UNIT 7: Sensation and perception

Question 1

transduction

Answer 1

The process of converting one form of energy into another that your brain can use

Question 2

absolute threshold

Answer 2

minimum stimulation needed to detect a particular stimulus (light, sound, pressure, taste or odour) 50% of the time

Question 3

‘just noticeable difference’

Answer 3

the minimum difference a person can detect between any two stimuli half of the time

Question 4

Weber’s Law

Answer 4

principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage

Question 5

Different thresholds

Answer 5

increase in proportion to the size of the stimulus. When stimulation is unchanging, you become less sensitive to the stimulus

Question 6

sensation adaptation

Answer 6

diminished sensitivity as a consequence of constant stimulation. When we are constantly exposed to a stimulus that does not change, we become less aware of it because our nerve cells fire less frequently

Question 7

sensation

Answer 7

the process by which our sensory receptors and nervous system receive and represent stimulus from our environment

Question 8

Perception

Answer 8

the process of organising and interpreting sensory information, enabling us to recognise meaningful objects and events.

Question 9

Bottom up processing

Answer 9

analysis that begins with the sensory receptors and works up to the level of the brain
- relies on sensation over perception

Question 10

Top down processing

Answer 10

information processing is guided by higher-level mental processes, as we construct perceptions, drawing on our experience and expectations
-prone to bias (jumping to conclusion)
- occurs when you use prexisting knowledge
-perception over sensation

Question 11

‘selective attention’

Answer 11

focusing intently on one task

Question 12

inattentional blindness

Answer 12

when we become unaware of other visual stimulus around us

Question 13

change blindness

Answer 13

failing to notice changes in the environment
-EX: when we are watching a magician’s left hand we fail to notice him changing cards with his right.
VISUAL

Question 14

cocktail party effect

Answer 14

Think about trying to listen to your friend talking in the lunch queue - do you hear other people’s conversations, are you aware of everything else around you. Probably not because you are concentrating on one thing
AUDITORY

Question 15

Wavelengths

Answer 15

the distance from the peak of one light or sound, to the peak of the next.

Question 16

Lens

Answer 16

the transparent structure behind the pupil that changes shape to help focus images on the retina

Question 17

Retina

Answer 17

light sensitive inner surface of the eye, containing the photoreceptor rods and cones plus layers of neurons that begin the processing of visual information

Question 18

Fovea

Answer 18

the central focal point in the retina, around which the eyes cones cluster

Question 19

Optic (visual) Nerve

Answer 19

the nerve that carries neural impulses from the eye to the brain

Question 20

Blind spot

Answer 20

the point at which the optic nerve leaves the eye, creating a blind spot because no receptor cells are located there

Question 21

Cornea

Answer 21

protects the eye and bends light to provide focus

Question 22

Rods

Answer 22

retinal receptors that detect black, white and gray. They are necessary for peripheral and dim-light vision. Rods share bipolar cells: sending combined messages

Question 23

Cones

Answer 23

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Cones detect fine detail and enable you to perceive colour. In dim-light they become ineffectual

transmits to a single bipolar cell that relays the cone’s individual message to the visual cortex

Question 24

Near sighted

Answer 24

too much curvature (via accommodation) of the lens focuses the image in front of the retina so nearby objects are seen more clearly than distant objects

Question 25

Far sighted

Answer 25

too little curvature of the lens (via accommodation) focuses the image behind the retina so distant objects are seen more clearly than nearby ones

Question 26

Young-Helmholtz trichromatic (3-colour theory)’.

Answer 26

the retina contains 3 different colour receptors (cones), each one especially sensitive to 1 of the 3 colours When we stimulate combinations of these cones, we see other colours

Question 27

Colorblind

Answer 27

lack a functioning red or green, or both sensitive cones

Question 28

Monochromatic (one-colour)

Answer 28

Only 1 color

Question 29

Dichromatic (two-colour)

Answer 29

2 colors

Question 30

opponent-process theory.

Answer 30

the way humans perceive colors is controlled by three opposing systems Rather than interpreting information from each type of cone in an individual manner, our visual system records differences in the responses of cones.

Question 31

Afterimages

Answer 31

sense experiences that occur after a visual stimulus has been removed come from looking at one color for a long period, which causes those receptor cells to become fatigued

Question 32

Prosopagnosia (Face Blindness)

Answer 32

damage leads to an interruption of different aspects of the face-recognition process. The person has difficulty or cannot recognise other peoples faces, and even their own Caused by damage to the occipital lobe

Question 33

Blindsight

Answer 33

visual information from the eye is being processed unconsciously, so people with blindsight don’t know that they are visually processing.

Question 34

Gestalt psychologist

Answer 34

our brain organises various visual stimulus into one meaningful ‘whole’.

Question 35

Figure and ground process

Answer 35

The organisation of the visual field into objects (the figures) that stand out from their surroundings (ground). Visual stimulus is always organised into a figure, against the ground.

Question 36

proximity

Answer 36

we group nearby stimulus together.

Question 37

closure

Answer 37

we fill in gaps to create a whole object

Question 38

similarity

Answer 38

we group similar figures together

Question 39

visual cliff experiment

Answer 39

-shows us that depth perception is, to come degree, innate. -The ability to convert the 2D images that strike our retina, into 3D, in order to judge distance

Question 40

depth perception

Answer 40

the ability to judge the distance of objects. You interpret visual cues that tell you how near or far away objects are. Cues can either be binocular or monocular

Question 41

Binocular cues

Answer 41

-These are depth cues which depend on BOTH eyes -Our eyes are in different positions, so each receives a different image. The brain compares these images received from both eyes, to help judge distance

Question 42

Monocular cues

Answer 42

-Clues about distance based on the image of ONE eye

Question 43

Retinal disparity (BINOCULAR)

Answer 43

-Your eyes have slightly different views of the same object, because your eyes are positioned a few centimeters apart -The greater the difference between the image from your left and right eye: the closer the object is -The further away an object it, the more similar the images are from both eyes

Question 44

Convergence

Answer 44

-inward turning of your eyes that occurs when you look at an object that is close to you - you experience convergence when you look at the tip of your nose with BOTH eyes

Question 45

Interposition (MONOCULAR)

Answer 45

(aka ‘overlap’) can be seen when a closer object cuts off the view of part or all of a more distant one

Question 46

Relative size (MONOCULAR)

Answer 46

familiar objects provides a cue to their distance when the closer of two same-size objects casts a larger image on your retina than the farther one

Question 47

Relative clarity (MONOCULAR)

Answer 47

can be seen when closer objects appear sharper than more distant, hazy objects

Question 48

Texture gradient (MONOCULAR)

Answer 48

provides a cue to distance when closer objects have a coarser, more distinct texture than far away objects that appear more densely packed or smooth

Question 49

Linear perspective (MONOCULAR)

Answer 49

provides a cue to distance when parallel lines, such as edges of sidewalks, seem to converge in the distance

Question 50

Amplitude

Answer 50

How loud a sound is

Question 51

Frequency

Answer 51

length of a sound wave determines the pitch

Question 52

Eardrum

Answer 52

sound waves enter the eardrum and cause it to vibrate

Question 53

Middle ear

Answer 53

tiny bones pick up the vibrations of the eardrum and send them to the cochlea, which is located in the inner part of the ear

Question 54

Cochlea

Answer 54

-inner part of the ear -The vibrations cause the cochlea to vibrate, which in turn, disrupts the fluid inside of it

Question 55

basilar membrane

Answer 55

-The vibrations cause the cochlea to vibrate, which in turn, disrupts the fluid inside of it. The fluid movements cause ripples in the basilar membrane, which bend the hair cells which lie inside of it

Question 56

auditory nerve

Answer 56

The hair cell movements trigger nerve impulses which are sent down the auditory nerve to the auditory cortex in the brain (located in the temporal lobe)

Question 57

Place theory

Answer 57

we hear different pitches because different sound waves trigger activity at different places along the cochlea’s basilar membrane. The brain determines a sound’s pitch by recognising the specific place on the membrane that generated the neural signal.

Question 58

Frequency theory

Answer 58

the brain deciphers the frequency of the neural impulses travelling up the auditory nerve to the brain. The rate of nerve impulses travelling, matches the frequency of a tone, thus enabling us to understand pitch it cannot explain how we can still hear *very* high pitched sounds, such as the upper third of a piano. This pitch would require a nerve impulse rate of higher than 1000 waves per second - which does not exist. It is not possible, yet we still hear it

Question 59

Volley theory

Answer 59

This theory suggests that clusters of neurons take turns firing in sequence of rhythmic volleys - the number of volleys determines pitch

Question 60

Sensorineural (known as ‘nerve deafness’)

Answer 60

hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves

Question 61

conduction deafness

Answer 61

hearing loss caused by damage to the middle ear system, such as the eardrum, that conducts sound waves to the cochlea. People with conduction deafness can hear vibrations when they reach the cochlea by ways other than through the middle ear

Question 62

Olfactory receptor

Answer 62

The air we breathe in, reaches the olfactory receptor cells located at the top of the nasal cavity Smell is the only sense that is NOT processed first in the thalamus of the brain.

Question 63

Pheromones

Answer 63

chemical messengers that are secreted from other mammals. The most common known are sex pheromones which signal mating behaviours.

Question 64

Gustation

Answer 64

sense of taste

Question 65

taste buds/ taste receptors

Answer 65

inside each bump on your tongue there are over 200+ taste buds

Question 66

temporal lobe

Answer 66

receives information from the taste buds and processes it so you recognise the taste and can attribute it to something i.e. we all know what an apple tastes like

Question 67

Supertasters

Answer 67

more taste buds than the average person= can experience more intense taste

Question 68

medium tasters

Answer 68

average ability to taste

Question 69

nontasters

Answer 69

lower than average tasters

Question 70

kinesthesia

Answer 70

your sense of the position and movement of your body parts Vision plays a key role in helping your kinesthesia - you can look at where your are positioning your limbs and this helps direct movement

Question 71

vestibular system

Answer 71

which stems from balance systems in the ears, also help maintain position and balance

Question 72

semicircular canals

Answer 72

Any movement changes the fluids within small structures called the semicircular canals, found in the inner part of the ear

Question 73

cerebellum

Answer 73

the ‘little brain’ responsible for movement and balance which helps us sense our bodily position and maintain balance

Question 74

skin receptors

Answer 74

Touch is another sensory input, and some parts of our bodies are more sensitive to pressure, warmth, cold and pain

Question 75

Gate control theory

Answer 75

the theory that the spinal cord contains a neurological ‘gate’ that blocks pain signals or allows them to pass to the brain The ‘gate’ is opened by the activity of pain signals travelling up small nerve fibers. The ‘gate’ is closed by activity in larger fibers, or by information coming from the brain.

Question 76

endorphins

Answer 76

The brain can close the ‘gate’ and flood the body with endorphins to reduce or even completely eradicate pain sensation for a short duration

Question 77

Phantom limb sensation

Answer 77

The brain can often misinterpret signals, as it makes the mistake that we are always fully functioning This is why, those who have lost limbs, will often continue to ‘feel’ it and are compelled to use it during normal day to day life This is evidence that it is not entirely about the stimulus input, but it is our mind that let us experience senses

Question 78

sensory interaction

Answer 78

the principle that one sense may influence another. For example, how the smell of food influencing its taste