Sensation And Perception

Question 1

What is the difference between absolute threshold and difference threshold?

Answer 1

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.

Question 2

What is jnd?

Answer 2

Just noticeable difference: amount of change needed to predict e difference between two stimuli.

Question 3

What do Fechner’s law and Steven’s power law intend to measure?

Answer 3

The relationship between the intensity and the sensation of a stimulus.

Question 4

What is signal detection theory?

Answer 4

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.

Question 5

What are the four steps in sensory information processing?

Answer 5

Reception, transduction (from physical to neural energy), projection areas, and neural pathways.

Question 6

What is the duplicity theory of vision?

Answer 6

Retina contains two kinds of photoreceptors.

Question 7

What is the difference between rods and cones?

Answer 7

Rods are for dim light and more plentiful, cones are for colours, details, and bright lights (only receptors in fovea).

Question 8

What is the organization of cells in the eye?

Answer 8

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.)

Question 9

Who is Max Wertheimer and what is the phi phenomenon?

Answer 9

Founder of Gestalt Psychology, two lights flashing in succession often perceived as one.

Question 10

What happens at and after the optic chiasm?

Answer 10

The nasal fibers cross paths and transmit information to the lateral geniculate nucleus (thalamus), the visual cortex (occipital lobe), and the superior colliculus.

Question 11

What did Hubel and Wiesel study that earned them a Nobel Prize?

Answer 11

Feature detection theory, specialization do of simple (orientation and boundaries), complex (movement), and hyper complex (object shape, abstract) cells.

Question 12

What is the difference between brightness and illumination?

Answer 12

Illumination is the objective measurement of light on a surface whereas brightness is just the subjective impression of illumination.

Question 13

What are rhodopsins and what do they have to do with dark adaptation?

Answer 13

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.

Question 14

Want is simultaneous brightness contrast?

Answer 14

Idea that areas look brighter if surrounded by darkness, caused in part by lateral inhibition.

Question 15

Describe the difference between additive and subtractive colour mixture.

Answer 15

Subtractive - mixing pigments, like paint

Additive - lights, red blue and green, either we perceive actual light or get reflected off an object

Question 16

What is the Young-Hemholtz theory of colour vision?

Answer 16

Trichromatic theory: three types of cones differentials receptive to colours, the combination of stimulation to different degrees would determine the colour perceived

Question 17

What is Hering’s opponent process theory of colour vision?

Answer 17

Three opposing pairs: red green, blue yellow, black white.

Question 18

What are texture gradients?

Answer 18

Variations on perceived surface texture due to distance, things farther away seem smaller and denser.

Question 19

What is motion parallax and the kinetic depth effect?

Answer 19

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.

Question 20

Name one of the only binocular depth cues.

Answer 20

Binocular disparity/stereopsis - disparity between both eyes combined creates a form of depth.

Question 21

What are the five laws explaining form perception?

Answer 21

Proximity, similarity, good continuation, closure, prägnanz.

Question 22

What is the law of prägnanz?

Answer 22

Perceptual organization will always be simple, regular, and symmetric.

Question 23

What is the theory of isomorphism? Who posited it?

Answer 23

There is equivalent correspondence between what one perceives and its pattern of stimulation in the brain, posited by Kohler.

Question 24

What is the difference between bottom-up and top-down processing?

Answer 24

Bottom up: direct summation of sensory output (data driven)

Top down: guided by cognition, memories and expectations

Question 25

In what five ways can one make light appear to be moving?

Answer 25

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.

Question 26

What is the difference between proximal and distal stimuli?

Answer 26

Distal is the actual object, proximal is the sensory info we receive from the object.

Question 27

What are the four constants in visual perception?

Answer 27

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)

Question 28

At what age will infants not cross the glass in a visual cliff paradigm?

Answer 28

6 months.

Question 29

What is the relationship between frequency and wavelengths?

Answer 29

Inverse; the higher the frequency the shorter the waves.

Question 30

What is intensity?

Answer 30

Amplitude of a wavelength, merasured in decibels.

Question 31

Name important subjective dimensions of sound.

Answer 31

Loudness (intensity), pitch (frequency), timbre (instrument, complexity).

Question 32

Describe the processes in play when hearing.

Answer 32

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

Question 33

What is place resonance theory? Who posited it?

Answer 33

Each pitch causes different vibrations in the basilar membrane and different hair cells to bend. Proposed by Helmholtz and Young.

Question 34

What is frequency theory?

Answer 34

Rate of vibration of basilar membrane = frequency. Vibration = # of neural impulses per second. Pitch = number of impulses travelling up the nerve.

Question 35

What is the Békésy travelling wave?

Answer 35

Finding that lower frequencies maximally vibrate near the tip of the cochlea, and lower ones vibrate near the oval window.

Question 36

Name the regions involved in tasting.

Answer 36

Papillae on the tongue have taste buds, sensory info is transmitted to taste centre in thalamus.

Question 37

Name the regions involved in smelling.

Answer 37

Smell receptors in olfactory epithelium and travels to olfactory bulb.

Question 38

What is the gate theory of pain?

Answer 38

Theory that thee is a gating mechanism in the spinal cord that turns pain signals on and off.

Question 39

What two aspects are included in proprioception?

Answer 39

Vestibular and kinaesthetic senses.

Question 40

What piece of evidence goes against the all or nothing hypothesis of selective attention?

Answer 40

The cocktail party phenomenon!

Question 41

What is the Yerkes-Dodson law?

Answer 41

Law that states too little or too much arousal is bad for performance.

Question 42

What is the volley theory of pitch perception?

Answer 42

That high neural firing rates can be maintained in the frequency theory as long as nerve fibres work together.