The effects of strong irrelevant thirst on food-rewarded instrumental performance

In Experiment I, rats received one food rewarded trial per day in a runway. One group received all its trials under hunger (Group H); the second group received a random half of its trials under hunger and the other half of its trials under hunger plus thirst (Group H-HT). Group H-HT ultimately ran slower on HT trials than on H trials. In Experiment II, the effects of shifting from H to HT and vice versa were examined in a five-phase design. In general, rats run under H ran faster than rats run under HT, and shifts from H to HT produced rapid decreases in speed, while shifts from HT to H produced extremely slow increases in speed. The results of both experiments were interpreted as indicating that the reward value of food is greater under H than under HT and that the manipulation H vs. HT may be viewed as theoretically similar to manipulation of reward magnitude.     

Career choice motivation using behavioral strategies

Qualified teachers are a fundamental input for any education system. This paper presents the results of a large-scale intervention to attract high performing high-school students into the teaching profession in Chile. The intervention was a three-arm email campaign which made salient three types of motivations: intrinsic/altruistic, extrinsic, and prestige-related. The “intrinsic” and “prestige” arms reduced applications to teaching majors among high performers, while the “extrinsic” arm increased applications among low performers. A plausible interpretation could be that the “intrinsic” and “prestige” messages made more salient an issue that could otherwise be overlooked by high performing students (typically from more advantaged households), negatively impacting their program choice: that the social value of the teaching still lags behind other professions that are valued more by their families and social circles. In turn, the “extrinsic” arm made salient the recent improvements in the economic conditions of the teaching profession in Chile, thus appealing to low performing students who in general come from disadvantaged families and for whom monetary incentives are potentially more relevant. These results show that making salient certain types of motivations to the wrong target group could lead to undesired results.     

Direct effects on instrumental performance of outcome revaluation by drive shifts

In three experiments the sensitivity of instrumental responding to revaluation of the instrumental outcome in the absence of experience with the revalued outcome was examined. Hungry rats were trained to make one response for food pellets and a different response for sucrose liquid. In Experiment 1, these responses were tested in extinction when the animals were either thirsty or hungry. A significant preference for the sucrose-trained response was observed in the test conducted under thirst but not in that conducted under hunger. In Experiments 2 and 3, the effect of experience with sucrose under thirst on the magnitude of this preference was explored. Following training of the instrumental responses in Experiment 2, half of the animals received presentations of sucrose while they were thirsty; the other half received sucrose while they were hungry. In Experiment 3, the same design was used but these sucrose presentations were made contingent on an instrumental response. Also in Experiment 3, the specificity of the sucrose-response preference to a shift to thirst was examined by testing under increased and decreased levels of hunger. The results of those experiments indicated that the sucrose-response preference is exhibited only under thirst and that exposure to the sucrose under thirst only marginally enhanced that preference. These findings suggest that instrumental responding may be modified by changes in the value of its outcome in the absence of experience with the revalued outcome.     

Predicting reading performance using the slingerland procedures

The purpose in this study was to examine predictive relationships between the Slingerland Pre- Reading Screening Procedures and performance on measures of word recognition and reading comprehension. Longitudinal data were collected on 104 children administered the Slingerland Procedures in kindergarten and the Stanford Achievement Test at first, third, and fifth grades. Outcome measures included achievement subtests, Word Study Skills, Reading Comprehension, Reading and Listening Total. Significant relationships were found between Slingerland measures and reading outcomes. However, prediction varied across grades and according to the measure of reading used. Listening contributed to reading comprehension but not to word recognition, and visual skills influenced early but not later reading performance. Gender and socioeconomic status influenced the strength of associations.     

Pavlovian aversive to instrumental appetitive transfer: Evidence for across-reinforcement blocking effects

Rats received Pavlovian aversive (shock) conditioning in which white noise was established for different groups as a CS+, CSO, or CS?. Then, in an appetitive T-maze discrimination, the CSs were presented contingent upon a designated correct response for which food reinforcement was factorially varied at 0, 1, 2, or 4 pellets. Although the CS+ suppressed and the CS? facilitated speed of running in the correct arm at the start of discrimination training, these effects extinguished rapidly and did not interact with reward magnitude. Furthermore, choice learning was faciltated by the CS+ and retarded by the CS?, with these effects being comparable for the 1- to 4-pellet reinforcement conditions, but absent for the 0-pellet condition. These findings are difficult to reconcile with a transfer interpretation positing a general signaling property of the CS and are better interpreted as across-reinforcement blocking effects: By predicting a preferred outcome (safety) comparable to the preferred outcome of food reinforcement, the CS? blocks (retards) the association of reinforcement and the S^D; conversely, by predicting a nonpreferred (shock) outcome discrepant from the preferred food outcome, the CS+ “counterblocks” (enhances) the association of reinforcement and the S^D.     

Differential effects of delay of reinforcement on acquisition of affective and instrumental responses

Thirsty rats were allowed to choose between a striped arm of a T-maze that contained water and a black arm that contained a saccharin solution. After each exposure to the saccharin solution, half of the animals received a lithium chloride injection 1 min later and half received the same injection 30 min later. Comparable saline injections at these same delays were given after each exposure to the striped, water, arm. The results from saccharin aversion, spatial aversion, and instrumental learning tests generally supported the hypothesis that delayed reinforcement has a substantially greater negative impact on the acquisition of an instrumental response than it has on affective conditioning.     

The effects of the Kalamazoo Promise on college choice

On November 10, 2005, then Superintendent of the Kalamazoo Public School System, Janice Brown announced—to the surprise of Kalamazoo’s residents—the beginning of the Kalamazoo Promise. Fully funded by a set of anonymous donors, the Kalamazoo Promise is an urban revitalization program that offers up to four years of free tuition to any public college or university in the state of Michigan for graduates of the Kalamazoo Public School system who meet certain eligibility criteria. Using the subsidy as a source of exogenous variation in the price of college, we use quasi-experimental methods to evaluate the impact of the subsidy on college choice. We find that the Kalamazoo Promise increases the likelihood that students from Kalamazoo Public Schools consider public institutions in Michigan. In addition, we find that the Kalamazoo Promise especially impacts the college choice set of students from families who earn less than $50,000 in annual income.     

Social effects on spatial choice in the radial arm maze

Social memory was investigated in the context of a spatial working memory task. Pairs of rats were tested in an eight-arm radial maze. Under most conditions, there was a tendency to choose maze locations that had been visited earlier by the other rat. The possibility that this tendency is produced by common preferences for particular maze locations was ruled out. An opposite tendency to avoid visits to locations that had been visited earlier during the trial by another rat was found only when the maze location contained two pellets (rather than an undepletable supply), the rats’ ability to see each other in the maze was restricted to the central arena, and the maze location had been previously visited by the focal rat. The amount of food available in maze locations did not otherwise modulate social influences on spatial choice. The results indicate that memory for a rat’s own previous choices is combined with memory for the choices made by another rat.     

Creating a learner-centered teaching environment using student choice in assignments

Learner-centered teaching (LCT) has been found to be a more effective pedagogy for online students, as traditional teaching methods do not work well in online courses. Professors in an upper-level technology management class revised their online introductory course to incorporate cafeteria-style grading. This LCT approach allowed students to select assignments they wanted to complete. More assignments were offered than needed to achieve an A grade. They included traditional projects such as research papers as well as more engaged activities such as demonstrating or mastering skills. To determine whether these changes promoted active learning, course data were obtained and analyzed. Students completed a range of assignments, showed mastery on a number of skills, and were overwhelmingly positive about having flexible options. Tellingly, 36% of students completed more assignments than were needed to earn the top grade.     

漫谈器乐教学

器乐的种类很多,各有其独特的音色和表现力,教师应该根据学生所学的乐器特点,教给学生基本的器乐知识与器乐演奏技巧,并根据学生各自特点的不同,因材施教。另外,为了提高学生的综合素质,有必要调整音乐文化课、基础文化课及专业技巧课之间的比重,培养学生的人文素养,为学生完美的器乐演奏奠定基础。     

Temporal integration and instrumental conditioned reinforcement

Stimuli associated with primary reinforcement for instrumental behavior are widely believed to acquire the capacity to function as conditioned reinforcers via Pavlovian conditioning. Some Pavlovian conditioning studies suggest that animals learn the important temporal relations between stimuli and integrate such temporal information over separate experiences to form a temporal map. The present experiment examined whether Pavlovian conditioning can establish a positive instrumental conditioned reinforcer through such temporal integration. Two groups of rats received either delay or trace appetitive conditioning in which a neutral stimulus predicted response-independent food deliveries (CS1→US). Both groups then experienced one session of backward second-order conditioning of the training CS1 and a novel CS2 (CS1–CS2 pairing). Finally, the ability of CS2 to function as a conditioned reinforcer for a new instrumental response (leverpressing) was assessed. Consistent with the previous demonstrations of temporal integration in fear conditioning, a CS2 previously trained in a trace-conditioning protocol served as a better instrumental conditioned reinforcer after backward second-order conditioning than did a CS2 previously trained in a delay protocol. These results suggest that an instrumental conditioned reinforcer can be established via temporal integration and raise challenges for existing quantitative accounts of instrumental conditioned reinforcement.     

Motivational control after extended instrumental training

Hungry rats were trained to press a lever for food pellets prior to an assessment of the effect of a shift in their motivational state on instrumental performance in extinction. The first study replicated the finding that a reduction in the level of food deprivation has no detectable effect on extinction performance unless the animals receive prior experience with the food pellets in the nondeprived state (Balleine, 1992; Balleine & Dickinson, 1994). When tested in the nondeprived state, only animals that were reexposed to the food pellets in this state between training and testing showed a reduction in the level of pressing during the extinction test relative to animals tested in the deprived state. The magnitude of this reexposure effect depended, however, on the amount of instrumental training. Following more extended instrumental training, extinction performance was unaffected by reexposure to the food pellets in the nondeprived state whether or not the animals were food deprived at the time of testing. A second study demonstrated that the resistance to the reexposure treatment engendered by overtraining was due to the animals’ increased experience of the food pellets in the deprived state during training rather than to the more extensive exposure to the instrumental contingency. In contrast to the results of the first two experiments, however, a reliable reexposure effect was detected after overtraining in a final study, in which the animals were given greater reexposure to the food pellets in the nondeprived state.     

Spontaneous recovery of instrumental discriminative responding

In six experiments, rats received discriminative training in which making a response (R) during a stimulus (S) produced a particular outcome (O). In Experiment 1, that outcome was replaced by a second outcome and responding was tested either immediately or after a delay. More substantial responding was observed with the delayed test. In Experiment 2, a test of transfer to new responses suggested that the growth in performance was not attributable to greater use of particular S-O associations. However, in Experiment 3, the growth in responding was found to be specific to particular S-R combinations. Experiment 4 replicated that specificity and demonstrated the importance of using two different outcomes for obtaining the growth in responding with time. Experiments 5 and 6 repeated these observations for the case of extinction, in which O was replaced by nonreinforcement. These results are interpreted as suggesting that an outcome-independent inhibitory S-R process develops, both with extinction and with the use of a second outcome, but dissipates with time.     

Frustrative nonrelief in instrumental escape conditioning

The generality of the frustration effect in an aversive stimulus conditioning procedure was examined by training and testing 40 rats in a double cold-waterway escape conditioning apparatus. Experimental and control procedures analogous to appetitive conditioning experiments (e.g., Amsel & Roussel, 1952; Wagner. 1959) indicated that frustrative nonrelief (i.e., reinforcement omission) in the first goal tank yielded significant increments in swimming speed in the second waterway, and that these increments in performance were dependent upon initial training with continuous relief (i.e., reinforcement) in the first goal tank. Extensions of the generality of the frustration effect are discussed.