Weeek 6 Flashcards
Seansation and Perception
sensation
detecting physical energy with our sense organs
perception
the brains interpretation of the raw sensory information
does sensation always match perception
no
illusion
our perception does not match the physical reality
transduction
conversion of an external stimulus into a neural signal
sensory receptors
specialized cells designed to convert a certain kind of external information into a neural signal
sensory adaptation
sensory neurons adjust their sensitivity based on recent stimulus history
after effets
opposing sensory or perceptual distortions that occur after adaptation
steps of a perception
parts of a wave: crest, wavelength, trough, amplitude
loud sound
high amplitude
low sound
low frequency
For light, what psychological sensation corresponds to the wavelength of a light wave?
color
gamma, x-rays, UV
higher frequency
light spectrum
brighter light has
higher amplitudes
Do you think that by doubling the amplitude of a light wave, you would also double the perceived brightness?
no
psychophysics
the study of how our sensations (psychological events) correspond to physical events in the world
absolute threshold
the lowest level of a stimulus needed for the nervous system to detect a change 50% of the time
Just noticeable differences
the smallest change in the intensity of a stimulus that we can detect
webers law
the stronger the stimulus, the bigger the change needed to detect it
signal
what you are trying to detect
noise
similar stimuli that might compete with the signal and interfere with your ability to detect the signal
signal to noise ratio
Difficult of detecting the signal depends on the strength of the signal in relation to the strength of the noise
You were searching for your lost phone, which has an orange case. When you see a part of your orange t-shirt peeking out from a pile of clothes, for a moment you think it is your phone! You have just experienced a ______.
false alarm
attention
We know that attention is (at least somewhat) like a filter because of effects that show streams of information popping through the filter.
Dichotic listening
play different information through each ear of headphones. Inofmation reported only through the attended ear
cocktail party effect
happens when important information pops out in a conversation that you are no attending
inattentional blindness
occurs when unattended stimuli are ignored as if they werent true
bottom up processing
- constructing a representation from parts and basic features
- Starts with the raw data and construct meaning from that
- example) puzzle
top down processing
- processing influenced by previous experience and knowledge
- Start with meaning and use it to understand a stimulus
- example) dog image
- sunny day in the park audio
sensations sensation bottom up or top down processing
bottom up
is perception bottom up or top down processing
both
perceptual step
set formed when our expectations influence our perceptions
sclera
the white part of the eye
pupil
circular hole where light entersq
iris
colored portion of the eye that controls pupil size (letting in more or less light)
cornea
Curved, transparent layer covering the iris and pupil that helps focus light
lens
oval shaped disc that bends light
accomodation
changing of lens shape to focus on near/far objects
eyelid, pupil, slcera, iris
eye anatomy
myopia
eye is too long
- nearsightedness
hyperopia
eye is too short
- farsightedness
retina
membrane at the back of the eye responsible for converting light into a neural signal
fovea
central portion of the retina, responsible for visual acuity
- very small, takes up one percent of retina
acuity
sharpness of vision
saccades
small jerky movements of the eye allowing for rapid changes of focus
rods
- Respond under low levels of light
- Not color sensitive
- More common outside of fovea
cones
◦ Sensitive to fine detail
◦ Primarily located in fovea
◦ Color Sensitive
◦ Less plentiful than rods
optic nerve
bundle of axons that travel from the retina to the brain
blind spot
area of the retina where the optic nerve exits the eye
neural pathway
white objects
reflect all light
black objects
reflect no light
hue
the color of light corresponds to wavelength
opponent process theory
we perceive color in terms of three pairs of opponent colors
color blindess
inability to see some o all colors
binocular vs monocular depth cues
two eyes vs one eye
depth perception
ability to judge distance and spatial relations
binocular disparity
convergence
monocular depth cues
relative size
texture gradient
interposition
linear perspective
height in plane
light and shadow
motion paradox
perceptual constnacy
perceive stimuli as consistent across stimuli
shape constancy
perceived shape is constant even tho image on retina changes
size constancy
perceive stimuli as consistent across varied conditions
color constancy
perceive stimuli as consistent across varied conditions
