Jeffrey N. Weatherly

Delay Discounting of Different Commodities

ABSTRACT When outcomes are delayed, their value is decreased. Delay discounting is a much-studied topic because it is correlated with certain disorders (e.g., pathological gambling). The present study attempts to determine how people would delay discount a number of different commodities, ranging from money to dating partners to federal education legislation. Participants completed delay discounting tasks pertaining to 5 different commodities, with a different set of 5 commodities for 2 groups. Results showed that different commodities were often discounted differently. Both data sets were also subjected to factor analysis. A 2-factor solution was found for both, suggesting that there are multiple “domains” of commodities. This finding is of interest because it suggests that measuring delay discounting for one commodity within a particular domain of commodities will be predictive of how people discount other commodities within that domain but will not be predictive of how they discount commodities within another domain.

Satiety contributes little to within-session decreases in responding

Abstract Responding often increases to a peak and then decreases within experimental sessions when subjects respond during operant conditioning procedures. The present experiments tested three implications of the idea that “satiation” produces the late-session decreases in responding. In Experiment 1, the late-session decreases were not altered when the caloric density of the reinforcer changed. In Experiment 2, the late-session decreases were not altered by changing the subjects state of deprivation, or the amount of food they were intubated with before the session. In Experiment 3, the late-session decreases were not altered by changing the size of the reinforcer by a factor of 3. The decreases began earlier and were steeper when reinforcers were 5 times as large. These results indicate that satiation, as operationalized in these experiments, does not cause the late session decreases in responding. Satiation may alter these decreases if large amounts of reinforcement are delivered.

Within-session responding when different reinforcers are delivered in each half of the session

The present study investigated whether within-session responding was specific to the reinforcer currently being delivered and whether it was determined solely by retrospective factors. In four separate experiments, four rats pressed a lever on a multiple variable interval 60-s variable interval 60-s schedule during 60-min sessions. A different reinforcer (5% liquid sucrose or food pellets) was delivered in each half of the session. Rate of reinforcement in one half of the session varied across conditions. Response patterns in the second half of the session were unaffected by changes in the conditions of reinforcement of the other reinforcer in the first half of the session (specificity). Rate of responding was affected, however. The upcoming reinforcer influenced responding when sucrose was delivered in the first half of the session and food pellets were delivered in the second half, but not when their order was reversed. This effect makes contact with several other areas of research (e.g. behavioral contrast). They also suggest that the leading explanations for within-session changes in responding may be limited or incomplete.

On the contributions of responding and reinforcement to within-session patterns of responding

Operant responding may change systematically within experimental sessions even when the contingencies of reinforcement remain constant across the session. In two experiments, eight pigeons pecked a key for mixed grain delivered by variable interval or multiple variable interval schedules. Experiment 1 showed that changes in the rate at which reinforcers were delivered altered the within-session patterns even when the total amount of reinforcement presented per session was held constant. Experiment 2 showed that changing the overall rate of responding did not alter within-session response patterns. These results question the idea that within-session patterns of responding are produced by simple interpretations of satiation or fatigue. If within-session changes in responding were produced by satiation, then subjects receiving equal amounts of reinforcement should have shown similar within-session patterns of responding, but they did not (Experiment 1). If within-session changes were produced by fatigue, then the patterns should have differed when the overall response rate differed, but they did not (Experiment 2). The present study confirms that within-session patterns of responding are sensitive to changes in rate of reinforcement.

Comparing Delay Discounting Rates When Using the Fill-in-the-Blank and Multiple-Choice Methods

ABSTRACT Several methods have been devised to measure delay discounting. The present study recruited university students to complete a delay-discounting task involving five different outcomes (finding a dating partner, free cigarettes, winning

Providing Introductory Psychology Students Access to Lecture Slides via Blackboard 5: A Negative Impact on Performance

100,000, being owed

College Students Discount Money “Won” More Than Money “Owed”

100,000, and obtaining ones ideal body image) that was administered using either the fill-in-the blank (FITB) or multiple-choice (MC) method. Results showed that the different administration methods sometimes produced significantly different rates of discounting, the direction of which differed by outcome. Hyperbolic discounting and the area under the discounting curve were nearly always significantly correlated when the FITB method was used but were never significantly correlated when the MC method was used. Discounting across the five outcomes produced a two-factor solution when the FITB data were factor analyzed. The MC data were described by a one-factor solution. The present results illustrate that procedural variables have a potentially profound impact on delay-discounting data, and generalizing from studies on delay discounting should be done with caution until those variables are fully understood.

Within-session changes in responding during concurrent schedules that employ two different operanda

The present study investigated the impact of making lecture outlines available on-line via Blackboard 5 on exam performance of students enrolled in introductory psychology. Performance of students in a class with access to information on Blackboard was compared to that of students in a class without such access. These classes were held in successive semesters, but had the same instructor, teaching assistants, textbook, lectures, and exams. Results showed that, across the three exams, students in the course with access to information via Blackboard performed significantly poorer than did students in the class without access to it. Performance in the laboratory section of the course, in which Blackboard was not employed, did not differ between classes. Thus, despite several potential positive ramifications of allowing increased access to lecture information, the impact of such access was not positive. The decreased exam performance may have been the outcome of decreased lecture attendance due to access to lecture information outside of lecture and several measures are discussed which could potentially address this possibility. The present results should alert educators not to rush to introduce technology into their course without serious consideration of the potential positive and negative outcomes such an introduction might have.

Reinforcer value may change within experimental sessions

Evidence in the research literature indicates people may treat “won” money differently than they would their own money. The present study had a sample of 648 college students complete a delay-discounting task that involved the hypothetical monetary amounts of

On the determinants of induction in responding for sucrose when food pellet reinforcement is upcoming

1,000 or