Response-time dynamics: Evidence for linear and low-dimensional nonlinear structure in human choice sequences

Response time (RT) is a commonly used measure of cognitive performance, which is usually characterized as stochastic. However, useful information may be hidden in the apparently random fluctuations of RT. Dynamical systems analysis techniques allow an exploration of the alternative hypothesis that RT fluctuations are deterministic, albeit in a complex manner. We applied careful task construction and noise-reduction and surrogate series tests to show that RT series from a forced-pace serial response-time task have low-dimensional chaotic characteristics. In Experiment 1, 80% of subjects' filtered RT series had low dimensionality, sensitive dependence on initial conditions, spectra close to 1/ f , and stable attractor geometry across sessions. In Experiment 2, we showed that the size of the inter-stimulus interval (ISI) determined the number of subjects with low-dimensional chaotic series. A small ISI caused 100% of subjects to respond in the chaotic regime, whereas only 25% had a low-dimensional chaotic RT component when the ISI was large. We argue that demanding task requirements cause a reduction in the dimensionality of the dynamics, producing RT fluctuations that may reflect a response strategy for controlling RT.     

Correction to: Lambek Calculus with Conjugates

Studia Logica - We, the authors, would like to thank Guillaume Aucher for informing us of his “Displaying Updates in Logic”, published in the Journal of Logic and Computation,...     

Semi De Morgan Logic Properly Displayed

Studia Logica - In the present paper, we endow semi De Morgan logic and a family of its axiomatic extensions with proper multi-type display calculi which are sound, complete, conservative, and...     

The effects of hand and direction parameter preknowledge on choice reaction times

The two studies undertaken investigated how reaction times are affected by preknowledge concerning hand and direction parameters, and the order in which these data are disclosed. In the first experiment, preknowledge was manipulated by selecting 2-CRT pairs which had either a common hand or direction component. Reaction signal information content (as defined by the number of unknown response parameters) was controlled, but no parameter differences emerged. When parameter order was manipulated by sequential precuing, the ‘hand then direction’ order conferred a significant advantage. Motor preparation and response selection explanations for this effect are considered. Various difficulties with the paradigms used are discussed, including those of distinguishing between response selection and motor programming contributions, controlling and inferring the strategies adopted by subjects, and defining task difficulty. The prospects for independently fostering either response identification or motor preparation by means of an appropriate selection of precues are also discussed.     

Applying a longitudinal tracer methodology to evaluate complex interventions in complex settings

Long-running multi-faceted intervention studies are particularly problematic in large complex organizations where traditional methods prove too resource intensive and can yield inaccurate and incomplete findings. This paper describes the first use of, longitudinal tracer methodology (LTM), a realist approach to evaluation, to examine the links between multiple complex intervention activities (processes) and their outcomes on a construction megaproject. LTM is especially useful when the researcher has little control over intervention delivery but has evidence drawn from multiple sources to evaluate the intervention activities effects over time. This methodology has rarely been deployed in complex organizational settings and not on a construction megaproject. This paper presents a case study of its use over a period of three years, on 24 construction sites forming London’s Thames Tideway Tunnel (Tideway) megaproject. The study examines the “transformational” power of occupational safety and health (OSH) interventions across the multiple organizations and supply chains in the megaproject. The study shows how the method can be adapted in-flight to accommodate shifting lines of inquiry as the intervention activities progress and change. This feature along with its resource-efficient operation, make it an attractive option where interventions are likely to have differential effects across multiple sites of enactment.     

When the party for some becomes a problem for others: the effect of perceived secondhand consequences of drinking behavior on drinking norms

The authors examined the influence of fraternity men's expectancies regarding secondhand consequences of excessive drinking behavior on normative standards regarding alcohol use and consumption levels. Participants were 381 men from 26 chapters of 2 national fraternities. One organization participated in a brief intervention involving discussion of secondhand consequences of excessive drinking. Immediate influence of the intervention on perceived secondhand consequences of alcohol use was assessed using a posttest-only, randomized groups design. Results supported a hypothesized measurement model with 1 overall secondhand consequence expectancy construct and 4 subfactors: (a) Noise Disruptive of Sleep and Study, (b) Violence, (c) Sexual Assault, and (d) Property Damage. Cross-sectional analysis at the chapter and individual levels demonstrated that secondhand expectancies had an indirect effect on alcohol consumption, mediated by personal consumption standards for limiting alcohol consumption. The intervention had an effect on secondhand expectancies. Findings suggest that interventions with intact groups can increase secondhand expectancies regarding excessive drinking and may lead to a reduction in excessive alcohol consumption.     

Free the animals? Investigating attitudes toward animal testing in Britain and the United States

In this study, 185 British and 143 American undergraduates completed a battery of tests that measured attitudes toward animal testing and various individual difference variables. Attitudes toward animal testing factored into two interpretable factors: general attitudes toward animal testing, and animal welfare and conditions of testing. Overall, there was support for animal testing under the right conditions, although there was also concern for the welfare of animals and the conditions under which testing takes place. There were small but significant national difference on both factors (with Americans more positive about testing and less positive about animal welfare), and a significant sex difference on the first factor (women were more negative about testing). Correlation and regression analyses showed that there were few significant individual difference predictors of both factors. These results are discussed in relation to past and future work on attitudes toward animal testing.