Robert C. Beck

Test-retest reliability of a group-administered paper-pencil measure of delay discounting.

The purpose of this study was to determine the reliability of an easily administered paper-pencil temporal discounting task modeled loosely on the hypothetical money choice task (Rachlin, Raineri, & Cross, 1991). Our group-administered task used 2 descriptions of discounting, the slope constant (k) of the hyperbolic function V = A/(1 + kD) and the area under the curve (AUC). The task was initially administered to 387 (163 men, 188 women, and 35 unspecified gender) introductory psychology students in groups ranging in size from 15 to 45. Six weeks later, 299 students (131 men and 168 women) repeated the task in groups ranging from 15 to 30. At each test time, the data from participants who met specified discounting criteria (about 85%) were fit well with the hyperbolic function (mean r(2) = .90). The test-retest correlation for logk was r = .64; for AUC scores, it was r = .70, with a correlation of r = -.96 between logk and AUC scores at Test 1. The (dislike for) Cognitive Complexity and Cognitive Instability subscales of the Barratt Impulsivity Scales, Version 11, administered only at the retest correlated with k values (r = .20, p = .001, and r = .179, p = .003), and women discounted more than men (p < .001) at both test times. The results are discussed in terms of the utility of the procedure and a detailed comparison of k and AUC measures of discounting.

Mood-dependent memory for generated and repeated words: Replication and extension

Abstract Mood-dependent memory (MDM) has been difficult to demonstrate, but Eich and Metcalfe (1989) reported a strong effect with music-induced moods and learning of self-generated responses. Bower and Mayer (1989), however, could not obtain the MDM effect with self-generated responses. The present experiment attempted to replicate Eich and Metcalfe, but induced positive and negative moods with self-referent statements rather than music. Sixty-four subjects (32 males, 32 females) were randomly assigned in equal numbers to one of four mood conditions, same or opposite mood at learning and testing. At learning, immediately following mood induction subjects (Ss) generated 16 response words and 16 repeated words. Forty-eight hours later, Ss were given recall and recognition tests. For recall, there was a significant learn mood by test mood interaction (P < 0.0001), with greater recall for generated than repeated words (P < 0.0001). The interaction for repeated words approached significance (P = 0.07). For re...

Sucrose reinforcement thresholds for hungry, thirsty, and non-deprived rats

Sucrose reinforcement thresholds were determined for bar pressing. Hungry Ss showed lower thresholds than non-deprived Ss and thirsty Ss did not prefer sucrose at all.

Effects of Variations in Water Need and Incentive Concentration on Bar-Pressing

3 groups of 5 rats each were given daily bar-press training while 22.5 hr. water deprived. Each group always received the same reinforcement: 4%, 12%, or 36% sucrose. In counterbalanced order every S was given 5 different saline or water stomach loads, spaced at 1-wk. intervals. These were given an hour prior to regular training which followed as usual. Both water and saline loads depressed responding, and there was a significant interaction between loads and reinforcements. The only differential effect of sucrose reinforcements during training or testing came after a stomach load of 5% body weight of water.

Sucrose Preference Thresholds for Satiated and Water-Deprived Rats

16 female rats were given 4-min. drinking tests in a 2-choice situation, water vs either .16%, 32%, 64%, or 1.28% sucrose. All Ss were tested with all solutions while satiated and while 23 5-hr water deprived. The preference thresholds were found to be: satiated, .43% and deprived, 1.16%. The results are discussed in terms of hedonic theory.

Bitter and sweet saccharin preferences as a function of food deprivation.

16 rats were given 23-hr. tests with each of 2 low-concentration (sweet by human report) pairs of saccharin (.05% vs .15% and .05% vs .35%) and 2 high-concentration (bitter) pairs (1.15% vs 1.25% and 1.15% vs 1.45%). All Ss were tested under each condition while on ad lib. feeding and while on a 23-hr. food deprivation schedule. Results with the 2 low-concentration pairs showed the typical deprivation-concentration interaction, greatly increased intake for the higher concentration of a pair. There was also an interaction with the “bitter” pairs, due to Ss drinking more of the 1.15% concentration when food-deprived than when non-deprived.

Incentive properties of sucrose and saccharin under different deprivation conditions

Abstract In Expt 1 it was found that hungry rats developed a 100% preference for 8% sucrose over water in a maze-choice situation, whereas thirsty rats developed no preference. When deprivation conditions for the two groups were reversed the pattern of preference relations also reversed. In a 2nd experiment nondeprived rats developed a preference for either 8% sucrose or 0.2% saccharin over water while thirsty S s did not develop a preference for either of these over water. The results are discussed in terms of incentive theory.

ASSESSING CHILDREN'S RACIAL ATTITUDES VIA A SIGNAL DETECTION MODEL

Previous research indicated that, in relative choice situations, both Caucasian and Negro preschool children tend to associate positive evaluative adjectives with light-skinned human figures and negative evaluative adjectives with dark-skinned ones. The present study utilized a signal-detection model with figures presented singly so that response bias, as well as sensitivity to the color-signal, could be evaluated. 30 Caucasian and 30 Negro preschool children were given 48 trials on which either a dark-skinned or light-skinned figure was accompanied by a story containing a positive or a negative adjective and were asked if the story described the figure. Dark-skinned figures carried a negative “signal” for Ss of both races. While the light-skinned figure carried a positive signal for the Caucasian Ss, the evidence for Negro Ss was unclear. The data also showed strong acquiescent (“yea-saying”) response biases, i.e., the children tended to respond “yes” much more frequently than “no,” regardless of the type of adjective employed or the skin-color of the presented figure. It was concluded that the basic phenomena previously shown with the relative choice methodology can also be shown with the absolute judgment methodology of the signal-detection model.

Human judgments of stimuli associated with shock onset and termination

Single and dual stimuli were paired with electric shock in various temporal contingencies and were rated by Ss on the semantic differential The presence of a second stimulus strongly influenced judgments, to the extent that a stimulus paired with shock offset could be judged either “better” or “worse.” The results are interpreted according to adaptation level theory.

Thirsty rats do prefer sucrose solutions

In three experiments it was demonstrated that water-deprived rats preferred sucrose solutions to water or lower concentration sucrose within the first 5 min of a test period. The preferences were as great as those shown by food-deprived rats. An hypothesis is offered to explain the discrepancy between these results and the indiscriminate behavior of rats toward sucrose solutions in bar-pressing situations.