Sensation and Perception

Question 1

Absolute Threshold

Answer 1

Minimum amount of physical energy (stimulation) needed for a person to notice a stimulus

Question 2

Signal Detection Theory

Answer 2

Decision making with uncertainty - suggests that detecting a signal depends on the strength of the signal, background noise and the subjects level of alertness
Also looks at sensory sensitivity (d’) and states that habituation reduces sensitivity to a signal

Question 3

Subliminal perception

Answer 3

The tendency to percieve information outside of our consciousness

Question 4

Difference threshold (or JND)

Answer 4

The lowest level of stimulation required to sense a change in stimulation or detect a difference 50% of the time

Question 5

Trichromatic theory of colour vision

Answer 5

Young-Hemholtz theory that the retina contains 3 types of cones that are sensitive to red, blue and green

Question 6

Resonance theory of hearing

Answer 6

Hemholtz theory that the different parts of the cochlea respond to different frequencies

Question 7

Gestalt psychology and three of it’s laws

Answer 7

School of psychology that suggests that we percieve entire patterns or configurations, not just individual parts.
Laws include proximity, closure and similarity

Question 8

Sensory adaptation

Answer 8

Tendency of sensory systems to respond less to stimuli that continue without change

Question 9

Subliminal perception

Answer 9

Unconscious perception of a stimulus

Question 10

What are the 3 physical dimensions of colour?

Answer 10

Hue (colour - determined by wavelength), brightness (amplitude of light wave) and saturation (purity of light)

Question 11

Two types of photoreceptor

Answer 11

Cones - specialised for colour and high visual acuity

Rods - monochromatic vision, low acuity

Question 12

Bottom-up processing

Answer 12

Perception begins with raw sensory data that ‘feed’ up to the brain

Question 13

Top-down processing

Answer 13

Perception driven by prior experience, knowledge and context

Question 14

Form perception

Answer 14

Organisation of sensations into meaningful shapes and patterns (as in Gestalt psychology)

Question 15

Depth perception

Answer 15

Distance perception - organisation of perception in 3 dimensions

Question 16

Motion perception

Answer 16

Perception of movement in objects

Question 17

Ganglion cells

Answer 17

Nerve cells in the retina that combine information from bipolar cells. Their axons bundle together to form the optic nerve

Question 18

Accomodation

Answer 18

When the lens adjusts its curvature to alter visual focus (flattens for distant objects, more rounded for nearer objects)

Question 19

Complexity of sound

Answer 19

Combination of sound waves of different frequencies. Also known as “texture” of a sound (timbre)

Question 20

Just noticible difference (jnd)

Answer 20

The smallest difference in intensity between stimuli that a person can detect

Question 21

Percepts

Answer 21

Meaningful perceptual units (such as images of particular objects)

Question 22

Monocular cues

Answer 22

Visual input from only one eye that contributes to depth perception

Question 23

Binocular cues

Answer 23

Visual input from both eyes that provides perception of depth

Question 24

Hair cells

Answer 24

Sound receptors attatched to basilar membrane of cochlea

Question 25

Basilar membrane

Answer 25

Membrane within cochlear - vibrates in response to sound and stimulates hair cells

Question 26

Opponent-process theory of colour

Answer 26

Our minds can only register the presence of one color of a pair at a time because the two colors oppose one another. Colour pairs are red-green, blue-yellow, black-white.
Explains after images

Question 27

What component of sound is measured in Hertz?

Answer 27

Frequency which determines the pitch of sound

Question 28

What component of sound is measured in decibels?

Answer 28

Amplitude which we percieve as “loudness” of a sound

Question 29

Three principles that apply to all senses

Answer 29

1. there is no one-to-one match between the physical objects and our psychological experience of them
2. Senstation and perception are active, not passive
3. Sensory and perceptual processes reflect adaptive pressures over the course of evolution

Question 30

Fovea

Answer 30

Small area of the retina that contains only cones - for central vision and is where visual acuity is the highest

Question 31

Perceptual constancy

Answer 31

Organisation of changing senstations into percepts that are relatviely stable (size, shape, colour)

Question 32

Retina

Answer 32

Thin layer of tissue at the back of the eye - absorbs light, processes images and sends visual information to the brain.