Behavioral scientists routinely publish broad claims about human psychology and behavior in the world's top journals based on samples drawn entirely from Western, Educated, Industrialized, Rich, and Democratic (WEIRD) societies. Researchers - often implicitly - assume that either there is little variation across human populations, or that these "standard subjects" are as representative of the species as any other population. Are these assumptions justified? Here, our review of the comparative database from across the behavioral sciences suggests both that there is substantial variability in experimental results across populations and that WEIRD subjects are particularly unusual compared with the rest of the species - frequent outliers. The domains reviewed include visual perception, fairness, cooperation, spatial reasoning, categorization and inferential induction, moral reasoning, reasoning styles, self-concepts and related motivations, and the heritability of IQ. The findings suggest that members of WEIRD societies, including young children, are among the least representative populations one could find for generalizing about humans. Many of these findings involve domains that are associated with fundamental aspects of psychology, motivation, and behavior - hence, there are no obvious a priori grounds for claiming that a particular behavioral phenomenon is universal based on sampling from a single subpopulation. Overall, these empirical patterns suggests that we need to be less cavalier in addressing questions of human nature on the basis of data drawn from this particularly thin, and rather unusual, slice of humanity. We close by proposing ways to structurally re-organize the behavioral sciences to best tackle these challenges.

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The WEIRDest People in the World

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WEIRD languages have misled us, too [Comment on Henrich et al.]

An important component of routine visual behavior is the ability to find one item in a visual world filled with other, distracting items. This ability to performvisual search has been the subject of a large body of research in the past 15 years. This paper reviews the visual search literature and presents a model of human search behavior. Built upon the work of Neisser, Treisman, Julesz, and others, the model distinguishes between a preattentive, massively parallel stage that processes information about basic visual features (color, motion, various depth cues, etc.) across large portions of the visual field and a subsequent limited-capacity stage that performs other, more complex operations (e.g., face recognition, reading, object identification) over a limited portion of the visual field. The spatial deployment of the limited-capacity process is under attentional control. The heart of the guided search model is the idea that attentional deployment of limited resources isguided by the output of the earlier parallel processes. Guided Search 2.0 (GS2) is a revision of the model in which virtually all aspects of the model have been made more explicit and/or revised in light of new data. The paper is organized into four parts: Part 1 presents the model and the details of its computer simulation. Part 2 reviews the visual search literature on preattentive processing of basic features and shows how the GS2 simulation reproduces those results. Part 3 reviews the literature on the attentional deployment of limited-capacity processes in conjunction and serial searches and shows how the simulation handles those conditions. Finally, Part 4 deals with shortcomings of the model and unresolved issues.

/pdf/guided-search-2-0-a-revised-model-of-visual-search-1qi4v6qhev.pdf

Guided Search 2.0 A revised model of visual search

This paper introduces a new technique for the analysis of the chromatic properties of neurones, and applies it to cells in the lateral geniculate nucleus (l.g.n.) of macaque. The method exploits the fact that for any cell that combines linearly the signals from cones there is a restricted set of lights to which it is equally sensitive, and whose members can be exchanged for one another without evoking a response. Stimuli are represented in a three-dimensional space defined by an axis along which only luminance varies, without change in chromaticity, a 'constant B' axis along which chromaticity varies without changing the excitation of blue-sensitive (B) cones, a 'constant R & G' axis along which chromaticity varies without change in the excitation of red-sensitive (R) or green-sensitive (G) cones. The orthogonal axes intersect at a white point. The isoluminant plane defined by the intersection of the 'constant B' and 'constant R & G' axes contains lights that vary only in chromaticity. In polar coordinates the constant B axis is assigned the azimuth 0-180 deg, and the constant R & G axis the azimuth 90-270 deg. Luminance is expressed as elevation above or below the isoluminant plane (-90 to +90 deg). For any cell that combines cone signals linearly, there is one plane in this space, passing through the white point, that contains all lights that can be exchanged silently. The position of this 'null plane' provides the 'signature' of the cell, and is specified by its azimuth (the direction in which it intersects the isoluminant plane of the stimulus space) and its elevation (its angle of inclination to the isoluminant plane). A colour television receiver was used to produce sinusoidal gratings whose chromaticity and luminance could be modulated along any vector passing through the white point in the space described. The spatial and temporal frequencies of modulation could be varied over a large range. When stimulated by patterns of low spatial and low temporal frequency, two groups of cells in the parvocellular laminae of the l.g.n. were distinguished by the locations of their null planes. The null planes of the larger group were narrowly distributed about an azimuth of 92.6 deg and more broadly about an elevation of 51.5 deg, which suggests that they receive opposed, but not equally balanced, inputs from only R and G cones. These we call R-G cells.(ABSTRACT TRUNCATED AT 400 WORDS)

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphysiol.1984.sp015499

Chromatic mechanisms in lateral geniculate nucleus of macaque.

PsychoPy is a software library written in Python, using OpenGL to generate very precise visual stimuli on standard personal computers. It is designed to allow the construction of as wide a variety of neuroscience experiments as possible, with the least effort. By writing scripts in standard Python syntax users can generate an enormous variety of visual and auditory stimuli and can interact with a wide range of external hardware (enabling its use in fMRI, EEG, MEG etc.). The structure of scripts is simple and intuitive. As a result, new experiments can be written very quickly, and trying to understand a previously written script is easy, even with minimal code comments. PsychoPy can also generate movies and image sequences to be used in demos or simulated neuroscience experiments. This paper describes the range of tools and stimuli that it provides and the environment in which experiments are conducted.

/pdf/generating-stimuli-for-neuroscience-using-psychopy-4mfednlriv.pdf

Generating Stimuli for Neuroscience Using PsychoPy.

In a space where Cartesian coordinates represent the excitations of the three cone types involved in color vision, a plane of constant luminance provides a chromaticity diagram in which excitation of each cone type (at constant luminance) is represented by a linear scale (horizontal or vertical), and in which the center-of-gravity rule applies with weights proportional to luminance.

Chromaticity diagram showing cone excitation by stimuli of equal luminance.

Four methods of heterochromatic photometry were employed, using the same four observers in each case. These were (i) two types of direct heterochromatic photometry (direct comparison with white, and step by step), (ii) flicker photometry, and (iii) the minimally distinct-border method (MDB). The MDB method is shown to yield results that are linear and obey Abney’s law. Flicker and MDB methods generate relative luminous-efficiency functions that agree well with each other and also with the CIE standard observer as modified by Judd; the methods of direct heterochromatic photometry yield data that agree fairly well with each other, whereas they differ greatly from the data obtained by flicker or MDB. Luminous efficiency as measured by the direct methods seems to receive a contribution from two sources, (a) achromatic signals of the photopic visual system, which exclusively determine the MDB setting, and (b) chromatic signals of the visual system, which produce extra brightness, the amount of which is related to the saturation of the stimulus used.

Comparison of Four Methods of Heterochromatic Photometry

The color specimens developed by the OSA Committee on Uniform Color Scales are intended to provide a uniform sampling of the three-dimensional domain of realizable surface colors. The research of this article confirms the distinction between basic and nonbasic color terms and defines the locations of the eleven basic surface colors within the OSA space through systematic, monolexemic color naming of 424 samples of the OSA set seen against a gray background. It is concluded that the coordinate system of the OSA color space is well suited to the specification of color order: The locations of the basic colors are reasonably arranged and can be conveniently and precisely visualized.

Locating basic colors in the OSA space

Three experiments on the Bezold–Brucke phenomenon (change in the hue of spectral colors caused by change in field luminance) are reported. The first is an exact replication of Purdy’s classic experiment, where the shift between 100 and 1000 trolands is investigated by direct matching in a steadily presented bipartite field. The second is a modification of Purdy’s experiment where the observer is asked to match on the basis of 300-msec flashes of the bipartite field. The third is an experiment where no matches are required, but where the observer is asked to judge the hue of a flashing stimulus using a forced-choice color-naming technique. The results of the three experiments are compared: differences are discussed in terms of viewing time and simultaneous contrast.

Robert M. Boynton

Papers

Chromaticity diagram showing cone excitation by stimuli of equal luminance.

Comparison of Four Methods of Heterochromatic Photometry

Locating basic colors in the OSA space

Bezold–Brücke Hue Shift Measured by Color-Naming Technique*

Interactions among chromatic mechanisms as inferred from positive and negative increment thresholds.