Concurrent visual search and time reproduction with cross-talk

Previous experiments indicate that humans can reproduce a time interval while concurrently searching a visual display presented near the beginning of the reproduced interval (Fortin, C., Rousseau, R., Bourque, P. & Kirouac, E. (1993). Time estimation and concurrent nontemporal processing: Specific interference from short-term-memory demands. Perception & Psychophysics, 53, 536-548.). In the earlier experiments, reproduced intervals were either insensitive to or shortened with increasing duration of visual search, suggesting that reproduction and search proceeded concurrently but sometimes with cross-talk. Here we test concurrency of time reproduction and visual search using a different methodology than before. Assuming the underlying mental processes are in a critical path network, factors selectively influencing concurrent processes are predicted to produce certain patterns in response time means and, through recent developments, certain patterns in cumulative distribution functions. Processes in an experiment were influenced by manipulating four factors, the time interval to be produced, stimulus onset asynchrony, display size, and target presence/absence. Patterns in response times provide evidence for concurrent time reproduction and visual search. However, a prediction based on selective influence failed in a manner suggesting the presence of cross-talk produced by a filled interval illusion.     

Pertinence Generation in Radiological Diagnosis: Spreading Activation and the Nature of Expertise

An empirical study of human expert reasoning processes is presented. Its purpose is to test a model of how a human expert's cognitive system learns to detect, and does detect, pertinent data and hypotheses. This process is called pertinence generation. The model is based on the phenomenon of spreading activation within semantic networks. Twenty-two radiologists were asked to produce diagnoses from two very difficult X-ray films. As the model predicted, pertinence increased with experience and with semantic network integration. However, the experts whose daily work involved explicit reasoning were able, in addition, to go beyond and to generate more pertinence. The results suggest that two qualitatively different kinds of expertise, basic and super, should be distinguished. A reinterpretation of the results of Lesgold et al. (1988) is proposed, suggesting that apparent nonmonotonicities in performance are not representative of common radiological expertise acquisition but result from the inclusion of basic and super expertise on the same curve.     

Reentry as Experienced by Women in Jail: Advocating for Change

We conducted a phenomenological study with 35 women in a substance abuse treatment jail program about their lived experiences in preparing for reentry. The women addressed their past, the needs of their families, and education of criminal justice personnel, providers, and the whole citizenry. The women advocated for effective reentry practices.     

To count or not to count: the effect of instructions on expecting a break in timing

When a break is expected during a time interval production, longer intervals are produced as the break occurs later during the interval. This effect of break location was interpreted as a result of distraction related to break expectancy in previous studies. In the present study, the influence of target duration and of instructions about chronometric counting strategies on the break location effect was examined. Using a strategy such as chronometric counting enhances the reliability of temporal processing, typically in terms of reduced variability, and could influence how timing is affected by break expectancy, especially when relatively long target durations are used. In two experiments, results show that time productions lengthened with increasing value of break location at various target durations and that variability was greater in the no-counting than in the counting instruction condition. More important, the break location effect was stronger in the no-counting than in the counting instruction condition. We conclude that chronometric counting orients attention toward timing processes, making them less likely to be disrupted by concurrent nontemporal processes.     

Word frequency and the mixed-list paradox in immediate and delayed serial recall

In free recall tasks, when low- and high-frequency items are mixed within the to-be-remembered lists, the usual recall advantage found for high-frequency words is eliminated or reversed. Recently, this mixedlist paradox has also been demonstrated for short-term serial recall (Hulme, Stuart, Brown, & Morin, 2003). Although a number of theoretical interpretations of this mixed-list paradox have been proposed, researchers have also suggested that it could simply be a result of participant-controlled strategies (M. J. Watkins, LeCompte, & Kim, 2000). The present study was designed to assess whether this explanation could be applied to immediate and delayed serial recall. The results showed that high-frequency words were recalled better than low-frequency words in pure lists, but that this effect was eliminated in mixed lists, whether they were given under intentional or incidental learning conditions. This pattern suggests that the mixed-list paradox cannot be explained by participant-controlled strategies.     

The use of moral dilemmas for teaching agricultural engineers

Agricultural engineers’ jobs are especially related to sustainability and earth life issues. They usually work with plants or animals, and the aim of their work is often linked to producing food to allow people to improve their quality of life. Taking into account this dual function, the moral requirements of their day-to-day professional practice are arguably greater than those of other professions. Agricultural engineers can develop their ability to live up to this professional responsibility by receiving ethical training during their university studies, not only by taking courses specifically devoted to ethics, but also by having to deal with moral questions that are integrated into their technical courses through a program of Ethics Across the Curriculum (EAC). The authors feel that a suitable pedagogical technique for achieving this goal is the use of moral dilemmas, following Kohlberg’s theory of levels of morality (1981), with the final objective of attaining a post-conventional level. This paper examines the possibilities and limitations of using moral dilemmas as a pedagogical technique for training agricultural engineers. The cases, discussions, and evaluation used in the Agricultural Engineering Department of the Technical University of Valencia (Spain) are also presented. An earlier version of this paper was presented at the 2005 conference, Ethics and Social Responsibility in Engineering and Technology, Linking Workplace Ethics and Education, co-hosted by Gonzaga University and Loyola Marymount University, Los Angeles, CA, USA, 9–10 June 2005.     

Estimating averages from distributions of tone durations

We examined whether estimating average duration was influenced by the distribution peak location. We presented participants with samples of various tone durations and then presented comparison tone durations. Participants judged whether each comparison duration was longer than the average sample duration. Estimates of the averages were inferred from the psychophysical functions. The durations were sampled from three distributions: one positively skewed, one symmetric, and one negatively skewed. In Experiment 1, every participant was presented with every distribution. Estimates of the averages were unbiased for the symmetric distribution but were biased toward the long tail of each skewed distribution. This would occur if participants combined the sample to be judged with the previous, irrelevant samples, or with the comparison durations. In Experiment 2, each participant was presented with samples from only one of the distributions. Estimates of the averages were still biased toward the long tails of the skewed distributions. This would occur if participants combined the sample to be judged with the comparison durations, which were the same for the three distributions. In Experiment 3, each participant was presented with only one distribution, and each distribution was tested with its own comparison durations, selected as percentiles from the distribution. The estimates were accurate for the smallest population mean (positively skewed distribution) but underestimated the larger means. These results could be explained by subjective shortening of the durations in memory, with a simple equation from scalar timing theory. This equation correctly predicted two results: The estimated averages were a linear function of the stimulus means, and the variances were a linear function of the squared stimulus means. Neither prediction was dependent on the skewness of the stimulus durations.