Visual Cues Ch 1 Flashcards
(75 cards)
What allows humans to receive visual cues from their environment?
Binocular cues
Binocular cues provide depth perception through retinal disparity and convergence.
What is retinal disparity?
The slight difference in views received by each eye due to their ~2.5 inches apart distance
Retinal disparity helps in depth perception.
What is convergence in terms of depth perception?
The degree to which the eyes turn inward when focusing on an object
Muscles of the eyes relax for distant objects and contract for nearby objects.
What are monocular cues?
Visual cues that do not require two eyes
Monocular cues provide information about form, motion, and constancy.
How does relative size serve as a monocular cue?
Closer objects are perceived as larger
This gives us an idea of the form of an object.
What does interposition indicate in visual perception?
If one object overlaps another, the overlapping object is perceived as closer
This is also known as overlap.
What is relative height in terms of visual perception?
Objects that are higher in the visual field are perceived as farther away
This helps in determining distance.
What role does shading and contour play in visual perception?
Using light and shadows to perceive form and depth
Helps in identifying contours such as craters or mountains.
What is motion parallax?
The perception that objects farther away move slower than those closer
This is a monocular cue related to motion.
Define constancy in visual perception.
Our perception of an object remains unchanged despite variations in the image cast on the retina
Types include size constancy, shape constancy, and color constancy.
What is size constancy?
The perception that an object maintains the same size even when it appears larger due to proximity
Example: A closer car appears larger but is still the same size as one farther away.
What is shape constancy?
The perception that an object maintains its shape despite changes in orientation
Example: A door opening appears as a different shape but is still perceived as a rectangle.
What is color constancy?
The perception that an object retains its color despite changes in lighting
This allows us to recognize the same object in different lighting conditions.
Define sensory adaptation.
The process by which our senses adjust to stimuli over time
Examples include hearing adaptation, touch, smell, and proprioception.
What happens during hearing adaptation?
The inner ear muscles contract in response to high noise levels
This dampens vibrations and protects the eardrum.
What is proprioception?
The sense of the body’s position in space
Often referred to as the sense of balance.
How do pupils respond to bright light?
Pupils constrict to reduce light entering the eye
This is part of the down regulation process.
What is Weber’s Law?
The principle that the just noticeable difference (JND) is a constant proportion of the initial stimulus intensity
It is expressed as ΔI (JND)/I (initial intensity) = k (constant).
If a 2 lb weight feels the same as a 2.05 lb weight, what can be inferred?
The difference is below the just noticeable difference (JND)
The JND varies with the initial intensity of the stimulus.
What is the relationship predicted by Weber’s Law?
A linear relationship between incremental threshold and background intensity
It shows how sensitivity to changes in stimuli varies based on initial intensity.
How do neurons encode timing?
Neurons encode timing in three ways: non-adapting, fast adapting, or slow adapting.
What is a non-adapting neuron?
A non-adapting neuron fires at a constant rate.
What is a slow-adapting neuron?
A slow-adapting neuron fires at the beginning of a stimulus and calms down after a while.
What is a fast-adapting neuron?
A fast-adapting neuron fires as soon as a stimulus starts, then stops firing, and starts again when the stimulus stops.
