sensation and perception Flashcards
sensation
receiving energies from the environment and turning it into neural energy
Perception
process of organizing and interpreting sensory info
top down processing
cognition to sensory input (perception)
bottom up processing
sensory receptors send info to brain (sensation)
sensory receptors
cells that transmit stimulus info to sensory (afferent) nerves to the brain
Absolute threshold
the absolute minium amount of stimulus energy a person can detect (50% detection rate)
difference threshold
degree of difference that exists between two stimuli before that difference is detected
webers law
Minimum percentage over minimum amount (drop of water in glass example)
signal detection theory
approach to perception that highlights decision making about stimuli under conditions of uncertainty
selective attention
focusing on a specific aspect of experience, while ignoring others
sensory adaptation
change in responsiveness of sensory system based on average level of surrounding stimulation
perceptual set
Predisposition/readiness to perceive something in a certain way
sensory transduction
process where our bodies turn (transduce) external/physical/chemical stimuli into electrical impulses for brain to interpret
wavelengths
distance between peak of waves
light
energy that travels in waves
increasing energy results in
decreasing wavelenghts
Amplitude
height of wave (equates to brightness)
hue
color
saturation
intensity of color
Brightness
white/black
cornea
what is outside the eye
lens
gets light to reach the back of the eyeball
muscles
open and close the pupil
fovea centralls
where the refracted light is sent
optic nerve
goes from the eye to the brain
cones
help us see color
rods
help us see monochromatic grey scale
rods and cones
send things forward
1st step of vision
lightwaves hit the eye
2nd step of vision
structures focus light on retina
3rd step of vision
rods and cones take the image and convert light waves to electrical energy
4th step of vision
electrical signal transfers to bipolar and then ganglion cells
5th step of vision
axons of the ganglion cells create the optic nerve, sending electrical signals to the brain
Nearsighted
focal point is in front of the retina
Farsighted
focal point is behind the retina
sound waves
measured in height and length of wave
Frequency
the number of waves in a given interval (a sounds pitch)
Amplitude
measured in decibels (how loud a sound is)
timbre
Saturation of complex sounds
waveform
quality of timbre
outer ear
pinna/auditory canal
middle ear
ear drum (tympanic membrane) malleus (hammer) incus (anvil) stapes (stirrup)
inner ear
oval window, cochlea, basilar membrane, hair cells, tectorial membrane, eustachian tube
1st step of process of hearing
sound is sent through auditory canal where vibrations then hit the eardrum
2nd step of process of hearing
3 bones vibrate and send waves through the oval window into the inner ear
3rd step of process of hearing
mechanisms in ear transduce sound vibrations into neural impulses sent by the auditory nerve to the temporal lobe
1st step of transduction process of hearing
bones in the middle ear couple sound vibrations from the air to fluid vibrations in the cochlea of the inner ear
2nd step of transduction process of hearing
an elastic partition (basilar membrane) runs from beginning to end of the cochlea, splitting to an upper and lower part
3rd step of transduction process of hearing
once vibrations cause fluid in the cochlea to ripple, a traveling wave forms along the basilar membrane
4th step of transduction process of hearing
hair cells ride the wave
5th step of transduction process of hearing
hair cells move up and down, stereocilia that perch on top of the hair cells bump against an overlying structure and bend
6th step of transduction process of hearing
pore like channels at the tip of the stereocilia open up. chemicals then rush into the cell causing an electrical signal
visual cortex
located in occipital lobe. most visual info hits the visual cortex before being processed elsewhere
feature detection
in visual cortex, individual neurons acting in order to allow for definition of stimulus
binding
visual inputs to make a unified whole
Parallel processing
Simultaneous distribution of sensory input across different neurological pathways
Trichromatic theory
there are 3 types of cone receptors (red, blue, green) that are sensitive to different overlapping ranges of wavelengths (doesn’t explain afterimages)
opponent process theory
4 types of cone receptors (red-green. blue-yellow)
color blindness
1/3 cones doesnt work
contour
sudden change in brightness
figure ground relationship
figure= stimuli that stand out back/ground= stimuli that is left over once figure is established
gestalt principles
the whole is different than the sum of its parts
closure
filling in spaces to create a whole
Proximity
closer objects are seen as one compared to far away objects
Similarity
similar objects are seen as a unit
common fate
group together things that are pointing to/moving in the same direction
Symmetry/order
Ambiguous shapes seen as simple a manner as possible
continuity
eye will follow the smoothest path
figure ground
larger area of an image as the ground and smaller as the figure
depth perception
3D viewing
binocular cues
depth cues dependent on combo of left/right eye input
Convergence
muscle movement determines how far/close something is
Monocular cues
depth based on one eye
familiar size
things aren’t actually smaller when further away
height in field of view
higher in field = further away
linear perspective/relative size
lines converge to a point that looks like they extend out
overlap
partial concealment seen as closer
shading
based on light sources
texture gradient
denser/finer = further away
presbycusis
the loss of hearing that gradually occurs as you get older
tinnitus
perception of ringing in the ears
cochlear implants
internal devices to bypass the inner ear and send impulses directly to remaining nerves
mcgurk effect
when what we see does not match what we hear
volley principle
suggests clutters of nerves can act in concert to produce more firings than one single neuron
cocktail party effect
ability to pick up certain stimuli while ignoring othes
place theory
each frequency produces vibrations at particular location on basal membrane (explains high but not low frequency noises)
frequency theory
how often the auditory nerve fires faster it fires= higher sound (math doesn’t add up for tones that require faster firing)
sound shadow
pinpoints where sound comes from due to differences in intensity and timing
papillae
bumps on tongue
fungiform papillae
front of tongue (3-5 taste buds)
circumvallate papillae
back of tongue (over 100 taste buds)
foliate papillae
sides of tongue (100 taste buds)
sweet
caused by sugar/fructose/lactose
sour
lemon juice, organic acids, hydrogen ions
bitter
35 proteins respond to bitter substances
savory/unami
broth, tomatoes, meat, cheese, asparagus
fatty
maybe receptors for this? natural fats and oils
more
Alkaline, metallic, water-like
gustation
taste
scent habituation
the inability to distinguish a particular scent as a result of ongoing exposure
mechanoreceptors
touch sensations (pressure, vibrations, texture)
thermoreceptors
Temperature of food (cold sensations if skin is below 95, hot sensations of skin is below 41)
chemical receptors
flavor profiles
orthonasal
out-there
retronasal
in the mouth
Olfactory epithelium
special receptors sensitive to odor molecules that travel through air
Olfaction
smell
1st step of smell
receptors interpret odor molecules
2nd step of smell
Olfactory receptors catch odor molecules and bind with them
3rd step of smell
action potential travels along receptor to olfactory bulb
Nociceptors
Pain picked up by damage (fast pathway- thalamus, motor/sensory areas of cerebral cortex. Slow pathway- limbre system, motor/sensory areas of cerebral cortex)
4th step of smell
bulb sends info to the brain
Where receptors are found
Dermis layer of skin
Location of highest concentration of thermoreceptors
Face and ears
Process of thermoreceptors
Skin sends action potential to spinal cord, spinal cord sends to brain stem then to thalamus, thalamus puts map of body into somasensory areas of parietal lobes in cerebral cortex
Gate control theory
Non-painful input closes nerve gates to painful input, preventing pain sensations to travel to CNS- this is explains why rubbing an injury makes it hurt less (the gating mechanism takes place in the dorsal horn of the spinal cord)
Kinesthetic senses
Movement, posture, orientation
Proprioceptors
Throughout body- mainly in spindles but also in skin & joints
Vestibular senses
Balance and movement, orientation of head
Golgi tendon organ
Tension on joint
Joint kinesthetic receptors
Angle/movement of joints
Semicircular canals
Inner ear receptors for orientation
Synesthesia
Neurological condition where one sense stimulates others
