Deep Reinforcement Learning-Based Robotic Grasping in Clutter and Occlusion

In robotic manipulation, object grasping is a basic yet challenging task. Dexterous grasping necessitates intelligent visual observation of the target objects by emphasizing the importance of spatial equivariance to learn the grasping policy. In this paper, two significant challenges associated with robotic grasping in both clutter and occlusion scenarios are addressed. The first challenge is the coordination of push and grasp actions, in which the robot may occasionally fail to disrupt the arrangement of the objects in a well-ordered object scenario. On the other hand, when employed in a randomly cluttered object scenario, the pushing behavior may be less efficient, as many objects are more likely to be pushed out of the workspace. The second challenge is the avoidance of occlusion that occurs when the camera itself is entirely or partially occluded during a grasping action. This paper proposes a multi-view change observation-based approach (MV-COBA) to overcome these two problems. The proposed approach is divided into two parts: 1) using multiple cameras to set up multiple views to address the occlusion issue; and 2) using visual change observation on the basis of the pixel depth difference to address the challenge of coordinating push and grasp actions. According to experimental simulation findings, the proposed approach achieved an average grasp success rate of 83.6%, 86.3%, and 97.8% in the cluttered, well-ordered object, and occlusion scenarios, respectively.

Preliminary Characterization of Predictive Factors of the Visual Change after Epi-On and Epi-Off Corneal Collagen Crosslinking Techniques

Purpose. To investigate the potential predictive factors of the visual change achieved with accelerated epi-on and epi-off corneal collagen crosslinking (CXL) in keratoconus. Methods. This retrospective comparative study analyzed 67 eyes treated with an accelerated epithelium-on (epi-on group) and epithelium-off (epi-off group) CXL. The clinical outcomes were evaluated and compared during a 1-year follow-up. Likewise, the relationship of the change achieved with both CXL techniques in the corrected distance visual acuity (CDVA) with different preoperative data was investigated. Results. The mean CDVA change at 3 months postoperatively was −0.04 ± 0.19 and −0.07 ± 0.25 in the epi-on and epi-off groups, respectively ( p = 0.809). In the epi-on group, this change was significantly correlated with the preoperative apical (r = −0.375, p = 0.045) and central corneal thickness (r = −0.402, p = 0.031). In the epi-off group, the CDVA change was significantly correlated with not only the preoperative apical (r = 0.402, p = 0.028) and central corneal thickness (r = 0.367, p = 0.046) but also with some topometric and aberrometric indices (r ≤ −0.374, p ≤ 0.042). Furthermore, the change in CDVA in the epi-on group could be predicted from age, preoperative refractive astigmatism J45 component, anterior corneal asphericity, and posterior corneal high order aberration root mean square ( p = 0.002, R2 = 0.503). In the epi-off group, the CDVA change could be predicted from the preoperative minimum corneal thickness and magnitude of the vertical anterior corneal primary coma component ( p = 0.001, R2 = 0.446). Conclusions. Clearly, different predictive factors of the visual change induced with the accelerated epi-on and epi-off CXL techniques are present, suggesting a different mechanism of action for stiffening the cornea and inducing changes in this structure.

Visual estimation of the force applied by another person

As observers, we believe that we can visually estimate the force that another person applies to an object. However, it is unclear what kind of cues we use to do this. We have focused on two types of visual change that occur when a person pushes an elastic object from above with his or her finger: the first one relates to a finger/hand shaking, known as an ``induced tremor'' and the second one relates to object deformation due to the application of force. This study shows that human observers of videos combine these two visual cues to estimate the force being applied by another person in the videos. Overall, the apparent force was stronger when the shaking was larger and when the magnitude of the deformation was larger, although systematic individual differences existed. The estimation of force was likely made in separate cognitive functions from the estimation of object softness. Estimating the force that another person applies seems to be done by perceptually interpreting both the actions of others and their external outcomes.

Schizotypy is associated with difficulties detecting emotional facial expressions

People with schizophrenia or subclinical schizotypal traits exhibit impaired recognition of facial expressions. However, it remains unclear whether the detection of emotional facial expressions is impaired in people with schizophrenia or high levels of schizotypy. The present study examined whether the detection of emotional facial expressions would be associated with schizotypy in a non-clinical population after controlling for the effects of IQ, age, and sex. Participants were asked to respond to whether all faces were the same as quickly and as accurately as possible following the presentation of angry or happy faces or their anti-expressions among crowds of neutral faces. Anti-expressions contain a degree of visual change that is equivalent to that of normal emotional facial expressions relative to neutral facial expressions and are recognized as neutral expressions. Normal expressions of anger and happiness were detected more rapidly and accurately than their anti-expressions. Additionally, the degree of overall schizotypy was negatively correlated with the effectiveness of detecting normal expressions versus anti-expressions. An emotion–recognition task revealed that the degree of positive schizotypy was negatively correlated with the accuracy of facial expression recognition. These results suggest that people with high levels of schizotypy experienced difficulties detecting and recognizing emotional facial expressions.

Adaptation supports short-term memory in a visual change detection task

The maintenance of short-term memories is critical for survival in a dynamically changing world. Previous studies suggest that this memory can be stored in the form of persistent neural activity or using a synaptic mechanism, such as with short-term plasticity. Here, we compare the predictions of these two mechanisms to neural and behavioral measurements in a visual change detection task. Mice were trained to respond to changes in a repeated sequence of natural images while neural activity was recorded using two-photon calcium imaging. We also trained two types of artificial neural networks on the same change detection task as the mice. Following fixed pre-processing using a pretrained convolutional neural network, either a recurrent neural network (RNN) or a feedforward neural network with short-term synaptic depression (STPNet) was trained to the same level of performance as the mice. While both networks are able to learn the task, the STPNet model contains units whose activity are more similar to the in vivo data and produces errors which are more similar to the mice. When images are omitted, an unexpected perturbation which was absent during training, mice often do not respond to the omission but are more likely to respond to the subsequent image. Unlike the RNN model, STPNet produces a similar pattern of behavior. These results suggest that simple neural adaptation mechanisms may serve as an important bottom-up memory signal in this task, which can be used by downstream areas in the decision-making process.

A CH-Controlled Colorimetric Probe Based on Anthracene Carboximide for the Near-Infrared Detection of Cyanide

A novel CH-controlled colorimetric probe based on anthracene carboximide was developed for the near-infrared detection of cyanide. The probe was constructed by attachment of a CHCN binding site to anthracene carboximide fluorophore, and it showed a significant visual change from yellow-green (535 nm) to deep violet (825 nm) with a larger redshift (≈290 nm) when interacting with cyanide. The C-H deprotonation sensing mechanism was confirmed by 1H NMR titration. Additionally, colorimetric test paper was conveniently used to detect cyanide in aqueous solutions. The near-infrared detection of cyanide by CH-controlled probes was founded for the first time.

Differential Effects of Experience and Information Cues on Metacognitive Judgments About Others’ Change Detection Abilities

This study explored the interaction between visual metacognitive judgments about others and cues related to the workings of System 1 and System 2. We examined how intrinsic cues (i.e., saliency of a visual change) and experience cues (i.e., detection/blindness) affect people’s predictions about others’ change detection abilities. In Experiment 1, 60 participants were instructed to notice a subtle and a salient visual change in a magic trick that exploits change blindness, after which they estimated the probability that others would detect the change. In Experiment 2, 80 participants watched either the subtle or the salient version of the trick and they were asked to provide predictions for the experienced change. In Experiment 1, participants predicted that others would detect the salient change more easily than the subtle change, which was consistent with the actual detection reported in Experiment 2. In Experiment 2, participants’ personal experience (i.e., whether they detected the change) biased their predictions. Moreover, there was a significant difference between their predictions and offline predictions from Experiment 1. Interestingly, change blindness led to lower predictions. These findings point to joint contributions of experience and information cues on metacognitive judgments about other people’s change detection abilities.

From universalism to the universatility. Bauhaus triad: subject, suit, dance

The relevance. The ХХ century universalism became the platform of the Bauhaus experiment. Author of different art forms took part in it. Today, universalism is transformed into universality. Over the course of a hundred years, the author’s thinking system has changed. The composition of the stage work was decided by using household stuff. Household object becomes worthy of the stage space and overlaps the person. The author of the ХХI century regains the right to be the main in interaction with the subject. This is the paradigm shift of the century. The purpose of the study. Analysis of the transformation of the idea of universality of movement and subject-suit from “Triadical Ballet” and O. Schlemmer’s theatre workshop to modern experimental performance projects. Art analysis of the interaction of movement and subject in the stage space of O. Schlemmer, G. Bohner and contemporary authors. The methodology: historical and comparative analysis. The result of the study was the analysis of the the author-creator’s thinking system of plastic modern work. The topicality of the study is the analysis of “Bauhaus tanzt II” (2018). Authors: M. Shurkal (Ukraine), A. Possarnig, P. Dominici (Austria). The practical significance. The experience discussed in the article proves that without the past there is no future. We analyze the change of consciousness of the author-creator, which was visualized in the change of the technique of staged activity. We make a visual change of the way the subject is used on the stage as a scenery or prop, and as an acting character. The conclusions. The mechanism of possible interaction of the object, costume, dance in the space of creative experiment gave universality to the Bauhaus triad. We see the value of the transformation of the “Triadic Ballet” of the ХХ century in changing the author’s thinking system. At the beginning of the ХХ century, the author’s focus is on the suit object, which should be moved. Аt the beginning of the ХХI century the author’s focus is on the interaction of the human performer and the object-suit by exploring the possibility of variety and amplitude of the movement.

State transitions in the statistically stable place cell population are determined by visual change

The hippocampus plays a central role in mammalian navigation and memory, yet an implementational understanding of the rules that govern the formation of individual place fields and the spatial-statistics of the population as a whole are lacking. We analysed large numbers of CA1 place fields recorded while rats foraged in different-sized environments up to 8.75 m2. We found that place cell propensities to form fields were proportional to open-field area, gamma-distributed, and conserved across environments. The properties of place fields varied positionally with a denser distribution of smaller fields near boundaries. Remarkably, the variation in field sizes and densities exactly countered each other, such that the population-level statistics were constant both within and between environments. Using a virtual reality replica of the environment, we showed that this variable rate of transition through the statistically stable place cell population was matched to change in the animals' visual scenes.