sensation
how an organism receives stimuli and information from the surrounding world via sensory organs
perception
cognitive processes of receiving, encoding, storing, and organizing sensations
bottom-up processing
starts with sensory receptors and works up to the brain’s integration of sensory info for processing
ex: stubbing your toe
top-down processing
the construction of perceptions from sensations (coming from bottom-up) and on our own experiences/experiences
ex: if you’re in a bad mood and eating, the food might taste bad
psychophysics
study of the links between physical stimuli and psychological experience
absolute threshold
weakest amount of a stimulus that a person can detect 50% of the time
signal detection theory
ability to identify a stimulus (signal) when it is embedded in a distraction background
subliminal stimulation
stimulus which is below one’s threshold for conscious awareness
difference threshold
smallest difference between two stimuli which a person can detect 50% of the time or more
aka: just noticeable difference (jnd)
weber’s law
the principle that two stimuli must differ by a constant proportion, not a constant amount, for a difference between them to be connected
just noticeable difference (jnd)
about 2% for everything
transduction
conversion of one form of energy into another; receptor cells take incoming energy and change it into neural impulses
in hearing: cochlea
in vision: retina
in olfaction: cilia
in gustation: taste receptors
in touch: touch receptors
cocktail party effect
phenomenon of being able to focus one's auditory attention on a particular stimulus while filtering out a range of other stimuli, much the same way that a partygoer can focus on a single conversation in a noisy room
sensory adaptation
reduction in sensitivity a stimulus after constant exposure to it
physiological adaptation
self-regulated
habituation
kind of learning; nervous system selectively filters out stimuli
psychological adaptation - decreased response
conscious
selective attention
process of directing our awareness to relevant stimuli while ignoring irrelevant stimuli in the environment
wavelength
distance from the peak of one light/sound wave to the peak of the next
in light: color/hue
in sound: pitch
amplitude
top to bottom of a wave
in light: intensity
in sound: intensity/volume
pupil
adjustable opening in the center of the eye
iris
muscle that controls pupil size
lens
changes shape to help focus, accommodates
retina
light sensitive surface with rods and cones
rods and cones → bipolar cells → ganglion cells → optic nerve
acuity
sharpness of vision
nearsightedness/myopia
light focuses in front of the retina
objects near are clear and objects far are blurry
farsightedness/hyperopia
light focuses behind the retina
objects far are clear and objects near are blurry
much rarer
rods
periphery of retina
120 million
no color vision
sensitive to light and give twilight vision
cones
clustered in the fovea
fewer than rod cells (6-7 million)
center of the retina
color and daylight vision
optic nerve
carries neural impulses to the thalamus
blind spot
where optic nerve leaves the eyeball
blindsight
condition in which a person can respond to a visual stimulis without consciously experiencing it
fovea
center focus point
malleus
another name for hammer
a small bone in the middle ear that transmits vibrations of the eardrum to the incus (anvil)
incus
another name for anvil
a small anvil-shaped bone in the middle ear, transmitting vibrations between the malleus (hammer) and stapes (stirrup)
stapes
another name for stirrup
a tiny, U shaped bone that passes vibrations from the anvil (incus) to the cochlea
stroop effect
\n brains recognize color first, interfering with our ability to read aloud
need selective attention to identify the color of the word
feature detectors
respond to visual aspects of the environment (shape, angle, movement)
visual cortex
send information to neural networks (supercell clusters) that can perform tasks like visualizing faces
cube, triangle (gestalt)
parallel processing
brain processes many aspects simultaneously
divides a visual scene into sub-dimensions
young-holtzman trichromatic theory
retina has three receptors sensitive to red, green, and blue
opponent-process theory
opposing retinal processes enable color vision
red and green, blue and yellow, white and black
color constancy
\n perceiving familiar objects as having consistent color under different conditions of illumination
ex: black and blue or white and gold dress
audition
sense/act of hearing
frequency theory
rate of nerve impulses travelling up the auditory nerve matches the frequency of a tone, enabling us to sense its pitch
explains how we sense low pitches
place theory
\n links the pitch we hear with the place where the cochlea's membrane is stimulated
explains how we sense high pitches
pinna
external part of the ear
auditory canal
tube that runs from outer ear to middle
eardrum
tympanic membrane that vibrates with sound waves
middle ear
hammer, anvil, sitrrup
smallest bones; vibrate from the eardrum
middle ear
cochlea
where transduction occurs
coiled, bony, fluid-filled tube where sound waves trigger neural impulses
filled with hair cells
inner ear
semicircular canals
fluid filled tubes to help keep balance; connect to vestibular sacs
inner ear
basilar membrane
a fibrous membrane within the cochlea that supports the organ of corti
synesthesia
to perceive together; perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to involuntary experiences in a second cognitive or sensory pathway
conduction hearing loss
damage to the system that conducts sound waves to the cochlea
most likely due to a punctured eardrum
sensorineural hearing loss
damage to the cochlea’s receptor cells or to the auditory nerves
gate-control theory
neurological “gate” in the spinal cord which opens to allow small fibers of pain through but large fibers can override small fibers to stop pain
a-delta fibers: small myelination; sharp, immediate pain
c-fibers: dull, aching pain (chronic)
beta fibers: sense touch
sensory interaction
experiences result in two or more senses working together because one sense can influence another
kinesthesis
system for sensing the position and movement of individual body parts
aka: proprioception
vestibular
sense of body movement, position, and spatial orientation; including sense of balance
located in the semicircular canal
gustation
taste, chemical sense
5 basic sensations:
sweet - energy source
salty - sodium essential to psychological processes
sour - potentially toxic acid
bitter - potential poisons
umami - proteins to grow and repair tissue
fungiform papillae
swellings on the anterior surface (front) of the tongue, in humans numbering about 200 and each shaped like a mushroom
taste buds
decrease with age
taste process
molecules enter taste pores of taste buds and stimulate taste cells
nerve impulses travel via the facial/glossopharyngeal nerve to the brain
impulse reaches the thalamus, where it is rerouted to the temporal lobe
taste stimuli is processed by the gustatory cortex
olfaction
smell, chemical sense
odorants enter the nasal cavity to stimulate five million receptors in the mucous membranes
phermones
chemical message sent by a chemical
smell process
olfactory receptors
olfactory bulb (below frontal lobe)
olfactory areas in the temporal lobe
limbic system
hippocampus and amygdala can create strong emotional responses and memories associated to smell
nociceptors
sensory receptors that detect pain
pain → brain process
nociceptors
nerve fibers
inattentional blindness
selectively attending to one part of the environment and missing another
change blindness
specific form of inattentional blindness
fail to notice changes in our environment
prosopagnosia
neurological disorder characterized by the inability to recognize faces
gestalt
an organized whole, tendency to integrate meaningful pieces of info into meaningful wholes
figure-ground
organization of the visual field onto objects that stand out from their surroundings
grouping
after distinguishing the figure from the ground, our perception needs to organize the figure into a meaningful form using grouping rules (proximity, similarity, continuity, closure, and connectedness)
convergence
neuromuscular cue to tell brain the closeness of an object
binocular
retinal disparity
difference between how each retina experiences the world
binocular
relative height
vertical dimensions seem longer than identical horizontal
monocular
relative size
allows you to determine how close objects are to an object of known size
monocular
relative motion (parallax)
as we’re moving, objects that are actually stable seem to move
monocular
interposition
if one object partially blocks our view of another, we percevie it as closer
monocular
relative clarity
hazy/blurry objects seem farther away than sharp, clear ones
monocular
texture gradient
gradual change from coarse, distinct texture to a fine, indistinct texture signals increasing distances
monocular
linear perspective
as lines converge, greater distance is perceived
monnocular
light/shadows
using light and shadows to perceive depth
monocular
stroboscopic movement
the apparent motion of a series of separate stimuli occurring in close consecutive order, as in motion pictures
depth perception
ability to see objects in 3d although the images that strike the retina are 2d
ponzo effet
visual illusion in which the upper of two parallel horizontal lines of equal length appears to be longer than the bottom of the two lines when they are flanked by oblique lines that are closer together at the top than they are at the bottom
distal stimuli
stimuli that lie outside of the body
proximal stimuli
stimulus energies that impinge directly on our sensory receptors
muller-lyer illusion
optical illusion in which two lines of the same length appear to be of different lengths
ames room illusion
an irregularly shaped but apparently rectangular room in which cues for depth perception are used experimentally to distort the viewer's perception of the relative size of objects within the room
lightness constancy
perceiving objects with the same level of brightness, even though the illumination may change
perceptual adaptation
adjust to artificially displaced or even inverted visual field
perceptual set
mental predisposition to perceive one thing and not another
mcgurk effect
occurs when a person perceives that another's lip movements do not correspond to what that individual is saying
gustav fechner
coined the term “absolute threshold”
david hubel
demonstrated that neurons in the occipital lobe's visual cortex receive information from individual ganglion cells in the retina (feature detector cells)
also proved that the brain divides a visual scene into several subdimensions (color, movement, etc.) and processes each separately
ernst weber
created “weber’s law”
daniel kahneman
conducted research to discover factors that influence human judgment and decision making
torsten wiesel
discovered feature detectors