Color Memory Research Articles

Deep Learning-Based Machine Color Emotion Generation

This paper investigates generating machine color emotion through deep learning. The grayscale image colorization model's training process resembles human memory color. Sixty images were recolored and quality evaluated to explore machine generated color impressions. Six experimental samples were recolored under D65, A, CWF, and TL84 light sources. Changes in lightness, chroma, and hue angle compared the original and colorized images, exploring light source effects on machine color perception. Analyzing differences in coloring results within the CIEL* a* b* color space for pixels with equal grayscale verified machine color emotion generation. Results show the machine learns to form color impressions from samples. Different light source color temperatures impact color prediction accuracy. The machine accurately colors images based on semantic context, demonstrating spontaneous color emotion generation through deep learning. This research positively contributes to the development of intelligent devices with color emotion.

Understanding Color Memory: A Study of Skin Tone Perception in Hue, Intensity, and Chroma

Understanding Color Memory: A Study of Skin Tone Perception in Hue, Intensity, and Chroma

Location has a privilege, but it is limited: Evidence from probing task-irrelevant location.

We investigated the extents of automaticity in location and orientation encoding in visual working memory (VWM) by manipulating their task relevance and assessing the amount of resource recruited by their encoding. Across five experiments, participants were surprised with a location report trial (Experiment 1A, 2A, and 3) or an orientation report trial (Experiment 2A and 2B) at a point when only the item's color had been task-relevant. This was followed by control trials to assess the memory quality of color when location or orientation had become task-relevant. We found the surprise trial performance to be significantly worse than the first control trial for both location and orientation, although to a greater extent for orientation for which there was virtually no measurable information from the subjects' reports. This was the case even when encoding was the only incidental memory process before the control trials (Experiment 2A and 2B), and the surprise memory costs cannot be attributed to the unexpectedness inherent to the surprise question (Experiment 3). The control trials revealed a consistent reduction of color memory only in the orientation experiments. These results suggest that although location encoding is more automatic than orientation, neither is encoded in a fully automatic manner. Our results show that incidentally encoded location is only coarse-grained, constraining the spatial precision of space-based indexing systems. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Correction: Simultaneous evaluation of the role of color preferences and the effect of color memory with the approach of improving students’ quality of learning: a case study—learning environments for 6-to-7-year-old children

Correction: Simultaneous evaluation of the role of color preferences and the effect of color memory with the approach of improving students’ quality of learning: a case study—learning environments for 6-to-7-year-old children

The role of memory color in visual attention.

The expected color of an object influences how it is perceived. For example, a banana in a greyscale photo may appear slightly yellow because bananas are expected to be yellow. This phenomenon is known as the memory color effect (MCE), and the objects with a memory color are called "color-diagnostic." The MCE is theorized to be a top-down influence of color knowledge on visual perception. However, its validity has been questioned because most evidence for the MCE is based on subjective reports. Here a change detection task is used as an objective measure of the effect and the results show that change detection differs for color-diagnostic objects. Specifically, it was predicted and found that unnaturally colored color-diagnostic objects (e.g., a blue banana) would attract attention and thus be discovered more quickly and accurately. In the experiment, two arrays alternated with the target present in one array and absent in the other while all other objects remained unchanged. Participants had to find the target as quickly and accurately as possible. In the experimental condition, the targets were color-diagnostic objects (e.g., a banana) presented in either their natural (yellow) or an unnatural (blue) color. In the control condition, non-color-diagnostic objects (e.g., a mug) were presented with the same colors as the color-diagnostic objects. Unnaturally colored color-diagnostic objects were found more quickly, which suggests that the MCE is a top-down, preattentive process that can influence a nonsubjective visual perceptual task such as change detection.

Simultaneous evaluation of the role of color preferences and the effect of color memory with the approach of improving students’ quality of learning: a case study—learning environments for 6-to-7-year-old children

Simultaneous evaluation of the role of color preferences and the effect of color memory with the approach of improving students’ quality of learning: a case study—learning environments for 6-to-7-year-old children

Feature-based attention warps the perception of visual features

Selective attention improves sensory processing of relevant information but can also impact the quality of perception. For example, attention increases visual discrimination performance and at the same time boosts apparent stimulus contrast of attended relative to unattended stimuli. Can attention also lead to perceptual distortions of visual representations? Optimal tuning accounts of attention suggest that processing is biased towards “off-tuned” features to maximize the signal-to-noise ratio in favor of the target, especially when targets and distractors are confusable. Here, we tested whether such tuning gives rise to phenomenological changes of visual features. We instructed participants to select a color among other colors in a visual search display and subsequently asked them to judge the appearance of the target color in a 2-alternative forced choice task. Participants consistently judged the target color to appear more dissimilar from the distractor color in feature space. Critically, the magnitude of these perceptual biases varied systematically with the similarity between target and distractor colors during search, indicating that attentional tuning quickly adapts to current task demands. In control experiments we rule out possible non-attentional explanations such as color contrast or memory effects. Overall, our results demonstrate that selective attention warps the representational geometry of color space, resulting in profound perceptual changes across large swaths of feature space. Broadly, these results indicate that efficient attentional selection can come at a perceptual cost by distorting our sensory experience.

Can memory color effects be explained by cognitive penetration?

ABSTRACT Orange heart shapes are commonly perceived as slightly reddish, which is an example of the memory color effect (MCE). Given that the MCE is a modulation of visual memories of typical colors of familiar objects, it can be considered to be a top-down effect. Whether cognitive penetration can explain MCEs has been actively debated since Macpherson argued that the belief that hearts are red alters orange perception. This paper aims to provide a credible explanation of the MCE that is consistent with scientific studies. I first prove that Macpherson’s theory is not properly supported by the psychological evidence that she provides. I also show that her model contradicts a report on the neural correlate of the MCE. Next, I examine color constancy, which enables the perception of colors as constant under various illuminations, as a possible noncognitive principle for the MCE. The relationship between them, however, is not well established. Using statistical analyses of scenes around us, Purves suggests that perception is determined by the most frequent percepts. I argue that Purves’ view better explains the noncognitive aspects of visual memory and is consistent with the finding of the neural correlate of the MCE.

The interplay of long-term memory and working memory: When does object-color prior knowledge affect color visual working memory?

Elaboration enriches newly encoded information by connecting it to prior knowledge. Here, we tested if prior knowledge about object-color associations improves visual working memory (VWM) for colors. A sequence of four colored objects was presented in four screen locations for a continuous color reproduction test. Object-color associations were either congruent with prior knowledge (e.g., red tomato) or incongruent (e.g., blue tomato). In Experiments 1 and 2, congruency had no effect on memory irrespective of memoranda format (images or words), encoding time (1,500 vs. 4,500 ms), and an instruction to elaborate. In Experiment 3, the object was also tested with a three-alternative forced-choice before or after probing color memory. We also included neutral objects (no color association) and abstract shapes and tested VWM and episodic memory. Congruent items were remembered better than in all other conditions, which did not systematically differ. In Experiment 4, we assessed the congruency effect when only color or both color and object were tested. Congruent objects were remembered better only when both features were tested. Hence, prior knowledge boosts VWM only when this knowledge is relevant at test. Our results suggest that retrieval manipulations can be critical for promoting the use of long-term memory knowledge. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A study of preferred and natural memory colours across different ethnic groups

AbstractA psychophysical experiment was carried out to specify the preferred and natural memory colours corresponding to 24 familiar objects on mobile displays. These objects were selected to cover a large colour gamut in CIELAB space. One hundred and six observers from five different ethnic groups participated. Forty‐nine colours for each object were rendered three‐dimensionally to cover a large colour range. The results showed inter‐observer variations are small between different ethnic groups, about 1.4 and 1.3 CIEDE2000 colour difference units for naturalness and preference, respectively. Comparing the preference and the naturalness colour centres, the preferred colours are brighter and more colourful than naturalness colours, by 1 and 2 units in L* and C*ab attributes, respectively. Both sets of data show a great hue consistency. The results showed that different ethnic groups agreed well on the objects studied. It was found that the best‐agreed objects are strawberry, green apple, tomato, corn and purple grape, and the worst‐agreed objects are blueberry, broccoli, smurf, green pepper and blue sky.

Newly learned shape-color associations show signatures of reliability-weighted averaging without forced fusion or a memory color effect.

Reliability-weighted averaging of multiple perceptual estimates (or cues) can improve precision. Research suggests that newly learned statistical associations can be rapidly integrated in this way for efficient decision-making. Yet, it remains unclear if the integration of newly learned statistics into decision-making can directly influence perception, rather than taking place only at the decision stage. In two experiments, we implicitly taught observers novel associations between shape and color. Observers made color matches by adjusting the color of an oval to match a simultaneously presented reference. As the color of the oval changed across trials, so did its shape according to a novel mapping of axis ratio to color. Observers showed signatures of reliability-weighted averaging-a precision improvement in both experiments and reweighting of the newly learned shape cue with changes in uncertainty in Experiment 2. To ask whether this was accompanied by perceptual effects, Experiment 1 tested for forced fusion by measuring color discrimination thresholds with and without incongruent novel cues. Experiment 2 tested for a memory color effect, observers adjusting the color of ovals with different axis ratios until they appeared gray. There was no evidence for forced fusion and the opposite of a memory color effect. Overall, our results suggest that the ability to quickly learn novel cues and integrate them with familiar cues is not immediately (within the short duration of our experiments and in the domain of color and shape) accompanied by common perceptual effects.

Direct interactions between working memory and perception for color and motion

Direct interactions between working memory and perception for color and motion

The Innate Influence of Colors on Learning

Color, a seemingly simple concept, has the power to predispose people to be attentive to certain colors. Colors have provided people with the chance to enhance their memories, with little effort. Color memory, as researchers have explored, is primarily innate, influencing much of the way humans store memories and thus the way learning occurs. Research has shown that learning can be made much more efficient with the help of certain colors, such as red. Certain colors significantly increase attention, which in turn has increased the capabilities of learning. By using colors while learning students are able to retain information more efficiently as information becomes part of their implicit memories. Learning can take place anywhere from classrooms to the workplace, one common factor in every place is color.

Task Demands Differentially Affect Processing of Intrinsic and Extrinsic Object Features in Working Memory

Some argue that visual working memory operates on integrated object representations. Here, we contend that obligatory feature integration occurs with intrinsic but not extrinsic object features. Working memory for shapes and colors was assessed using a change-detection task with a central test probe, while recording event-related potentials (ERPs). Color was either an intrinsic surface feature of a shape or connected to the shape via a proximal but spatially disjunct extrinsic frame. There were two types of test: The direct test required memory for shape and color; the indirect test required only shape memory. Study-test changes of color were therefore either task-relevant or task-irrelevant. We assessed performance costs and event-related potential (ERP) effects arising from color changes. In the direct test, performance was poorer for extrinsic than intrinsic stimuli; task-relevant color changes elicited enhanced frontal negativity (N2, FN400) for both intrinsic and extrinsic stimuli. In the indirect test, performance costs and ERP effects associated with irrelevant color change were larger for intrinsic than extrinsic stimuli. This suggests intrinsic information is more readily integrated into the working-memory representation and evaluated against the test probe. Findings imply that feature integration is not obligatory under all conditions but influenced by stimulus-driven and task-related focus of attention.

Impact of Cognitive Demand on Eye Movement Pattern in Patients with Alzheimer's Disease.

Eye-movement behavior has been used as a reliable tool to identify cognitive and behavioral patterns in individuals with different neuropsychiatric disorders including Alzheimer's disease (AD). Most studies in the field have been dedicated to evaluating eye-movement behavior during cognitive tasks in different protocols using multiple parameters. We aimed to evaluate the differences of eye-movement behavior in healthy subjects, subjects with mild cognitive impairment (MCI), and those with AD in a simple color task with and without cognitive demand. 91 subjects: 18 AD, 47 MCI, and 26 healthy controls had their oculomotor parameters assessed during baseline (no cognitive demand involved) and during a simple computational color memory task using an eye-tracker. Baseline showed statistically different and heterogeneous results between normal cognition and MCI groups. Familiarization phase of the task could not discriminate between groups in any of the analyzed parameters. AD subjects made longer fixations and visits on distractors, and more frequent fixations and visits on the target areas than other groups during the response phase. Eye-tracking time-related parameters differentiate AD subjects from other groups under cognitive demand even in a simple color memory task.

The ERP correlates of color-based center-surround inhibition in working memory

The color-based center-surround inhibition (CSI) in working memory (WM) refers to that remembering a color inhibits the memory of similar colors but not of distinct colors. This study aimed to investigate the neural activity of color-based CSI in WM. Two WM items (distance 0°, 10°, 20°, 30°, 40°, 50°, or 60° in color space) were displayed sequentially, then one of them was retrieved to compare with a later probe. Behavioral results revealed that participants showed longer RTs for distances 20° and 30° than distances 0° and 40°, suggesting a CSI between similar items. ERP results revealed that: 1) WM item-induced late positive component (LPC) was more positive for distance 30° than the other distances, suggesting an enhanced resource allocation process for encoding similar items; 2) Cue-induced LPC was more positive for distances 20° and 30° than distances 0° and 60°, suggesting a greater difficulty for retrieving similar items; Cue-induced contingent negative variation was less negative for distance 20° than distances 40°, 50°, and 60°, suggesting a reduced response preparation process during retrieving similar items; 3) Probe-induced LPC was more positive for distances 20° and 30° than distances 50° and 60°, suggesting a greater effort for comparing probe with one item retrieved from two similar items. These results revealed a colored-based CSI during WM encoding and retrieval processes. An enhanced top-down control might be required to resolve the greater interference between similar items than identical or distinct items conditions.

Are older adults susceptible to visual distraction when targets and distractors are spatially separated?

ABSTRACT Older adults show preserved memory for previously distracting information due to reduced inhibitory control. In some previous studies, targets and distractors overlap both temporally and spatially. We investigated whether age differences in attentional orienting and disengagement affect recognition memory when targets and distractors are spatially separated at encoding. In Experiments 1 and 2, eye movements were recorded while participants completed an incidental encoding task under covert (i.e., restricted viewing) and overt (i.e., free-viewing) conditions, respectively. The encoding task consisted of pairs of target and distractor item-color stimuli presented in separate visual hemifields. Prior to stimulus onset, a central cue indicated the location of the upcoming target. Participants were subsequently tested on their recognition of the items, their location, and the associated color. In Experiment 3, targets were validly cued on 75% of the encoding trials; on invalid trials, participants had to disengage their attention from the distractor and reorient to the target. Associative memory for colors was reduced among older adults across all experiments, though their location memory was only reduced in Experiment 1. In Experiment 2, older and younger adults directed a similar proportion of fixations toward targets and distractors. Explicit recognition of distractors did not differ between age groups in any of the experiments. However, older adults were slower to correctly recognize distractors than false alarm to novel items in Experiment 2, suggesting some implicit memory for distraction. Together, these results demonstrate that older adults may only be vulnerable to encoding visual distraction when viewing behavior is unconstrained.

Sar2color: Learning Imaging Characteristics of SAR Images for SAR-to-Optical Transformation

Optical images are rich in spectral information, but difficult to acquire under all-weather conditions, while SAR images can overcome adverse meteorological conditions, but geometric distortion and speckle noise will reduce the quality of SAR images and thus make image interpretation more challenging. Therefore, transforming SAR images to optical images to assist SAR image interpretation will bring opportunities for SAR image application. With the advancement of deep learning technology, the ability of SAR-to-optical transformation has been greatly improved. However, most of the current mainstream transformation methods do not consider the imaging characteristics of SAR images, and there will be failures such as noisy color spots and regional landform deformation in the generated optical images. Moreover, since the SAR image itself does not contain color information, there also exist many color errors in these results. Aiming at the above problems, Sar2color, an end-to-end general SAR-to-optical transformation model, is proposed based on a conditional generative adversarial network (CGAN). The model uses DCT residual block to reduce the effect of coherent speckle noise on the generated optical images, and constructs the Light atrous spatial pyramid pooling (Light-ASPP) module to mitigate the negative effect of geometric distortion on the generation of optical images. These two designs ensure the precision of texture details when the SAR image is transformed into an optical image, and use the correct color memory block (CCMB) to improve the color accuracy of transformation results. Towards the Sar2color model, we have carried out evaluations on the homologous heterogeneous SAR image and optical image pairing dataset SEN1-2. The experimental results show that, compared with other mainstream transformation models, Sar2color achieves the state-of-the-art effect on all three objective and one subjective evaluation metrics. Furthermore, we have carried out various ablation experiments, and the results show the effectiveness of each designed module of Sar2color.

The Study of Subjective Evaluations of Colour Rendering of White Light Sources with Variable Chromaticity

The effect of spectral composition of white light sources with variable chromaticity on objective and subjective evaluations of their colour rendering was studied. The dependences of the colour rendering indices on colour temperature were obtained for four light sources: a tungsten halogen lamp, white light emitting diodes with adjustable correlated colour temperature, fluorescent lamps of three colours, and three-colour light emitting diodes. The dependences of general colour rendering index (CRI) Ra and Smet’s memory colour rendering index (MCRI) Rm on the distance uv between a point corresponding to the studied radiation and the blackbody line in the 1960 CIE system (u, v) at constant correlated colour temperature 6500 K were also studied for an installation with three-colour light emitting diodes. The conditions, in which these indices reach their maximum values, were identified.

Enhancing the user authentication process with colour memory cues

ABSTRACT The authentication process is the first line of defence against potential impostors, and therefore is an important concern when protecting personal and organisational data. Although there are many options to authenticate digital users, passwords remain the most common authentication mechanism. However, with password numbers increasing, many users struggle with remembering multiple passwords, which affects their security behaviour. Previous researchers and practitioners have attempted to suggest ways to improve password memorability and security simultaneously. We introduce novel approach that utilises colour as a memory cue to increase password memorability and security. A longitudinal study examined in total over 3000 passwords that were created, learnt and recalled (password process) over a period of five-weeks. By adding colour to the password process, our results suggest that password memorability and security can be increased simultaneously. Through giving the user the option of choosing the colours (compared with colours being preselected), encourages users to create more personal and meaningful memory cues when creating their passwords. Additionally, colour also provided another security parameter by increasing password entropy. These unique results have practical implications for researchers and practitioners that could positively impact password security, and the financial losses suffered due to password security breaches.