Preface: Historical research on archives and knowledge cultures: an interdisciplinary wave

Introduces the collection of articles collected in the special issue "Knowledge Cultures.”     

Response strength and temporal control in fixed-interval schedules

Pigeons responded in a two-component peak procedure in which the components differed in terms of reinforcement magnitude (Experiment 1), immediacy (Experiment 2), or probability (Experiment 3). The prediction of behavioral momentum theory that responding in the relatively richer component should be more resistant to change was tested by (1) presenting response-independent food in the intervals between components according to a variable-time (VT) schedule, (2) prefeeding, and (3) extinction. In all the experiments, peak location in baseline occurred earlier, relative to the schedule value in the richer component. Peak response rate was more resistant to change in the richer component during the VT and prefeeding tests, and change in peak rate was more sensitive to differential reinforcement than change in overall response rate. Changes in measures of performance on peak trials during the disruptor tests were partially consistent with predictions of the behavioral theory of timing. The results suggest that peak response rate provides a more sensitive index of resistance to change for fixed-interval schedules than does overall response rate and that reinforcement strengthens both peak responding and temporal control.     

The effects of time and practice upon culture assimilator trainingLos efectos del tiempo y la practica en el entrenamiento de asimiladores de culturaEffets du temps et de la pratique sur l'entrainement avec l'assimilateur culturel

The culture assimilator is a technique for training persons from one culture to better understand the behavior of persons from another culture. A laboratory test, using 35 white female college students, of an assimilator for teaching Whites about black culture revealed significant improvements in trained subjects' knowledge of black culture and in their enjoyment of an interpersonal interaction with black confederates. Support was found for the hypothesis that assimilator training heightens subjects' anxiety with regard to interpersonal encounters with members of the target culture, but that the anxiety decreases over time. Results suggest a small positive effect of a supportive practice interaction with a target culture member prior to the behavioral measures. Some of the attitude measures were significant in the hypothesized direction, but others were significant in the opposite direction. Possible causes and implications of these results are discussed.     

Human nonverbal discrimination of relative and absolute number

The nonverbal discrimination of relative and absolute number of sequential visual stimuli was investigated with humans in bisection, reproduction, and report tasks. Participants viewed a sequence of 40 red and black objects on each trial, randomly intermixed, and had to identify the number of red objects, which varied from 1 to 20. To prevent the use of a verbal-counting strategy, participants were required to name the objects as they appeared. The characteristics of human performance resembled those of pigeons in analogous procedures (Tan & Grace Learning and Behavior 38:408-417, 2010; Tan, Grace, Holland, & McLean Journal of Experimental Psychology 33:409-427, 2007): Average response number increased systematically with sample number, and bisection points were located at the arithmetic, not the geometric, mean. Additionally, in both the reproduction and report tasks, coefficients of variation decreased for values less than 6 but increased or remained constant for larger values, suggesting that different representations were used for small and large numbers.