Binocular Rivalry, Color Perception, Colour Perception
Conditions
Keywords
Colour perception, Color perception, Binocular rivalry, Individual differences, Chronotype, Sleep, Subjective fatigue, Sex differences, Visual perception
Brief summary
This observational study aims to characterise individual differences in colour perception and binocular rivalry. Participants will complete computer-based visual perception tasks, including a colour perception task and a binocular rivalry task. The study will first examine whether individuals show measurable differences in these perceptual responses. It will then explore whether these differences are associated with chronotype, sex, sleep-related measures, and subjective fatigue. The findings may help clarify how stable individual characteristics and daily physiological states relate to visual perception.
Detailed description
Colour perception and binocular rivalry both show variability across individuals. However, the extent to which these individual differences are stable and whether they are associated with personal or physiological factors remains unclear. This study will use behavioural visual perception tasks to measure individual differences in colour perception and binocular rivalry. Participants will complete a colour perception task and a binocular rivalry task, along with questionnaire measures related to chronotype, sleep, fatigue, and demographic characteristics including sex. The primary aim is to determine whether measurable individual differences are present in colour perception and binocular rivalry performance. The secondary aim is to examine whether these differences are associated with chronotype, sex, sleep-related variables, and subjective fatigue. The study is observational and does not involve a clinical intervention, drug, biologic product, or medical device.
Interventions
OTHERComputer-Based Visual Perception Tasks
Participants will complete computer-based visual perception tasks, including a colour perception task and a binocular rivalry task. These tasks are used to measure individual differences in perceptual responses and are not intended as a clinical intervention.
Sponsors
The Hong Kong Polytechnic University
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 25 Years
Healthy volunteers
Yes
Inclusion criteria
* Adults aged 18 years or older. * Normal or corrected-to-normal visual acuity. * Normal or corrected-to-normal binocular vision. * Normal colour vision, or no self-reported colour vision deficiency. * Able to understand the study instructions and provide informed consent. * Able to complete computer-based visual perception tasks and self-report questionnaires.
Exclusion criteria
* Self-reported colour vision deficiency. * Uncorrected visual impairment or eye conditions that may interfere with visual perception tasks. * Strabismus, amblyopia, or other binocular vision problems that may interfere with binocular rivalry testing. * History of neurological disorders, photosensitive epilepsy, or severe sensitivity to flickering visual stimuli. * Current condition or medication that, in the investigator's judgment, may substantially affect visual perception, attention, or task performance. * Inability to complete the task procedures or provide valid responses.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean colour-adjustment values on the colour perception task | Day 1 (single laboratory session) | Colour perception will be measured using a computer-based colour adjustment task. Participants will adjust the appearance of a target object or stimulus, and outcome variables will include adjustment values in colour space, such as chromaticity, hue, saturation, or luminance-related measures, depending on the final task implementation. These measures will be used to characterise individual differences in colour perception. |
| Mean perceptual dominance duration during binocular rivalry | Day 1 (single laboratory session) | Binocular rivalry is measured with a computer-based dichoptic task in which a different image is presented to each eye. Perceptual dominance duration is the mean length of time, in seconds, that one stimulus remains exclusively visible before perception switches to the other. Longer mean durations indicate more stable, slower-switching rivalry. |
| Mean alternation rate during binocular rivalry | Day 1 (single laboratory session) | Binocular rivalry is measured with the same computer-based dichoptic task. Alternation rate is the mean number of perceptual switches between the two stimuli per minute of viewing. Higher alternation rates indicate faster perceptual switching between the two eyes' images. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Morningness-Eveningness Questionnaire (MEQ) score | Day 1 (single laboratory session) | Chronotype assessed using the Morningness-Eveningness Questionnaire (MEQ). Total scores range from 16 to 86; higher scores indicate greater morningness (a stronger morning-type preference) and lower scores indicate greater eveningness. |
| Pittsburgh Sleep Quality Index (PSQI) global score | Administered once, within 7 days before or at the single laboratory session (Day 1); the PSQI assesses sleep over the preceding 1 month. | Sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI). The global score is the sum of seven component scores and ranges from 0 to 21; higher scores indicate worse sleep quality (a global score above 5 indicates poor sleep quality). |
| Karolinska Sleepiness Scale (KSS) score | Day 1: assessed immediately before and immediately after the visual perception tasks, which are completed within a single session lasting up to approximately 1 hour. | Subjective sleepiness/fatigue assessed using the Karolinska Sleepiness Scale (KSS), a single-item 9-point scale. Scores range from 1 to 9; higher scores indicate greater sleepiness. The pre-task to post-task change in KSS score may also be reported. |
Countries
Hong Kong
Contacts
CONTACTCehao Yu, PhD
CONTACTJunkai Che, Master
PRINCIPAL_INVESTIGATORCehao Yu, PhD
The Hong Kong Polytechnic University
Outcome results
None listed