scholarly journals Microsaccades mediate perceptual alternations in Monet’s “Impression, sunrise”

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert G. Alexander ◽  
Ashwin Venkatakrishnan ◽  
Jordi Chanovas ◽  
Stephen L. Macknik ◽  
Susana Martinez-Conde

AbstractTroxler fading, the perceptual disappearance of stationary images upon sustained fixation, is common for objects with equivalent luminance to that of the background. Previous work showed that variations in microsaccadic rates underlie the perceptual vanishing and intensification of simple stimuli, such as Gabor patches. Here, we demonstrate that microsaccade dynamics also contribute to Troxler fading and intensification during the viewing of representational art. Participants fixated a small spot while viewing either a Gabor patch on a blank background, or Monet’s painting “Impression, Sunrise.” They continuously reported, via button press/release, whether the Gabor patch, or the sun in Monet’s painting, was fading versus intensifying, while their eye movements were recorded with high precision. Microsaccade rates peaked before reports of increased visibility, and dropped before reports of decreased visibility or fading, both when viewing Gabor patches and Monet’s sun. These results reveal that the relationship between microsaccade production and the reversal and prevention of Troxler fading applies not only to the viewing of contrived stimuli, but also to the observation of “Impression, Sunrise.” Whether or not perceptual fading was consciously intended by Monet, our findings indicate that observers’ oculomotor dynamics are a contributor to the cornerstone of Impressionism.

1975 ◽  
Vol 38 (5) ◽  
pp. 1140-1161 ◽  
Author(s):  
A. F. Fuchs ◽  
J. Kimm

Single units were recorded from the vestibular nuclei of unanesthetized monkeys that were rotated in the horizontal plane while simultaneously pressing individual buttons in a controlled array which turned with hem. Using this behavioral paradigm, it was possible to 1) determine the relationship of unit discharge to eye movements measured by the DC-coupled electrooculogram and calibrated by the button-press task, and 2) determine the relationship of unit discharge to horizontal acceleration, either with or without the compensatory eye movements evoked by vestibular stimulation. Based on their responses during vestibular stimulation and/or eye movements, neurons in the vestibular nuclei (77% of our sample was in the medial nucleus) could be divided into four groups...


2018 ◽  
Vol 3 (2) ◽  
pp. 207-216 ◽  
Author(s):  
David Fisher ◽  
Lionel Sims

Claims first made over half a century ago that certain prehistoric monuments utilised high-precision alignments on the horizon risings and settings of the Sun and the Moon have recently resurfaced. While archaeoastronomy early on retreated from these claims, as a way to preserve the discipline in an academic boundary dispute, it did so without a rigorous examination of Thom’s concept of a “lunar standstill”. Gough’s uncritical resurrection of Thom’s usage of the term provides a long-overdue opportunity for the discipline to correct this slippage. Gough (2013), in keeping with Thom (1971), claims that certain standing stones and short stone rows point to distant horizon features which allow high-precision alignments on the risings and settings of the Sun and the Moon dating from about 1700 BC. To assist archaeoastronomy in breaking out of its interpretive rut and from “going round in circles” (Ruggles 2011), this paper evaluates the validity of this claim. Through computer modelling, the celestial mechanics of horizon alignments are here explored in their landscape context with a view to testing the very possibility of high-precision alignments to the lunar extremes. It is found that, due to the motion of the Moon on the horizon, only low-precision alignments are feasible, which would seem to indicate that the properties of lunar standstills could not have included high-precision markers for prehistoric megalith builders.


Cortex ◽  
2016 ◽  
Vol 85 ◽  
pp. 182-193 ◽  
Author(s):  
Rosanna K. Olsen ◽  
Vinoja Sebanayagam ◽  
Yunjo Lee ◽  
Morris Moscovitch ◽  
Cheryl L. Grady ◽  
...  

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 972
Author(s):  
Susana Santiago ◽  
Itziar Zazpe ◽  
Cesar I. Fernandez-Lazaro ◽  
Víctor de la de la O ◽  
Maira Bes-Rastrollo ◽  
...  

No previous study has assessed the relationship between overall macronutrient quality and all-cause mortality. We aimed to prospectively examine the association between a multidimensional macronutrient quality index (MQI) and all-cause mortality in the SUN (Seguimiento Universidad de Navarra) (University of Navarra Follow-Up) study, a Mediterranean cohort of middle-aged adults. Dietary intake information was obtained from a validated 136-item semi-quantitative food-frequency questionnaire. We calculated the MQI (categorized in quartiles) based on three quality indexes: the carbohydrate quality index (CQI), the fat quality index (FQI), and the healthy plate protein source quality index (HPPQI). Among 19,083 participants (mean age 38.4, 59.9% female), 440 deaths from all causes were observed during a median follow-up of 12.2 years (IQR, 8.3–14.9). No significant association was found between the MQI and mortality risk with multivariable-adjusted hazard ratio (HR) for the highest vs. the lowest quartile of 0.79 (95% CI, 0.59–1.06; Ptrend = 0.199). The CQI was the only component of the MQI associated with mortality showing a significant inverse relationship, with HR between extreme quartiles of 0.64 (95% CI, 0.45–0.90; Ptrend = 0.021). In this Mediterranean cohort, a new and multidimensional MQI defined a priori was not associated with all-cause mortality. Among its three sub-indexes, only the CQI showed a significant inverse relationship with the risk of all-cause mortality.


2018 ◽  
Vol 615 ◽  
pp. A153 ◽  
Author(s):  
Rodolfo G. Cionco ◽  
Dmitry A. Pavlov

Aims. The barycentric dynamics of the Sun has increasingly been attracting the attention of researchers from several fields, due to the idea that interactions between the Sun’s orbital motion and solar internal functioning could be possible. Existing high-precision ephemerides that have been used for that purpose do not include the effects of trans-Neptunian bodies, which cause a significant offset in the definition of the solar system’s barycentre. In addition, the majority of the dynamical parameters of the solar barycentric orbit are not routinely calculated according to these ephemerides or are not publicly available. Methods. We developed a special version of the IAA RAS lunar–solar–planetary ephemerides, EPM2017H, to cover the whole Holocene and 1 kyr into the future. We studied the basic and derived (e.g., orbital torque) barycentric dynamical quantities of the Sun for that time span. A harmonic analysis (which involves an application of VSOP2013 and TOP2013 planetary theories) was performed on these parameters to obtain a physics-based interpretation of the main periodicities present in the solar barycentric movement. Results. We present a high-precision solar barycentric orbit and derived dynamical parameters (using the solar system’s invariable plane as the reference plane), widely accessible for the whole Holocene and 1 kyr in the future. Several particularities and barycentric phenomena are presented and explained on dynamical bases. A comparison with the Jet Propulsion Laboratory DE431 ephemeris, whose main differences arise from the modelling of trans-Neptunian bodies, shows significant discrepancies in several parameters (i.e., not only limited to angular elements) related to the solar barycentric dynamics. In addition, we identify the main periodicities of the Sun’s barycentric movement and the main giant planets perturbations related to them.


2017 ◽  
Vol 35 (6) ◽  
pp. 1275-1291 ◽  
Author(s):  
Allan R. Macneil ◽  
Christopher J. Owen ◽  
Robert T. Wicks

Abstract. The development of knowledge of how the coronal origin of the solar wind affects its in situ properties is one of the keys to understanding the relationship between the Sun and the heliosphere. In this paper, we analyse ACE/SWICS and WIND/3DP data spanning  > 12 years, and test properties of solar wind suprathermal electron distributions for the presence of signatures of the coronal temperature at their origin which may remain at 1 AU. In particular we re-examine a previous suggestion that these properties correlate with the oxygen charge state ratio O7+ ∕ O6+, an established proxy for coronal electron temperature. We find only a very weak but variable correlation between measures of suprathermal electron energy content and O7+ ∕ O6+. The weak nature of the correlation leads us to conclude, in contrast to earlier results, that an initial relationship with core electron temperature has the possibility to exist in the corona, but that in most cases no strong signatures remain in the suprathermal electron distributions at 1 AU. It cannot yet be confirmed whether this is due to the effects of coronal conditions on the establishment of this relationship or due to the altering of the electron distributions by processing during transport in the solar wind en route to 1 AU. Contrasting results for the halo and strahl population favours the latter interpretation. Confirmation of this will be possible using Solar Orbiter data (cruise and nominal mission phase) to test whether the weakness of the relationship persists over a range of heliocentric distances. If the correlation is found to strengthen when closer to the Sun, then this would indicate an initial relationship which is being degraded, perhaps by wave–particle interactions, en route to the observer.


2014 ◽  
Vol 7 (1) ◽  
Author(s):  
John J. H. Lin ◽  
Sunny S. J. Lin

The present study investigated the following issues: (1) whether differences are evident in the eye movement measures of successful and unsuccessful problem-solvers; (2) what is the relationship between perceived difficulty and eye movement measures; and (3) whether eye movements in various AOIs differ when solving problems. Sixty-three 11th grade students solved five geometry problems about the properties of similar triangles. A digital drawing tablet and sensitive pressure pen were used to record the responses. The results indicated that unsuccessful solvers tended to have more fixation counts, run counts, and longer dwell time on the problem area, whereas successful solvers focused more on the calculation area. In addition, fixation counts, dwell time, and run counts in the diagram area were positively correlated with the perceived difficulty, suggesting that understanding similar triangles may require translation or mental rotation. We argue that three eye movement measures (i.e., fixation counts, dwell time, and run counts) are appropriate for use in examining problem solving given that they differentiate successful from unsuccessful solvers and correlate with perceived difficulty. Furthermore, the eye-tracking technique provides objective measures of students’ cognitive load for instructional designers.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Zhen Yu ◽  
Yuan Zhang

High-precision reducer is the core component of industrial robots. In order to achieve the comprehensive performance testing of precision reducers, an instrument with a vertical layout and a cylindrical structure is designed. As a rotating machine, the inevitable coupling misalignment of the instrument can lead to vibration faults which lead to errors in the test. So it is pretty necessary to diagnose and monitor the coupling misalignment while the instrument is working. The causes of the coupling misaligned fault of the instrument and the relationship between the misalignment fault and torque ripple are analyzed in this paper. A method of using the torque transducer in the measurement chain of the instrument to diagnose the coupling misalignment is proposed in this paper. Many experiments have been done to test the capability of detecting the coupling misalignment using this method. Experimental results show that the amplitude of torque ripple of the shaft is linearly related to the coupling misalignment and is quadratically related to the rotation speed of the shaft when the misalignment exists in the shaft. The combination of components at the rotation frequency (fr) and the additional components can be used to diagnose faults due to coupling misalignment.


Sign in / Sign up

Export Citation Format

Share Document