Effects of visual and motion simulation cueing systems on pilot performance during takeoffs with engine failures

Data are presented that show the effects of visual and motion during cueing on pilot performance during takeoffs with engine failures. Four groups of USAF pilots flew a simulated KC-135 using four different cueing systems. The most basic of these systems was of the instrument-only type. Visual scene simulation and/or motion simulation was added to produce the other systems. Learning curves, mean performance, and subjective data are examined. The results show that the addition of visual cueing results in significant improvement in pilot performance, but the combined use of visual and motion cueing results in far better performance

Improving precision and reducing bias in biological surveys: estimating false-negative error rates

The use of presence/absence data in wildlife management and biological surveys is widespread. There is a growing interest in quantifying the sources of error associated with these data. We show that false-negative errors (failure to record a species when in fact it is present) can have a significant impact on statistical estimation of habitat models using simulated data. Then we introduce an extension of logistic modeling, the zero-inflated binomial (ZIB) model that permits the estimation of the rate of false-negative errors and the correction of estimates of the probability of occurrence for false-negative errors by using repeated. visits to the same site. Our simulations show that even relatively low rates of false negatives bias statistical estimates of habitat effects. The method with three repeated visits eliminates the bias, but estimates are relatively imprecise. Six repeated visits improve precision of estimates to levels comparable to that achieved with conventional statistics in the absence of false-negative errors In general, when error rates are less than or equal to50% greater efficiency is gained by adding more sites, whereas when error rates are >50% it is better to increase the number of repeated visits. We highlight the flexibility of the method with three case studies, clearly demonstrating the effect of false-negative errors for a range of commonly used survey methods

Strategies that reduce Stroop interference

A remarkable example of reducing Stroop interference is provided by the word blindness post-hypnotic suggestion (a suggestion to see words as meaningless during the Stroop task). This suggestion has been repeatedly demonstrated to halve Stroop interference when it is given to highly hypnotizable people. In order to explore how highly hypnotizable individuals manage to reduce Stroop interference when they respond to the word blindness suggestion, we tested four candidate strategies in two experiments outside of the hypnotic context. A strategy of looking away from the target words and a strategy of visual blurring demonstrated compelling evidence for substantially reducing Stroop interference in both experiments. However, the pattern of results produced by these strategies did not match those of the word blindness suggestion. Crucially, neither looking away nor visual blurring managed to speed up incongruent responses, suggesting that neither of these strategies is the likely underlying mechanism of the word blindness suggestion. Although the current results did not unravel the mystery of the word blindness suggestion, they showed that there are multiple voluntary ways through which participants can dramatically reduce Stroop interference

The effect of high-frequency rTMS over left DLPFC and fluid abilities on goal neglect

Goal neglect refers to when an aspect of task instructions is not utilised due to increased competition between goal representations, an attentional limit theoretically linked to working memory. In an attempt to alleviate goal neglect and to investigate the association between dorsolateral prefrontal cortex (DLPFC)-supported working memory and goal neglect, we used high-frequency repetitive transcranial magnetic stimulation to the left DLPFC whilst participants completed the letter-monitoring task, a measure of goal neglect, and an N3-back task, a working memory task known to be affected by rTMS of the left DLPFC, following 20 min of active and sham stimulation (run on separate days). We found increased accuracy on the N3-back task in addition to decreased goal neglect in the active compared to sham condition when controlling for age and fluid abilities (as assessed by matrix reasoning performance). Furthermore, analysis showed that active stimulation improvements on both the N3-back and letter-monitoring tasks were greater for those with higher fluid abilities. These findings provide support for the link between the DLPFC-support working memory and goal neglect. Increased performance on the N3-back task also supports the literature reporting a link between left DLPFC and verbal working memory. Results are evaluated in the context of potential use to alleviate symptoms of disorders related to goal neglect

Structure, magnetic and transport properties of Ti-substituted La0.7Sr0.3MnO3

Ti-substituted perovskites, La0.7Sr0.3Mn1-xTixO3, with x between 0 to 0.20, were investigated by neutron diffraction, magnetization, electric resistivity, and magnetoresistance (MR) measurements. All samples show a rhombohedral structure (space group R3c) from 10 K to room temperature. At room temperature, the cell parameters a, c and the unit cell volume increase with increasing Ti content. However, at 10 K, the cell parameter a has a maximum value for x = 0.10, and decreases for x greater than 0.10, while the unit cell volume remains nearly constant for x greater than 0.10. The average (Mn,Ti)-O bond length increases up to x=0.15, and the (Mn,Ti)-O-(Mn,Ti) bond angle decreases with increasing Ti content to its minimum value at x=0.15 at room temperature. Below the Curie temperature T_C, the resistance exhibits metallic behavior for the x _ 0.05 samples. A metal (semiconductor) to insulator transition is observed for the x_ 0.10 samples. A peak in resistivity appears below T_C for all samples, and shifts to a lower temperature as x increases. The substitution of Mn by Ti decreases the 2p-3d hybridization between O and Mn ions, reduces the bandwidth W, and increases the electron-phonon coupling. Therefore, the TC shifts to a lower temperature and the resistivity increases with increasing Ti content. A field-induced shift of the resistivity maximum occurs at x less than or equal to 0.10. The maximum MR effect is about 70% for La0.7Sr0.3Mn0.8Ti0.2O3. The separation of TC and the resistivity maximum temperature Tmax enhances the MR effect in these compounds due to the weak coupling between the magnetic ordering and the resistivity as compared with La0.7Sr0.3MnO3.Comment: zip fil

Can unconscious intentions be more effective than conscious intentions? Test of the role of metacognition in hypnotic response

While several theories assume that responses to hypnotic suggestions can be implemented without executive intentions, the metacognitive class of theories postulate that the behaviors produced by hypnotic suggestions are intended and the accompanying feeling of involuntariness is only a consequence of strategically not being aware of the intention. Cold control theory asserts that the only difference between a hypnotic and non-hypnotic response is this metacognitive one, that is, whether or not one is aware of one's intention to perform the relevant act. To test the theory, we compared the performance of highly suggestible participants in reducing the Stroop interference effect in a post-hypnotic suggestion condition (word blindness: that words will appear as a meaningless foreign script) and in a volitional condition (asking the participants to imagine the words as a meaningless foreign script). We found that participants had equivalent expectations that the posthypnotic suggestion and the volitional request would help control the conflicting information. Further, participants felt they had more control over experiencing the words as meaningless with the request rather than the suggestion; and they experienced the request largely as imagination and the suggestion largely as perception. That is, we set up the interventions we required for the experiment to constitute a test of cold control theory. Both the suggestion and the request reduced Stroop interference. Crucially, there was Bayesian evidence that the reduction in Stroop interference was the same between the suggestion and the volitional request. That is, the results support the claim that responding hypnotically does not grant a person greater first order abilities than they have non-hypnotically, consistent with cold control theory

Classical motion in force fields with short range correlations

We study the long time motion of fast particles moving through time-dependent random force fields with correlations that decay rapidly in space, but not necessarily in time. The time dependence of the averaged kinetic energy and mean-squared displacement is shown to exhibit a large degree of universality; it depends only on whether the force is, or is not, a gradient vector field. When it is, p^{2}(t) ~ t^{2/5} independently of the details of the potential and of the space dimension. Motion is then superballistic in one dimension, with q^{2}(t) ~ t^{12/5}, and ballistic in higher dimensions, with q^{2}(t) ~ t^{2}. These predictions are supported by numerical results in one and two dimensions. For force fields not obtained from a potential field, the power laws are different: p^{2}(t) ~ t^{2/3} and q^{2}(t) ~ t^{8/3} in all dimensions d\geq 1

What type of inhibition underpins performance on Luria's Fist-Edge-Palm task?

OBJECTIVE: The Fist-Edge-Palm task is a motor sequencing task believed to be sensitive to frontal lobe impairment. The present study aimed to investigate the inhibitory processes underlying successful execution of this task. METHOD: Seventy-two healthy participants were asked to perform the Fist-Edge-Palm task paced at 120 bpms, 60 bpms and self-paced. They also completed assessments sensitive to recently dissociated forms of inhibition (the Hayling Sentence Completion Test and the Stroop Color-Word Test) that have recently been shown to be differentially lateralized (the right and left Prefrontal Cortex, respectively), and Cattell's Culture Fair Intelligence test. RESULTS: Analysis revealed that performance on the Hayling Sentence Completion Test predicted the amount of crude errors and the overall score on the Fist-Edge-Palm task, and that pacing condition had no effect on this outcome. Neither the Stroop Color-Word Test nor Cattell's Culture Fair Intelligence Test predicted performance on the Fist-Edge-Palm task. CONCLUSIONS: Consistent with some previous neuroimaging findings, the present findings suggest that Fist-Edge-Palm task performance relies on right lateralized inhibitory processes