Chapter 4- Sensation and Perception Flashcards
sensation
the detection of sensory stimuli by the sensory organs..ex) looking at a traffic green light is due to sensory receptors that detect it
perception
the organization, identification, and interpretation of the sensory stimuli…what we perceive is the result of what we sense..ex)the green traffic light is understood and percieved to be a sign of continuing to drive.
Transduction
first step of sensation is sensory coding, which involves Transduction..which is when external stimulus is changed into chemical and elecrical signals that the brain can interepret.
Qualitative processing
the quality of a stimulus…ex the sweetness vs salty of something
quantitative
the magnitude of the qualities, they are detected by different firing rates..ex) the relative degree of saltiness or sweetness
Psychophysics
develped by weber, fechner, helmholtz,…it is the psychological expereince of physical stimul
Sensory thresholds-absolute threshold
the minimum intensity needed before experiencing a sensation @ least half of the time,,,,So its the stimuli intensity you would detect more often then by chance.Ex–1taaspoon of sugar in 2gal of water
sublimal(below the threshold) perception
perception of a stimuli that doesn’t meet the absolute sensory threshold.
Difference threshold
the minimum amount of difference btw two stimuli so that you can notice the difference…(just noticeable diff.(JND..Ex-..difference btw a show your friend is watching and a commercial, while you read a book….webers law argued they must differ by a constant minimum %.
Signal detection theory
Due to how detection of a stimulus requires making a judgement based on presence or absense of it,this detection may depend on a persons experiences, expectations alertness, and motivation….therfore subjective. if hit=detects a presnt stimuli, miss, doesnt detect a present stimuli, false alarm detects an absent stimui, and correct rejection doesnt detect cuz not there
sensory adaptation
detection decrease overtime of a stimuli present @ constant levels allowing focus on informative changes—-example if you live near an airport the loudness becomes usual and your sense don’t really don’t detect it because you adapted to that noise
Gustation-(Basic sensory processes)
the sense of taste..where chemicals are dissolved in your mouth and picked up by receptors or organs(taste buds) that compose an experience from 5 basic tastes-sour, bitter, sweet, salty, umanii throughout ….the entire taste experience occurs not in your mouth but in your brain…taste relies heavily on the sense of smell(when you get sick you cant taste because you cant really smell)
olfaction
sense of smell, closesly related to snese of taste, and has a direct route to the brain, so doesnt go through the thalamus. but the smell intensity is processed in brain areas involved with emotion and memory..(reason smells remind us)
haptic sense
sense of tempwarm, cold) pressureat base of hair follices, and pain(receptors everywheere)..where skin is the largest sensoryreception
Audition sense-hearing
hearing, and second to vision as a source of info,..movement of hair cells transmits neural signal to auditory nerve
Sound Wave-wavelength, Amplitude, Frequency
WL- distance ofrom a point on a wave to same point on the next wave….ampl is the height of the wave, it determines intensity(volume)b/c higher amp higher louder sound, Frequency-# of wavelengths in a given time period, determines pitch.
Pinna(ear structure)
place in ear where the sound waves enter to move down the ear canal
tympanic membrane:(ear drum)
sound wave makes the ear drum vibrate, which in turn causes the ossicles vibrate
ossicles
contain the hammer, anvilm and stirrup, .the ear drum causes it to vibrate and this then makes the oval window vibrate, creating waves in the cochlear fluid(snail looking area)
cornea
the eyes thick transparant layer, through whihch the light reaches the eye and is focused
pupil
takes role of dertmininh how much light enters eye by dilating and contracting
Iris
colored part of the ey that controls the puil movement
retina
inner surface at back of the eye that has neurons that transduce light….to right o optic nerve..photoreceptor(rods & cones), bipolar cells, ganglion cells,,,to left of optic nerve
Photreceptors-rods & cones
rods are found in periphery, resond to low light and help with night vision…..cones are found in center, respond to high light, color vision, and visual acuity, the fovea is packed with these cones
Bipolar cells
cells in the retina that collect neural signals dfrom the rods and cones and then pass on to retinal gangluaon cells
ganglion cells
cells that come itno contact with th ef rist neruons in the visual pathway with axons, They collect and organize neural signals to be sent to optic nerve
optic nerve
through which neural signals are transmitted to the brain. the optic nerve leaves the eye through hole called blind spot(no rods nor cones)
pathway to brain
the right eye and optic nerve signals go to the left visual cortex and the left eye singals go to the right visual cortex
kinestetic sense
position of body and limbs in space and in relation to one another
vestibular sense
sense of balance…..fluid in our head moves as our head moves
gate control theory
says there is a “gate” in the spinal cord allowing pain transmission, small fibers open the gate to let pain go through but large fibers close the gate…showng pain may be perceptual process in the brains..bc you can be distracted and the gates are closed so dont feel pain
figure ground
in recognizing any figure the rain assigns the rest of the scene a background…ex..the letters made from looking up at the sky with surrounding skyscrapers.
Young=helmholtz trichromatic theory
the eye contains cones sensitive to red, green, blue wavelengths that when stimulated in combo can produce diff colors
subtractive color mixing
physical mixing of diff color wavelengths to remove reflective wavelengths..ex mixing paints where pigments absorb some colors of the spectrum and what is reflected are the left colors. the subtractive colors are red, blue and yellow
additive color mixing
psychological process ocurring when different wavelengths ineteract or are percieved by the eye within the eyes receptors….ex stage ligths..so we get brighter colors
opponent process theory
opposing processes in the retina allow for the perception of colors besides red green blue..but red and green,,are opposite completely bc when neuron is on then green is off and vise versa
color constancy
we percieve objects to haea consistent clor even if they are different tones of it -perception is contextual based on surroundings..ex..grass is green even if its night time and it doesnt look green
gestalts principles-proximity
the closer two figures are the more likely we are to see them as part of the same object
Gestalt-similarity
figures are grouped together depending on how similar they are to each other
gestalt-continuation
we interepret ntersecting lines as being continuis rather than individual parts…example a rectangle in the back with a cylinder in the middle…the rectangle is still continuous acc to us
gestalt-closure
we mentally complete figures even if there are gaps in their boundaries…ex a triangle with gaps is still seen as a triangle
illusory contours
tend to perceive contours(boundary) even when they dont exist…
cross race effect
ppl are better at recognizing members of their own race or ethicity
prosopaganda
the inability to recognize faced
depth perception-monocular, binocular, motion
3d obejcts are only 2d on retina, but are percieved 3d….
monocular cue
cues of depth available to each eye alone..such as linear perspective-parallel lines converging in the distance,,,the greater convergence the greater distance perceived..sunset)…..texture gradient=uniform pattern.the smaller the pattern the greater the distance.cherries in big pile
binocular cue-retinal disparity
cues of depth perception ariisng from fact that we have 2 eyes…. gathered from slightly diff retinal images from each eye,…the greater the dispartiy btw images the closer object is
binocular-convergence
how much the eye turns inward when looking a en object is used to judge the distance to it
motion cue-motion parallax
relative moments of objects at varying distance…objects further move slower while those closer zoom by–ex)when we are inside a car looking out a window at the diff objects
size, shape, color, lightness constancy
size is same…ex…railroad tracks or ppl behind in the distance are not miniature….shape:door open or closed is still a rectangle..color…depending on background reflected colors look different,,,lightness..leafs are have same lightness even under shade
