Incentive learning and the motivational control of instrumental performance by thirst

The role of incentive learning in instrumental performance following a shift in the degree of water deprivation was analyzed in three experiments. In Experiments 1A and IB, rats trained to perform an instrumental action reinforced with either sucrose or maltodextrin solutions when in a high-deprivation state were subsequently shifted to a low-deprivation state and tested in extinction. This within-state shift in water deprivation reduced instrumental performance only when the animals had been exposed to the reinforcer in the low-deprivation state prior to instrumental training. In Experiment 2, a concurrent training procedure was used to assess whether the change in the value of the reinforcer brought about by preexposurewas mediated by the contingency between the instrumental action and the reinforcer. Preexposure to the reinforcer under the low-deprivation state produced a selective reduction of the performance of the action upon which it was contingent during training when testing was conducted in extinction following a shift from the high- to the low-deprivation state. These experiments provide evidence that animals have to learn about the incentive value of a reinforcer in a particular motivational state through exposure to the reinforcer in that state.     

The influence of context-reinforcer associations on instrumental performance

In each of two experiments, rats were trained to press the lever in a Skinner box, food reinforcement being available on a variable-interval 60-sec schedule (VI 60). There followed an “exposure phase” for which the levers were removed from the boxes, and then a final test with the levers replaced to assess the effects of the intervening treatment on instrumental responding. Experiment 1 showed that simple exposure to the box reduced the vigor of instrumental performance in comparison with a condition in which food was made available during the exposure phase. Animals which received no exposure treatment also showed a relatively high rate of response. Experiment 2 demonstrated that an exposure treatment in which the occurrence of food is signaled by a light stimulus also leads to a decline in instrumental responding. These results are held to support the notion that associations between the context and the reinforcer serve to energize appetitive instrumental behavior.     

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.     

Perceiving school performance as instrumental to future goal attainment: Effects on graded performance

Three studies examined the perception among college students that school performance is instrumental to future goal attainment. Study 1, an exploratory study involving free report goal assessments, indicated that perceived instrumentality (PI) is a subjectively salient aspect of college students’ achievement motivation. Study 2 provided evidence for the structural distinctiveness of PI from self-efficacy, task value, and the achievement goals, and also demonstrated that PI prospectively predicts unique variance in graded performance beyond that accounted for by these motivational variables. Study 3 demonstrated that PI prospectively predicts unique variance in graded performance independently of future time orientation. We argue that a comprehensive understanding of the purposes underlying classroom achievement behavior requires consideration of how school performance may be perceived as instrumental to the attainment of valued life goals.     

The effects of Greek affiliation on academic performance

We use a difference-in-differences approach to estimate the effects of Greek affiliation on academic performance. There are strong negative effects in some periods but smaller effects in others: fraternity affiliation hurts performance by 0.32 standard deviations in the Freshman Spring; sorority affiliation hurts performance by 0.22 standard deviations in Spring semesters after Freshman year. We estimate both ceteris-paribus effects and non-ceteris-paribus effects which allow Greek affiliation to influence course choice behavior. We account for censoring of grades and show ignoring censoring leads to attenuation bias. We also document heterogeneity in treatment effects by student preparation and organization social status.     

Licking one saccharin solution for access to another in rats: Contingent and noncontingent effects in instrumental performance

Separation of the contingent and noncontingent effects of a schedule on amount of instrumental responding is desirable but difficult in schedules that involve instrumental and contingent responses that are either highly probable or very similar. Three studies in which rats were required to lick a solution of .1% saccharin for access to a preferred solution of .4% saccharin showed that neither single nor paired operant baselines of the instrumental response allowed accurate separation of the contingent and noncontingent effects of a fixed-ratio schedule. Two within-subject yoking procedures provided the best baselines of noncontingent effects: the massed baseline measured amount of .1% licking when each subject received free access to the total amount of .4% licking it obtained at asymptote under the schedule; the matched baseline measured .1% licking when each subject received the same access to the .4% solution, but presented in the intermittent pattern obtained during the schedule. Of the three algebraic models used to predict noncontingent effects, the substitution model was most promising, but still not adequate. The procedure of a between-subjects yoked control was also not effective.     

The effects of new science curricula on student performance

This study summarizes the results of a quantitative synthesis of the retrievable primary research dealing with the effects of new science curricula on student performance. This study synthesizes the results of 105 experimental studies involving more than 45,000 students and utilizes the quantitative synthesis perspective to research integration known as meta-analysis (Glass, 1976). A total of 27 different new science curricula involving one or more measures of student performance are included in this meta-analysis. Data were collected for 18 a priori selected student performance measures. The results of this meta-analysis reveal definite positive patterns of student performance in new science curricula. Across all new science curricula analyzed, students exposed to new science curricula performed better than students in traditional courses in general achievement, analytic skills, process skills, and related skills (reading, mathematics, social studies and communication), as well as developing a more positive attitude toward science. On a composite basis, the average student in new science curricula exceeded the performance of 63% of the students in traditional science courses.     

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.     

Selective reinstatement of instrumental performance depends on the discriminative stimulus properties of the mediating outcome

We conducted three experiments to investigate the associative structure underlying the reinstatement of instrumental performance after extinction. In each experiment, rats were initially rewarded on two responses with different outcomes. At test, both responses were extinguished in order to assess the impact of a single noncontingent outcome delivery on response selection. Experiment 1 found evidence of outcome-selective reinstatement (i.e., more responses were performed on the lever that was trained with the reinstating outcome than on the other lever). Experiment 2 demonstrated that the outcome’s capacity to reinstate performance was not affected by a reduction in its motivational value. Experiment 3 found evidence that the reinstating outcome selectively retrieved the response it signaled rather than the response it followed during training. Together, these findings are consistent with the view that instrumental reinstatement depends on the discriminative stimulus properties of the reinstating outcome.     

The effect of irrelevant visual input on working memory for sign language

We report results showing that working memory for American Sign Language (ASL) is sensitive to irrelevant signed input (and other structured visual input) in a manner similar to the effects of irrelevant auditory input on working memory for speech. Deaf signers were disrupted on serial recall of lists of ASL signs when either pseudosigns or moving shapes were presented during a retention interval. Hearing subjects asked to recall lists of printed English words did not show disruption under the same interference conditions. The results favor models that hypothesize modality-specific representations of language within working memory, as opposed to amodal representations. The results further indicate that working memory for sign language involves visual or quasi-visual representations, suggesting parallels to visuospatial working memory.     

The effects of contingent feedback on perceived control and performance

The purpose of this study was to examine the impact on students’ performance of three contingent feedback strategies used by teachers. Contigency means that the feedback strongly corresponds with task behaviour that can be controlled by the students. Elementary school students (N=296) received individualized feedback about their performance during a series of five lessons. Within this contingent feedback structure, three strategies were applied which were assumed to enhance the perceived controllability of the task situation: (1) enhancing the perceptibility of the contingency between feedback and task behavior; (2) explicit reference to effort as part of the feedback, and (3) setting of goals. As predicted, the three contingent feedback strategies had a significant positive effect on perceived controllability, and led to better task performance.     

No discrimination on the basis of irrelevant qualifications

This paper argues that social justice demands that discrimination on the basis of irrelevant qualifications be made illegal. Just as historically it was seen as ‘natural’ for discrimination in employment and education to be made on the basis of class, gender, ethnicity, sexuality, disability and age, so (at present) most people see discrimination on the basis of irrelevant qualifications as ‘natural’. That ‘naturalness’ is challenged in this paper and proposals are put forward to rectify this injustice.     

The effects of extraneous speech on visual vigilance performance of children

First-grade males performed a 30-min visual vigilance task under 5 conditions of auditory background stimulation. The 5 conditions consisted of (1) continuous conversation, in which subjects listened to a tape of conversation spliced so that there were no intervals of silence lasting longer than 3 sec; (2) continuous reverse, in which subjects heard the continuous conversation tape played in reverse; (3) intermittent conversation, in which subjects heard alternating segments of conversation and silence; (4) intermittent reverse, in which subjects heard alternating segments of reverse conversation and silence; and (5) silence control. Compared with silence or continuous stimulation, intermittent stimulation produced better detection regardless of whether or not it was meaningful. High achievers made more correct detections than low achievers, but only in the second and third time periods. Few subjects made errors of commission.     

The effects of performance-based school closure and restart on student performance

We study the effects of closing and restarting low-performing schools as charter schools in New Orleans and Baton Rouge. Using matched difference-in-differences identification with students in Louisiana, we estimate effects for the students who attended the treated schools at the time of treatment. We find positive and precise effects of closure/restart on elementary/middle school test scores, but no clear effects on high school graduation or college entry in New Orleans. However, in Baton Rouge high schools, the interventions reduced high school graduation by 11–15 percentage points. We also provide evidence about how and why these effects emerge. The variation in test score effects within and across cities is positively related to the increase in school value-added that treated students experienced and negatively related to student age/grade and the extent of student disruption. The effects of school closure and restart therefore depend, predictably, on policy design and implementation. This work builds on prior closure/restart research and helps explain the positive effects of the post-Katrina school reforms in New Orleans.     

The effects of group size on kindergarten children's listening comprehension performance

The present study assessed the effect of small, medium, and large group size on kindergarten children's listening comprehension. Approximately 120 children were divided by sex and randomly assigned to one of four groups which varied from one another only in size. To determine the children's entry listening comprehension skill level, subtests of four reading tests were administered to all children. Those children participating in one adult to one child instruction, one adult to seven or eight children instruction, and one adult to fifteen children instruction interacted daily for ten sessions with an instructor who posed specific comprehension questions, read a carefully selected piece of children's literature, then restated the comprehension questions to assess the children's understanding of the story. All responses were recorded on a pictorial answer sheet. Those children in the control group received no instruction. The children's exit level listening comprehension skills were reassessed by administering the same preinstruction subtests to all children immediately following the ten sessions. Group size was found to affect significantly the children's performance, with one to one instruction resulting in the greatest gains.     

The effects of maze-arm length on performance in the radial-arm maze

Rats trained in a 16-arm radial maze with arms half the standard length demonstrated extremely low, but above chance, choice accuracy (Experiment 1). Rats trained in a 12-arm maze with short arms demonstrated a substantially higher degree of adjacent-arm responding than did rats trained in the same maze with long maze arms and, when response stereotypy was disrupted by a forced-choice procedure, the short-arm group chose less accurately than the long-arm group (Experiment 2). In a 16-arm maze with 8 short arms and 8 long arms, there was a strong preference for short arms and no evidence for a difference in the ability to discriminate previously visited arms from unvisited arms as a function of arm length, as measured by a two-alternative forced-choice procedure (Experiment 3). These results are interpreted as indicating that arm length affects a choice criterion, with a relatively lax criterion being applied to shorter arms.     

The effects of school board consolidation and financing on student performance

Over the last 20 years, states and provinces have become increasingly involved in the financing and administration of elementary and secondary education. Local school boards, however, still retain control over key aspects of the provision of education. Historically, these boards were organized at the community level so as to meet the wants of the local community. Today, states and provinces have become more interested in consolidating school boards and moving to a more centralized funding scheme. Do these changes result in improved student achievement? This paper attempts to answer these questions by examining the school board consolidation and funding changes instituted by the province of Ontario. We differentiate the effects of the policy changes based on observed differences in the school boards prior to consolidation. We show that students in previously high wealth school boards perform worse after the policy change compared to students in previously low wealth school boards.