Water can induce better spatial memory performance than food in radial maze learning by rats1

Abstract: Two experiments were carried out to test the differential effects of hunger and thirst on memory performance. In Experiment 1, two groups of rats were exposed to an original radial‐maze task and then to a 30‐min retention‐memory task. The food‐deprived group completed the original task more quickly than the water‐deprived group, but the thirsty group mastered the memory task more quickly than the hungry group (p < 0.01). In Experiment 2, deprivation conditions were changed from the original to the memory task. The food‐water group completed the memory task more rapidly than the water‐food group (p < 0.05). Thirst proved to constitute a more favorable condition for retention‐memory learning. The applicability of several theories is discussed.     

Measuring perceived ceiling height in a visual comparison task

When judging interior space, a dark ceiling is judged to be lower than a light ceiling. The method of metric judgments (e.g., on a centimetre scale) that has typically been used in such tasks may reflect a genuine perceptual effect or it may reflect a cognitively mediated impression. We employed a height-matching method in which perceived ceiling height had to be matched with an adjustable pillar, thus obtaining psychometric functions that allowed for an estimation of the point of subjective equality (PSE) and the difference limen (DL). The height-matching method developed in this paper allows for a direct visual match and does not require metric judgment. It has the added advantage of providing superior precision. Experiment 1 used ceiling heights between 2.90?m and 3.00?m. The PSE proved sensitive to slight changes in perceived ceiling height. The DL was about 3% of the physical ceiling height. Experiment 2 found similar results for lower (2.30?m to 2.50?m) and higher (3.30?m to 3.50?m) ceilings. In Experiment 3, we additionally varied ceiling lightness (light grey vs. dark grey). The height matches showed that the light ceiling appeared significantly higher than the darker ceiling. We therefore attribute the influence of ceiling lightness on perceived ceiling height to a direct perceptual rather than a cognitive effect.     

Influence of cognitive stance and physical perspective on subjective and autonomic reactivity to observed pain and pleasure: An immersive virtual reality study

Observing others’ pain may induce a reaction called personal distress that may be influenced by top-down (imagine self or other in pain, i.e., self- vs other-oriented stance) and bottom-up (physical perspective of those who suffer, i.e., first vs third person perspective- 1PP vs 3PP) processes. The different contributions of these processes have not been teased apart. By capitalizing on the power of Immersive Virtual Reality, we explored how behavioural (subjective ratings) and physiological reactivity (skin conductance reactivity, SCR) to pain and pleasure delivered to an avatar was influenced by Cognitive stance and Physical perspective. Taking an Other-Oriented stance leads to attributing higher congruent valence (i.e. pain rated as unpleasant and pleasure as pleasant) and intensity to the stimuli and induces reduced SCR. Ownership over the virtual limb was maximal in 1PP where physiological reactivity to the stimuli was comparable. Our results highlight different components underpinning reactivity to pain and pleasure.     

DeLanda’s ontology: assemblage and realism

Manuel DeLanda is one of the few admitted realists in present-day continental philosophy, a position he claims to draw from Deleuze. DeLanda conceives of the world as made up of countless layers of assemblages, irreducible to their parts and never dissolved into larger organic wholes. This article supports DeLanda’s position as a refreshing new model for continental thought. It also criticizes his movement away from singular individuals toward disembodied attractors and topological structures lying outside all specific beings. While endorsing DeLanda’s realism, I reject his shift from the actual to the virtual.

Formalization of Reliability Block Diagrams in Higher-order Logic

Reliability Block Diagrams (RBDs) allow us to model the failure relationships of complex systems and their sub-components and are extensively used for system reliability, availability and maintainability analyses. Traditionally, these RBD-based analyses are done using paper-and-pencil proofs or computer simulations, which cannot ascertain absolute correctness due to their inaccuracy limitations. As a complementary approach, we propose to use the higher-order logic theorem prover HOL to conduct RBD-based analysis. For this purpose, we present a higher-order logic formalization of commonly used RBD configurations, such as series, parallel, parallel-series and series-parallel, and the formal verification of their equivalent mathematical expressions. A distinguishing feature of the proposed RBD formalization is the ability to model nested RBD configurations, which are RBDs having blocks that also represent RBD configurations. This generality allows us to formally analyze the reliability of many real-world systems. For illustration purposes, we formally analyze the reliability of a generic Virtual Data Center (VDC) in a cloud computing infrastructure exhibiting the nested series-parallel RBD configuration.     

Effect of exposure to lithium-paired or amphetamine-paired saccharin solution on open arm avoidance in an elevated plus maze

Recent evidence suggests that drug-induced conditioned taste avoidance may be mediated by conditioned fear (e.g., Parker, 2003). The experiments reported here evaluated the effect of exposure to a drug-paired flavor on open arm exploration in an elevated plus maze (EPM), a measure of fear. When rats were tested on a familiar (trial 2) EPM, but not on a novel (trial 1) EPM, prior exposure to a lithium-paired saccharin solution enhanced open arm activity relative to saline-paired saccharin. On the other hand, when rats were exposed to lithium-paired saccharin during plus maze exposure, they displayed suppressed open arm activity relative to unpaired controls when tested in a familiar maze. The pattern of results was specific to the conditional affective properties of the taste, because exposure to unconditional sickness produced by administration of lithium, and unconditionally unpalatable quinine solution did not produce this pattern. These results were interpreted in terms of the opponent process model of motivation; that is, exposure to a lithium-paired flavor elicits conditioned fear which is immediately followed by conditioned relief when the exposure is terminated. On the other hand, exposure to an amphetamine-paired flavor either before or during EPM testing enhanced open arm exploration. Since the strength of taste avoidance did not differ among amphetamine and lithium conditioned rats, these results provide further evidence that the nature of a saccharin-lithium association differs from that of a saccharin-amphetamine association.     

3D feedback and observation for motor learning: Application to the roundoff movement in gymnastics

In this paper, we assessed the efficacy of different types of visual information for improving the execution of the roundoff movement in gymnastics. Specifically, two types of 3D feedback were compared to a 3D visualization only displaying the movement of the expert (observation) as well as to a more ‘traditional’ video observation. The improvement in movement execution was measured using different methods, namely subjective evaluations performed by official judges, and more ’quantitative appraisals based on time series analyses. Video demonstration providing information about the expert and 3D feedback (i.e., using 3D representation of the movement in monoscopic vision) combining information about the movement of the expert and the movement of the learner were the two types of feedback giving rise to the best improvement of movement execution, as subjectively evaluated by judges. Much less conclusive results were obtained when assessing movement execution using quantification methods based on time series analysis. Correlation analyses showed that the subjective evaluation performed by the judges can hardly be predicted/ explained by the ‘more objective’ results of time series analyses.     

Research and application of virtual user context information security strategy based on group intelligent computing

This article first introduced the current technology of the privacy protection model, and analyzed their characteristics and deficiencies. Afterwards, from the point of view of revenue, the shortcomings of the traditional privacy protection model have analyzed through the group intelligent computing method. Based on this, this paper proposes a research and application of virtual user information of security strategy based on group intelligent computing, through the collection of visitor's private information historical access data, intelligent calculation of the strategy group between the visitor and the interviewee. The setting of the threshold of the visited person can protect the privacy information of the user more effectively. In this paper, the implementation flow, algorithm implementation process, and specific architecture design of the proposed virtual user of privacy protection model based on group intelligent computing are introduced respectively. The specific algorithms include PCA, BP neural network, and genetic algorithm. Finally, the proposed privacy has verified through experiments. Protection model can protect user privacy more effectively than traditional privacy protection model. In the future, we will further expand and improve the privacy protection model of virtual users based on group intelligent computing, including considering the dynamic and inconsistency of access to the privacy information, that is, accessing different private information will produce different overlay effects and parallelism. We will also study how to apply this model to actual systems such as shopping websites and social platforms, and use commercial data to evaluate the performance of the model and further improve it.     

The production of false recognition and the associated state of consciousness following encoding in a naturalistic context in aging

Using virtual reality, we implemented a naturalistic variant of the DRM paradigm in young and older adults to evaluate false recall and false recognition. We distinguished false recognition related to the highest semantic association (the critical lures), semantic similarity (i.e. items that belong to the same semantic category), and perceptual similarity (i.e. items that are similar, but not identical in terms of shape or color). The data revealed that younger adults recalled and recognized more correct elements than older adults did while the older adults intruded more critical items than younger adults. Both age groups produced false recognition related to the critical items, followed by perceptually and then semantically related items. False recognitions were highly recollective as they were mainly associated with a sense of remembering, even more so in older adults than in young adults. The decline of executive functions and working memory predicted age-related increases in false memories.     

Is the street-crossing behavior with a head-mounted display different from that behavior in a CAVE? A study among young adults and children

The use of virtual reality (VR) has become increasingly popular in the field of traffic psychology, where realistic traffic situations can be simulated and pedestrians‘ actual crossing behavior can be studied. There are two main kinds of pedestrian simulators: one uses a technology based on rear-projection screens (Cave Automatic Virtual Environment, or CAVE); the other uses a head-mounted display (HMD). Despite their extensive use, it is yet to determine whether they are equally suitable for studying street crossing. The present study was aimed at comparing street-crossing behavior and subjective evaluations in an HMD-based (HTC vive pro) pedestrian simulator and a CAVE-like pedestrian simulator, among young adults and 12-year-old children. Thirty young adults and twenty-six children performed 36 street-crossing trials (combining different speeds, traffic conditions, and gap sizes) on each of the two simulators. The results indicated that, compared to the CAVE-condition participants, HMD-condition participants accepted more crossing trials (hence, shorter gaps), initiated their crossings sooner, crossed at a slower speed, had shorter safety margins, and caused more collisions. The main difference between the two devices was in crossing initiation, which occurred markedly earlier (1.72 s) with the HMD than in the CAVE: the perception–action coupling was less finely tuned in the CAVE, probably because visual information in front of the pedestrian was missing due the absence of ground projection and 3D rendering. A significant effect of vehicle-approach speed was observed for both devices, with more unsafe behaviors at 60 km/h than at 40 km/h. Children displayed riskier crossing behavior than young adults did, with more accepted crossings, slower crossing speeds, shorter safety margins, and higher collision rates, especially in the HMD. Compared to the CAVE, the HMD received higher ratings for level of presence and a preference for VR, but also higher simulator-sickness scores. No adverse effects of exposure to virtual reality was found on stereoacuity or postural balance. The suitability of using CAVE and HMD simulators is discussed, especially for studying child pedestrians.