Virtual reality (VR) has seen increasing application in cognitive psychology in recent years. There is some debate about the impact of VR on both learning outcomes and on patterns of information access behaviors. In this study we compare performance on a category learning task between three groups: one presented with three-dimensional (3D) stimuli while immersed in the HTC Vive VR system (n = 26), another presented with the same 3D stimuli while using a flat-screen desktop computer (n = 26), and a third presented with a two-dimensional projection of the stimuli on a desktop computer while their eye movements were tracked (n = 8). In the VR and 3D conditions, features of the object to be categorized had to be revealed by rotating the object. In the eye tracking control condition (2D), all object features were visible, and participants’ gaze was tracked as they examined each feature. Over 240 trials we measured accuracy, reaction times, attentional optimization, time spent on feedback, fixation durations, and fixation counts for each participant as they learned to correctly categorize the stimuli. In the VR condition, participants had increased fixation counts compared to the 3D and 2D conditions. Reaction times for the 2D condition were significantly faster and fixation durations were lower compared to the VR and 3D conditions. We found no significant differences in learning accuracy between the VR, 3D, and 2D conditions. We discuss implications for both researchers interested in using VR to study cognition, and VR developers hoping to use non-VR research to guide their designs and applications.

Electroporation-based mono-gene therapy has received great interest in recent years but coadministration of different therapeutic genes for treatment of tumors has not been well explored. We hypothesize that electroporation is capable of delivering multiple genes that induce an additive or synergistic antitumor effect. To test this hypothesis, we used mice that were bearing SCCVII or TRAMP tumors. Established tumors with a diameter of 4-5 mm were injected with control plasmid DNA or plasmid DNA encoding B7.1, IL-12 or both via electroporation. Tumor regression, CTL activity and the level of B7.1, IL-12 and Stat1 expression were determined in both wild-type mice and in mice with a knockout of the Stat1 gene. Remarkably, a single coadministration of the plasmids that encoded IL-12 and B7.1 eradicated tumors in 80% of mice. The therapeutic effect was associated with high levels of endogenous B7.1 expression, activity of cytotoxic lymphocytes, and activation of Stat1. Both exogenous B7.1 and IL-12 were required for inducing a high level of Stat1 activation in tumors, which occurred through a mechanism that was independent of the host Stat1. Both stimulators were also required for inducing the strong cytotoxic lymphocyte activity and for increasing the level and extending the duration of endogenous B7.1 expression. We therefore propose a 2-signal stimulation model to explain the synergistic effect of the coadministration of IL-12 and B7.1 on the regression of the tumors. ' 2006 Wiley-Liss, Inc.

Active sensing theory is founded upon the dynamic relationship between information sampling and an observer's evolving goals. Oculomotor activity is a well studied method of sampling; a mouse or a keyboard can also be used to access information past the current screen. We examine information access patterns of StarCraft 2 players at multiple skill levels. The first measures are analogous to existing eye-movement studies: fixation frequency, fixation targets, and fixation duration all change as a function of skill, and are commensurate with known properties of eye movements in learning. Actions that require visual attention at moderate skill levels are eventually performed with little visual attention at all. This (a) confirms the generalizability of laboratory studies of attention and learning using eye movements to digital interface use, and (b) suggests that a wide variety of information access behaviors may be considered as a unified set of phenomena.

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In six sheep anaesthetised with ketamine blood was sampled from the jugular and femoral veins and the femoral artery at frequent intervals for 12 minutes following the intravenous administration of 5 or 10 mg/kg sodium thiopentone. Samples were also taken from cubital veins and radial arteries of five patients who received 5 mg/kg thiopentone. The plasma concentration of thiopentone was determined by an HPLC assay. The time course of plasma concentration of thiopentone showed considerable variation according to sampling site as well as variation between individuals. Such sampling site-dependent variation may result in the appearance of acute tolerance.