Perceptual task drives later fixations and long latency saccades, while early fixations and short latency saccades are more automatic.

We used a simple stimulus, dissociating perceptually relevant information in space, to differentiate between bottom-up and task-driven fixations. Six participants viewed a dynamic scene showing the reaction of an elastic object fixed to the ceiling being hit. In one condition they had to judge the object's stiffness and in the other condition its lightness. The results show that initial fixations tend to land in the centre of an object, independent of the task. After the initial fixation, participants tended to look at task diagnostic regions. This fixation behaviour correlates with high perceptual performance. Similarly, low-latency saccades lead to fixations that do not depend on the task, whereas higher latency does.

Effect of polishing and bleaching on color, whiteness, and translucency of CAD/CAM monolithic materials.

OBJECTIVE: To evaluate the effect of polishing and bleaching on the recovery of lightness, color, whiteness, and relative translucency parameter (RTP) in CAD/CAM materials and changes in these properties when another staining in coffee was conducted after the treatments. MATERIALS AND METHODS: Disks of Lava Ultimate (LU), Vita Enamic (VE), IPS Empress CAD (EMP), IPS e.max CAD (EMAX), and Vita Suprinity (VS) were (1) not treated (control), (2) polished with Proxyt or (3) Ceramisté, (4) bleached with Opalescence PF or (5) Whiteness HP Blue, and (6) air polished with Clinpro Prophy Powder. CIE L*a*b* color coordinates were registered at baseline (R0), after staining with coffee for 30 min daily for 36.5 days and treatment (R1), and after another staining (R2). Differences (R1-R0 and R2-R0) in lightness (ΔL00), color (ΔE00), RTP (ΔRTP00), and whiteness (ΔWID) were evaluated by mixed repeated measures ANOVA and 95% confidence intervals (α = 0.05) and interpreted in function of their respective 50:50% PT and AT thresholds. Topography was evaluated by scanning electron microscopy (SEM). RESULTS: In LU, Opalescence PF and Proxyt decreased Δ L 00 R 1 - R 0 $$ {\Delta L}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , Δ E 00 R 1 - R 0 $$ {\Delta E}_{00\left({R}_1\hbox{--} {\mathrm{R}}_0\right)} $$ , and ΔWI D R 1 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_1\hbox{--} {R}_0\right)} $$ and showed lower Δ L 00 R 2 - R 0 $$ {\Delta L}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , and ΔWI D R 2 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_2\hbox{--} {R}_0\right)} $$ . In VE, all treatments decreased Δ L 00 R 1 - R 0 $$ {\Delta L}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , Δ E 00 R 1 - R 0 $$ {\Delta E}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , and ΔWI D R 1 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_1\hbox{--} {R}_0\right)} $$ , whereas Δ L 00 R 2 - R 0 $$ {\Delta L}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , and ΔWI D R 2 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_2\hbox{--} {R}_0\right)} $$ were lower in Opalescence PF than in the control group. In both moments, ΔE00 and ΔWID in EMP (also ΔL00) and EMAX were higher in Opalescence PF than in the control group, from which the other treatments did not differ in R1-R0. In EMP, Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ in Whiteness HP Blue (also Δ L 00 R 2 - R 0 $$ {\Delta L}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ ) and Proxyt were also higher in comparison to the control group and in VS, Ceramisté decreased Δ L 00 R 1 - R 0 $$ {\Delta L}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , Δ E 00 R 1 - R 0 $$ {\Delta E}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , and Δ R T P 00 R 1 - R 0 $$ \varDelta RT{P}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , whereas Opalescence PF increased ΔRTP 00 R 1 - R 0 $$ {\Delta \mathrm{RTP}}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ . Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ of Ceramisté and ΔWI D R 2 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_2\hbox{--} {R}_0\right)} $$ and Δ R T P 00 R 2 - R 0 $$ \varDelta RT{P}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ of Proxyt were lower than those of the control group. CONCLUSIONS: The most suitable treatment to recover the lightness, color, whiteness, and RTP without changing these properties after another coffee exposure is material-dependent. CLINICAL SIGNIFICANCE: Although the effectiveness of the treatment was material-dependent, Proxyt was the only treatment that promoted clinically acceptable changes for both LU and VE, while for purely ceramic materials, this condition was observed with Ceramisté and Clinpro Prophy Powder.

Perceptibility and acceptability of lightness difference of a single maxillary central incisor.

OBJECTIVES: The aim of this study was to assess the lightness difference perceptibility and acceptability thresholds, for a single maxillary central incisor, and to investigate possible differences in these thresholds regarding the direction (+ΔL* vs. -ΔL*), the observer group (dentists vs. laypersons), and the gender and age of the observers. MATERIALS AND METHODS: A series of images with varying lightness (L*), were created by altering the right maxillary central incisor of a male Caucasian, on a frontal view full-portrait image. Digital modification of one central incisor by 1 ΔL* unit resulted in 15 different images: one control, seven with increased and seven with decreased lightness. The images were presented in random order, on a digitally calibrated monitor, to 158 observers, grouped into 79 dentists, and 79 laypersons, who were asked to evaluate every image and answer whether they perceive a difference and if yes, whether they accept this difference. A multifactorial analysis of covariance was performed to analyze the perception and acceptance of any difference in the central incisors and to estimate the thresholds. The statistical significance level was α = 0.05. RESULTS: Overall, the magnitude of ΔL*, direction of ΔL*, observer group and age were each significant (p < 0.001), as was gender (p = 0.03). The effect of the magnitude of ΔL* interacted with its direction and the observer group (p = 0.045), and the effect of age interacted with the direction of ΔL*, and the gender and the group of the observers. Estimated 50%:50% perceptibility thresholds ranged from 0.1 to 2.7, and 50%:50% acceptability thresholds ranged from 2.3 to 4.5. Overall, dentists perceived lightness differences at lower magnitudes than laypersons; difference in lightness was perceived and accepted at lower magnitudes when the tooth become lighter instead of darker; and female observers perceived and accepted lightness differences at lower magnitudes compared to males. As age increased overall, differences of lightness were perceived and accepted at higher magnitudes. CONCLUSIONS: Perceptibility and acceptability of lightness differences of a single maxillary central incisor are affected by the magnitude and the direction of lightness change, as well as the gender, the age, and the type of the observers. CLINICAL SIGNIFICANCE: Even small changes in lightness are perceivable; however, thresholds of perception and acceptance are dependent on the magnitude and the direction of change and are also dependent on the observer, with women, dentists and younger people perceiving and accepting changes at lower magnitudes of ΔL*.

Lightness constancy in reality, in virtual reality, and on flat-panel displays.

Virtual reality (VR) displays are being used in an increasingly wide range of applications. However, previous work shows that viewers often perceive scene properties very differently in real and virtual environments and so realistic perception of virtual stimuli should always be a carefully tested conclusion, not an assumption. One important property for realistic scene perception is surface color. To evaluate how well virtual platforms support realistic perception of achromatic surface color, we assessed lightness constancy in a physical apparatus with real lights and surfaces, in a commercial VR headset, and on a traditional flat-panel display. We found that lightness constancy was good in all three environments, though significantly better in the real environment than on the flat-panel display. We also found that variability across observers was significantly greater in VR and on the flat-panel display than in the physical environment. We conclude that these discrepancies should be taken into account in applications where realistic perception is critical but also that in many cases VR can be used as a flexible alternative to flat-panel displays and a reasonable proxy for real environments.

Stratification patterns of anammox granular sludge bed: Linking particle size distribution to microbial activity and community.

Anammox granular sludge processes are an attractive and efficient biotechnology in the field of wastewater treatment. In this study, the stratification patterns of anammox granular sludge bed (GSB) at steady states were illustrated and its relationship to microbial activity and community were systematically investigated under different nitrogen loading rates (NLRs). Morphological observation and quantitive particle size distribution analysis demonstrated that the GSB at low NLR was mainly composed of micro and fine granules with a big difference between bottom and top sludge layers. But at high NLR, the volumetric mean diameter (VMD) of GSB increased with the size distribution width (Span) declined forming a more homogeneous and coarse granules population. The particle size distribution parameters of GSB could be fast characterized by the optical lightness (L*) parameter (r = -0.771, p < 0.01, n = 16) and held a significant correlation with the nitrogen removal rate (NRR) of anammox system (r > 0.9, p < 0.05). The microbial spatial distribution patterns of different sludge layers were further investigated by high-throughput sequencing. The microbial community α-diversity index and microbial abundance matrix proved that the community structure tend to coverage at high NLR. Significant difference of the relative abundance of microbial community was detected under different NLRs. The VMD of GSB held a significant correlation with the relative abundance of AnAOB (r = 0.556, p < 0.01, n = 16) and other common accompanying bacteria (Denitratisoma and Chloroflexi). This study proved that the apparent particle size distribution patterns of GSB could be a potential auxiliary indicator to reflect the microbial activity and community, which can facilitate the innovative process monitor of anammox system based on visual features.

Age-related dental phenotypes and tooth characteristics of FAM83H-associated hypocalcified amelogenesis imperfecta.

OBJECTIVES: Autosomal-dominant hypocalcified amelogenesis imperfecta (ADHCAI) shows phenotypic heterogeneity. Our aim was to characterise the ADHCAI phenotypes, tooth properties and genotypes. METHODS: Three unrelated ADHCAI probands and seven additional affected members of the three families were recruited. Mutations were identified by exome and Sanger sequencing, and haplotypes by SNP array. Tooth colour, roughness, density, nanohardness, minerals and ultrastructure were investigated. RESULTS: Ten participants were heterozygous for the FAM83H mutation c.1387C>T (p.Gln463*). All shared a 3.43 Mbp region on chromosome 8q24.3 encompassing the FAM83H variant, indicating a common ancestry. The c.1387C>T was estimated to be 23.8 generations or 600 years. The FAM83H enamel had higher roughness and lower lightness, density, nanohardness, and calcium and phosphorus levels than controls. Blunted enamel rods, wide interrod spaces and disorganised dentinoenamel junctions were observed. Evaluating the patients with the same mutation and reviewing others with different mutations in FAM83H revealed that the FAM83H heterogeneous phenotypes are age-influenced. Tooth colour and surface texture change with ageing. CONCLUSIONS: FAM83H enamel demonstrated decreased lightness, density, hardness, calcium, phosphorus and defective ultrastructure. We have identified that the phenotypic variation in FAM83H-associated ADHCAI is age-related. Awareness of the correlation between age and clinical features of FAM83H-ADHCAI can help dentists make an accurate diagnosis.

Genome-wide association mapping reveals new loci associated with light-colored seed coat at harvest and slow darkening in carioca beans.

BACKGROUND: Common bean (Phaseolus vulgaris L.) is a legume whose grain can be stored for months, a common practice among Brazilian growers. Over time, seed coats become darker and harder to cook, traits that are undesirable to consumers, who associate darker-colored beans with greater age. Like commercial pinto and cranberry bean varieties, carioca beans that have darker seeds at harvest time and after storage are subject to decreased market values. RESULTS: The goal of our study was to identify the genetic control associated with lightness of seed coat color at harvest (HL) and with tolerance to post-harvest seed coat darkening (PHD) by a genome-wide association study. For that purpose, a carioca diversity panel previously validated for association mapping studies was used with 138 genotypes and 1,516 high-quality SNPs. The panel was evaluated in two environments using a colorimeter and the CIELAB scale. Shelf storage for 30 days had the most expressive results and the L* (luminosity) parameter led to the greatest discrimination of genotypes. Three QTL were identified for HL, two on chromosome Pv04 and one on Pv10. Regarding PHD, results showed that genetic control differs for L* after 30 days and for the ΔL* (final L*-initial L*); only ΔL* was able to properly express the PHD trait. Four phenotypic classes were proposed, and five QTL were identified through six significant SNPs. CONCLUSIONS: Lightness of seed coat color at harvest showed an oligogenic inheritance corroborated by moderate broad-sense heritability and high genotypic correlation among the experiments. Only three QTL were significant for this trait - two were mapped on Pv04 and one on Pv10. Considering the ΔL, six QTL were mapped on four different chromosomes for PHD. The same HL QTL at the beginning of Pv10 was also associated with ΔL* and could be used as a tool in marker-assisted selection. Several candidate genes were identified and may be useful to accelerate the genetic breeding process.

Most Findings Obtained With Untimed Visual Illusions Are Confounded.

Visual illusions have been studied extensively, but their time course has not. Here we show, in a sample of more than 550 people, that unrestricted presentation times-as opposed to presentations lasting only a single second-weaken the Ebbinghaus illusion, strengthen lightness contrast with double increments, and do not alter lightness contrast with double decrements. When presentation time is unrestricted, these illusions are affected in the same way (decrease, increase, no change) by how long observers look at them. Our results imply that differences in illusion magnitude between individuals or groups are confounded with differences in inspection time, no matter whether stimuli are evaluated in matching, adjustment, or untimed comparison tasks. We offer an explanation for why these three illusions progress differently, and we spell out how our findings challenge theories of lightness, theories of global-local processing, and the interpretation of all research that has investigated visual illusions, or used them as tools, without considering inspection time.

Behavioural and electrophysiological correlates of lightness contrast and assimilation.

Lightness contrast and assimilation are opposite phenomena: in contrast grey targets appear darker when bordering bright rather than dark surfaces; in assimilation grey targets appear lighter when bordering bright rather than dark surfaces. The underlying neurophysiological mechanisms of these phenomena are not known. The aim of this study was to investigate the relationship between contrast and assimilation, and the timing and levels of perceptual and cognitive processing using combined behavioural and electrophysiological methods. Thirty undergraduate students (23 female, age range 18-48 years) participated in a forced-choice (grey target is lighter/darker than a comparison square) task, using stimuli designed such that the inducers were in two configurations (small and large) and two shades (white and black). The behavioural data (more consistent and faster responses) corroborated previous findings of stronger contrast effects with white inducers and stronger assimilation effects with black inducers. According to the Event-Related Potentials (ERP) results the mean amplitude was larger in conditions with less consistent and slower behavioural responses. Thus, with contrast responses P1 amplitude was larger with black than white inducers, and N1 amplitude was larger to assimilation than contrast when the configuration of the stimulus was held constant. These results suggest contrast may occur as early as P1 (~ 110 ms) and assimilation may occur later in N2 (~ 220 ms), whereas in some conditions, differences in ERPs associated with contrast vs assimilation may happen as early as in N1 (~ 170 m), in occipital and parietal cortical sites.

Prediction of future wrinkles for middle-aged women: A 7-year longitudinal study on the progression of wrinkles in Japanese women.

BACKGROUND: It is commonly believed that there is serious heterogeneity in the rate of wrinkle progression among individuals. Although several skin characteristics have been shown to influence wrinkle progression, the ability to predict which individuals with skin characteristics are likely to develop wrinkles is still limited. OBJECTIVES: The purpose of this study is to develop and validate an effective prediction model for longitudinal changes in wrinkles. METHODS: We collected annual wrinkle scores and multiple skin physiological characteristics in 48 Japanese women over a period of 7 years. We developed a multivariable prediction model for predicting future wrinkle status based on the various skin physiological characteristics using a linear mixed-effects model. RESULTS: After variable selection by backwards, the final wrinkle prediction model included age, sebum volume, redness of skin color, lightness of skin color, and an interaction term between sebum volume and redness of skin color. The developed prediction model showed favorable prediction accuracy (R2  = 87.92%, 95% confidence interval 84.27%-90.68%). CONCLUSIONS: The developed model accurately predicted levels of wrinkles in Japanese women aged 22-60 years. The prediction model is based on age and three practical skin characteristics, which might implicate an essential insight to prevent wrinkle progression in individuals.

Influence of lightness difference of single anterior tooth to smile attractiveness.

OBJECTIVES: To evaluate the influence of lightness difference of a single anterior maxillary tooth on difference smile attractiveness. METHODS: A frontal view full-portrait image of a smiling male Caucasian, was digitally modified altering a single tooth, creating a series of images with varying lightness (ΔL) for the maxillary central, lateral and canine. A total of 160 participants (80 dentists, 80 laypersons) were asked to fill out a Visual Analog Scale questionnaire for every image recording smile attractiveness. RESULTS: For central incisors ΔL≥1 negatively affected attractiveness. There was a higher tolerance for lightness mismatch when one lateral incisor is lighter and the same applies when the canine was darker. Difference in lightness affected smile attractiveness both for dentists and laypersons. No difference between males and females was observed for the dentists. For laypersons, females perceived smiles with lightness difference as significantly less attractive compared to males. Dentist's age did not affect smile attractiveness perception. Younger laypersons perceived darker color, as less attractive. CONCLUSIONS: Changes in lightness of a single anterior tooth significantly affected smile attractiveness in a different way for the central vs lateral vs canine. For the dentists, age and gender did not significantly affect smile perception, in contrast to laypeople. CLINICAL SIGNIFICANCE: Lightness differences of a single anterior tooth affects smile attractiveness.

An Upward-Facing Surface Appears Darker: The Role Played by the Light-From-Above Assumption in Lightness Perception.

The human visual system can extract information on surface reflectance (lightness) from light intensity; this, however, confounds information on reflectance and illumination. We hypothesized that the visual system, to solve this lightness problem, utilizes the internally held prior assumption that illumination falls from above. Experiment 1 showed that an upward-facing surface is perceived to be darker than a downward-facing surface, proving our hypothesis. Experiment 2 showed the same results in the absence of explicit illumination cues. The effect of the light-from-left prior assumption was not observed in Experiment 3. The upward- and downward-facing surface stimuli in Experiments 1 and 2 showed no difference in a two-dimensional configuration or three-dimensional structure, and the participants' perceived lightness appeared to be affected by the observers' prior assumption that illumination is always from above. Other studies have not accounted for this illusory effect, and this study's finding provides additional insights into the study of lightness perception.

Neuronal population mechanisms of lightness perception.

The way that humans and animals perceive the lightness of an object depends on its physical luminance as well as its surrounding context. While neuronal responses throughout the visual pathway are modulated by context, the relationship between neuronal responses and lightness perception is poorly understood. We searched for a neuronal mechanism of lightness by recording responses of neuronal populations in monkey primary visual cortex (V1) and area V4 to stimuli that produce a lightness illusion in humans, in which the lightness of a disk depends on the context in which it is embedded. We found that the way individual units encode the luminance (or equivalently for our stimuli, contrast) of the disk and its context is extremely heterogeneous. This motivated us to ask whether the population representation in either V1 or V4 satisfies three criteria: 1) disk luminance is represented with high fidelity, 2) the context surrounding the disk is also represented, and 3) the representations of disk luminance and context interact to create a representation of lightness that depends on these factors in a manner consistent with human psychophysical judgments of disk lightness. We found that populations of units in both V1 and V4 fulfill the first two criteria but that we cannot conclude that the two types of information in either area interact in a manner that clearly predicts human psychophysical measurements: the interpretation of our population measurements depends on how subsequent areas read out lightness from the population responses. NEW & NOTEWORTHY A core question in visual neuroscience is how the brain extracts stable representations of object properties from the retinal image. We searched for a neuronal mechanism of lightness perception by determining whether the responses of neuronal populations in primary visual cortex and area V4 could account for a lightness illusion measured using human psychophysics. Our results suggest that comparing psychophysics with population recordings will yield insight into neuronal mechanisms underlying a variety of perceptual phenomena.

"Glowing Gray" Does Exist: Luminance Gradients' Influence on Whiteness Perception.

Studies on brightness and lightness that employed luminance gradients (i.e., glare stimuli) have suggested that we can perceive luminosity even when the brightness target is darker than white. Although such studies had great impact on research in luminosity perception, whether the whiteness threshold in glare stimuli was lower or higher than the luminosity threshold remained unclear. This study indicated that it is higher than the luminosity threshold, confirming the existence of glowing gray. Moreover, we measured the luminance gradients' effect on whiteness perception but found no significant effect. Discrepancy in the degree of gradients' effect on perceived luminosity and perceived white suggests that different mechanisms underlie luminosity (brightness) perception and whiteness (lightness) perception.

Hair Color and Skin Color Together Influence Perceptions of Age, Health, and Attractiveness in Lightly-Pigmented, Young Women.

OBJECTIVE: Research documents that even subtle changes in visible skin condition affect perceptions of age, health, and attractiveness. There is evidence that hair quality also affects the assessment of physical appearance, as variations in hair diameter, hair density, and hair style have systematic effects on perception. Here, we consider combined effects of hair color and skin color on the perception of female physical appearance. METHODS: In two experiments, we digitally manipulated facial skin color of lightly-pigmented, young women, both between-subjects (Experiment 1) and within-subjects (Experiment 2), and investigated possible interactions with hair color in regard to age, health, and attractiveness perception. RESULTS: In both experiments, we detected hair color and skin color interaction effects on men's and women's assessments. For between-subjects comparisons, participants with lighter hair color were judged to be younger than those with darker shades; this effect was more pronounced in women with light skin color. No such effect was observed for within-subjects variation in skin color. Both experiments showed that smaller perceived contrast between hair color and skin color resulted in more positive responses. CONCLUSION: We conclude that hair color and facial skin color together have an effect on perceptions of female age, health, and attractiveness in young women, and we discuss these findings with reference to the literature on the role of hair and skin in the assessment of female physical appearance. This article is protected by copyright. All rights reserved.

Infant skin maturation: Preliminary outcomes for color and biomechanical properties.

BACKGROUND: Newborn infant skin changes after birth but studies have focused on the epidermal barrier. Dermal properties are relevant for care, but literature on postnatal changes is sparse. We further characterized skin maturational changes in lightness, color and response to biomechanical stress. METHODS: Normal skin sites from subsets of participants in a trial on the progression and stage of infantile hemangiomas were retrospectively examined. Standardized photographs were analyzed as L*, a*, and b* images. Biomechanics were measured with the Cutometer® . RESULTS: Color changed significantly with increasing age. Skin was darker and redder at 2.0 vs. 5.4, 8.5 and 12.8 months. Yellow color increased, with higher values at 12.8 vs. 2.0, 3.5 and 5.4 months. Chest tissue was consistently more elastic than arm and face sites, with significantly higher elasticity for the youngest and oldest age groups. Biological elasticity, elastic recovery, and total recovery were significantly greater for the oldest subjects. Viscoelasticity and elastic deformation were lower at 5.5 vs. 8.8 and 17.6 months. Arm viscoelastic creep was highest at 2.8 months. CONCLUSION: Skin maturation continues into year two. Increasing elasticity and decreasing viscoelasticity may reflect increased collagen structure/function. The findings have implications for prevention of skin injury associated with mechanical forces.

How biological vision succeeds in the physical world.

Biological visual systems cannot measure the properties that define the physical world. Nonetheless, visually guided behaviors of humans and other animals are routinely successful. The purpose of this article is to consider how this feat is accomplished. Most concepts of vision propose, explicitly or implicitly, that visual behavior depends on recovering the sources of stimulus features either directly or by a process of statistical inference. Here we argue that, given the inability of the visual system to access the properties of the world, these conceptual frameworks cannot account for the behavioral success of biological vision. The alternative we present is that the visual system links the frequency of occurrence of biologically determined stimuli to useful perceptual and behavioral responses without recovering real-world properties. The evidence for this interpretation of vision is that the frequency of occurrence of stimulus patterns predicts many basic aspects of what we actually see. This strategy provides a different way of conceiving the relationship between objective reality and subjective experience, and offers a way to understand the operating principles of visual circuitry without invoking feature detection, representation, or probabilistic inference.

[Analysis of the color changes in teeth at different depths preparation]. / Analiz izmeneniia tsveta zubov pri ikh soshlifovyvanii na razlichnuiu glubinu.

Spectrophotometric analysis of the extract and intact teeth revealed the color characteristic of teeth ranged from the cervical area to the cutting edge, as well as by preparation of dental hard tissue to 0.3 mm, 0.6 mm, 0.9 mm depth. Lightness increased as preparation approached dentine. The intensity of the Lightness was more pronounced in the cervical region which is associated with a thin layer of enamel performing the lens function. It is found that Hue values weakly depend on the depth and location of the preparation, the tooth reflecting a relatively constant range of visible wavelengths. During preparation of the hard tissue at different depths the color difference δE* was greater than 2.6 meaning that the color must be registered before and after preparation.

[Spectrophotometric method for objective focal enamel demineralization diagnostics]. / Spektrofotometricheskii metod diagnostiki ochagovoi demineralizatsii émali zubov.

The article presents the results of spectrophotometric tooth enamel scanning. Research was conducted in vitro on extracted teeth. Numeric color parameters measurements were made by VITA EasyShade spectrophotometer after the 37% phosphoric acid enamel conditioning, that was made for an artificial tooth enamel demineralization reconstruction. Then transverse section of this enamel part was evaluated by scanning electronic microscopy. The scale of enamel demineralization depth in mm/microns and its' lightness parameter compliance was created.

The Interaction Between Vision and Eye Movements †.

The existence of a central fovea, the small retinal region with high analytical performance, is arguably the most prominent design feature of the primate visual system. This centralization comes along with the corresponding capability to move the eyes to reposition the fovea continuously. Past research on visual perception was mainly concerned with foveal vision while the observers kept their eyes stationary. Research on the role of eye movements in visual perception emphasized their negative aspects, for example, the active suppression of vision before and during the execution of saccades. But is the only benefit of our precise eye movement system to provide high acuity of the small foveal region, at the cost of retinal blur during their execution? In this review, I will compare human visual perception with and without saccadic and smooth pursuit eye movements to emphasize different aspects and functions of eye movements. I will show that the interaction between eye movements and visual perception is optimized for the active sampling of information across the visual field and for the calibration of different parts of the visual field. The movements of our eyes and visual information uptake are intricately intertwined. The two processes interact to enable an optimal perception of the world, one that we cannot fully grasp by doing experiments where observers are fixating a small spot on a display.