Chapter 4 – Sensation & Perception Flashcards
Perception
Interpretation of sensory info (relies on experience)
Sensation
Receiving information from the environment
Threshold
Limits of perception
Absolute threshold
The least amount of info needed for you to understand that the stimulus is actually present
Difference threshold
The amount of stimulus needed to determine that there has been a change in a stimulus
Just – noticeable difference
The amount of difference that actually exists in detection; the size
Weber’s law
The rule that a constant percentage of magnitude change is necessary to detect the difference
Signal detection
Signals are always embedded in noise, and so the challenge is to distinguish the signal from the noise
Noise
Distracting things
Sensitivity
Lower threshold for distinguishing a stimulus
Bias
Willingness to report a stimulu
Signal detection table
Report(+)-Present(+) = HIT
Report(+)-Present(-) = False Alarm
Report(-) -Present(+) = MISS
Report(-) -Present(-) = Correct Rejection
D’
The difference of how discriminable of the two distributions are; distance between two means
How does D’ change?
D’ is large if distr. are very discriminable
D’ is small when they are not very discriminable
Sensory adaptation
When your body quickly adjust to account for rapidly changing stimulus; going to a dark place/catching a ball
Cornea
The thin layer covering the outside of the eye that is responsible for bending light ways to help focus the waves on the back of the .
Sclera
The white part of the eye; provides nutrients
Iris
The colored part of the eye; muscle that controls size of pupil
Pupil
Hole that controls amount of ambient light
Lens
A structure that works with cornea to bend light so it falls onto the fovea; changes shape to help focus stimulus
Retina
The structure most responsible for visual acuity; contains the actual photoreceptors
Rods
Found in the periphery of the retina; darks/lights/black and whites
Cones
Center of the retina; color
fovea
The center of greatest visual acuity located in the center of the retina
Bipolar cells
The first layer of cells directly in front of the retina; translate info from rods/cones into ganglion cells
Ganglion cells
Transfer optic impulses down towards optic nerve
Blind spot
The point where the optic nerve exits the eye; no Rods/cones = no vision
Optic nerve
Large bundle of nerve fibers carrying impulses from the retina into the brain
Optic chiasmus
Connects images from the correct hemispheres of each eyeball and send info to thalamus
Thalamus
Send signals to occipital lobe
Occipital lobe
Corrects visual perception
Bottom-up processing
Start with sensory receptors and work your way up to higher – level processing
Top – down processing
Start with experiences and expectations
Selective attention
The focusing of conscious awareness on a particular stimulus
Selective inattention
Ignoring other stimuli so we can focus
Unintentional blindness
Failing to see visible objects when our attention is directed elsewhere; Gorilla suit test video