Key Color Research Articles

WHY PIGEONS SAY WHAT THEY DO: REINFORCER MAGNITUDE AND RESPONSE REQUIREMENT EFFECTS ON SAY RESPONDING IN SAY—DO CORRESPONDENCE

The effects of reinforcer magnitude and response requirement on pigeons' say choices in an experimental homologue of human say-do correspondence were assessed in two experiments. The procedure was similar to a conditional discrimination procedure except the pigeons chose both a sample stimulus (the say component) and a comparison stimulus that corresponded to it (the do component). Correspondence was trained on red, green, and white key colors before the duration of food presentations following correspondence on each key color (Experiment 1) and the number of key pecks required as the say response on each key color (Experiment 2) were manipulated in an attempt to influence the initial say response. The frequency of say responses on each key color coincided with programmed changes in the duration of food presentations and the key-peck requirements assigned to each key color. Correspondence accuracy remained stable in all conditions, even those in which the say responding occurred primarily on two of the three key colors. Implications for human behavior are discussed.

Example-based painting guided by color features

In this paper, by analyzing and learning the color features of the reference painting with a novel set of measures, an example-based approach is developed to transfer some key color features from the template to the source image. First, color features of a given template painting is analyzed in terms of hue distribution and the overall color tone. These features are then extracted and learned by the algorithm through an optimization scheme. Next, to ensure the spatial coherence of the final result, a segmentation based post processing is performed. Finally, a new color blending model, which avoids the dependence of edge detection and adjustment of inconvenient tune parameters, is developed to provide a flexible control for the accuracy of painting. Experimental results show that the new example-based painting system can produce paintings with specific color features of the template, and it can also be applied to changing color themes of art pieces, designing color styles of paintings/real images, and specific color harmonization.

Baseline training history and effects of methamphetamine on performance of pigeons on an interval-bisection task

Length of baseline training influences how methamphetamine disrupts temporal performance under a peak interval schedule. Acute methamphetamine produces overestimation of time following relatively brief training, but following extended training, methamphetamine produces more general loss of stimulus control. The current study extends the study of training length on the effects of methamphetamine to an interval-bisection procedure. Six pigeons responded under a psychophysical choice procedure in which responses to one key color were correct after presentation of four shorter sample durations and responses to another key color were correct after presentation of four longer sample durations. One group of three pigeons received briefer baseline training (45 sessions), while another group received more extended training (223 sessions) prior to methamphetamine administration. There was no evidence of overestimation of time or generalized loss of stimulus control in either group. Sensitivity (precision of timing) was higher in the group with more extensive training and was disrupted by methamphetamine.

Effects of acute and chronic d-amphetamine on two variations of a temporal discrimination procedure

This study assessed temporal discrimination using a procedure in which pigeons classified temporal intervals as short or long based on different responses following visually presented stimulus durations. For the Location group, response alternatives were defined by the location of response keys, whereas for the Color group response alternatives were defined by key color. Temporal parameters were derived from psychophysical curves for time, and the impact of d-amphetamine was determined during acute and chronic dosing. Results showed that classification of temporal intervals was disrupted dose dependently during the acute drug assessment, regardless of the procedural variation. During the chronic drug assessment, differences in one of the psychophysical parameters, Range, were found between groups, as well as a significant effect of Dose on Standard Deviation values in the Color group. These data suggest that procedural variation does not lead to differential effects of d-amphetamine when administered in an acute regimen; however, differences found during chronic administration suggest that procedural variations may influence the development of tolerance as evidenced by differing Range values between groups and marked disruption of Standard Deviation values at the low dose in the Color group. The influence exerted on temporal behavior and tolerance by procedural variations during acute and chronic regimens of d-amphetamine should be explored further.

Study on the Five-color Harmony and Resonance Theory of Livable Ecosystem Construction

Ecological industry, resource guarantee, environment ecological safety and ecological control are key parts which should be emphasized in the construction of livable eco-city. To more visual and lively express this idea, we endow every key part bright color and put forward the five-color harmony and resonance theory of livable ecosystem construction based on that.

Nicotine does not enhance discrimination performance in a temporal bisection procedure

Recent reports of selective disruption of stimulus control by drug administration and other disruptive operations in temporal discrimination procedures may be interpreted as a disruption of attention to the temporal sample stimuli. This experiment assessed the effects of nicotine, a compound that has been widely shown to increase measures of attention, on temporal discrimination performance. Pigeons responded under a psychophysical choice procedure in which responses to one key color were correct after presentation of four shorter sample durations and responses to another key color were correct after presentation of four longer sample durations. Performance under nicotine was characterized by using a model that differentiates the effects of nicotine on stimulus control, bias, and sensitivity of temporal discrimination. Nicotine selectively decreased the measure of stimulus control, but did not systematically affect the measures of timing. Mecamylamine (1.0 mg/kg) failed to antagonize the disruptive effects of nicotine. These results suggest that disruption of temporal discrimination performance in this preparation may not have been dependent on the specific pharmacology of nicotine and underscore the importance of quantitative separation of the effects of various manipulations on stimulus control from effects on timing.

Progressive ratio schedules of reinforcement.

Pigeons' pecks produced grain under progressive ratio (PR) schedules, whose response requirements increased systematically within sessions. Experiment 1 compared arithmetic (AP) and geometric (GP) progressions. Response rates increased as a function of the component ratio requirement, then decreased linearly (AP) or asymptotically (GP). Experiment 2 found the linear decrease in AP rates to be relatively independent of step size. Experiment 3 showed pausing to be controlled by the prior component length, which predicted the differences between PR and regressive ratio schedules found in Experiment 4. When the longest component ratios were signaled by different key colors, rates at moderate ratios increased, demonstrating control by forthcoming context. Models for response rate and pause duration based on Bizo and Killeen (1997) described performance on AP schedules; GP schedules required an additional parameter representing the contextual reinforcement.

Hyperspectral imaging-based credit card verifier structure with adaptive learning

We propose and experimentally demonstrate a hyperspectral imaging-based optical structure for verifying a credit card. Our key idea comes from the fact that the fine detail of the embossed hologram stamped on the credit card is hard to duplicate, and therefore its key color features can be used for distinguishing between the real and counterfeit ones. As the embossed hologram is a diffractive optical element, we shine a number of broadband light sources one at a time, each at a different incident angle, on the embossed hologram of the credit card in such a way that different color spectra per incident angle beam are diffracted and separated in space. In this way, the center of mass of the histogram on each color plane is investigated by using a feed-forward backpropagation neural-network configuration. Our experimental demonstration using two off-the-shelf broadband white light emitting diodes, one digital camera, and a three-layer neural network can effectively identify 38 genuine and 109 counterfeit credit cards with false rejection rates of 5.26% and 0.92%, respectively. Key features include low cost, simplicity, no moving parts, no need of an additional decoding key, and adaptive learning.

Diversity and evolution of coral fluorescent proteins.

GFP-like fluorescent proteins (FPs) are the key color determinants in reef-building corals (class Anthozoa, order Scleractinia) and are of considerable interest as potential genetically encoded fluorescent labels. Here we report 40 additional members of the GFP family from corals. There are three major paralogous lineages of coral FPs. One of them is retained in all sampled coral families and is responsible for the non-fluorescent purple-blue color, while each of the other two evolved a full complement of typical coral fluorescent colors (cyan, green, and red) and underwent sorting between coral groups. Among the newly cloned proteins are a “chromo-red” color type from Echinopora forskaliana (family Faviidae) and pink chromoprotein from Stylophora pistillata (Pocilloporidae), both evolving independently from the rest of coral chromoproteins. There are several cyan FPs that possess a novel kind of excitation spectrum indicating a neutral chromophore ground state, for which the residue E167 is responsible (numeration according to GFP from A. victoria). The chromoprotein from Acropora millepora is an unusual blue instead of purple, which is due to two mutations: S64C and S183T. We applied a novel probabilistic sampling approach to recreate the common ancestor of all coral FPs as well as the more derived common ancestor of three main fluorescent colors of the Faviina suborder. Both proteins were green such as found elsewhere outside class Anthozoa. Interestingly, a substantial fraction of the all-coral ancestral protein had a chromohore apparently locked in a non-fluorescent neutral state, which may reflect the transitional stage that enabled rapid color diversification early in the history of coral FPs. Our results highlight the extent of convergent or parallel evolution of the color diversity in corals, provide the foundation for experimental studies of evolutionary processes that led to color diversification, and enable a comparative analysis of structural determinants of different colors.

REINFORCER CONTROL BY COMPARISON‐STIMULUS COLOR AND LOCATION IN A DELAYED MATCHING‐TO‐SAMPLE TASK

Six pigeons were trained in a delayed matching-to-sample task involving bright- and dim-yellow samples on a central key, a five-peck response requirement to either sample, a constant 1.5-s delay, and the presentation of comparison stimuli composed of red on the left key and green on the right key or vice versa. Green-key responses were occasionally reinforced following the dimmer-yellow sample, and red-key responses were occasionally reinforced following the brighter-yellow sample. Reinforcer delivery was controlled such that the distribution of reinforcers across both comparison-stimulus color and comparison-stimulus location could be varied systematically and independently across conditions. Matching accuracy was high throughout. The ratio of left to right side-key responses increased as the ratio of left to right reinforcers increased, the ratio of red to green responses increased as the ratio of red to green reinforcers increased, and there was no interaction between these variables. However, side-key biases were more sensitive to the distribution of reinforcers across key location than were comparison-color biases to the distribution of reinforcers across key color. An extension of Davison and Tustin's (1978) model of DMTS performance fit the data well, but the results were also consistent with an alternative theory of conditional discrimination performance (Jones, 2003) that calls for a conceptually distinct quantitative model.

Discriminative control of variability: Effects of successive stimulus reversals

A growing body of evidence suggests that behavioral variability can come under control of discriminative stimuli. The present experiment further examined discriminative control of variability in a novel way by using the discrimination-reversal paradigm. Eight pigeons responded under a multiple schedule of Vary and Yoke components signaled by different-colored keylights. In the Vary component, 4-response sequences that differed from the previous 10 produced food, while in the Yoke component, any 4-response sequence had a fixed probability of producing food, yoked to the prior Vary component. Following stability in this procedure, the key colors signaling the Vary and Yoke components were reversed across four successive conditions. Across the experiment, variability of keypeck sequences was higher in the Vary than in the Yoke component. Across successive reversals, the level of variability in the Vary component adapted more rapidly to the reversed contingencies, while the rate of adaptation in the Yoke component did not change systematically. These results are interpreted in terms of the different contingencies in the Vary and Yoke components. In addition, the improvement in the rate of adaptation across successive reversals in the Vary component appears consistent with a proactive interference account of discrimination-reversal performance. These results join others in suggesting that variability may be an operant dimension of behavior.

Spiders (review)

Reviewed by: Soupy Saturdays with the Pain & the Great One Hope Morrison Blume, Judy Soupy Saturdays with the Pain & the Great One; illus. by James Stevenson. Delacorte, 2007108p Library ed. ISBN 978-0-385-90324-0$16.99 Trade ed. ISBN 978-0-385-73305-2$12.99 Ad Gr. 2-4 Renowned nature photographer and illustrator of Sy Montgomery's The Tarantula Scientist (BCCB 4/04), Bishop now offers an overview focused on spiders and spiders alone. Text describes spider characteristics and diet, spider behavior and reproduction in compact and pithy prose, but the gallery of vivid, closeup spider photographs almost renders the text superfluous. Each spread features a large image, sometimes full page, sometimes three-quarter spread, sometimes full-spread with text nestling in a less-busy corner of the picture, with page color carefully corresponding to a key color in the photograph; pictured spiders are varied in species (yes, fans, the black widow and the tarantula each make an appearance). The foldout spread in the middle depicts a stop-motion-style view of a jumping spider making its leap, but kids will already be sucked in by closeups of fangs and writhing masses of spider babies; this is one self-selling book. A concluding note describes Bishop's sometimes exacting photographic techniques, and an index and glossary are included. Copyright © 2007 The Board of Trustees of the University of Illinois

Characterizing the effects of d-amphetamine on temporal discrimination

Although the effects of dopamine agonists on temporal discrimination have been widely studied, conclusions as to their behavioral and neurophysiological effects are difficult due to a number of discrepant findings in the literature. This study examined whether a previously unexplored procedural difference could account for some of these discrepancies. In three experiments, pigeons categorized the duration of temporal samples during two variants of the interval-bisection procedure. In the position variant, responses to a side key that corresponded to the sample duration produced food. In the color-matching variant, responses to the key color that corresponded to the sample duration produced food. Across experiments, d-amphetamine produced a general disruption of temporal discrimination not accompanied by over or underestimation of time in both procedures. This effect occurred whether pigeons were exposed to both procedures within session (Experiment 1) or across conditions (Experiments 2 and 3) and whether the pigeons were drug experienced (Experiments 1 and 2) or naïve (Experiment 3). Analyses of the cumulative normal functions fitted to the proportion-long response data indicated that d-amphetamine produced its effects by selectively decreasing stimulus control, rather than by affecting timing.

Disruption of temporal discrimination and the choose-short effect

The present experiment examined the effects of several disruptors on temporal discrimination. Pigeons responded under a 0-delay symbolic matching-to-sample procedure in which responses to one key color were reinforced following the presentation of four shorter sample durations, and responses to another key color were reinforced following the presentation of four longer sample durations. Steady-state performance was disrupted by presession feeding, intertrial-interval food, visual distraction, and extinction. All disruptors decreased temporal-discrimination accuracy. Analyses of the fitted cumulative normal functions indicated that decreases in accuracy were produced mainly by decreases in overall stimulus control rather than specific effects on timing. In addition, all disruptors selectively decreased accuracy on long-sample trials--a choose-short effect. This effect is interpreted in terms of decreased attention to the samples under disruption. Current theories of the choose-short effect do not appear to easily account for these results.

Structured Public Involvement in Context-Sensitive Noise Wall Design Using Casewise Visual Evaluation

The research team extended its structured public involvement (SPI) protocol to the field of context-sensitive noise wall design. Subject to a minimum sound attenuation capacity, noise walls must present a pleasing visual aspect to their user communities including residents, commuters, and others. This paper details the casewise visual evaluation (CAVE) methodology and discusses its application to a context-sensitive noise wall design in Arizona. The research team designed a fuzzy logic nonlinear modeling process, CAVE, that predicts group preference for specific designs even when such designs have not been created. CAVE offers significant advantages over current visual assessment methods such as the visual preference survey. Key noise wall design parameters, including height, topological variation, color value, plant coverage, and plant complexity, were identified by landscape architecture experts. Group preferences were gathered rapidly, anonymously, and fairly from a focus group by using electronic polling technology to evaluate digital images of samples and potential designs. Highest preference was achieved with berm-type walls combining medium-value, smooth stone featuring a basic pattern with undulating topographic variation and a higher degree of plant complexity. A range of nonlinear preference variations in response to changes in value and plant complexity were noted. Other preferred designs were documented for this context-specific Arizona case study. The advantages of the SPI process using CAVE and obstacles in its implementation are discussed.

Structured Public Involvement in Context-Sensitive Noise Wall Design Using Casewise Visual Evaluation

The research team extended its structured public involvement (SPI) protocol to the field of context-sensitive noise wall design. Subject to a minimum sound attenuation capacity, noise walls must present a pleasing visual aspect to their user communities including residents, commuters, and others. This paper details the casewise visual evaluation (CAVE) methodology and discusses its application to a context-sensitive noise wall design in Arizona. The research team designed a fuzzy logic nonlinear modeling process, CAVE, that predicts group preference for specific designs even when such designs have not been created. CAVE offers significant advantages over current visual assessment methods such as the visual preference survey. Key noise wall design parameters, including height, topological variation, color value, plant coverage, and plant complexity, were identified by landscape architecture experts. Group preferences were gathered rapidly, anonymously, and fairly from a focus group by using electronic polling technology to evaluate digital images of samples and potential designs. Highest preference was achieved with berm-type walls combining medium-value, smooth stone featuring a basic pattern with undulating topographic variation and a higher degree of plant complexity. A range of nonlinear preference variations in response to changes in value and plant complexity were noted. Other preferred designs were documented for this context-specific Arizona case study. The advantages of the SPI process using CAVE and obstacles in its implementation are discussed.

Effects of D-amphetamine on temporal discrimination in pigeons

Two experiments used a matching to sample of durations procedure to examine changes in temporal discrimination evoked by D-amphetamine (0.75, 1.50, 2.25 and 3.0 mg/kg i.m.) in pigeons. Responses to one key color were reinforced after long (8-s) stimuli: responses to the alternative key color were reinforced after short (2-s) stimuli. Stimuli of intermediate duration were reinforced in Experiment 1 and were not reinforced in Experiment 2. Sigmoid functions relating percent of choices of the key reinforced after long-duration stimuli to the duration of stimulus presented were fit by a cumulative normal function. In addition to a parameter giving the left/right position of the sigmoid curves (which indexes temporal perception), this function also provided estimates of the range and slope of the curve (measures of stimulus control). The results showed that, contrary to many published reports, amphetamine had no effect on the left/right positioning of the sigmoid curve. There was, however, an effect of amphetamine on stimulus control, as shown by the general flattening of the psychophysical functions. Little evidence of tolerance to the drug's behavioral effects was found after 30 consecutive days of behavioral testing under amphetamine.

Absolute pitch and pupillary response: Effects of timbre and key color

The pitch identification performance of absolute pitch possessors has previously been shown to depend on pitch range, key color, and timbre of presented tones. In the present study, the dependence of pitch identification performance on key color and timbre of musical tones was examined by analyzing hit rates, reaction times, and pupillary responses of absolute pitch possessors (n = 9) and nonpossessors (n = 12) during a pitch identification task. Results revealed a significant dependence of pitch identification hit rate but not reaction time on timbre and key color in both groups. Among absolute pitch possessors, peak dilation of the pupil was significantly dependent on key color whereas the effect of timbre was marginally significant. Peak dilation of the pupil differed significantly between absolute pitch possessors and nonpossessors. The observed effects point to the importance of learning factors in the acquisition of absolute pitch.

Content-Based Color Image Retrieval Using Multi-Variate Feature Vectors

This paper introduces a content-based image retrieval system which utilizes color, spatial frequency, and structural features of an object in the image. The major key color areas are extracted by image segmentation applying Bayesian classifier with k-means starter in CIELAB space and the color similarity is measured by summing up the inter-cluster color distances. The mutual correlations in DCT components are used to discriminate the spatial frequency features that carry textural details. In addition, a structural feature of image is simply characterized by down sampled color mosaic pattern. A target color image is retrieved by searching the image with the maximum similarity by cross correlations in the multi-dimensional feature vector space. Color similarity was indispensable to narrow the reliable candidate for almost all the tested images. Although an appropriate combination of spectral or structural features worked effective to retrieve the image with textural similarity, but we have not any definitive solution to select the frequency region yet. Finally, we report a method for evaluating the performance of our system based on psychophysical experiments using z-score.

A Region-based Automatic Scene Color Interchange

This paper proposes a color interchange model between different objects in different scenes based on image segmentation. Proposed system is applied to preferred color reproduction, scene simulation, industrial design, etc. First, unsupervised image segmentation method in our previous paper is improved by coupling the Bayesian decision rule with K-means classifier as a starter for setting the initial seeds points. Here, we tested new methods for choosing the initial seeds points, such as, finding the higher population density center in color distribution or searching the mountain peaks in color histogram. Secondly we applied this model for automatic segmentation of key color areas in an image. After the segmentation, each segmented color area is projected onto PC (Principal Component) space and the paired segments are selected to transfer or mutually interchange the colors one to another between the corresponding pairs. Finally a color atmosphere in reference scene is transferred into a source scene by matching the PCs through the hue rotation and the variance scaling in PC axes between the corresponding paired segments. The paper introduces the experiments on typical applications to scene color change, scene-referred color correction, or flesh-tint reproduction for facial images.