EFFECTS OF MORPHINE ON TEMPORAL DISCRIMINATION AND COLOR MATCHING: GENERAL DISRUPTION OF STIMULUS CONTROL OR SELECTIVE EFFECTS ON TIMING?

Discrepant effects of drugs on behavior maintained by temporal-discrimination procedures make conclusive statements about the neuropharmacological bases of timing difficult. The current experiment examined the possible contribution of a general, drug-induced disruption of stimulus control. Four pigeons responded on a three-component multiple schedule that included a fixed-interval 2-min, temporal discrimination, and color-matching component. Under control conditions, response rates and choice responses during the first two components showed evidence of control by time, and accuracy for color matching was high in the third component. Morphine administration flattened the distribution of fixed-interval responding and produced a general disruption of accuracy in the temporal-discrimination component, whereas accuracy in the color-matching component was relatively unaffected. Analysis of the psychophysical functions from the temporal-discrimination component indicated that morphine decreased accuracy of temporal discrimination by decreasing overall stimulus control, rather than by selectively affecting timing. These results suggest the importance of determining the neurophysiological bases of stimulus control as it relates to temporal discrimination.     

COMPATIBILISM EVOLVES?: ON SOME VARIETIES OF DENNETT WORTH WANTING

Abstract: I examine the extent to which Dennett's account in Freedom Evolves might be construed as revisionist about free will or should instead be understood as a more traditional kind of compatibilism. I also consider Dennett's views about philosophical work on free agency and its relationship to scientific inquiry, and I argue that extant philosophical work is more relevant to scientific inquiry than Dennett's remarks may suggest.     

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.     

DO ADJUSTING‐AMOUNT AND ADJUSTING‐DELAY PROCEDURES PRODUCE EQUIVALENT ESTIMATES OF SUBJECTIVE VALUE IN PIGEONS?

The current experiment examined whether adjusting-amount and adjusting-delay procedures provide equivalent measures of discounting. Pigeons' discounting on the two procedures was compared using a within-subject yoking technique in which the indifference point (number of pellets or time until reinforcement) obtained with one procedure determined the value of the corresponding variable in the yoked condition with the other procedure. Behavior on each procedure was well described by a hyperbolic discounting function. Results revealed no systematic differences in the degree of discounting as measured by the discounting rate parameter of the hyperbola in Experiment 1, which used 20-mg pellets. These results were replicated in Experiment 2 using smaller, 14-mg pellets, which potentially yield more precise measurement of indifference points on the adjusting-amount procedure. The finding that estimates of the k parameter in the hyperbolic discounting function obtained with one procedure did not differ systematically from estimates obtained from the same subjects with the other procedure represents strong support for the hypothesis that the same process underlies the discounting of delayed rewards on both adjusting-amount and adjusting-delay procedures.     

IF OUR GENES ARE FOR US,WHO CAN BE AGAINST US? THOUGHTS OF A PRAGMATIST ON SCIENCE AND MORALITY

Abstract. The philosopher Michael Ruse accounts for the difference between hypothetical and categorical imperatives, and thus the origin of distinctively moral obligations like that of altruism, in genetic terms. This is part of an attempt to develop a philosophy that takes Darwin seriously by substituting respectable scientific entities, specifically those of evolutionary biology, for suspect theological or philosophical ones, like God or the transcendental ego, as a basis for addressing philosophical questions. Pragmatists take Darwin seriously, but in a very different way from that proposed by Ruse. Darwin introduced a “logic” into the study of living things—including human beings, the human mind, and culture— that leads philosophers to ask new and different questions about morality rather than trying to supply new answers to the same old questions. This essay contrasts these two different ways of taking Darwin seriously for purposes of philosophy and claims certain advantages for the pragmatist way over Ruse's.     

HOW MUCH DO HIGH‐PERFORMANCE WORK PRACTICES MATTER? A META‐ANALYSIS OF THEIR EFFECTS ON ORGANIZATIONAL PERFORMANCE

Although there is growing evidence that high performance work practices (HPWPs) affect organizational performance, varying sample characteristics, research designs, practices examined, and organizational performance measures used has led extant findings to vary dramatically, making the size of the overall effect difficult to estimate. We use meta-analysis to estimate the effect size and test whether effects are larger for (a) HPWP systems versus individual practices, (b) operational versus financial performance measures, and (c) manufacturing versus service organizations. Statistical aggregation of 92 studies reveals an overall correlation that we estimate at .20. Also, the relationship is stronger when researchers examine systems of HPWPs and among manufacturers, but it appears invariant across performance measures. We use our findings as a basis to offer 4 suggestions intended to shape research practices such that future meta-analyses might answer today's emerging questions.     

THE EFFECTS OF THE QUESTION “WHAT DO YOU WANT?” ON MAND TRAINING OUTCOMES OF CHILDREN WITH AUTISM

Mands sometimes are taught using the question “What do you want?” as a supplement to the required features of the mand relation: an establishing operation and a related consequence. Although verbal prompts have been used during mand training, they also may result in undesirable stimulus control. However, no direct empirical evidence exists to support this concern. The purpose of the present study was to compare mand training with and without supplemental questions on acquisition rate and maintenance when those questions were no longer presented. The 2 training conditions did not differ substantially in their outcomes for 2 children with autism.     

CHALLENGE‐ORIENTED ORGANIZATIONAL CITIZENSHIP BEHAVIORS AND ORGANIZATIONAL EFFECTIVENESS: DO CHALLENGE‐ORIENTED BEHAVIORS REALLY HAVE AN IMPACT ON THE ORGANIZATION'S BOTTOM LINE?

Virtually all of the studies that have examined the relationship between organizational citizenship behaviors (OCBs) and unit or organizational effectiveness have focused on affiliation‐oriented as opposed to challenge‐oriented forms of OCB, and no study has examined the mechanisms through which OCBs influence unit or organizational effectiveness. Therefore, the purpose of this study is to examine the main and interactive effects that challenge‐oriented and affiliation‐oriented OCBs have on organizational effectiveness through their impact on workgroup task performance. Results from a sample of 150 limited‐menu restaurants showed that the relationship between challenge‐oriented OCBs and workgroup task performance has an inverted‐U shape and is moderated by affiliation‐oriented OCBs, and that workgroup task performance completely mediated the impact of challenge‐ and affiliation‐oriented OCBs (and their interaction) on organizational outcomes (i.e., sales dollars, profit as a percentage of sales, and employee turnover). Specifically, the findings showed that challenge‐oriented OCBs have a positive impact on workgroup task performance up to a point, and beyond that point only when certain enabling conditions (i.e., high levels of affiliation‐oriented OCBs) are present. Implications are discussed.