Sensation and Perception Flashcards
Sensation
The conversion of the stimulus to neural impulses
Perception
Interpreting stimuli and making sense of them
How is an external stimulus experienced?
Stimulus: anything that activates our sensation systems
Constancy
We experience perceptual stability even though the sensed stimulus changes. The three constancies are shape constancy, size constancy, and brightness constancy
The Autokinetic Effect
Stationary objects can appear to move
Transduction
translation of stimulus energy into an electrical code/neural impulse
Difference Threshold
The minimum difference for a person to be able to detect the difference half the time. (in color weight, pitch, temperature, etc.)
Weber’s law
For two stimuli to be perceived as different, they must differ by a constant minimum percentage and not a constant amount.
Color Perception: The Trichromatic Theory
three kinds of cones sensitive to different wavelengths, explains color blindness well.
Color Perception: Opponent Process Theory
Receptor cells are linked in pairs, working in opposition to each other, explains afterimages
Rods
a type of receptor cell in the retina, helps with low light (night vision) and peripheral vision. There are approximately 120 million rods in the retina.
Cones
A type of receptor cell in the retina, helps with bright light and near the fovea (centralized). Approximately 6 million cones in the retina.
Afterimages-color opposites
red-green
blue-yellow
black-white
Bipolar cells
receive information directly from rods and cones and sends this information to ganglion cells
Ganglion Cells
collect and summarize visual information, which is moved out of the back of the eyeball through a bundle of ganglion axons called the optic nerve
simultaneous contrast
objects look lighter against a dark back ground than against a light background
Lateral inhibition
when a receptor (a cone) fires, it inhibits its neighbors because they serve a similar function, its purpose is to emphasize change.
Binocular disparity
a depth cue using both eyes
What is are three examples of monocular depth cues? And what are they?
Texture gradient: distant objects are denser
Linear Perspective: parallel lines appear to converge in the distance
Relative Size: distant objects are smaller
Place Theory
the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated
Frequency Theory
the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequencies of a tone, thus enabling us to sense pitch
McGurk Effect
Visual and auditory information interact, can cause mistakes in perception
Name four skin sensations
touch/pressure
warmth
cold (warm and cold have different receptors)
pain
Gate-control theory
the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on to the brain
gate opened by the activity of pain signals traveling up small nerve fibers
gate closed by activity in larger fibers (transmitting touch or warmth signals) or by information coming from the brain (expectations)
What type of smell do we have? How many different types of smell receptors do we have and how many different odors can we smell?
A poor sense of smell. 350 different types, of smell receptors and we can detect about 10,000 different odors.
