Long-distance air pressure differences correlate with European rain.

Precipitation in Europe shows natural fluctuations that differ considerably between seasons and geographical regions. A number of studies have linked local or seasonal rainfall variability to various long-distance air pressure differences in north-south or west-east direction. This paper presents the first continent-wide analysis of European rainfall variability on a month-by-month and country-by-country basis. We calculated Pearson r values for unsmoothed monthly rainfall data of 39 European countries over the period 1950-2019 with five potential climatic drivers, namely the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO), the North Sea Caspian Pattern (NCP), and two indices of Mediterranean Oscillation (MOI2, WeMOI). For a variety of countries and months we found substantial and statistically significant r values of up to r = 0.7 and more. The dynamic temporal-spatial evolution of the Pearson correlations was mapped out across the continent, tracking the gradual or abrupt expansion, displacement and subsequent waning of the various effects over the course of the year. The correlation analysis was complemented by best subset multiple regression, controlling for intercorrelation of the potential drivers. Our results may help to improve short- to midterm rainfall prognoses in Europe and provide important calibration data for the further refinement of climate models.

Comparison of a perfusion simulator to a clinical operating room: evaluation of eye tracking data and subjective perception. A pilot study.

BACKGROUND: With the aim of evaluating the perfusion simulator at the German Heart Center Berlin, similarity between simulation and clinical operation room (OR) was investigated regarding subjective perception and eye movement. METHODS: Eight perfusionists performed an operation on the heart-lung machine (HLM) wearing eye tracking glasses, each in real OR and simulator. The three most important phases for perfusionists (going on bypass, cardioplegia administration and coming off bypass) were considered. Additional to eye tracking data as objective measure, questionnaires were completed, and interviews conducted afterwards. RESULTS: The structure of simulator and real OR is perceived as basically the same. Yet there are differences in the HLM-models used and the temporal sequence. Different perception of both situations is reported in interviews and reflected in significant differences in the rating scales (NASA-TLX) on three of six subscales. In eye tracking data, certain AOIs could be identified for the individual phases, both in OR and simulator-an indication of fundamental similarity. However, differences regarding the proportions of the individual AOIs, especially in the first and third phase, are leading to the assumption that the simulator, and especially the simulation process, is only valid to a limited extent regarding subjective perception and eye tracking data. CONCLUSION: The use of the simulator for (advanced) training is accepted and explicitly requested by perfusionists. Yet further research is needed to identify the decisive factors (like simulation duration or additional tasks) for a valid execution in the simulator. Furthermore, a larger sample size should be regarded to allow statistical analysis.

Simulation in perfusion: evaluating the efficacy of a specific training with eye-tracking.

BACKGROUND: With the aim of integrating simulation training into the training of perfusionists, we examined whether the participants were able to transfer a specific learning content to the same and different situations and assessed their feedback on the simulation training. Eye-tracking was tested as a measure and supplemented by additional measures. METHODS: A 2 × 2 mixed design was used, with test time (pre- and post-test) and training group (same and different content training) as factors. In the pre- and post-test, the participant had to handle a critical situation on the cardiopulmonary bypass, namely, a drop in arterial partial oxygen pressure. Between the two test times, the participant practised under guidance the handling of either the same critical situation (Group 1) or a different one, that is, impaired venous return (Group 2). Dependent measures were fixations of the eyes on specific areas of interest on the heart-lung machine, measures of latency and subjective assessments. Moreover, participants gave feedback on the simulation training. RESULTS: Fixation analyses showed that the training led to an increased gaze on areas of interest relevant to the drop in arterial partial oxygen pressure in both groups, with a significant increase only for Group 1. The surveys revealed a great interest in the integration of simulation training into education. CONCLUSION: In combination with other measures, eye-tracking is suitable for the evaluation of simulation training. Due to the positive training effects and positive participant feedback, the integration of simulation into the training of perfusionists is advocated. Concerning transfer of learning content, more research is needed.

Exogenous attention can be counter-selective: onset cues disrupt sensitivity to color changes.

In peripheral spatial cueing paradigms, exogenous attentional capture is commonly observed after salient onset cues or with cues contingent on target characteristics. We proposed that exogenously captured attention disrupts the selectivity to target features. We tested this by experimentally emulating the everyday observation that in a viewing situation in which the observer is monitoring a stationary display fort change to occur, the onset of a salient stimulus (onset cue) or a change in a stationary stimulus similar to the expected one (contingent cue) has a distracting effect. As predicted, we found that both types of cues reduced the target detection sensitivity but enhanced the bias to respond in a go-nogo-paradigm. With the onset cue, the sensitivity loss was more pronounced at the side of the cue, whereas the contingent cue affected both sides likewise. Moreover, the effects of the onset cue interacted with the task difficulty: the more selectivity a task required the more immune it was against disruption, but the more likely was a response. We concluded that onset capture disrupts selective attention by adding noise to the processing of the target location. The effects of contingent capture could be explained with cue-target confounding. Finally, we suggest a new model of attentional capture in which exogenous and endogenous components interact in a dynamic way.

Deficits in subprocesses of visual feature search after frontal, parietal, and temporal brain lesions--a modeling approach.

Deficits in visuospatial attention are commonly observed after different kinds of brain lesions. However, the structure-function relationships are not well understood. We investigated whether our response time (RT) model, strategies of visual search (STRAVIS), combined with a linear model of brain lesions, enables us to relate specific impairments in cognitive processes to specific sites of focal brain lesions. In STRAVIS, RTs in overt visual feature search with graded target-distractor similarity are decomposed into the durations of successive search steps. Fitting the model to an observer's RTs yields individual estimates of the parameters "attentional focus size," "attentional dwell time," and "movement time of attention or the eyes." In 28 patients with various focal lesions to the frontal, parietal, and/or temporal cortex and 28 matched controls, we determined with the help of linear models which lesions were most predictive for each parameter. Predictions were validated with a second sample of 12 patients and 12 controls. Critical lesion areas for the STRAVIS focus size were the dorsolateral prefrontal cortex and the temporal lobe, with dorsolateral prefrontal cortex lesions reducing the focus and temporal lesions enlarging it. The STRAVIS dwell time was reduced in patients with lesions to the anterior insula and the superior parietal lobe. Lesions to the frontal eye fields, the superior parietal lobe, and the parieto-occipital cortex were most detrimental to the STRAVIS movement time. Applying linear models to a patient sample with heterogeneous lesions may be a promising new method for investigating how different brain areas interplay in a complex task.

Localizing subprocesses of visual search by correlating local brain activation in fMRI with response time model parameters.

In a complex cognitive task such as overt visual search, several subprocesses interact in quick alternation, such as attentional selections (i.e., spatially constrained modulation of perception) and attentional shifts/eye movements. Since temporal resolution in fMRI is low, it is difficult to assign local brain activations to these subprocesses with traditional analysis. The present paper investigates a new approach: with the response time model STRAVIS [Müller-Plath G, Pollmann S. Determining subprocesses of visual feature search with reaction time models. Psychol Res 2003;67:80-105], a visual search process is decomposed into hypothetical cognitive subprocesses and quantitatively described by individually estimated parameters like the size of the attentional focus or the attentional dwell time. In the fMRI experiment we administered the search task, correlated the estimated model parameter values for dwell time and (reciprocal) focus size to BOLD-responses, and thereby identified putative neural networks that are jointly active in the task but differentially specialized to the subprocesses attentional selection and attentional shift. First, the methodological approach was validated by the results agreeing with the literature for predefined brain areas. Second, our findings might add to the literature by specifying several more brain areas probably belonging to the two networks. Third, compared to a more traditional data analysis (contrasts of mean BOLD responses in the factorial experimental design) the method of individually correlating model parameters to BOLD proved superior provided one accepts the theoretical assumptions underlying each of the approaches. Our results demonstrate the utility of combining mathematical modeling and fMRI to investigate the neural substrates of a complex task such as visual search.

Determining subprocesses of visual feature search with reaction time models.

After the classic serial/parallel dichotomy of visual search mechanisms has been increasingly doubted, we investigated what search mechanisms are used between the two poles termed "pop-out" and "strictly serial search" in an overt feature search paradigm. Since reaction time slopes do not contain sufficient information for this purpose, we developed a novel technique for analyzing reaction times. Individual reaction times are modeled as sums of the durations of successive search steps. Model parameters are task characteristics (similarity, number and arrangement of target and distractors) and processing characteristics of the participant (e.g., attention dwell and shift durations). In Experiment 1, several model variants were fitted numerically to empirical reaction times. The best fitting model suggested that more than one item can be processed in a single fixation, movement of attention is abrupt and not continuous, and even in pop out search, attention is often explicitly moved to the target. In Experiment 2, we measured the central model parameter, the so-called range of attention, more directly and thereby validated the model. The model provides an explanation for the strong variation in the slope of reaction time functions, which is not based on an explicit distinction between parallel and serial search processes.