Sensory Perception Flashcards
What visual cues allow humans to perceptually organize information?
Depth, form, motion, and constancy
How can humans sense the depth of an object?
Binocular cues give people a sense of depth
Retinal disparity: the distance between the two eyes gives a slightly difference image projected onto each retina
Convergence: the degree to which the eyes are turned gives humans a sense of how far away something is
How can humans sense the form of an object?
Monocular cues give people a sense of form
These cues allow people to determine the relative size and height of an object, interposition (overlap) of two objects, and shading/contour of an object
How can humans sense motion?
Monocular cues give people a sense of motion
Motion parallax
Objects that are further away appear to move slower, while those that are closer appear to move faster
What is constancy and how to humans sense it?
Constancy is refers to how the perception of an object’s size, shape, and color does not change even if the image projected on the retina changes
Monocular cues give people a sense of constancy
What is sensory adaptation and what are some ways that our senses adapt over time?
Sensory adaptation is the ability of our senses to change their sensitivity to stimuli
The eyes adjust to bright stimuli by constricting the pupils and desensitizing the rods and cones. Temperature receptors become less sensitive to cold over time. The inner ear muscle contracts due to loud noises
Weber’s Law
The threshold at which you can notice a change in a sensation is the just noticeable difference (JND), also called the difference threshold
ΔI= IK
ΔI= JND
I= initial intensity
As the initial intensity increases, the JND increases (directly proportional)
Absolute Threshold of Sensation
Minimum intensity of stimulus required for a subject to reliably detect the stimulus 50% of the time
Many psychological factors influence absolute threshold (motivations, expectations, alertness)
Subliminal stimuli
Those that are below the absolute threshold of sensation
What are the four types of somatosensation?
- Proprioception: position
- Thermoception: temperature
- Mechanoception: pressure
- Nociception: pain
How is the intensity of a stimulus coded for?
The rate of firing of action potentials
What are the three ways a neuron can encode the timing of a stimulus?
- Nonadapting: the neuron fires at a consistent rate
- Slow adapting: the neuron fires quickly a the begininning of a stimulus then slows down
- Fast adapting: the neuron fires quickly at first then stops, then fires again
How is the location of a stimulus coded for?
Location-specific stimuli are sent by nerves to the brain, relies on dermatomes
What is the vestibular system and what organs are involved?
The vestibular system is a sensory system controlling balance and spatial orientation
It is controlled by the semicircular canals of the inner ear, which detect rotation, and the otolithic organs which detect linear acceleration
Signal Detection Theory
Looks at how people make decisions under conditions of uncertainty
d’ strength
When a stimulus is strong, people will make more hits than misses
When a stimulus is weak, people will make more misses than hits
c: strategy
2 types of signal detection strategies:
- Conservative: always say no unless 100% sure the signal is present
- Liberal: always say yes, even if it gets false alarms
Bottom up processing
Begins with the stimulus, which influences what we perceive.
This is inductive reasoning and is always correct
Top down processing
Background knowledge influences what we perceive
This is deductive reasoning and is influenced by our expectations
Gestalt principles
Set of theories that explain why we perceive things the way that we do
Law of Similarity
Things that are similar to one another are grouped together by the brain
Law of Pragnanz
Reality is reduced to the simplest form
Law of proximity
Objects that are close to one another are grouped together
Law of continuity
Lines are seen as following the smoothest patj
Law of Closure
Objects close together are seen as a whole, the mind fills in the missing information
Law of symmetry
the mind perceives objects as being symmetrical and forming around a center point.
