The role of head movements in the discrimination of 2-D shape by blind echolocation experts

Similar to certain bats and dolphins, some blind humans can use sound echoes to perceive their silent surroundings. By producing an auditory signal (e.g., a tongue click) and listening to the returning echoes, these individuals can obtain information about their environment, such as the size, distance, and density of objects. Past research has also hinted at the possibility that blind individuals may be able to use echolocation to gather information about 2-D surface shape, with definite results pending. Thus, here we investigated people’s ability to use echolocation to identify the 2-D shape (contour) of objects. We also investigated the role played by head movements—that is, exploratory movements of the head while echolocating—because anecdotal evidence suggests that head movements might be beneficial for shape identification. To this end, we compared the performance of six expert echolocators to that of ten blind nonecholocators and ten blindfolded sighted controls in a shape identification task, with and without head movements. We found that the expert echolocators could use echoes to determine the shapes of the objects with exceptional accuracy when they were allowed to make head movements, but that their performance dropped to chance level when they had to remain still. Neither blind nor blindfolded sighted controls performed above chance, regardless of head movements. Our results show not only that experts can use echolocation to successfully identify 2-D shape, but also that head movements made while echolocating are necessary for the correct identification of 2-D shape.     

Competing stimulus assessments: A systematic review

The current review summarizes the literature on competing stimulus assessments (CSAs). CSAs are pretreatment assessments designed to systematically identify stimuli that reduce problem behavior (PB), ostensibly through reinforcer competition or substitution. We report on the participant characteristics, outcomes, and predictive validity of published CSAs that included (a) no-stimulus control trial(s), (b) test trials during which each stimulus was available singly and noncontingently, and (c) measurement of PB and stimulus engagement or contact. Results showed that CSAs have broad utility across a variety of topographies and functions of PB. In the majority of CSA applications for which extended analyses, or validations, were performed, stimuli shown to reduce PB during the CSA produced similar reductions during extended analysis. This was the case regardless of topography or function of PB, or whether the stimuli were assumed to be “matched” to the stimulation thought to be produced by PB. Implications for future research are discussed.     

Retracted: The Three-Step Theory of Suicide: An Independent Replication and Conceptual Extension

Retraction: Christopher R. Hagan PhD, Jennifer J. Muehlenkamp PhD, “The Three-Step Theory of Suicide: An Independent Replication and Conceptual Extension,” Suicide and Life-Threatening Behavior, Wiley, © American Association of Suicidology The above article, published online on 30 September 2019 in Wiley Online Library ( wileyonlinelibrary.com ), has been retracted by agreement between the authors, the journal Editor in Chief, Thomas Joiner, PhD, and John Wiley and Sons Ltd. The retraction has been agreed due to errors in variable calculation and a post-publication reviewer's concerns that some analyses did not accurately test the theoretical model. An updated version of this article will soon undergo review for publication at Suicide and Life-Threatening Behavior, and if accepted for publication, will be accompanied by an editorial from the Editor-in-Chief.     

A Sociobiological Analysis of Namesaking Patterns in 322 American Families1

A study of the naming patterns used for 648 children in 322 American families provided mixed support for a number of hypotheses that are derived from the propositions that namesaking (the naming of a child after another person) functions as advertisement of genetic kinship when it may be in doubt and as a strategy to procure future investment of resources from the father and other relatives. Males and second-born children with older sisters were more likely to be namesaked, and birth order was a significant predictor of the probability of being namesaked for males. First-borns were more likely to be named after a patrilineal relative, but there was no tendency for children born early in a marriage to be namesaked more frequently than children born after many years of marriage. Parents who themselves were namesaked were more likely to namesake their own children.     

Around the world,adolescence is a time of heightened sensation seeking and immature self‐regulation

The dual systems model of adolescent risk‐taking portrays the period as one characterized by a combination of heightened sensation seeking and still‐maturing self‐regulation, but most tests of this model have been conducted in the United States or Western Europe. In the present study, these propositions are tested in an international sample of more than 5000 individuals between ages 10 and 30 years from 11 countries in Africa, Asia, Europe and the Americas, using a multi‐method test battery that includes both self‐report and performance‐based measures of both constructs. Consistent with the dual systems model, sensation seeking increased between preadolescence and late adolescence, peaked at age 19, and declined thereafter, whereas self‐regulation increased steadily from preadolescence into young adulthood, reaching a plateau between ages 23 and 26. Although there were some variations in the magnitude of the observed age trends, the developmental patterns were largely similar across countries.