learning gains in physics during an inquiry-learning activity. Eighth graders (n?=?189) answered research questions about variables that influence the force of electromagnets and the brightness of light bulbs by designing, running, and interpreting experiments. We measured knowledge of electricity and electromagnets, scientific reasoning skills, and cognitive skills (analogical reasoning and reading ability). Using structural equation modelling we found no direct effects of cognitive skills on students’ content knowledge learning gains; however, there were direct effects of scientific reasoning skills on content knowledge learning gains. Our results show that cognitive skills are not sufficient; students require specific scientific reasoning skills to learn science content from inquiry activities. Furthermore, our findings illustrate that what students learn during guided inquiry activities becomes visible when we examine both the skills used during inquiry learning and the process of knowledge construction. The implications of these findings for science teaching and research are discussed.     

简论后工业时代美国少数民族文学的崛起

美国少数民族文学的崛起与第二次世界大战之后蔓国社会种族和文化多元化的重新抬头密切相关，也有赖于50年代60年代民权运动的蓬蓬发展，而它获得承认和广泛接受，则离不开坚持多元文化观的学者们的努力和70年代以来文学研究自身的一系列发展。