Flashcards in Sensation And Perception Deck (42):
What is the difference between absolute threshold and difference threshold?
Absolute threshold is the amount necessary to be perceived, difference is the amount of difference between multiple stimuli needed before they are perceived as being different.
What is jnd?
Just noticeable difference: amount of change needed to predict e difference between two stimuli.
What do Fechner's law and Steven's power law intend to measure?
The relationship between the intensity and the sensation of a stimulus.
What is signal detection theory?
A theory that allows researches to test the response biases and stimulus a sensitivity of participants with a valid paradigm of hits, misses, false alarms, correct negatives via ROC curves. John Swets refined these.
What are the four steps in sensory information processing?
Reception, transduction (from physical to neural energy), projection areas, and neural pathways.
What is the duplicity theory of vision?
Retina contains two kinds of photoreceptors.
What is the difference between rods and cones?
Rods are for dim light and more plentiful, cones are for colours, details, and bright lights (only receptors in fovea).
What is the organization of cells in the eye?
Rods and cones connect to bipolar cells which connect with ganglion cells. Gang lions group together to form the optic nerve. (Horizontal and amacrine cells as well.)
Who is Max Wertheimer and what is the phi phenomenon?
Founder of Gestalt Psychology, two lights flashing in succession often perceived as one.
What happens at and after the optic chiasm?
The nasal fibers cross paths and transmit information to the lateral geniculate nucleus (thalamus), the visual cortex (occipital lobe), and the superior colliculus.
What did Hubel and Wiesel study that earned them a Nobel Prize?
Feature detection theory, specialization do of simple (orientation and boundaries), complex (movement), and hyper complex (object shape, abstract) cells.
What is the difference between brightness and illumination?
Illumination is the objective measurement of light on a surface whereas brightness is just the subjective impression of illumination.
What are rhodopsins and what do they have to do with dark adaptation?
Rhodopsins are the only photo pigments for rods made of a vitamin A derivative. When it absorbs light, it decomposes, so the light entering rods before you enter the theatre decompose a large amount of your rods through a process called bleaching. Adaptation is waiting for the rods to regenerate.
Want is simultaneous brightness contrast?
Idea that areas look brighter if surrounded by darkness, caused in part by lateral inhibition.
Describe the difference between additive and subtractive colour mixture.
Subtractive - mixing pigments, like paint
Additive - lights, red blue and green, either we perceive actual light or get reflected off an object
What is the Young-Hemholtz theory of colour vision?
Trichromatic theory: three types of cones differentials receptive to colours, the combination of stimulation to different degrees would determine the colour perceived
What is Hering's opponent process theory of colour vision?
Three opposing pairs: red green, blue yellow, black white.
What are texture gradients?
Variations on perceived surface texture due to distance, things farther away seem smaller and denser.
What is motion parallax and the kinetic depth effect?
Morton parallax - direction and speed of objects in relation to a fixation point when you are moving changes
Kinetic - when the object moves but the perceived doesn't.
Name one of the only binocular depth cues.
Binocular disparity/stereopsis - disparity between both eyes combined creates a form of depth.
What are the five laws explaining form perception?
Proximity, similarity, good continuation, closure, prägnanz.
What is the law of prägnanz?
Perceptual organization will always be simple, regular, and symmetric.
What is the theory of isomorphism? Who posited it?
There is equivalent correspondence between what one perceives and its pattern of stimulation in the brain, posited by Kohler.
What is the difference between bottom-up and top-down processing?
Bottom up: direct summation of sensory output (data driven)
Top down: guided by cognition, memories and expectations
In what five ways can one make light appear to be moving?
Real motion: (move the light)
Apparent motion (stroboscopic/phi phenomenon): two dots flashing on opposite sides are perceived as one
Induced motion: everything around the light moves
Auto kinetic effect: light seems erratic without frame of reference
Motion aftereffect: after movement a spot of light will appear to move in the opposite direction.
What is the difference between proximal and distal stimuli?
Distal is the actual object, proximal is the sensory info we receive from the object.
What are the four constants in visual perception?
Size: depends on apparent distance, the brain will further compensate its scaling the farther away an object is.
Shape: a shape doesn't change even if it's manipulated (door)
Lightness: lightness in colour remains the same despite illumination
Colour: colour doesn't change when we change which wavelength we see (sunglasses)
At what age will infants not cross the glass in a visual cliff paradigm?
What is the relationship between frequency and wavelengths?
Inverse; the higher the frequency the shorter the waves.
What is intensity?
Amplitude of a wavelength, merasured in decibels.
Name important subjective dimensions of sound.
Loudness (intensity), pitch (frequency), timbre (instrument, complexity).
Describe the processes in play when hearing.
Outer ear: pinna and eardrum/tymphanic membrane
Middle ear: ossicles (malleus, incus, stapes) transmit to inner ear
Inner ear: entrance (oval window), basilar membrane runs along cochlea, organ of corti rest on the basilar membrane (hair cells), from cochlea to auditory nerve
What is place resonance theory? Who posited it?
Each pitch causes different vibrations in the basilar membrane and different hair cells to bend. Proposed by Helmholtz and Young.
What is frequency theory?
Rate of vibration of basilar membrane = frequency. Vibration = # of neural impulses per second. Pitch = number of impulses travelling up the nerve.
What is the Békésy travelling wave?
Finding that lower frequencies maximally vibrate near the tip of the cochlea, and lower ones vibrate near the oval window.
Name the regions involved in tasting.
Papillae on the tongue have taste buds, sensory info is transmitted to taste centre in thalamus.
Name the regions involved in smelling.
Smell receptors in olfactory epithelium and travels to olfactory bulb.
What is the gate theory of pain?
Theory that thee is a gating mechanism in the spinal cord that turns pain signals on and off.
What two aspects are included in proprioception?
Vestibular and kinaesthetic senses.
What piece of evidence goes against the all or nothing hypothesis of selective attention?
The cocktail party phenomenon!
What is the Yerkes-Dodson law?
Law that states too little or too much arousal is bad for performance.