Ch 4: Sensation and Perception Flashcards
sensation
detection of physical energy by our sense organs
perception
brain’s interpretation of raw sensory data
transduction
when the neurons system converts an external stimulus into electrical signals within neurons
sensory adaption
activation is highest when the stimulus is first detected
absolute threshold
lowest level of a stimulus we can detect 50% of the time
just noticeable difference (JND)
the smallest amount of stimulus change we can detect
weber’s law
the stronger the stimulus, the larger the JND
- JND/original stimulus intensity
signal detection theory
regards how stimuli are detected under diff. conditions
- response bias
signal to noise ratio
harder to detect a signal as background noise increase
selective attention
brain picks and chooses important sensory information
- other “channels” are still processed at some level
cocktail party effect
the ability to focus one’s attention on a particular stimulus while filtering out a range of other stimuli (usually auditory)
inattentional blindness
failure to see stimuli that are in plain sight when our attention is focused elsewhere
- ex.: monkey business allusion
change blindness
failure to detect changes in the environment
- ex.: door study
the binding problem
how do our brains combine all the various stimuli around us into a coherent whole?
light
see color based on what is absorbed and reflected
- white things reflect all wavelengths
- black things absorb all wavelengths
qualities of light
- brightness: intensity of reflected light
- hue (color): absorbed light
sclera
white portion of the eye
iris
colored portion of the eye that has muscles which control the pupil
pupil
where light enters
- dilate (get bigger)
- constrict (get smaller)
rods (in the retina)
responsible for basic chapes and forms
cones (in the retina)
responsible for color and detail
occipital lobe
primary visual cortex
trichromatic theory
- we perceive 3 primary colors: red, blue, and green
- support: 3 types of specialized cones
- color blindness
- challenges: can’t explain everything
color blindness
- monochromats can’t see color at all
- cause by: absence/reduced number of cones
- brain damage to a color vision area in the brain
opponent process theory
explains what trichromatic theory can’t
- 3 pairs of opponent cells: red/green, blue/yellow, black/white
- support: afterimages appear in complementary colors
coping with blindness
- rely on other senses more heavily
- brain may reproduce visual cortex
blindsight
blind people performing above-average on visual tests
- happens without conscious awareness
sound
sound waves are mechanical vibrations
- usually traveling through air or other mediums
pitch (frequency, Hz)
- high frequency = higher pitch
- lower frequency = lower pitch
loudness (amplitude, dB)
- higher amplitude = louder
- lower amplitude = quieter
outer ear
funnels sound to the ear drum
pinna
- part of the outer ear
- visible cartilage flap
ear canal
- part of the outer ear
- carries sound waves to the ear drum
middle ear
transmits sound from ear drum to inner ear
ossicles
- part of the middle ear
- hammer, anvil, stirrup (small bones)
inner ear
site of auditory transduction
cochlea
- part of the inner ear
- converts vibrations into neural activity
- contains fluid that is disturbed by sound vibrations, and this fluid movement exerts pressure on hair cells
hair cells
- part of the inner ear
- convert sound waves into action potentials
- located in the organ of corti and basilar membrane
place theory (pitch perception)
- base = high pitch
- top = low pitch
- only accounts for high-pitched tones
- 5,000 - 20,000 Hz
frequency theory (pitch perception)
- neurons rate of firing reproduces the frequency of the sound
- only accounts for very low pitches
- up to 100 Hz
volley theory (pitch perception)
- sets of neurons fire together at their maximum rate to produce higher pitches
- tones between 100 - 5,000 Hz
olfaction
smell
gustation
taste
- individual differences are caused by “supertasters”, smoking, age-related declines, etc
taste
- sweet
- salty
- sour
- bitter
- umami (meaty or savory)
smell receptors
- each olfactory neuron contains a single type of receptor
- they recognize an odorant based on its shape
taste receptors
taste buds are contained in bumps on the tongue
somatosensory
touch, temperature, pain
sensory receptors
nerve endings in the skin
post transduction
travel first to the spinal cord, then to the brain stem and somatosensory cortex
gate control theory
- spinal nerves act as gates to let pain travel through to reach the brain
OR - close these gates and prevent pain messages from getting through at all
acute pain
short lived
chronic pain
enduring
proprioception
kinesthetic sense - body position
- your body’s ability to sense movement, action, and location
vestibular sense
equilibrium and balance
perception
sense meet the brain
- after transduction data is organized/consolidated in the brain
parallel processing
attending to multiple senses at the same time
bottom up processing
features of the stimulus affect perception
top down processing
beliefs, expectations, stereotypes
perceptual constancy: shape
can perceive diff. stimuli are the same thing
facial perception
recognize whole faces, not just individual features
monocular cues (one eye)
relative size, texture gradient, interposition, etc.
binocular cues (both eyes)
binocular disparity
- the difference in image location of an object seen by the left and right eyes
- ex.: alternate closing one eye w/ a pen in front
binocular convergence
eyes turn inward to closer stimuli
subliminal perception
stimuli presented outside of awareness
- may affect behavior
- NOT equal to subliminal persuasion
- effects tend to disappear when subjects gain awareness
psychic predictions
- often do no come true
- they use other methods to make it seem as if they are accurate
- cold read techniques
