Behavioral variability is controlled by discriminative stimuli

Previous research has demonstrated that behavioral variability can be modified by reinforcers contingent on it, but there has been no convincing evidence of discriminative stimulus control over such variability. We therefore rewarded 20 rats for variable response sequences in the presence of one stimulus and provided equal rewards independently of sequence variability in the presence of a second stimulus. We found that sequence variability was significantly higher during the first stimulus than during the second, with the greatest difference occurring immediately following onset of the stimuli. Removing the discriminative stimuli caused levels of variability to converge. These experiments provide strong evidence that behavioral variability can be controlled by discriminative stimuli, which may be important for general theories of operant behavior and their applications.     

Memory for recent actions in the bottlenosed dolphin (Tursiops truncatus): Repetition of arbitrary behaviors using an abstract rule

Little is known about how animals represent their own actions in working memory. We investigated whether bottlenosed dolphins could recall actions they had recently performed and reveal those recollections using an abstract rule. Two dolphins were trained to respond to a specific gestural command by repeating the last behavior performed. Both dolphins proved to be able to repeat a wide variety of behaviors on command and were able to generalize the repeating rule to novel behaviors and situations. One dolphin was able to repeat all 36 behaviors she was tested on, including behaviors involving multiple simultaneous actions and self-selected behaviors. These results suggest that dolphins can flexibly access memories of their recent actions and that these memories are of sufficient detail to allow for reenactments. The repeating task can potentially be used to investigate short-term action and event representations in a variety of species.     

School-based bullying experiences as reflected by adults with visual impairments

The purpose of this study was to describe the reflections of adults with visual impairments regarding bullying experiences during their school-based education. An interpretative phenomenological analysis research approach was used and 11 participants (aged 20–35 years; seven women, four men) participated in this study. The sources of data were semi-structured audiotaped telephone interviews and reflective field notes. Thematic development was undertaken utilizing a three-step analytical process guided by the research approach. Based on the data analysis, three interrelated themes were constructed: (a) “It would be when they knew there weren't teachers watching”: bullying experiences in unowned and unstructured spaces; (b) “Going through the motions”: feelings about verbal, social, and physical victimization; and (c) “They had their own insecurities”: understanding the bullies and bystanders. The emerged themes provide a unique insight into the way in which those with visual impairments experienced bullying in schools and the meaning they ascribed to those experiences.     

Comparison of ergometer- and track-based testing in junior track-sprint cyclists. Implications for talent identification and development

Talent identification (TID) and talent development (TDE) programmes in track sprint cycling use ergometer- and track-based tests to select junior athletes and assess their development. The purpose of this study was to assess which tests are best at monitoring TID and TDE. Ten male participants (16.2 ± 1.1 year; 178.5 ± 6.0 cm and 73.6 ± 7.6 kg) were selected into the national TID squad based on initial testing. These tests consisted of two 6-s maximal sprints on a custom-built ergometer and 4 maximal track-based tests (2 rolling and 2 standing starts) using 2 gear ratios. Magnitude-based inferences and correlation coefficients assessed changes following a 3-month TDE programme. Training elicited meaningful improvements (80–100% likely) in all ergometer parameters. The standing and rolling small gear, track-based effort times were likely and very likely (3.2 ± 2.4% and 3.3 ± 1.9%, respectively) improved by training. Stronger correlations between ergometer- and track-based measures were very likely following training. Ergometer-based testing provides a more sensitive tool than track-based testing to monitor changes in neuromuscular function during the early stages of TDE. However, track-based testing can indicate skill-based improvements in performance when interpreted with ergometer testing. In combination, these tests provide information on overall talent development.     

Comparison of Most-to-Least Prompting to Flexible Prompt Fading for Children with Autism Spectrum Disorder

This study compared most-to-least prompting to flexible prompt fading for teaching four children with an autism spectrum disorder various expressive tasks. Using a parallel treatment design nested into a multiple probe design, researchers taught each participant how to expressively label six pictures with most-to-least prompting and six pictures with flexible prompt fading. The researchers evaluated effectiveness, maintenance, efficiency, and performance across both prompting conditions and across all participants. Results indicated that both prompting procedures were effective across all four participants. Results also indicated that flexible prompt fading led to a higher percentage of independent correct responding during teaching trials. For three of the participants, flexible prompt fading was also a more efficient procedure. Results were mixed in terms of maintenance across the four participants.     

National Evidence of the Impact of First-Year Online Enrollment on Postsecondary Students’ Long-Term Academic Outcomes

This study examines the influence of first-year online enrollment on the long-term academic outcomes of postsecondary students. Using a nationally representative sample and propensity score weighting, I find that enrolling in some online courses is associated with lower odds of dropping out of college. Additional results reveal a positive relationship between enrolling in some online courses and sub-baccalaureate indicators of long-term academic success, such as earning an associate’s degree and transferring from a community college to a 4-year institution.     

The Stigma of Tenure Denied: An Exploration of Individual and Institutional Implications

Research in Higher Education - Although tenure denial is a familiar feature of the faculty profession, the dearth of specific research on the subject indicates that it is a phenomenon not...     

God keep me a damned fool

This article appeared in the October 1994 issue of theDartmouth Alumni Magazine.