Integrated chemo- and biostratigraphic calibration of early animal evolution: Neoproterozoic-early Cambrian of southwest Mongolia

Five overlapping sections from the thick Neoproterozoic to early Cambrian sediments of western Mongolia were analysed to yield a remarkable carbon-isotope, strontium-isotope and small shellyfossil (SSF) record. Chemostratigraphy suggests that barren limestones of sequences 3 and 4, which lie above the two Maikhan Uul diamictites, are post-Sturtian but pre-Varangerian in age. Limestones and dolomites of sequence 5, with Boxonia grumulosa, have geochemical signatures consistent with a post-Varangerian (Ediacarian) age. A major negative δ13C anomaly (feature ‘W') in sequence 6 lies a shortdistance above an Anabarites trisulcatus Zone SSF asemblage with hexactinellid sponges, of probable late Ediacarian age. Anomaly ‘W' provides an anchor point for cross-correlation charts of carbon isotopes and small shelly fossils. Trace fossil assemblages with a distinctly Cambrian character first appear in sequence 8(Purella Zone), at the level of carbon isotopic feature ‘B', provisionally correlated with the upper part of cycle Z in Siberia. A paradox is found from sequence 10 to 12 in Mongolia: Tommotian-type SSFs continue to appear, accompanied by Nemakit-Daldynian/Tommotian-type 87Sr/86Sr ratios but by increasingly heavyδ13C values that cannot be matched in the Tommotian of eastern Siberia. The steady rate of generic diversification in Mongolia also contrasts markedly with the Tommotian ‘diversity explosion' in eastern Siberia, which occurs just above a major karstic emergence surface. One explanation is that sequences 10 to 12 in Mongolia preserve a pre-Tommotian portion of the fossil record that was missing or removed in easternSiberia. The Mongolian sections certainly deserve an important place in tracing the true course and timing of the ‘Cambrian radiation

Categorial Featuresof Perception of Facial Expressions

The article gives a review of the modern condition of researching categorial features of perception of facial expressions. On the material of the experiments made by the authors the factors influencing the display of the categorial effect are considered: the type of the discriminatory task, the basic level of the efficiency of the image distinction, the time of the exposition, the specifics of the concrete incentive material

Depth and Perspective Perception of Flat Images in Static and Dynamic Visual Scenes

© 2020 Fazlyyyakhmatov et al.; Licensee Lifescience Global. The paper shows that a sense of depth can arise from two-dimensional (2D) scenes without the presence of a stereoscopic depth signal. Experimental information was obtained on three-dimensional (3D) visual perception of 2D static and dynamic scenes. The technique is based on fixing the conditions of eye movement during the perception of two-dimensional stimulus scenes. To obtain registration of the depth perception effects, they used volume and spatial perspective of 2D images (3D phenomenon), and a binocular eye tracker. The 3D phenomenon is identified using 3D raster images. It is assumed that the comparison of eye movements during a 3D raster image viewing allows you to identify uniquely the effects of the 3D phenomenon of stimulus planar scenes displayed on the monitor screen. The first part of the work shows the conditions for the emergence of a 3D phenomenon on two plots of dynamic and static scenes. The second part demonstrates the three-dimensional attributes of dynamic scenes with the highlighting of various video components. We emphasize that dynamic and static scenes are obtained directly from TV programs. The proposed graphical and mathematical method of analysis made it possible to show qualitatively the perception of the 3D phenomenon by KFU students and revealed the features of volume observation for planar images without the occurrence of binocular disparity

Процесс сравнения изображений эмоциональных экспрессий

Introduction. We conducted an experiment in the paradigm of direct comparison of images of strong and weakly expressed emotional expressions with a detailed justification of the assessment made and registration of eye movements. Methods. Photo images from the VEPEL database (video images of natural transient facial expressions: joy, sadness, fear, surprise, anger, disgust, calm face) were used as stimulus material. The subjects were students of Moscow universities (72 people, of which 10 men, 62 women; age from 18 to 39 years, average age = 22.0, standard deviation = 4.0. Exposure time is unlimited, until the justification is completed. Research objective: image comparison (rank scale of similarity between images from 1 to 9) with registration of eye movements. Results. Based on individual assessments of similarity between images of emotional expressions, the reconstruction of the two-dimensional space was performed using the multidimensional scaling method. The reconstruction is described by Core Affect model by J. Russell. The presence of individual variability of similarity scores (the tendency to select a certain range of scores) is shown. The following individual indicators were singled out for further search of possible predictors: the average similarity score between images, the standard deviation of the similarity score between images, and the average individual duration of fixations. The presence of variability of estimates for different pairs of compared images is shown. The minimum variability of similarity estimates is achieved for the next pairs: fear–fear weak, joy – joy weak; anger – anger weak; disgust weak – anger; neutral – sadness weak. The maximum variability of similarity estimates is achieved for pairs of joy weak – fear weak; joy – fear weak; sadness – joy weak; joy weak – anger weak; neutral – joy weak. The analysis of the duration of visual fixations during the similarity assessment was carried out. It is shown that different similarity scores correspond to different distribution patterns of fixation durations in the evaluation process. Discussion. Based on our results, we can conclude that there are several convergent evaluation justification processes based on an initial similarity score between images.Введение. Нами проведен эксперимент в парадигме прямого сравнения изображений сильно- и слабо- выраженных эмоциональных экспрессий с развернутым обоснованием сделанной оценки и регистрацией движений глаз. Методы. В качестве стимульного материала были использованы фотоизображения из базы ВЕПЭЛ (видеоизображения естественных переходных экспрессий лица) радость, печаль, страх, удивление, гнев, отвращение, спокойное лицо). Испытуемыми выступили студенты московских вузов (72 человека, из которых 10 мужчин, 62 женщины; возраст от 18 до 39 лет, средний возраст = 22,0, стандартное отклонение = 4,0. Время экспозиции – неограниченное, до завершения обоснования. Задача исследования: сравнение изображений (ранговая шкала сходства между изображениями от 1 до 9) с регистрацией движений глаз. Результаты. На основе индивидуальных оценок сходства между изображениями эмоциональных экспрессий методом многомерного шкалирования выполнена реконструкция двумерного пространства, описываемого моделью Core Affect Дж. Расселла. Показано наличие индивидуальной вариативности оценок сходства (тенденция к выбору определенного диапазона оценок). Выделены для дальнейшего поиска возможных предикторов следующие индивидуальные показатели: средняя оценка сходства между изображениями, стандартное отклонение оценки сходства между изображениями, средняя индивидуальная продолжительность фиксаций. Показано наличие вариативности оценок для разных пар сравниваемых изображений. Минимальная вариативность оценок сходства достигается для пар страх – страх сл; радость – радость сл; гнев – гнев сл; отвращение сл – гнев; нейтральное – печаль сл. Максимальная вариативность оценок сходства достигается для пар радость сл – страх сл; радость - страх сл; печаль – радость сл; радость сл – гнев сл; нейтральное – радость сл. Проведен анализ продолжительности зрительных фиксаций при выполнении оценки сходства. Показано, что разным оценкам сходства соответствуют различные паттерны распределения продолжительности фиксаций в процессе оценки. Обсуждение результатов. На основании полученных нами результатов можно сделать вывод о возможности нескольких конвергентных процессов обоснования оценки, опирающихся на первоначальную оценку сходства между изображениями.&nbsp