SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Human eye

262

We tested whether eye color influences perception of trustworthiness. Facial photographs of 40 female and 40 male students were rated for perceived trustworthiness. Eye color had a significant effect, the brown-eyed faces being perceived as more trustworthy than the blue-eyed ones. Geometric morphometrics, however, revealed significant correlations between eye color and face shape. Thus, face shape likewise had a significant effect on perceived trustworthiness but only for male faces, the effect for female faces not being significant. To determine whether perception of trustworthiness was being influenced primarily by eye color or by face shape, we recolored the eyes on the same male facial photos and repeated the test procedure. Eye color now had no effect on perceived trustworthiness. We concluded that although the brown-eyed faces were perceived as more trustworthy than the blue-eyed ones, it was not brown eye color per se that caused the stronger perception of trustworthiness but rather the facial features associated with brown eyes.

Concepts: Eye, Photoreceptor cell, Color, Qualia, Rod cell, Cone cell, Human eye, Eye color

163

Multispectral imaging is a powerful tool that extends the capabilities of the human eye. However, multispectral imaging systems generally are expensive and bulky, and multiple exposures are needed. Here, we report the demonstration of a compact multispectral imaging system that uses vertical silicon nanowires to realize a filter array. Multiple filter functions covering visible to near-infrared (NIR) wavelengths are simultaneously defined in a single lithography step using a single material (silicon). Nanowires are then etched and embedded into polydimethylsiloxane (PDMS), thereby realizing a device with eight filter functions. By attaching it to a monochrome silicon image sensor, we successfully realize an all-silicon multispectral imaging system. We demonstrate visible and NIR imaging. We show that the latter is highly sensitive to vegetation and furthermore enables imaging through objects opaque to the eye.

Concepts: Eye, Demonstration, Image sensor, Imaging, Visible spectrum, Human eye, Eye color, Multi-spectral image

7

Human eyes serve two key functions in face-to-face social interactions: they provide cues about a person’s emotional state and attentional focus (gaze direction). Both functions critically rely on the morphologically unique human sclera and have been shown to operate even in the absence of conscious awareness in adults. However, it is not known whether the ability to respond to social cues from scleral information without conscious awareness exists early in human ontogeny and can therefore be considered a foundational feature of human social functioning. In the current study, we used event-related brain potentials (ERPs) to show that 7-mo-old infants discriminate between fearful and nonfearful eyes (experiment 1) and between direct and averted gaze (experiment 2), even when presented below the perceptual threshold. These effects were specific to the human sclera and not seen in response to polarity-inverted eyes. Our results suggest that early in ontogeny the human brain detects social cues from scleral information even in the absence of conscious awareness. The current findings support the view that the human eye with its prominent sclera serves critical communicative functions during human social interactions.

Concepts: Brain, Human brain, Cerebral cortex, Eye, Mind, Consciousness, Event-related potential, Human eye

3

Vascularized composite allotransplantation of the eye is an appealing, novel method for reconstruction of the nonfunctioning eye. The authors' group has established the first orthotopic model for eye transplantation in the rat. With advancements in immunomodulation strategies together with new therapies in neuroregeneration, parallel development of human surgical protocols is vital for ensuring momentum toward eye transplantation in actual patients.

Concepts: Eye, Organ transplant, Ophthalmology, Rat, Human eye, Eye color, 2004 films

3

To quantify changes in ocular dimensions associated with age, refractive error, and accommodative response, in vivo, in 30- to 50-year-old human subjects.

Concepts: Refraction, In vivo, Eye, Ophthalmology, Myopia, Human eye, Eye color

1

Cells are minute-typically too small to be seen by the human eye. Even so, the cellular world encompasses a range of scales, from roughly a tenth of a nanometer (10(-10) m) to a millimeter (10(-3) m) or larger, spanning seven orders of magnitude or more. Because they are so far from our experience, it is difficult for us to envision such scales. To help our imagination grasp such dimensions, I propose the adoption of a ‘perceptive scale’ that can facilitate a more direct experience of cellular sizes. From this, as I argue below, will stem a new perception also of biological shape, cellular space and dynamic processes.

Concepts: Biology, Organism, Species, Cell biology, Orders of magnitude, Eye, Perception, Human eye

1

The human eye has typically more optical aberrations than conventional artificial optical systems. While the lower order modes (defocus and astigmatism) are well studied, our purpose is to explore the influence of genes versus the environment on the higher order aberrations of the optical components of the eye.

Concepts: Biology, Optics, Natural environment, Eye, Lens, Geometrical optics, Human eye, Eye color

1

We have developed a real-time, dynamic holographic material that exhibits rapid colouration upon irradiation with UV light and successive fast thermal bleaching within tens of milliseconds at room temperature. Photochromic polymer films were prepared by a simple solution-casting method from the benzene solution of the mixture of the photochromic molecule, poly(ethyl acrylate), and poly(phenoxyethyl acrylate). The real-time control of holographic images using the photochromic polymer film yields a speed equivalent to the time resolution of the human eye. This new type of dynamic holographic material based on fast photochromism opens up an exciting new area of research in the future development of a large dynamic 3D display.

Concepts: DNA, Time, Sun, Polymer, Chemical substance, Sunlight, Eye, Human eye

0

Movement screens are frequently used to identify abnormal movement patterns that may increase risk of injury or hinder performance. Abnormal patterns are often detected visually based on the observations of a coach or clinician. Quantitative, or data-driven methods can increase objectivity, remove issues related to inter-rater reliability and offer the potential to detect new and important features that may not be observable by the human eye. Applying principal components analysis (PCA) to whole-body motion data may provide an objective data-driven method to identify unique and statistically important movement patterns, an important first step to objectively characterize optimal patterns or identify abnormalities. Therefore, the primary purpose of this study was to determine if PCA could detect meaningful differences in athletes' movement patterns when performing a non-sport-specific movement screen. As a proof of concept, athlete skill level was selected a priori as a factor likely to affect movement performance.

Concepts: Scientific method, Multivariate statistics, Factor analysis, Eye, Principal component analysis, Singular value decomposition, A priori, Human eye

0

Defects in sterile surgical wrapping are identified by the presence of holes through which light can be seen. However, it is unknown how reliably the human eye can detect these defects.

Concepts: Eye, Visual system, Ophthalmology, Book of Optics, Human eye, Eye color