Observation and discrimination learning in the rat: Effects of stimulus substitution

Effects of prior observation of modeling performances upon learning simultaneous visual discriminations were studied in nine groups of rats. Stimulus patterns which had been positive (“Cued”) or negative (“Uncued”) for the model animal and novel stimuli were presented. Observers learned faster if discriminations required approach to, rather than avoidance of, the previously positive stimulus. Approach to the negative stimulus was acquired more rapidly only if the second stimulus was novel. Approaches to a substituted new stimulus combined with either of the previously viewed stimulus patterns required nearly twice the training needed for a similar response attachment when both stimuli were novel. Attentional changes appear to underlie the stimulus control exerted over the observer rat in instrumental learning situations.     

JOHN LOCKE: BETWEEN CHARITY AND WELFARE RIGHTS

In the past quarter century C. B. MacPherson's reading of Locke has enjoyed a wide appeal. We are all by now familiar with Locke as the ardent proponent of possessive individualism, with its accompanying acquisitive tendencies and egoism. To be sure, MacPherson's interpretation has not gone unopposed. Of late it has been challenged in all its fundamentals by the scholarly and ingenious work of James Tully. Far from seeing Locke as providing the theoretical underpinnings for unbridled capitalism, Tully puts forward the view that Locke was sympathetic to the possibility of radical redistributive measures. That is, that he was not in principle opposed to rights to welfare.     

The existence and role of retinotopic and spatiotopic forms of visual persistence

Current theoretical conceptualizations of visual persistence fail to address the issue of its functional role. Based on extant experimental data we tentatively identify two general types of visual persistence: one resides in activity along the afferent visual pathway and is retinotopically organized; the other resides at central levels and is spatiotopically organized. Moreover, whereas the former afferent persistence is eliminated via saccadic suppression mechanisms in order to separate successive, retinotopic frames of pattern information, the latter, central one, in contrast, is generated and enhanced via extraretinal signals accompanying saccades in order to preserve phenomenal continuity of a stable spatiotopic representation of the environment from one fixation to the next.     

Contraction,Infinitary Quantifiers,and Omega Paradoxes

Our main goal is to investigate whether the infinitary rules for the quantifiers endorsed by Elia Zardini in a recent paper are plausible. First, we will argue that they are problematic in several ways, especially due to their infinitary features. Secondly, we will show that even if these worries are somehow dealt with, there is another serious issue with them. They produce a truth-theoretic paradox that does not involve the structural rules of contraction.     

Bayesian inference for psychology. Part II: Example applications with JASP

Bayesian hypothesis testing presents an attractive alternative to p value hypothesis testing. Part I of this series outlined several advantages of Bayesian hypothesis testing, including the ability to quantify evidence and the ability to monitor and update this evidence as data come in, without the need to know the intention with which the data were collected. Despite these and other practical advantages, Bayesian hypothesis tests are still reported relatively rarely. An important impediment to the widespread adoption of Bayesian tests is arguably the lack of user-friendly software for the run-of-the-mill statistical problems that confront psychologists for the analysis of almost every experiment: the t-test, ANOVA, correlation, regression, and contingency tables. In Part II of this series we introduce JASP (http://www.jasp-stats.org), an open-source, cross-platform, user-friendly graphical software package that allows users to carry out Bayesian hypothesis tests for standard statistical problems. JASP is based in part on the Bayesian analyses implemented in Morey and Rouder’s BayesFactor package for R. Armed with JASP, the practical advantages of Bayesian hypothesis testing are only a mouse click away.     

Computerized cognitive training during physical inactivity improves executive functioning in older adults

The hippocampus is closely tied to spatial navigation, a central component in cognitive functioning, and critically involved in age-associated cognitive decline and dementia. This study evaluated a novel, cognitive computerized spatial navigation training (CSNT) program targeting the hippocampus, with expectation of mitigating possible cognitive decline with bed rest (BR). During a 14-day BR study with 16 healthy, older men (mean age = 60 ± 3, range = 55–65 years), half received CSNT for 12 days in 50-min sessions and half were controls (watching documentaries). This design uniquely controlled diet, sleep, and other personal and environmental activities. Although there were no cognitive declines in controls post-BR, CSNT participants demonstrated significant increases in executive/attention ability and processing speed, and continued spatial navigation testing showed improvement to 400 days post-BR. This intervention may prove useful to mitigate cognitive declines known to occur in long periods of immobilization and could have broader implications in protecting against age-related cognitive decline.     

Uterus Transplantation: The Ethics of Using Deceased Versus Living Donors

Research teams have made considerable progress in treating absolute uterine factor infertility through uterus transplantation, though studies have differed on the choice of either deceased or living donors. While researchers continue to analyze the medical feasibility of both approaches, little attention has been paid to the ethics of using deceased versus living donors as well as the protections that must be in place for each. Both types of uterus donation also pose unique regulatory challenges, including how to allocate donated organs; whether the donor / donor's family has any rights to the uterus and resulting child; how to manage contact between the donor / donor's family, recipient, and resulting child; and how to track outcomes moving forward.