UNIT 3 SENSATION AND PERCEPTION Flashcards
Stimulus
Anything that brings about a Reaction
Sensation
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
Bottom-up processing
Analysis that begins with the the sensory receptors and works up to the brains integration of sensory information
Top-down processing
Information processing guided by higher level mental processes, as when we construct perceptions drawing on our experiences and expectation
Selective attention
The Focusing of conscious awareness on a particular stimulus
EXAMPLE cocktail party effect (hear one voice among many)
Inarrentional blindness
Failing to see visible objects when ones attention is directed else where
EXAMPLE gorilla in room
Change blindness
Failing to notice changes in environment
Transduction
Conversion of one energy to another
Transforming stimulus energies (sights &smells) into neural impulses our brains can interpret
Threshold
The level of stimulus required to trigger a a neural impulse
KICKING OFF POINT
Absolute threshold
The minimum stimulation needed to detect a particular stimulus 50% of the time
What is absolute threshold used for?
To detect light, sound, pressure, taste or odor
MAY VARY WITH AGE
Signal detection theory
Predicts when we will detect weak signals
ASSUME DETECTION DEPENDS ON EXPERIENCE, EXPECTATIONS, MOTIVATION AND ALERTNESS
Subliminal stimulation.
Below one’s absolute threshold for conscience awareness
BELOW THRESHOLD
Priming
The activation of certain associations, thus predisposing one’s perceptions, memory, or response
Difference threshold (noticeable difference)
The minimum difference between two stimuli required for detection 50% of the time
DETECTABLE DIFFERENCE INCREASE WITH THE SIZE OF THE STIMULUS
Weber’s law
The principle that to be perceived as different, two stimuli must differ by a constant percentage rather than by a constant amount
Sensory adaptation
Diminished sensitivity as its consequences of constant stimulation
What does sensory adaptation do?
Gives the freedom to focus on information changes in our environment without being distracted by background chatter
Cornea
Light enters through it
Protects eye
Bends light to provide focus
Pupil
Adjustable opening in the center of the eye through which light enters
Iris
A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
Lens
The transparent structure behind the pupil that changes the chaos to help focus images on retina
Accommodation
The process by which the eye’s lens changes shape to focus near and far objects on the retina
Nearsightedness
When the lens focuses objects in Front of the retina
Farsightedness
When the lens focuses objects behind the retina
Retina
Light sensitive inner surface of the eye
What is in a retina?
Receptor rods (NIGHT) more Cones (DAY) less
Fovea
Central focus point in the retina
The eyes cones cluster around it
Optic nerve
The nerve that carries neural impulses from the eye to the brain
Blind spot
The point at which the optic nerve leaves the eye
No receptor cells are located there
Binocular fusion
Process of combining images received from the two eyes into 1 image
Why binocular fusion?
2 eyes the vision system gets two images but we only see one
Rental disparity
Difference between images stimulating each eye
DEPTH PERCEPTION
Difference between retinal disparity
Large disparity close to you
Small disparity far from you
Transduction
Conversion of one form of energy into another
Wavelength
The distance from one wave peak to another
Determines color