Transitions between color categories mapped with a reverse Stroop task

2006 ◽  
Vol 23 (3-4) ◽  
pp. 453-460 ◽  
Author(s):  
HANNAH E. SMITHSON ◽  
SABAH S. KHAN ◽  
LINDSAY T. SHARPE ◽  
ANDREW STOCKMAN
Keyword(s):  
Stroop Task ◽  
Color Word ◽  
Color Space ◽  
Reaction Times ◽  
Color Appearance ◽  
Target Color ◽  
Color Category ◽  
Color Categories ◽  
Distractor Color ◽  
Hue Scaling

In the reverse Stroop task, observers are instructed to ignore the ink color in which a color word is printed (the distractor color) and to respond to the meaning of the color word (the target). Reaction times (RTs) are faster with congruent combinations when the ink color matches the word than with incongruent combinations when the ink color does not match the word. We manipulated the distracting ink color from congruent to incongruent and measured the transition from facilitation to interference. In Experiment 1, we confirmed that this transition could be assessed independently from the contextual influence of particular sets of stimuli and responses, implying that the color space in which interference and facilitation occurs is generalizable. In Experiment 2, we obtained reverse Stroop data for transitions between red and yellow, yellow and green, green and blue, and blue and red, and compared them with independent estimates of color appearance obtained by hue scaling for the same chromaticity samples. We find that the magnitude of the reverse Stroop effect can provide a reliable index of the similarity of color appearance between the distracting chromaticity and the color category represented by the target color word. Moreover, it will allow us to quantify the mapping between the chromaticity space defined at the cone photoreceptors and a cognitive color space defined at an advanced level of neural processing.

scholarly journals Flower Color as Predictor for Nectar Reward Quantity in an Alpine Flower Community

2021 ◽  
Vol 9 ◽  
Author(s):  
Martin Streinzer ◽  
Johann Neumayer ◽  
Johannes Spaethe
Keyword(s):  
Sugar Content ◽  
Color Space ◽  
Flower Color ◽  
Bumble Bees ◽  
Color Category ◽  
Flower Visitors ◽  
Floral Color ◽  
High Reward ◽  
Color Categories ◽  
Floral Displays

Entomophilous plants have evolved colorful floral displays to attract flower visitors to achieve pollination. Although many insects possess innate preferences for certain colors, the underlying proximate and ultimate causes for this behavior are still not well understood. It has been hypothesized that the floral rewards, e.g., sugar content, of plants belonging to a particular color category correlate with the preference of the flower visitors. However, this hypothesis has been tested only for a subset of plant communities worldwide. Bumble bees are the most important pollinators in alpine environments and show a strong innate preference for (bee) “UV-blue” and “blue” colors. We surveyed plants visited by bumble bees in the subalpine and alpine zones (>1,400 m a.s.l.) of the Austrian Alps and measured nectar reward and spectral reflectance of the flowers. We found that the majority of the 105 plant samples visited by bumble bees fall into the color categories “blue” and “blue-green” of a bee-specific color space. Our study shows that color category is only a weak indicator for nectar reward quantity; and due to the high reward variance within and between categories, we do not consider floral color as a reliable signal for bumble bees in the surveyed habitat. Nevertheless, since mean floral reward quantity differs between categories, naïve bumble bees may benefit from visiting flowers that fall into the innately preferred color category during their first foraging flights.

Semantic Conflict Processing in the Color-Word Stroop and the Emotional Stroop

2013 ◽  
Vol 27 (4) ◽  
pp. 149-164 ◽  
Author(s):  
Montserrat Zurrón ◽  
Marta Ramos-Goicoa ◽  
Fernando Díaz
Keyword(s):  
Stroop Task ◽  
Color Word ◽  
Event Related Potentials ◽  
Semantic Content ◽  
Emotional Stroop ◽  
Semantic Equivalence ◽  
Incongruent Color ◽  
Semantic Conflict ◽  
Related Potentials ◽  
Temporal Locus

With the aim of establishing the temporal locus of the semantic conflict in color-word Stroop and emotional Stroop phenomena, we analyzed the Event-Related Potentials (ERPs) elicited by nonwords, incongruent and congruent color words, colored words with positive and negative emotional valence, and colored words with neutral valence. The incongruent, positive, negative, and neutral stimuli produced interference in the behavioral response to the color of the stimuli. The P150/N170 amplitude was sensitive to the semantic equivalence of both dimensions of the congruent color words. The P3b amplitude was smaller in response to incongruent color words and to positive, negative, and neutral colored words than in response to the congruent color words and colored nonwords. There were no differences in the ERPs induced in response to colored words with positive, negative, and neutral valence. Therefore, the P3b amplitude was sensitive to interference from the semantic content of the incongruent, positive, negative, and neutral words in the color-response task, independently of the emotional content of the colored words. In addition, the P3b amplitude was smaller in response to colored words with positive, negative, and neutral valence than in response to the incongruent color words. Overall, these data indicate that the temporal locus of the semantic conflict generated by the incongruent color words (in the color-word Stroop task) and by colored words with positive, negative, and neutral valence (in the emotional Stroop task) appears to occur in the range 300–450 ms post-stimulus.

Hearing words changes color perception: Facilitation of color discrimination by verbal and visual cues

2017 ◽  
Author(s):  
Lewis Forder ◽  
Gary Lupyan
Keyword(s):  
Visual Cues ◽  
Color Word ◽  
Color Perception ◽  
Color Discrimination ◽  
Target Color ◽  
Discrimination Accuracy ◽  
Verbal Cues ◽  
The Moment

As part of learning some languages, people learn to name colors using categorical labels such as “red”, “yellow”, and “green”. Such labeling clearly facilitates communicating about colors, but does it also impact color perception? We demonstrate that simply hearing color words enhances categorical color perception, improving people’s accuracy in discriminating between simultaneously presented colors in an untimed task. Immediately after hearing a color word participants were better able to distinguish between colors from the named category and colors from nearby categories. Discrimination was also enhanced between typical and atypical category members. Verbal cues slightly decreased discrimination accuracy between two typical shades of the named color. In contrast to verbal cues, a preview of the target color, an arguably more informative cue, failed to yield any changes to discrimination accuracy. The finding that color words strongly affect color discrimination accuracy suggests that categorical color perception may be due to color representations being augmented in-the-moment by language.

scholarly journals The effect of high-frequency rTMS of the left dorsolateral prefrontal cortex on the resolution of response, semantic and task conflict in the colour-word Stroop task

2021 ◽  
Author(s):  
Benjamin A. Parris ◽  
Michael G. Wadsley ◽  
Gizem Arabaci ◽  
Nabil Hasshim ◽  
Maria Augustinova ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Task Performance ◽  
Stroop Task ◽  
Word Reading ◽  
Reaction Times ◽  
Task Conflict ◽  
General Effect ◽  
Task Set ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal

AbstractPrevious work investigating the effect of rTMS of left Dorso-Lateral Prefrontal Cortex (DLPFC) on Stroop task performance reports no changes to the Stroop effect but reduced reaction times on both congruent and incongruent trials relative to sham stimulation; an effect attributed to an enhanced attentional (or task) set for colour classification. The present study tested this account by investigating whether, relative to vertex stimulation, rTMS of the left DLPFC modifies task conflict, a form of conflict that arises when task sets for colour classification and word reading compete, given that this particular type of conflict would be reduced by an enhanced task set for colour classification. Furthermore, the present study included measures of other forms of conflict present in the Stroop task (response and semantic conflict), the potential effects on which would have been hidden in previous studies employing only incongruent and congruent stimuli. Our data showed that left DLPFC stimulation had no effect on the magnitude of task conflict, nor did it affect response, semantic or overall conflict (where the null is supported by sensitive Bayes Factors in most cases). However, consistent with previous research left DLPFC stimulation had the general effect of reducing reaction times. We, therefore, show for the first time that relative to real vertex stimulation left DLPFC stimulation does not modify Stroop interference. Alternative accounts of the role of the left DLPFC in Stroop task performance in which it either modifies response thresholds or facilitates responding by keeping the correct response keys active in working memory are discussed.

Differential Cued-Stroop Performance in Cognitively Asymptomatic Older Adults with Biomarker-Identified Risk for Alzheimer’s Disease: A Pilot Study

2018 ◽  
Vol 15 (9) ◽  
pp. 820-827 ◽  
Author(s):  
Ryan Van Patten ◽  
Anne M. Fagan ◽  
David A.S. Kaufman
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Stroop Task ◽  
Coefficient Of Variation ◽  
Reaction Times ◽  
Preclinical Alzheimer’S Disease ◽  
Cerebrospinal Fluid Biomarkers ◽  
Accuracy Rates

Background: There exists a need for more sensitive measures capable of detecting subtle cognitive decline due to Alzheimer's disease. Objective: To advance the literature in Alzheimer’s disease by demonstrating that performance on a cued-Stroop task is impacted by preclinical Alzheimer's disease neuropathology. Method: Twenty-nine cognitively asymptomatic older adults completed a computerized, cued-Stroop task in which accuracy rates and intraindividual variability in reaction times were the outcomes of interest. Cerebrospinal fluid biomarkers of Aβ42 and tau were measured and participants were then grouped according to a published p-tau/Aβ42 cutoff reflecting risk for Alzheimer’s disease (preclinical Alzheimer's disease = 14; control = 15). Results: ANOVAs indicated that accuracy rates did not differ between the groups but 4-second delay incongruent color-naming Stroop coefficient of variation reaction times were higher in the preclinical Alzheimer’s disease group compared to the control group, reflecting increased within-person variability. Moreover, partial correlations showed no relationships between cerebrospinal fluid biomarkers and accuracy rates. However, increases in coefficient of variation reaction times correlated with decreased Aβ42 and increases in p-tau and the p-tau/Aβ42 ratio. Conclusion: Results supported the ability of the computerized, cued-Stroop task to detect subtle Alzheimer’s disease neuropathology using a small cohort of cognitively asymptomatic older adults. The ongoing measurement of cued-Stroop coefficient of variation reaction times has both scientific and clinical utility in preclinical Alzheimer’s disease.

scholarly journals What we talk about when we talk about color

2020 ◽  
Author(s):  
Colin R. Twomey ◽  
Gareth Roberts ◽  
David Brainard ◽  
Joshua B. Plotkin
Keyword(s):  
Visible Light ◽  
Color Space ◽  
Color Perception ◽  
Geographic Location ◽  
Cross Cultural ◽  
Cultural Variation ◽  
Inference Algorithm ◽  
Color Categories ◽  
New Directions ◽  
Different Color

Names for colors vary widely across languages, but color categories are remarkably consistent [1–5]. Shared mechanisms of color perception help explain consistent partitions of visible light into discrete color vocabularies [6–10]. But the mappings from colors to words are not identical across languages, which may reflect communicative needs – how often speakers must refer to objects of different color [11]. Here we quantify the communicative needs of colors in 130 different languages, using a novel inference algorithm. Some regions of color space exhibit 30-fold greater demand for communication than other regions. The regions of greatest demand correlate with the colors of salient objects, including ripe fruits in primate diets. Using the mathematics of compression we predict and empirically test how languages map colors to words, accounting for communicative needs. We also document extensive cultural variation in communicative demands on different regions of color space, which is partly explained by differences in geographic location and local biogeography. This account reconciles opposing theories for universal patterns in color vocabularies, while opening new directions to study cross-cultural variation in the need to communicate different colors.

scholarly journals Neural Dynamics of Conflict Control in Working Memory

2021 ◽  
pp. 1-14
Author(s):  
Khoi D. Vo ◽  
Audrey Siqi-Liu ◽  
Alondra Chaire ◽  
Sophia Li ◽  
Elise Demeter ◽  
...  
Keyword(s):  
Working Memory ◽  
Stroop Task ◽  
Color Word ◽  
Color Naming ◽  
Control Task ◽  
Attentional Processing ◽  
Shared Representations ◽  
Color Representation ◽  
And Performance ◽  
External Stimuli

Abstract Attention and working memory (WM) have classically been considered as two separate cognitive functions, but more recent theories have conceptualized them as operating on shared representations and being distinguished primarily by whether attention is directed internally (WM) or externally (attention, traditionally defined). Supporting this idea, a recent behavioral study documented a “WM Stroop effect,” showing that maintaining a color word in WM impacts perceptual color-naming performance to the same degree as presenting the color word externally in the classic Stroop task. Here, we employed ERPs to examine the neural processes underlying this WM Stroop task compared to those in the classic Stroop and in a WM-control task. Based on the assumption that holding a color word in WM would (pre-)activate the same color representation as by externally presenting that color word, we hypothesized that the neural cascade of conflict–control processes would occur more rapidly in the WM Stroop than in the classic Stroop task. Our behavioral results replicated equivalent interference behavioral effects for the WM and classic Stroop tasks. Importantly, however, the ERP signatures of conflict detection and resolution displayed substantially shorter latencies in the WM Stroop task. Moreover, delay-period conflict in the WM Stroop task, but not in the WM control task, impacted the ERP and performance measures for the WM probe stimuli. Together, these findings provide new insights into how the brain processes conflict between internal representations and external stimuli, and they support the view of shared representations between internally held WM content and attentional processing of external stimuli.

Using ACES Look Modification Transforms (LMTs) in VFX Environments – Part 2: Gamut Mapping

2021 ◽  
Vol 2021 (3) ◽  
pp. 108-1-108-14
Author(s):  
Eberhard Hasche ◽  
Oliver Karaschewski ◽  
Reiner Creutzburg
Keyword(s):  
Dynamic Range ◽  
List Item ◽  
Color Space ◽  
High Dynamic Range ◽  
Target Color ◽  
List Type ◽  
Color Spaces ◽  
Gamut Mapping ◽  
Scale Down ◽  
Image Production

In modern moving image production pipelines, it is unavoidable to move the footage through different color spaces. Unfortunately, these color spaces exhibit color gamuts of various sizes. The most common problem is converting the cameras’ widegamut color spaces to the smaller gamuts of the display devices (cinema projector, broadcast monitor, computer display). So it is necessary to scale down the scene-referred footage to the gamut of the display using tone mapping functions [34].In a cinema production pipeline, ACES is widely used as the predominant color system. The all-color compassing ACES AP0 primaries are defined inside the system in a general way. However, when implementing visual effects and performing a color grade, the more usable ACES AP1 primaries are in use. When recording highly saturated bright colors, color values are often outside the target color space. This results in negative color values, which are hard to address inside a color pipeline. "Users of ACES are experiencing problems with clipping of colors and the resulting artifacts (loss of texture, intensification of color fringes). This clipping occurs at two stages in the pipeline: <list list-type="simple"> <list-item>- Conversion from camera raw RGB or from the manufacturer’s encoding space into ACES AP0</list-item> <list-item>- Conversion from ACES AP0 into the working color space ACES AP1" [1]</list-item> </list>The ACES community established a Gamut Mapping Virtual Working Group (VWG) to address these problems. The group’s scope is to propose a suitable gamut mapping/compression algorithm. This algorithm should perform well with wide-gamut, high dynamic range, scene-referred content. Furthermore, it should also be robust and invertible. This paper tests the behavior of the published GamutCompressor when applied to in- and out-ofgamut imagery and provides suggestions for application implementation. The tests are executed in The Foundry’s Nuke [2].

Sign in / Sign up

Export Citation Format

Share Document