Sensory Perception Flashcards
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Visual Cues
Sensory cues received by the eye in the form of light and processed by the visual system during visual perception. Important for perception of depth
Binocular Cues
Visual cues that involve the use of both eyes
Retinal Disparity
Our eyes are 2.5 inches apart (binocular)
Convergence
For things far away, our eyes relax. For things closer, our eyes contract (binocular)
Monocular Cues
Cues that involve a single eye
Relative Height
Things that are higher are perceived as farther away (monocular)
Motion Parallax
Things farther away move slower (monocular)
Interposition
Something that is covered by another thing is perceived as farther away than the latter (monocular)
Relative size
Two comparable things of the same size – a smaller one is perceived as more distant
Shading and Contour
Light and darkness can help us perceive depth
Constancy
Perception of an object doesn’t change even if it looks different on our retina
Size constancy
Size of objects are consistent even though the sizes on the retina vary greatly with distance
Shape constancy
We perceive the shapes of objects the same even if viewing conditions (angles, etc.) change considerably
Color constancy
We perceive the color of an object the same even under different illuminants
Sensory Adaptation of Hearing
The inner ear muscle contracts in loud noises to reduct vibrations and control volume
Sensory Adaptation of Touch
Temperature sensors are desensitized
Sensory Adaptation of Smell
Desensitization to molecules
Sensory Adaptation of Sight
Down regulation through contraction of pupils and desensitization of rods and conse
Up regulation through dilation of pupils
Weber’s Law
The change in intensity of a sensation divided by the value of the original intensity is a constant
Delta I = I k
Just noticeable difference
The smallest difference in intensity that can be detected 50% of the time (Weber’s Law)
Absolute Threshold (definition + factors)
Minimum intensity needed to detect a stimulus at least 50% of the time
Factors: Expectations, Experiences, Motivation, Alertness
Subliminal Stimuli
Stimuli that are under the Absolute Threshold
Vestibular System
Balance and spatial orientation – focus in the inner ear
Semicircular Canals
In the inner ear, filled with endolymph. Shift makes us detect head movement and intensity of rotation
Posterior, lateral, and anterior
Otolithic Organs
Part of the vestibular system. Detect linear acceleration and head positioning
Ca crystals attached to hair cells. Movement pulls on these cells which fire neurons
Signal Detection Theory
Discerning between important stimuli and noise; can be broken down into four scenarios
Hit: stimulus present and there is a response.
Miss: stimulus present and there is no response
False alarm: stimulus not present and there is a response
Correct rejection: stimulus not present and there is no response
Strategies of Signal Detection
Three strategies
- Liberal: Respond to every stimulus
- Conservative: Do not respond unless you’re 100% sure
- Ideal: respond when 50% sure
Bottom-up Processing
Stimulus influences perception; processing sensory information as it comes in
Top-down Processing
Background knowledge influences perception (driven by cognition)
Gestalt Principles (definition + principles)
Rules that explain how we perceive visual elements
- Similarity: similar items are grouped together
- Proximity: items close to each other are grouped together
- Continuity: lines are perceived as following a smooth continuous path
- Closure: objects close together are perceived as being a whole
- Pragnanz: Reality is reduced to the simplest form possible
- Symmetry: We perceive objects as symmetrical around a midpoint
Law of Common Fate
If some objects are doing one thing (ex. moving in one direction) and some other objects are doing another thing (ex. moving in the other direction), we perceive them as two distinct sets of objects
Law of Past Experience
Visual stimuli are categorized based off of common experience (ex. the letters L and I are not subject to the Law of Similarity)
