Unit price as a useful metric in analyzing effects of reinforcer magnitude.

In this paper, we applied the behavioral-economic concept of unit price to the study of reinforcer magnitude in an attempt to provide a consistent account of the effects of reinforcer magnitude on behavior. Recent research in the experimental analysis of behavior and in behavioral pharmacology suggests that reinforcer magnitude interacts with the schedule of reinforcement to determine response rate and total consumption. The utility of the unit-price concept thus stems from its ability to quantify this interaction as a cost-benefit ratio (i.e., unit price = characteristics of the schedule of reinforcement divided by magnitude of reinforcement). Research employing the unit-price concept has shown that as unit price increases, a positively decelerating function exists for consumption (i.e., a function with an increasingly negative slope, when plotted on log coordinates) and a bitonic function exists for response rate. Based on these findings, the present analysis applied the unit-price concept to those studies of reinforcer magnitude and drug self-administration that examined the effects of reinforcer magnitude on response rate using simple schedules of reinforcement (e.g., fixed-ratio schedule). This resulted in three findings: (a) Reinforcer-magnitude manipulations and schedule manipulations interact in a manner that can be quantified in terms of unit price as benefit and cost factors, respectively; (b) different reinforcer-magnitude manipulations are functionally interchangeable as benefit factors in the unit-price ratio; and (c) these conclusions appear warranted despite the differences in reinforcers (food or drug), species (dogs, monkeys, or rats), and schedules (interval or ratio), and despite the fact that these studies were not designed for a unit-price analysis. In methodological terms, these results provide further evidence that employing the unit-price concept is a parsimonious method for examining the effects of reinforcer magnitude. In theoretical terms, these results suggest that a single process may underlie the effect of combined reinforcer-magnitude and schedule manipulations.     

TEMPORAL CONTROL ON INTERVAL SCHEDULES: WHAT DETERMINES THE POSTREINFORCEMENT PAUSE?

On fixed-interval or response-initiated delay schedules of reinforcement, the average pause following food presentation is proportional to the interfood interval. Moreover, when a number of intervals of different durations occur in a programmed cyclic series, postreinforcement pauses track the changes in interval value. What controls the duration of postreinforcement pauses under these conditions? Staddon, Wynne, and Higa (1991), in their linear waiting model, propose control by the preceding interfood interval. Another possibility is that delay to reinforcement, signaled by a key peck and/or stimulus change, determines the subsequent pause. The experiments reported here examined the role of these two possible time markers by studying the performance of pigeons under a chained cyclic fixed-interval procedure. The data support the linear waiting model, but suggest that more than the immediately preceding interfood interval plays a role in temporal control.     

Some relationships between the information function of IRT and the signal/noise ratio and reliability coefficient of classical test theory

It is shown that IRTs information function for an item is functionally related to local versions of classical test theories' signal/noise ratio and reliability coefficient.     

Coming to terms with stress: Effects of stress location in sentence processing

The purpose of this research was to determine the role of syllabic stress in language processing during the early on-line processing of speech and later in the representation of a sentence in memory. Experiment 1 used a syllable monitoring task while Experiment 3 used a probe task in which subjects heard a sentence and then were asked to determine whether a probe syllable had occurred in the sentence. In the monitoring task, stressed syllables were detected more rapidly in word-initial position, but unstressed syllables were detected more rapidly in word-final position. Stress facilitation in initial syllables was strongly related to high relative F0, but not to changes in perceived vowel quality as assessed in Experiment 2. This pattern is interpreted as evidence that lexical stress is used on-line to guide lexical access and/or lexical segmentation. The probe task of Experiment 3 showed stress facilitation in both positions, indicating that stress is independently retained in the postperceptual representation of a sentence.The research reported in this paper was supported by grant 80-0416 to Harvard University (Peter C. Gordon, Principal Investigator) from the Air Force Office of Scientific Research Life Sciences Directorate. We thank Chris Thurber for his extensive and competent assistance in testing subjects and making acoustic measurements, and Jay Rueckl for comments on an earlier version of this paper     

Dynamic spatial performance and general intelligence

A computerized video-game-like dynamic spatial ability measure and a paper-and-pencil group test of intelligence were administered to 94 university students. The purpose of the study was threefold: (a) to evaluate the reliability of the dynamic spatial measure; (b) to investigate the extent to which the dynamic spatial measure is saturated with variance associated with traditional measures of fluid and crystallized intellectual ability; and (c) to explore the possibility that dynamic computer based performance measures define factors that are distinct from those associated with traditional paper-and-pencil measures. The number of times the participant hit a moving target served as the dependent variable for the dynamic spatial measure. Number of hits proved to be correlated with Performance IQ, but was not significantly correlated with Verbal IQ. Maximum likelihood factor analysis revealed that the dynamic spatial measure did not load substantially on a factor of general intellectual ability but provided additional evidence that it is related to a performance component.     

Why Religion Should Be an Integral Part of Public School Education

Studies of classroom climates completed in the 1980s concluded that religion, even broadly defined, is seldom discussed in public schools. This situation is inconsistent with important precedents of our society, and therefore, public schools ought rightly to provide opportunities for students to discuss religion, broadly defined, in a scholarly fashion throughout their normal school routine. This article delineates 10 logical and cultural underpinnings for religious instruction in public schools.     

Attitude change following persuasive communication: Integrating Social Judgment Theory and the Elaboration Likelihood Model

An experiment was conducted to examine the influence of the perceived extremity of a message and motivation to elaborate upon the process of persuasion. The first goal was to test a model of attitude change relating Social Judgment Theory to the Elaboration Likelihood Model. The second objective was to develop an instrument to measure attitude structure (latitudes of acceptance, non-commitment, and rejection) that allowed for a more refined assessment of the discrepancy between the position advocated in a message and the recipient's initial attitude. The main dependent variable was the attitude towards the use of automobiles in relation to environmental issues. Subjects were confronted with a message located in their own latitude of acceptance, rejection or non-commitment. Shortly after, a second measurement of attitude took place. The results showed that messages within the latitudes of non-commitment gave rise to the greatest attitude change. The data support the susceptibility hypothesis that subjects elaborate messages mainly in the latitude of non-commitment.