Gray Background Research Articles

Effects of Closed Mouth vs. Exposed Teeth on Facial Expression Processing: An ERP Study

The current study examines the neural mechanisms underlying facial recognition, focusing on how emotional expression and mouth display modulate event-related potential (ERP) waveforms. 42 participants categorized faces by gender in one of two experimental setups: one featuring full-face images and another with cropped faces presented against neutral gray backgrounds. The stimuli included 288 images balanced across gender, race/ethnicity, emotional expression (“Fearful”, “Happy”, “Neutral”), and mouth display (“closed mouth” vs. “open mouth with exposed teeth”). Results revealed that N170 amplitude was significantly greater for open-mouth (exposed teeth) conditions (p < 0.01), independent of emotional expression, and no interaction between emotional expression and mouth display was found. However, the P100 amplitude exhibited a significant interaction between these variables (p < 0.05). Monte Carlo simulations analyzing N170 latency differences showed that fearful faces elicited a faster response than happy and neutral faces, with a 2 ms delay unlikely to occur by chance (p < 0.01). While these findings challenge prior research suggesting that N170 is directly influenced by emotional expression, they also highlight the potential role of emotional intensity as an alternative explanation. This underscores the importance of further studies to disentangle these effects. This study highlights the critical need to control for mouth display when investigating emotional face processing. The results not only refine our understanding of the neural dynamics of face perception but also confirm that the brain processes fearful expressions more rapidly than happy or neutral ones. These insights offer valuable methodological considerations for future neuroimaging research on emotion perception.

Modeling the dynamics of contextual cueing effect by reinforcement learning.

Humans use environmental context for facilitating object searches. The benefit of context for visual search requires learning. Modeling the learning process of context for efficient processing is vital to understanding visual function in everyday environments. We proposed a model that accounts for the contextual cueing effect, which refers to the learning effect of scene context to identify the location of a target item. The model extracted the global feature of a scene and gradually strengthened the relationship between the global feature and its target location with repeated observations. We compared the model and human performance with two visual search experiments (letter arrangements on a gray background or a natural scene). The proposed model successfully simulated the faster reduction of the number of saccades required before target detection for the natural scene background compared with the uniform gray background. We further tested whether the model replicated the known characteristics of the contextual cueing effect in terms of local learning around the target, the effect of the ratio of repeated and novel stimuli, and the superiority of natural scenes.

Investigating the Effect of Polyetheretherketone (PEEK) Veneers on Bond Strength and Discoloration When Repairing Various Composites.

This study aimed to examine the impact of the strength and color change of composite materials that could be utilized in the repair of polyetheretherketone (PEEK) veneer fractures. The 220 nanoceramic-filled PEEK specimens used in the study were divided into four groups, and color measurements were made on a gray background (n=55): Group N, 1-mm-thick monochromatic composite; Group NN, 2-mm-thick monochromatic composite; Group F, 1-mm-thick 2-mm-diameter short fiber-reinforced composite, placed in the center and polymerized; and Group FF, 2-mm-thick 2-mm-diameter short fiber-reinforced composite, placed in the center and polymerized. The remaining mating surfaces were restored by filling with monochromatic composite and adhesion strength testing by re-measuring the color. The results of the two-way ANOVA indicated that there was a significant color change caused by both thickness and composite type (p<0.001). Additionally, a significant difference in bond strength was observed between the groups. In PEEK restorations, short fiber-reinforced composites significantly increase bond strength, while the use of monochromatic composites of a certain thickness ensures that color change remains within acceptable limits. Although PEEK has a superior mechanical structure, it does not meet the aesthetic expectations and needs to be veneered. However, fractures are frequently seen due to low bond strength. Therefore, this study is important because it aims to provide guidance to clinicians on aesthetic and mechanical methods that can be used in PEEK prosthesis repair.

Correlation between repeated low-level red light-induced afterimage and axial changes in myopia control

PurposeTo explore the correlation between afterimages induced by repeated low-level red light (RLRL) and changes in refraction. MethodPatients who used RLRL for myopia control from 2023.02 to 2024.06 were included in this study. The afterimage appeared on a gray background (RGB 217,217,217; Lab 87,0,0). Afterimage color was recorded with CIELAB nomenclature (R, G, B; L, a, b), and afterimage duration (T) was recorded in seconds. Axial length (AL) and axial length-to-corneal radius ratio (AL/CR) were followed up at 1-, and 3-month. Participants were divided into groups based on a = 0 for GroupR (a>0,red bias in afterimage) and GroupG (a<0,green bias in afterimage); b = 0 for GroupY (b>0,yellow bias in afterimage) and GroupB (b<0,blue bias in afterimage), and T = 50.50 for GroupS (T<50.50,shorter afterimage duration) and GroupL (T>50.50,longer afterimage duration). ResultsA total of 52 participants were included in this study, with an age of 9.25 (1.75) years, 27 (51.92 %) males. The T median (P25, P75) was 50.50 (31.25,85.50) s. After RLRL treatment, divided by a = 0, GroupG showed significantly more shortening in the AL changes than GroupR at 1month and 3months (both P<0.05) and the AL/CR changes difference was not significant. Divided by T = 50.50, GroupS showed significantly greater shortening in the AL changes than GroupL at only 1month (P<0.05) and the AL/CR changes difference was not significant. Divided by b = 0, the difference between GroupY and GroupB was not statistically significant (P>0.05). ConclusionThe change of AL after RLRL treatment showed a correlation to the afterimage. Patients with green afterimage and shorter afterimage duration have a better AL shortening after RLRL treatment. Afterimage may serve as a biomarker for more effective myopia control.

Lichen Planus: Health Related Quality of Life, Dermoscopic Features and Clinical Variants in Uganda

Background: Lichen planus is a chronic, lichenoid inflammatory disorder affecting skin, mucous and appendages that can negatively impact patients’ quality of life. The clinical variants and dermoscopic feature vary based on skin type and race. Such an understanding can ease the diagnosis of lichen planus among dark skinned people. Aims and Objective: The goal of this study was to assess the quality of life and to describe the clinical variants and dermoscopic features among adult patients with lichen planus attending a Regional Referral Hospital skin clinic. Methods: A cross-sectional study was conducted from January to June 2024. A questionnaire was used to collect patients’ data, a standardized tool (DLQI) to assess the quality of life, dermoscopy for describing dermoscopic features and data analyzed using Stata version 17.0. Results: We enrolled 52 adult patients, the median age was 34.5 IQR= 25 – 47. There was a significant relationship between itch X2(1, n = 52) =17.5102, p&lt;.001), embarrassment X2(1, n = 52) =9.5510, p&lt;.002) with patients’ impaired quality of life. More patients had a very large effect on their quality of life (36.54%). The most common variants were classical (50%) and hypertrophic (23.08%). On dermoscopy 104 lesions were examined, (25.96%) of lesions had a violet, (22.11%) gray, (15.38%) gray-blue and (15.38%) gray-violet background. The pigmentary changes seen were mostly brown (69.23%). Wickham’s striae patterns were reticulate (21.15%) and diffuse (14.42%). Limitation: A single study site. Conclusions: lichen planus exerts a very large effect on patient’s quality of life. Itchy skin and a feeling of embarrassment significantly affected the quality of life. Classical and hypertrophic were the most common forms of lichen planus. The most lesions had violaceous or a grayish background, and had brown pigments with a reticulate and diffuse wickham’s striae patterns. Routine screening of quality of life should be practiced on patients with lichen planus.

Evaluation of the Effect of Background Color on the Color Change of Composite Resins of Different Translucencies

Aim: To evaluate the effect of background color on the color change evaluation of composite resins of different translucency. Material and Method: In our study, Estelite ∑ Quick (EQ) CE, OA2 and Filtek Ultimate (FU) A2 Enamel, A2 Dentin composites were used. Disc-shaped samples were prepared from the composites of both brands by layering enamel and dentin alone and enamel + dentin (n=10). After preparation, samples were kept in distilled water for 24 hours and then in coloring solution (NescafeClassic) for 10 days. Colors of the composite samples were measured with a spectrophotometer (VıtaEasyshade) on black, white and gray backgrounds after 24 hours (initial) and after coloring. Color change value (ΔE00) was calculated using two measurement values for each background. Color change values of the same composites measured on different backgrounds were compared. Additionally, the ΔE00 values of different translucent tones from the same company were compared on different backgrounds. One-way ANOVA and Tukey's post-hoc tests were used for statistical analysis. (α=0.05). Results: When used layered with dentin, enamel composites consistently showed lower ΔE00 values than enamel composites alone (p&lt;0.05). When comparing ΔE00 values of the same composite resin samples on different background colors, the ΔE00 values measured on black background were found to be higher only for FU enamel compared to the values measured on the other two backgrounds (p&lt;0.05). When different translucent shades from the same company were compared on different backgrounds, the ΔE00 ranking was found to be enamel &gt; dentin &gt;/=mine + dentin for all backgrounds. Conclusion: Different backgrounds did not affect the color evaluation of samples containing an opaque composite resin, dentin composite; however, they did affect the color evaluation of FU enamel, which is a translucent composite resin. When translucent composite resins are layered with more opaque composite resins, more accurate color evaluation can be achieved.

Evaluation of Color and Translucency Changes of PEEK Material Veneered with Single-Shade Composite Resins

Aim: The aim of this study was to evaluate the color and translucency changes of single-shade composites used in veneering polyetheretherketone (PEEK) material after aging. Materials and Methods: 3 single-shade composites with different chemical structures and 1 conventional composite resin were applied on the PEEK material with a thickness of 2 mm (N=40, n=10). L, a, and b color coordinates of each specimen were measured three times with a spectrophotometer on a black, gray, and white background from the center of the specimen, and the average of these measurements was recorded. The specimens were subjected to 5000 cycles of thermal aging at 5-55°C. After aging, color measurements were repeated. Color changes (ΔE00) and translucency parameters (ΔTP00) of composite resin specimens were determined before and after aging using CIEDE 2000 color formulas. The data obtained were analyzed by one-way analysis of variance and Tukey HSD test (p&lt;0.05). Results: As a result of the study, the color change of all composite resin materials was found to be below the clinically acceptable limit (ΔE = 1.8). The lowest color change was observed in the traditional composite group, and a statistically significant difference was found between the other groups (p&lt;0.05). The translucency change of single-shade composite materials was found to be statistically lower than that of conventional composite resin (p&lt;0.05). Conclusion: This study's results show that single-shade composite resins can be used as an optical alternative to traditional composites in direct veneering of the PEEK material.

Microsaccadic suppression of peripheral perceptual detection performance as a function of foveated visual image appearance.

Microsaccades are known to be associated with a deficit in perceptual detection performance for brief probe flashes presented in their temporal vicinity. However, it is still not clear how such a deficit might depend on the visual environment across which microsaccades are generated. Here, and motivated by studies demonstrating an interaction between visual background image appearance and perceptual suppression strength associated with large saccades, we probed peripheral perceptual detection performance of human subjects while they generated microsaccades over three different visual backgrounds. Subjects fixated near the center of a low spatial frequency grating, a high spatial frequency grating, or a small white fixation spot over an otherwise gray background. When a computer process detected a microsaccade, it presented a brief peripheral probe flash at one of four locations (over a uniform gray background) and at different times. After collecting full psychometric curves, we found that both perceptual detection thresholds and slopes of psychometric curves were impaired for peripheral flashes in the immediate temporal vicinity of microsaccades, and they recovered with later flash times. Importantly, the threshold elevations, but not the psychometric slope reductions, were stronger for the white fixation spot than for either of the two gratings. Thus, like with larger saccades, microsaccadic suppression strength can show a certain degree of image dependence. However, unlike with larger saccades, stronger microsaccadic suppression did not occur with low spatial frequency textures. This observation might reflect the different spatiotemporal retinal transients associated with the small microsaccades in our study versus larger saccades.

Influence of preheating and water storage on the color, whiteness, and translucency of modern resin-based composites.

To evaluate the influence of preheating and water storage on color, whiteness, and translucency of one-shaded, group-shaded, and multi-shaded resin-based composites. A total of 270 samples were fabricated from one-shaded (Omnichroma), group-shaded (Optishade MD), and multi-shaded (Enamel Plus HRI) resin-based composites and divided into six groups: no heating (control) and 1-5 heatings (test) (n = 15). The CIE L*, a*, b*, C*, and h° color coordinates were registered over white, black, and gray backgrounds with a spectrophotometer before and after 24, 72, 144 h water storage. Kruskal-Wallis test was used to evaluate differences in the color coordinates, whiteness index, and translucency parameter (α = 0.05). The Mann-Whitney U test was performed with a Bonferroni correction (p < 0.001) for pairwise comparisons. CIEDE2000 color, whiteness, and translucency differences between groups and subgroups were evaluated using their respective 50%:50% perceptibility and acceptability thresholds. Preheating influenced color coordinates, whiteness index, and relative translucency parameters (p < 0.001). Although color differences were below the acceptability threshold for all materials, translucency differences were above the acceptability threshold for Omnichroma. Water storage significantly influenced the whiteness index of Optishade MD (p < 0.001). Preheating had a more considerable effect on the color, whiteness, and translucency of one-shaded resin-based composite, while water storage influenced group-shaded resin-based composite more importantly. Preheating influences the color, whiteness level, and translucency of the resin-based composites, but the variations remain generally clinically acceptable; however, practitioners should be aware that the modifications in translucency for one-shaded resin-based composites could be more important than for group-shaded and multi-shaded resin-based composites.

Implied occlusion and subset underestimation contribute to the weak-outnumber-strong numerosity illusion.

Four experimental studies are reported using a total of 712 participants to investigate the basis of a recently reported numerosity illusion called "weak-outnumber-strong" (WOS). In the weak-outnumber-strong illusion, when equal numbers of white and gray dots (e.g., 50 of each) are intermixed against a darker gray background, the gray dots seem much more numerous than the white. Two principles seem to be supported by these new results: 1) Subsets of mixtures are generally underestimated; thus, in mixtures of red and green dots, both sets are underestimated (using a matching task) just as the white dots are in the weak-outnumber-strong illusion, but 2) the gray dots seem to be filled in as if partially occluded by the brighter white dots. This second principle is supported by manipulations of depth perception both by pictorial cues (partial occlusion) and by binocular cues (stereopsis), such that the illusion is abolished when the gray dots are depicted as closer than the white dots, but remains strong when they are depicted as lying behind the white dots. Finally, an online investigation of a prior false-floor hypothesis concerning the effect suggests that manipulations of relative contrast may affect the segmentation process, which produces the visual bias known as subset underestimation.

Your Eyes on Speed: Using Pupil Dilation to Adaptively Select Speed-Reading Parameters in Virtual Reality

Rapid Serial Visual Presentation (RSVP) improves the reading speed for optimizing the user's information processing capabilities on Virtual Reality (VR) devices. Yet, the user's RSVP reading performance changes over time while the reading speed remains static. In this paper, we evaluate pupil dilation as a physiological metric to assess the mental workload of readers in real-time. We assess mental workload under different background lighting and RSVP presentation speeds to estimate the optimal color that discriminates the pupil diameter varying RSVP presentation speeds. We discovered that a gray background provides the best contrast for reading at various presentation speeds. Then, we conducted a second study to evaluate the classification accuracy of mental workload for different presentation speeds. We find that pupil dilation relates to mental workload when reading with RSVP. We discuss how pupil dilation can be used to adapt the RSVP speed in future VR applications to optimize information intake.

A chart-based test of contrast sensitivity in noise: reference ranges, effects of age and optical abnormality

ABSTRACT Clinical relevance Contrast sensitivity plays an important role in the comprehensive assessment of visual function; however, measurement with standard eye charts can be affected by age and optical abnormality. Background This study describes a novel chart-based test of letter contrast sensitivity (CS) in luminance noise (the Illinois Eye and Ear Noise CS test), defines normal reference ranges, estimates test-retest repeatability, and assesses the effects of age and simulated optical abnormalities. Methods Seventy-five individuals with normal visual function (age 18–85 years) participated. Subjects identified letter optotypes that spanned a broad contrast range (0.9% to 59.6%) printed in a book-based test. Letters were presented against a grey background (no-noise condition) and in luminance noise that consisted of light and dark checks (noise condition). A subset of 10 subjects repeated the test to define short-term variability and performed the test under three additional conditions: simulated cataract, +2.00D defocus, and low room illuminance. Results In the no-noise condition, CS was independent of age (mean log CS of 1.74) until approximately 54 years, and declined for older subjects (CS loss of 0.1 log unit/decade). CS measured in noise was independent of age across the range of ages tested (mean log CS of 0.91). The 95% limits of agreement for test-retest repeatability was 0.19 log units. Simulated cataract, +2.00D defocus, and reduced illumination significantly reduced CS in the no-noise condition (F = 102.6, p < 0.001), whereas these optical manipulations did not significantly affect CS in noise (F = 2.58, p = 0.074). Conclusions Measurements of CS in luminance noise may be valuable, as these measures are largely independent of age and certain forms of optical degradation. CS measurements in noise may provide useful insight into visual function in patients who have combined neural and optical abnormality, as noise minimises CS loss from optical defects.

Red Backgrounds Enhance Dominance in Human Faces and Shapes.

Red color signals dominance in both animals and humans. This study investigated whether a red background color influences the perception of dominance in human faces and geometric shapes. The facial stimuli consisted of computer-generated faces, quantitatively morphed into nine levels of dominance, ranging from less dominant to more dominant. This included East-Asian female faces in Experiment 1 and male faces in Experiment 2. The face stimuli were presented against three background colors: red, green, and gray. Participants were instructed to categorize the faces as either obedient or dominant by pressing the corresponding labeled keys. The results showed that faces were more likely to be perceived as dominant when presented against a red background than against green or gray backgrounds, for both female and male faces. Additionally, two questionnaire surveys showed that the perception of dominance also increased for shapes presented against a red background. However the effect of red diminished in the absence of the actual perception of the color red. These results suggest that the perception of dominance in both human faces and objects is enhanced by the presence of red, possibly due to evolutionary factors related to the perception of red.

The effect of target and background texture on relative depth discrimination in a virtual environment

The spatial frequency (SF) content of an object’s texture is an important cue for depth perception, although less is known about the role of background texture. Here, we used bandpass-filtered noise patterns to systematically study the interactions between target and background textures in a virtual environment. During the trials, three square targets were presented at 3 m against a background wall 6 m away from the observer. One of the squares was presented closer than the other two, and the subjects had to indicate it with a key press. The threshold distance from the two reference tiles was determined using a staircase procedure. Both the target and background were tested with different combinations of SF textures and a non-textured gray, which were rendered onto the flat surfaces. Against a gray background, the distance thresholds were smallest when the targets were presented with a mid-SF texture. Performance declined significantly with a non-textured target against a textured background. With different combinations of target-background texture, the background texture significantly affected the performance. We propose several hypotheses to explain the behavioral result. Understanding the effect of surrounding texture can be useful in improving the depth perception experience in virtual reality.

Translucency and Color Difference of Monolithic Zirconia Restorations: The Effect of Surface Finishing on Background Color

Aim: This study evaluates the effect of different surface finishing procedures on the color and translucency values of monolithic zirconia materials on three different colored composite backgrounds. Materials and Methods: Sixty monolithic zirconia blocks of three different translucency levels were prepared in vitro using computer-aided design/computer-aided manufacturing (CAD/CAM) systems. The correlation between repeat measurements was 0.5, resulting in a sample size of nine samples per group to detect a medium effect size, f = 0.25. Half of the zirconia blocks in each group were subjected to glazing, while the other half were polished ( n = 10). Composite blocks of three different colors were prepared to simulate dental substrates, and the zirconia specimens were placed on these composite backgrounds. The color parameters of the specimens were measured using a spectrophotometer on gray, black, and white backgrounds. Three-way repeated measure ANOVA was used to assess the interaction between the three independent variables (zirconia brand, surface finishing technique, and background color) and the effects of each tested variable on the changes in color and translucency. Results: The surface finishing techniques had a significant effect on the color and translucency of the monolithic zirconia materials. Glazing resulted in higher color differences and lower translucency values compared to polishing. For backgrounds of the same color, no significant differences were detected between the glazed zirconia groups for the same condition ( p &gt; .016). Conclusion: Overall, the study demonstrated the importance of selecting the appropriate surface finishing technique and translucency property of the monolithic zirconia materials to obtain the optimal esthetic results in dental restorations.

Scotopic and Photopic Conventional Visual Acuity and Hyperacuity - Binocular Summation.

The purpose of this study was to determine and compare binocular summation (BiS) of conventional visual acuity (cVA) versus hyperacuity (hVA) for photopic and scotopic luminance conditions as a potential biomarker to assess the outcome of interventions on binocular function. Sixteen young adults (age range [years] = 21-31; 8 women; cVA logMAR < 0.0) participated in this study. The Freiburg Visual Acuity Test (FrACT) was used for VA testing and retested on another day. Both cVA and hVA were determined for dark grey optotypes on light grey background. Participants underwent 40minutes of dark adaptation prior to scotopic VA testing. Binocular and monocular VA testing was performed. The eye with better VA over the 2 days of testing was selected, the BiS was quantified (binocular VA - better monocular VA) and repeated measures ANOVAs were performed. Binocular VA exceeded monocular VA for all luminance conditions, VA-types, and sessions. We report BiS estimates for photopic and scotopic cVA and hVA, (logMAR BiS ± SEM [decimal BiS]): photopic = -0.01 ± 0.01 [1.03] and -0.06 ± 0.03 [1.15]; and scotopic = -0.05 ± 0.01 [1.12] and -0.11 ± 0.04 [1.28], respectively). Improvement for binocular vision estimates ranged from 0.01 to 0.11 logMAR. A repeated-measures ANOVA (RM ANOVA) did not reveal significant effects of LUMINANCE or VA TYPE on BiS, albeit a trend for strongest BiS for scotopic hVA (15% vs. 28%, photopic versus scotopic, respectively) and weakest for photopic cVA (3% vs. 12%, photopic versus scotopic conditions, respectively). Our results indicate that BiS of VA is relevant to scotopic and photopic hVA and cVA. It appears therefore a plausible candidate biomarker to assess the outcome of retinal therapies restoring rod or cone function on binocular vision. Binocular summation of visual acuity might serve as a clinical biomarker to monitor therapy outcome on binocular rod and cone-mediated vision.

Characterization of Microstructure, Optical Properties, and Mechanical Behavior of a Temporary 3D Printing Resin: Impact of Post-Curing Time.

The present study aimed to characterize the microstructure of a temporary 3D printing polymer-based composite material (Resilab Temp), evaluating its optical properties and mechanical behavior according to different post-curing times. For the analysis of the surface microstructure and establishment of the best printing pattern, samples in bar format following ISO 4049 (25 × 10 × 3 mm) were designed in CAD software (Rhinoceros 6.0), printed on a W3D printer (Wilcos), and light-cured in Anycubic Photon for different lengths of time (no post-curing, 16 min, 32 min, and 60 min). For the structural characterization, analyses were carried out using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The mechanical behavior of this polymer-based composite material was determined based on flexural strength tests and Knoop microhardness. Color and translucency analysis were performed using a spectrophotometer (VITA Easy Shade Advanced 4.0), which was then evaluated in CIELab, using gray, black, and white backgrounds. All analyses were performed immediately after making the samples and repeated after thermal aging over two thousand cycles (5-55 °C). The results obtained were statistically analyzed with a significance level of 5%. FT-IR analysis showed about a 46% degree of conversion on the surface and 37% in the center of the resin sample. The flexural strength was higher for the groups polymerized for 32 min and 1 h, while the Knoop microhardness did not show a statistical difference between the groups. Color and translucency analysis also did not show statistical differences between groups. According to all of the analyses carried out in this study, for the evaluated material, a post-polymerization time of 1 h should be suggested to improve the mechanical performance of 3D-printed devices.

Errors in visual search: Are they stochastic or deterministic?

In any visual search task in the lab or in the world, observers will make errors. Those errors can be categorized as “deterministic”: If you miss this target in this display once, you will definitely miss it again. Alternatively, errors can be “stochastic”, occurring randomly with some probability from trial to trial. Researchers and practitioners have sought to reduce errors in visual search, but different types of errors might require different techniques for mitigation. To empirically categorize errors in a simple search task, our observers searched for the letter “T” among “L” distractors, with each display presented twice. When the letters were clearly visible (white letters on a gray background), the errors were almost completely stochastic (Exp 1). An error made on the first appearance of a display did not predict that an error would be made on the second appearance. When the visibility of the letters was manipulated (letters of different gray levels on a noisy background), the errors became a mix of stochastic and deterministic. Unsurprisingly, lower contrast targets produced more deterministic errors. (Exp 2). Using the stimuli of Exp 2, we tested whether errors could be reduced using cues that guided attention around the display but knew nothing about the content of that display (Exp3a, b). This had no effect, but cueing all item locations did succeed in reducing deterministic errors (Exp3c).

Accuracy and Speed of Emotion Recognition With Face Masks.

Wearing face masks is one of the important actions to prevent the spread of COVID-19 among people around the world. Nevertheless, social interaction is limited via masks, and this impacts the accuracy and speed of emotional perception. In the present study, we assess the impact of mask-wearing on the accuracy and speed of emotion recognition. Fifty people (female n = 39, male n = 11) aged 19-28 participated in the study (M = 21.1 years). We used frontal photos of a Kosova woman who belonged to the same participants' age group, with a grey background. Twelve different pictures were used that showed the emotional states of fear, joy, sadness, anger, neutrality, and disgust, in masked and unmasked conditions. The experiment was conducted in a controlled laboratory setting. Participants were faster for identifying emotions like joy (1.507 ms) and neutral (1.971 ms). The participants were more accurate (emotions identification) in unmasked faces (M = 85.7%) than in masked faces (M = 73.8%), F(1,98) = 20.73, MSE = 1027.66, p ≤ .001, partial η² = 0.17. Masks make confusion and reduce the accuracy and speediness of emotional detection. This may have a notable impact on social interactions among peoples.

Effects of binocular disparity on binocular luminance combination.

This study aimed to examine the effects of binocular disparity on binocular combination of brightness information coming from luminance increments and decrements. The point of subjective equality was determined by asking the observers to judge which stimulus appeared brighter-a bar stimulus with variable disparity or another stimulus with zero disparity. For the bar stimulus, the interocular luminance ratio was varied to trace an equal brightness curve. Binocular disparity had no effect on luminance increments presented on a gray or black background. In contrast, when luminance decrements were presented on a gray background, non-zero disparities elevated points of subjective equality for stimuli with interocular luminance differences. This means that the binocular brightness combination of the two monocular signals shifted from winner-take-all summation toward linear averaging. It has been argued that this effect may be caused by non-zero binocular disparities attenuating interocular suppression, which is deemed to operate normally with zero disparity.