The touchscreen cognitive testing method for rodents: how to get the best out of your rat

The touchscreen testing method for rodents is a computer-automated behavioral testing method that allows computer graphic stimuli to be presented to rodents and the rodents to respond to the computer screen via a nose-poke directly to the stimulus. The advantages of this method are numerous; however, a systematic study of the parameters that affect learning has not yet been conducted. We therefore sought to optimize stimuli and task parameters in this method. We found that when parameters were optimized, Lister Hooded rats could learn rapidly using this method, solving a discrimination of two-dimensional stimuli to a level of 80% within five to six sessions lasting ~30 min each. In a final experiment we tested both male and female rats of the albino Sprague-Dawley strain, which are often assumed to have visual abilities far too poor to be useful for studies of visual cognition. The performance of female Sprague-Dawley rats was indistinguishable from that of their male counterparts. Furthermore, performance of male Sprague-Dawley rats was indistinguishable from that of their Lister Hooded counterparts. Finally, Experiment 5 examined the ability of Lister Hooded rats to learn a discrimination between photographic stimuli. Under conditions in which parameters were optimized, rats were remarkably adept at this discrimination. Taken together, these experiments served to optimize the touchscreen method and have demonstrated its usefulness as a high-throughput method for the cognitive testing of rodents.     

The effects of curvature on haptic judgments of extent in sighted and blind people

A series of experiments was carried out to examine the effect of curvature on haptic judgments of extent in sighted and blind individuals. Experiment 1 showed that diameters connecting the endpoints of semicircular lines were underestimated with respect to straight lines, but failed to show an effect of visual experience on length judgments. In experiment 2 we tested are lengths. The effects of curvature on perceived path length were weaker, but were still present in this experiment. Visual experience had no effect on path length judgments. Another experiment was performed to examine the effect of repeated tracing (1, 5, 9, or unlimited number of traces) on judgments of the lengths of straight lines and diameters of semicircles. Judgments of extent were more accurate when subjects engaged in larger numbers of traces. There was no effect of number of traces on curve-height judgments, suggesting that subjects were not using height estimates to judge diameters of semicircles. In a further experiment we tested the effect of number of traces on curves that varied in height. Restricting subjects to a single trace magnified the effect of path length on judgments of the distance between the endpoints of curves. Additional experiments showed that curvature effects on diameter judgments were not eliminated when stimuli were in the frontal plane or when the curves were explored with the use of two hands. Arm support had no effect on judged length in experiment 7. A final experiment showed a robust horizontal vertical illusion in haptic perception of convex curves, with overestimation of the heights of the curves compared with their widths. The practical and theoretical implications of the results are discussed.     

Reasoning under Scarcity

Practical deliberation consists in thinking about what to do. Such deliberation is deemed rational when it conforms to certain normative requirements. What is often ignored is the role that an agent's context can play in so-called ‘failures’ of rationality. In this paper, I use recent cognitive science research investigating the effects of resource-scarcity on decision-making and cognitive function to argue that context plays an important role in determining which norms should structure an agent's deliberation. This evidence undermines the view that the norms of ‘ideal’ rationality are necessary and universal requirements on deliberation. They are a solution to the problems faced by cognitively limited agents in a context of moderate scarcity. In a context of severe scarcity, the problems faced by cognitively limited agents are different and require deliberation structured by different norms. Agents reason rationally when they use the norms best suited to their context and cognitive capacities.     

Implementation of a Suicide Nomenclature within Two VA Healthcare Settings

Suicide and suicide attempts are significant issues for military, Veterans Affairs (VA), and civilian healthcare systems. The lack of uniform terms related to self-directed violence (SDV) has inhibited epidemiological surveillance efforts, limited the generalizability of empirical studies of suicide and non-lethal forms of SDV, and complicated the implementation of evidence-based assessment and treatment strategies for individuals with suicidal thoughts and/or behaviors. The Department of Veterans Affairs recently adopted the Centers for Disease Control and Prevention’s (CDC) SDV Classification System (SDVCS). This paper describes an implementation study of the SDVCS in two VA Medical Centers. The Veterans Integrated Service Network (VISN) 19 Mental Illness Research, Education and Clinical Center (MIRECC) training program for the SDVCS, including the SDVCS Clinical Tool (CT), will be discussed. Although preliminary data suggest that the CT and SDVCS are generally perceived as being acceptable and useful, further work will likely be required to facilitate widespread adoption. Potential next steps in this process are presented.     

Acute nonhypothermic exposure to cold impedes motor skill performance in video gaming compared to thermo-neutral and hot conditions

The study examined whether or not acute exposure to unfamiliar hot or cold conditions impairs performance of highly skilled coordinative activities and whether prior physical self-efficacy beliefs were associated with task completion. Nineteen volunteers completed both Guitar Hero and Archery activities as a test battery using the Nintendo Wii console in cold (2 degrees C), neutral (20 degrees C), and hot (38 degrees C) conditions. Participants all completed physical self-efficacy questionnaires following experimental familiarization. Performances of both Guitar Hero and Archery significantly decreased in the cold compared with the neutral condition. The cold trial was also perceived as the condition requiring both greater concentration and effort. There was no association between performance and physical self-efficacy. Performance of these coordinative tasks was compromised by acute (nonhypothermic) exposure to cold; the most likely explanation is that the cold condition presented a greater challenge to attentional processes as a form of environmental distraction.