Sensory Perception

Question 1

binocular cues

Answer 1

1. retinal disparity - eyes are 2.5 inches apart, allowing you to see different angles
2. convergence - things far away, eyes relax; things close up, eyes contract

Question 2

monocular cues

Answer 2

1. relative size - see the relative size of 2 objects and infer their proximity to us
2. interposition - rectangle in front of oval means it’s closer to us
3. Relative height - perceive higher things to be further away
4. shading and contour
5. motion parallax - cars further away move slower - gives you an idea of how far away objects are
6. Constancy - a. size - two women appear to be different sizes based on how far away they are even though they’re basically the same; b. shape; c. color

Question 3

sensory adaptation

Answer 3

1. Hearing - inner ear muscle contracts in response to increased noise; 2. Touch - sensory nerves can become saturated and thus you adapt to hand being in cold water; 3. Smell - sensory receptors get desensitized; 4. Proprioception - goggles that change orientation of objects - eventually your brain adjusts; 5. Sight - pupils dilate and rods/cones adjust to adapt to bright vs. dark environments

Question 4

Weber’s Law

Answer 4

K (constant) = (delta I)/I

You need a larger change in stimulus to notice the change if your background intensity is higher. Ex: notice difference between 2 lbs vs. 2.2 lbs but not 5 lbs vs 5.2 lbs. You need 5 lbs vs. 5.5 lbs for larger initial stimulus.

Question 5

Absolute threshold of sensation

Answer 5

the minimum intensity stimulus needed to detect a difference 50% of the time. The JND is the minimum DIFFERENCE between two stimuli that can be detected, while the absolute threshold is the minimum intensity stimulus that can be detected 50% of the time.

Question 6

Factors that influence absolute threshold of sensation

Answer 6

expectations, experience, motivation, alertness

Question 7

subliminal stimuli

Answer 7

stimuli below the absolute threshold

Question 8

Vestibular system

Answer 8

controls balance and spatial orientation. comes from receptors in our inner ear

Question 9

semi-circular canals

Answer 9

there are 3 of these in our inner ear and they’re all at right angles to each other (x, y, and z axes)

Question 10

endolymph

Answer 10

fluid that fills semi-circular canals. The way the fluid moves in the canals allows us to detect the direction and intensity of movement

Question 11

Otolithic organs

Answer 11

help us detect linear acceleration and head positioning. Two otolithic organs are the utricle and sacule. Calcium crystals attach to hair in ear - when head moves, crystals move b/c they’re heavier than hair - sends an action potential (signal) to the brain

Question 12

Somatosensation - sensations

Answer 12

1. temperature - thermoception
2. pressure - mechanoception
3. pain - nocieception
4. position - proprioception

Question 13

intensity of sensation

Answer 13

determined by how quickly neurons fire

Question 14

timing

Answer 14

when does the sensation start or stop? (1) non-adapting - no change in firing rate of neuron the whole time the stimulus is being applied (2) slow-adapting neuron - starts firing really fast and then slows down; (3) fast-adapting - fires a lot at the beginning of the stimulus and then stops and fires again when stimulus stops

Question 15

bottom up processing

Answer 15

stimulus influences our perception. data driven

Question 16

top down processing

Answer 16

background influences perception (e.g. where’s Waldo?); theory driven

Question 17

Gestalt principles

Answer 17

1. similarity –> items that are similar are grouped together (e.g. your brain recognizes pattern of squares and circles)
2. Pragnanz –> reality reduced to its simplest form (e.g. 5 circles juxtaposed on top of one another instead of tons of different shapes and lines)
3. Proximity –> objects closer together we group together
4. continuity –> lines are seen as following smoothest path
5. closure –> objects grouped together are seen as a whole

Question 18

sensation vs. perception

Answer 18

–Sensation refers to the process of sensing our environment through touch, taste, sight, sound, and smell. This information is sent to our brains in raw form where perception comes into play. Perception is the way we interpret these sensations and therefore make sense of everything around us.

Question 19

perception

Answer 19

–the process by which sensory information and prior knowledge are integrated to form a representation of the environment

Question 20

bottom-up vs. top-down processing

Answer 20

• -There are two general processes involved in sensation and perception. Bottom-up processing refers to processing sensory information as it is coming in. … Top-down processing, on the other hand, refers to perception that is driven by cognition.
• -Top-down processing requires exerting cognitive control over sensation, while bottom-up means sensation drives things