Learning is enhanced by tailoring instruction to individual genetic differences.

It is widely argued that personalized instruction based on individual differences in learning styles or genetic predispositions could improve learning outcomes. However, this proposition has resisted clear demonstration in human studies, where it is difficult to control experience and quantify outcomes. Here, we take advantage of the tractable nature of vocal learning in songbirds (Lonchura striata domestica) to test the idea that matching instruction to individual genetic predispositions can enhance learning. We use both cross-fostering and computerized instruction with synthetic songs to demonstrate that matching the tutor song to individual predispositions can improve learning across genetic backgrounds. Moreover, we find that optimizing instruction in this fashion can equalize learning differences across individuals that might otherwise be construed as genetically determined. Our results demonstrate potent, synergistic interactions between experience and genetics in shaping song, and indicate the likely importance of such interactions for other complex learned behaviors

Light during darkness and cancer: relationships in circadian photoreception and tumor biology

The relationship between circadian phototransduction and circadian-regulated processes is poorly understood. Melatonin, commonly a circadian phase marker, may play a direct role in a myriad of physiologic processes. The circadian rhythm for pineal melatonin secretion is regulated by the hypothalamic suprachiasmatic nucleus (SCN). Its neural source of light input is a unique subset of intrinsically photosensitive retinal ganglion cells expressing melanopsin, the primary circadian photopigment in rodents and primates. Action spectra of melatonin suppression by light have shown that light in the 446–477 nm range, distinct from the visual system’s peak sensitivity, is optimal for stimulating the human circadian system. Breast cancer is the oncological disease entity whose relationship to circadian rhythm fluctuations has perhaps been most extensively studied. Empirical data has increasingly supported the hypothesis that higher risk of breast cancer in industrialized countries is partly due to increased exposure to light at night. Studies of tumor biology implicate melatonin as a potential mediator of this effect. Yet, causality between lifestyle factors and circadian tumor biology remains elusive and likely reflects significant variability with physiologic context. Continued rigorous empirical inquiry into the physiology and clinical implications of these habitual, integrated aspects of life is highly warranted at this time

Resin-Transfer-Molding of a Tool Face

A resin-transfer-molding (RTM) process has been devised for fabricating a matrix/graphite-cloth composite panel that serves as tool face for manufacturing other composite panels. Heretofore, RTM has generally been confined to resins with viscosities low enough that they can readily flow through interstices of cloth. The present process makes it possible to use a high-temperature, more-viscous resin required for the tool face. First, a release layer and then a graphite cloth are laid on a foam pattern that has the desired contour. A spring with an inside diameter of 3/8 in. (.9.5 mm) is placed along the long dimension of the pattern to act as a conduit for the resin. Springs with an inside diameter of 1/4 in. (.6.4 mm) are run off the larger lengthwise spring for distributing the resin over the tool face. A glass cloth is laid on top to act as breather. The whole layup is vacuum-bagged. Resin is mixed and made to flow under vacuum assistance to infiltrate the layup through the springs. The whole process takes less than a day, and the exposure of personnel to resin vapors is minimized

Hunter-Gatherer Color Naming Provides New Insight into the Evolution of Color Terms

SummaryMost people name the myriad colors in the environment using between two and about a dozen color terms [1], with great variation within and between languages [2]. Investigators generally agree that color lexicons evolve from fewer terms to more terms, as technology advances and color communication becomes increasingly important [3]. However, little is understood about the color naming systems at the least technologically advanced end of the continuum. The Hadza people of Tanzania are nomadic hunter-gatherers who live a subsistence lifestyle that was common before the advent of agriculture (see Supplemental Experimental Procedures, section I; [4]), suggesting that the Hadzane language should be at an early stage of color lexicon evolution. When Hadza, Somali, and US informants named 23 color samples, Hadza informants named only the black, white, and red samples with perfect consensus. Otherwise, they used low-consensus terms or responded “don’t know.” However, even low-consensus color terms grouped test colors into lexical categories that aligned with those found in other world languages [5]. Furthermore, information-theoretic analysis showed that color communication efficiency within the Hadza, Somali, and US language communities falls on the same continuum as other world languages. Thus, the structure of color categories is in place in Hadzane, even though words for many of the categories are not in general use. These results suggest that even very simple color lexicons include precursors of many color categories but that these categories are initially represented in a diverse and distributed fashion

Detection of changes in luminance distributions

How well can observers detect the presence of a change in luminance distributions? Performance was measured in three experiments. Observers viewed pairs of grayscale images on a calibrated CRT display. Each image was a checkerboard. All luminances in one image of each pair consisted of random draws from a single probability distribution. For the other image, some patch luminances consisted of random draws from that same distribution, while the rest of the patch luminances (test patches) consisted of random draws from a second distribution. The observers' task was to pick the image with luminances drawn from two distributions. The parameters of the second distribution that led to 75% correct performance were determined across manipulations of (1) the number of test patches, (2) the observers' certainty about test patch location, and (3) the geometric structure of the images. Performance improved with number of test patches and location certainty. The geometric manipulations did not affect performance. An ideal observer model with high efficiency fit the data well and a classification image analysis showed a similar use of information by the ideal and human observers, indicating that observers can make effective use of photometric information in our distribution discrimination task

Color and material perception: Achievements and challenges

There is a large literature characterizing human perception of the lightness and color of matte surfaces arranged in coplanar arrays. In the past ten years researchers have begun to examine perception of lightness and color using wider ranges of stimuli intended to better approximate the conditions of everyday viewing. One emerging line of research concerns perception of lightness and color in scenes that approximate the three-dimensional environment we live in, with objects that need not be matte or coplanar and with geometrically complex illumination. A second concerns the perception of material surface properties other than color and lightness, such as gloss or roughness. This special issue features papers that address the rich set of questions and approaches that have emerged from these new research directions. Here, we briefly describe the articles in the issue and their relation to previous work. Keywords: color perception, material perception Citation: Maloney, L. T., & Brainard, D. H. (2010). Color and material perception: Achievements and challenges. Journal of Vision, 10(9):19, 1-6, http://www.journalofvision.org/content/10/9/19, doi:10.1167/10.9.19. Introduction The classic perceptual correlates of object surface properties are lightness and color. Although there are notable exceptions (e.g., Over the past decade, research has increasingly begun to focus on two rich generalizations of the classic "flatmatte" paradigm (for reviews, see In 2004, we edited a special issue in the Journal of Vision entitled "Perception of color and material properties in complex scenes" Characterizing, estimating, and discriminating the light field One of the most important themes in color and material perception is the role of scene illumination. In flat-matte scenes, the placement and directionality of light sources was little emphasized Journal of Vision Complex light fields and surface color/lightness perception In parallel with direct assessment of the perception of the light field, the past decade has seen a slew of papers that study how the visual system achieves color and lightness constancy in the context of spatially complex light fields (e.g., Along these lines in the current issue, Radonjić, Todorović, and Gilchrist (2010) examine surface lightness perception in three-dimensional scenes with directional lighting and show how grouping principles such as adjacency and surroundedness can help organize the empirical phenomena. Olkkonen, Witzel, Hansen, and Gegenfurtner (2010) study color categorization for real surfaces and daylight illuminants. An entire room with controlled illumination served as the laboratory. They find that color categorization was little changed by marked changes in daylight illumination. Surface material perception: Gloss, roughness A very active area of research is the assessment of lighting and environmental conditions that affect the perception of material properties such as gloss and roughness, and how these properties interact with the perception of color and lightness. Important early work includes Surface material perception is represented by a number of papers in this issue; Kim and Anderson Interactions There are several studies that examined interactions among different material properties. In this issue, Giesel and Gegenfurtner (2010) systematically investigate color perception for real objects made of different materials varying in roughness and gloss from smooth and glossy to matte and corrugated. They show that hue is quite stable across their manipulations, but that other attributes interact. Olkkonen and Brainard (2010) study how changes in real-world illumination affect perceived glossiness and lightness with emphasis on testing independence principles. They show, for example, that the effect of geometric changes in the light field on perceived glossiness is independent of the diffuse reflectance component of the surfaces. Novel themes A number of papers in the current issue introduce novel themes. Wolfe and Myers (2010) examine visual search performance when targets and distractors are characterized by surface material. They find that, although it may be easy to discriminate "fur" or "stone," searching for a patch of fur among the stones is difficult and time-consuming. Visual search based on material differences is inefficient. Motoyoshi (2010) examines how the relationship between highlights and shading triggers perception of translucency and transparency. Goddard, Solomon, and Colin (2010) study the adaptable neural mechanisms responsible for surface color constancy. Boyaci, Fang, Murray, and Kersten (2010) also consider mechanism. They report behavioral results showing how lightness across occlusion depends on spatially distant image features and show (using brain imaging) that human early visual cortex responds strongly to occlusion-dependent lightness variations. They conclude that early cortical processing of lightness is affected by three-dimensional scene interpretation

Strategic Trade Policy With Incompletely Informed Policymakers

Ever since the inception of research on strategic trade policy, economists have warned that the informational requirements are high, and unlikely to be met in practice. This paper investigates the implications of incomplete information for a simple, rent-shifting trade policy of the type proposed in Brander-Spencer (1985). We find that asymmetric information undermines the precommitrnent effect of unilateral government intervention. This "screening" effect induces a downward distortion in the optimal subsidy, and it may be so great as to require a tax rather than a subsidy for high levels of uncertainty, given a zero-profit participation constraint. Second, in contrast to the full-information case with strategic substitutes, the introduction of a rival interventionist government reinforces rather than countervails the precommitment effect, by reducing the incentive for the domestic firm to misrepresent its private information. Finally, when a nonintervention-profit participation constraint is substituted for the conventional zero-profit participation constraint to take into account the special relationship between firms and policymakers in trade, the government eschews intervention altogether for high levels of uncertainty.

Adverse health effects of nighttime lighting: comments on american medical association policy statement.

The American Medical Association House of Delegates in June of 2012 adopted a policy statement on nighttime lighting and human health. This major policy statement summarizes the scientific evidence that nighttime electric light can disrupt circadian rhythms in humans and documents the rapidly advancing understanding from basic science of how disruption of circadian rhythmicity affects aspects of physiology with direct links to human health, such as cell cycle regulation, DNA damage response, and metabolism. The human evidence is also accumulating, with the strongest epidemiologic support for a link of circadian disruption from light at night to breast cancer. There are practical implications of the basic and epidemiologic science in the form of advancing lighting technologies that better accommodate human circadian rhythmicity