Joint perceptual decision-making: a case study in explanatory pluralism.

Traditionally different approaches to the study of cognition have been viewed as competing explanatory frameworks. An alternative view, explanatory pluralism, regards different approaches to the study of cognition as complementary ways of studying the same phenomenon, at specific temporal and spatial scales, using appropriate methodological tools. Explanatory pluralism has been often described abstractly, but has rarely been applied to concrete cases. We present a case study of explanatory pluralism. We discuss three separate ways of studying the same phenomenon: a perceptual decision-making task (Bahrami et al., 2010), where pairs of subjects share information to jointly individuate an oddball stimulus among a set of distractors. Each approach analyzed the same corpus but targeted different units of analysis at different levels of description: decision-making at the behavioral level, confidence sharing at the linguistic level, and acoustic energy at the physical level. We discuss the utility of explanatory pluralism for describing this complex, multiscale phenomenon, show ways in which this case study sheds new light on the concept of pluralism, and highlight good practices to critically assess and complement approaches

Exploring the movement dynamics of deception

Both the science and the everyday practice of detecting a lie rest on the same assumption: hidden cognitive states that the liar would like to remain hidden nevertheless influence observable behavior. This assumption has good evidence. The insights of professional interrogators, anecdotal evidence, and body language textbooks have all built up a sizeable catalog of non-verbal cues that have been claimed to distinguish deceptive and truthful behavior. Typically, these cues are discrete, individual behaviors—a hand touching a mouth, the rise of a brow—that distinguish lies from truths solely in terms of their frequency or duration. Research to date has failed to establish any of these non-verbal cues as a reliable marker of deception. Here we argue that perhaps this is because simple tallies of behavior can miss out on the rich but subtle organization of behavior as it unfolds over time. Research in cognitive science from a dynamical systems perspective has shown that behavior is structured across multiple timescales, with more or less regularity and structure. Using tools that are sensitive to these dynamics, we analyzed body motion data from an experiment that put participants in a realistic situation of choosing, or not, to lie to an experimenter. Our analyses indicate that when being deceptive, continuous fluctuations of movement in the upper face, and somewhat in the arms, are characterized by dynamical properties of less stability, but greater complexity. For the upper face, these distinctions are present despite no apparent differences in the overall amount of movement between deception and truth. We suggest that these unique dynamical signatures of motion are indicative of both the cognitive demands inherent to deception and the need to respond adaptively in a social context

Back belt effect on physiological strain and perceived discomfort and exertion during a continuous asymmetric stoop lift task.

This research effort evaluated the effect of wearing an elastic back belt on physiological and perceived strain during a continuous, high-frequency, asymmetric stoop lift task. Specifically, this effort examined the effect of the elastic back belt on work pulse (WP), change in systolic blood pressure during work versus rest ($\Delta$SBP), change in diastolic blood pressure during work versus rest ($\Delta$DBP), lower left back discomfort (LBD), lower right back discomfort (RBD), rating of perceived exertion (RPE), and static lift strength (SLS). A weight of lift of 25% of SLS was continuously lifted and lowered for 120 cycles from a low-lying position in the 90-degree lateral plane to knuckle height in the sagittal plane. Subjects were not allowed to pivot the feet, which were maintained in the near straight-ahead position.The second experiment was performed with four non-conditioned male subjects. A 4-hour back belt tension adjustment session revealed that back belt setting from day-to-day was highly repeatable for the 5% SLS load and the 25% SLS load, but not for the 15% SLS load. The tension set for the 25% load was significantly greater than for the 5% load, but neither tension was significantly different from the tension set for the 15% load. The preferred tension did not sufficiently compress the vasculature of the abdomen or trunk nor restrict venous return or muscle perfusion. It was also shown that preferred belt tension varies with the instructions, the task conditions, and/or the method of tension measurement. Wearing the back belt resulted in a significantly higher $\Delta$DBP.The third experiment demonstrated that rest period length combined with a belt tension that did not restrict breathing (7.9 kg) did not significantly affect heart rate, SBP or DBP during rest. The preferred tensions set in the two belt tension adjustment trials at the 25% SLS load were highly correlated $(r=0.84, \ p=0.008).$ Wearing the back belt resulted in a significantly higher $\Delta$SBP $(F(1,6)=7.6, \ p=0.033).$ (Abstract shortened by UMI.)A series of three experiments was performed. The first experiment, performed with two young male subjects of average fitness, demonstrated that a rest period of 10 minutes was a sufficient period of rest prior to work. Belt wearing with a tension of 5.6 kg at all of the weight levels (5%, 15% and 25% SLS) resulted in a lower WP than without belt wearing

Assessing the Benefits of Public Research Within an Economic Framework: The Case of USDA's Agricultural Research Service

Evaluation of publicly funded research can help provide accountability and prioritize programs. In addition, Federal intramural research planning generally involves an institutional assessment of the appropriate Federal role, if any, and whether the research should be left to others, such as universities or the private sector. Many methods of evaluation are available, peer review—used primarily for establishing scientific merit—being the most common. Economic analysis focuses on quantifying ultimate research outcomes, whether measured in goods with market prices or in nonmarket goods such as environmental quality or human health. However, standard economic techniques may not be amenable for evaluating some important public research priorities or for institutional assessments. This report reviews quantitative methods and applies qualitative economic reasoning and stakeholder interviewing methods to the evaluation of economic benefits of Federal intramural research using three case studies of research conducted by USDA’s Agricultural Research Service (ARS). Differences among the case studies highlight the need to select suitable assessment techniques from available methodologies, the limited scope for comparing assessment results across programs, and the inherent difficulty in quantifying benefits in some research areas. When measurement and attribution issues make it difficult to quantify these benefits, the report discusses how qualitative insights based on economic concepts can help research prioritization.Agricultural Research Service, Federal intramural research, publicly funded research, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Productivity Analysis,

Local Dynamics in Decision Making: The Evolution of Preference within and across Decisions

Within decisions, perceived alternatives compete until one is preferred. Across decisions, the playing field on which these alternatives compete evolves to favor certain alternatives. Mouse cursor trajectories provide rich continuous information related to such cognitive processes during decision making. In three experiments, participants learned to choose symbols to earn points in a discrimination learning paradigm and the cursor trajectories of their responses were recorded. Decisions between two choices that earned equally high-point rewards exhibited far less competition than decisions between choices that earned equally low-point rewards. Using positional coordinates in the trajectories, it was possible to infer a potential field in which the choice locations occupied areas of minimal potential. These decision spaces evolved through the experiments, as participants learned which options to choose. This visualisation approach provides a potential framework for the analysis of local dynamics in decision-making that could help mitigate both theoretical disputes and disparate empirical results.Engineering and Applied Science