Related Experiment Video
Updated: Aug 11, 2026
06:50
Enabling High Grayscale Resolution Displays and Accurate Response Time Measurements on Conventional Computers
Published on: February 29, 2012
The perception of luminosity on different backgrounds and in different illuminations
1Upsala College, East Orange, NJ 07019.
Perception
|January 1, 1994
Summary
The study found that a target appears luminous when its luminance is 1.7 times that of a white surface under the same lighting. This luminosity threshold demonstrates constancy, similar to surface grays, linking luminosity to lightness perception.
Area of Science:
- Visual perception
- Color science
- Psychophysics
Background:
- Understanding the perception of luminosity and its relationship to surface properties is crucial in visual science.
- Previous research has explored factors influencing lightness perception, but the precise conditions for luminosity perception remain debated.
Purpose of the Study:
- To determine the luminance threshold at which a target surface appears luminous under varying background and illumination conditions.
- To investigate whether luminosity perception exhibits constancy properties similar to those observed in lightness perception.
Main Methods:
- Participants viewed target surfaces of varying luminance against different backgrounds (white, gray, black) and within illuminated Mondrian patterns.
- Observers reported whether targets appeared luminous or opaque, establishing a luminosity threshold across experimental conditions.
Main Results:
- A consistent luminosity threshold was identified: targets appeared luminous when their luminance was approximately 1.7 times that of a surface perceived as white.
- This threshold demonstrated constancy concerning changes in illumination level and background reflectance, mirroring surface gray constancy.
Conclusions:
- The perception of luminosity is strongly linked to lightness perception for opaque surfaces.
- The findings challenge existing models and propose that defining luminosity conditions is integral to understanding lightness perception.
Related Concept Videos
02:16Light Acquisition
In order to produce glucose, plants need to capture sufficient light energy. Many modern plants have evolved leaves specialized for light acquisition. Leaves can be only millimeters in width or tens of meters wide, depending on the environment. Due to competition for sunlight, evolution has driven the evolution of increasingly larger leaves and taller plants, to avoid shading by their neighbors with contaminant elaboration of root architecture and mechanisms to transport water and nutrients.
01:05Difference from Background: Limit of Detection
The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals.
The LOD indicates the presence or absence...
The LOD indicates the presence or absence...
01:22Photoreceptors and Visual Pathways
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category, whereas...
01:21Gestalt Principles of Perception
Gestalt principles provide a framework for understanding how humans perceive objects as unified wholes within their context. These principles are essential in explaining the cognitive processes that make sense of complex visual stimuli by organizing them into coherent groups. One fundamental principle is proximity, which posits that objects located close to each other are perceived as a collective group. For instance, when dots are positioned near one another, the visual system interprets them...
01:25Factors Affecting Perception
Perception is influenced by perceptual set, context, motivation, and emotion. Perceptual set, or perceptual expectancy, refers to the tendency to perceive things in a particular way, influenced by previous experiences and expectations. This phenomenon affects the interpretation of stimuli, creating a set of mental tendencies and assumptions that impact sensory perceptions of sound, taste, touch, and sight.
An illustrative example of a perceptual set is the scenario where an airline pilot told...
An illustrative example of a perceptual set is the scenario where an airline pilot told...
01:12Perceptual Constancy
Perceptual constancy is the ability to recognize that objects remain consistent and unchanged even when their appearance varies due to changes in sensory input. There are four main types of perceptual constancy: size constancy, shape constancy, color constancy, and brightness constancy.
Size constancy is the recognition that an object remains the same size, even when its image on the retina changes. For instance, a bus is perceived to be large enough to carry people, even if it looks tiny from...
Size constancy is the recognition that an object remains the same size, even when its image on the retina changes. For instance, a bus is perceived to be large enough to carry people, even if it looks tiny from...