9.2 Human Performance And Limitations

Question 1

what is the basic structure of an eye

Answer 1

it consists of the iris, a lens and the retina

Question 2

what allows light to enter the eye

Answer 2

the cornea

Question 3

the cornea is responsible for what percentage range of the total focusing ability of the eye

Answer 3

70-80%

Question 4

what does the iris control

Answer 4

the amount of light enters the eye by varying the size of the pupil

Question 5

what is the factor that the amount of light can be adjusted by

Answer 5

5:1

Question 6

what changes in the lens to adjust the level of focus, so it can create a sharp image on the retina

Answer 6

ciliary muscles

Question 7

what happens to the lens when it focuses on a close object

Answer 7

it thickens

Question 8

what happens to the lens when it focuses on a distance object

Answer 8

it flattens

Question 9

what does reduced accommodation lead to

Answer 9

less sharp vision

Question 10

where is the retina located

Answer 10

on the back of the eyeball

Question 11

the retina has two types of light sensitive cells what are they

Answer 11

cones and rods

Question 12

what can cones function well in and what do they detect

Answer 12

they function in good light, can detect fine detail and are colour sensitive

Question 13

what are rods good at

Answer 13

detecting movement on the edge of the visual field

Question 14

what is the fovea made up entirely of

Answer 14

cone receptors

Question 15

where in the eye is there a blind spot

Answer 15

where the optic nerve joins the back of the eye

Question 16

what is the saccades

Answer 16

a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction

Question 17

what is the fovea

Answer 17

a small depression at the centre of the retina that is responsible for central vision

Question 18

where is the point at which visual acuity is at its highest

Answer 18

the fovea

Question 19

what is visual acuity

Answer 19

the eye’s ability to perceive sharp detail at varying distance

Question 20

what is hypermetropia and what causes it

Answer 20

long-sightedness, and is caused by a shorter than normal eyeball

Question 21

what is myopia and what causes it

Answer 21

short sightedness and is occurs when the eyeball is longer than normal

Question 22

what is catarcts

Answer 22

the clouding of the lens, usually associated with ageing

Question 23

what is astigmatisms

Answer 23

a misshapen cornea

Question 24

what is glaucoma

Answer 24

a build up in pressure of the fluif within the eye

Question 25

what is presbyopia

Answer 25

form of long sightedness due to ageing causing the lens to become less flexible

Question 26

how long does it take to adapt from dark to light

Answer 26

7 minutes for cones and 30 minutes for the rods

Question 27

what is the maximum wear time of contact lenses

Answer 27

8 to 12 hours

Question 28

what is colour blindness really cause

Answer 28

colour vision deficiency

Question 29

what is colour blindness caused by

Answer 29

a defect in the structure of the colour sensitive cones of the retina

Question 30

what are the three section of the ear

Answer 30

outer ear middle ear inner ear

Question 31

where does the middle ear sit

Answer 31

behind the eardrum

Question 32

what are the three small bones found in the middle ear

Answer 32

hammer, anvil and stirrup

Question 33

up to how many decibels does the two muscles in the mddle ear protect to

Answer 33

80 DB

Question 34

what does the two muscles in the middle ear use to protect against dB

Answer 34

the acoustic or aural reflex

Question 35

how much can the acoustic or aural reflex reduce incoming dB by

Answer 35

20 dB

Question 36

what is the last of the ossicles in the middle ear connected to

Answer 36

the cochlea

Question 37

what does the cochlea contain

Answer 37

a dine membrane e.g the basilar membrane

Question 38

wat reacts to movement in the fluid of the inner ear

Answer 38

the hair-like cells on the basilar membrane

Question 39

in the inner ear what is vibration transmitted by

Answer 39

the auditory nerve

Question 40

what is the range that a young person can hear sound between

Answer 40

20Hz - 20,000Hz

Question 41

how much can ear plug reduce noise levels

Answer 41

20dB

Question 42

how much can ear defenders reduce noise by

Answer 42

40dB

Question 43

what is NIHL

Answer 43

noise induced hearing loss

Question 44

what constitutes a noise dose

Answer 44

exposure to any sound over 80dB

Question 45

what can regular exposure to high levels over a long period of nose lead to

Answer 45

permanent damage to the hair like cells in the cochlea

Question 46

what is the different parts of the human brain

Answer 46

frontal lobe parietal lobe temporal lobe occipitial lobe brain stem cerebellum

Question 47

what is information processing the process of

Answer 47

receiving information through the sense analysing information deriving meaning from the information storing information

Question 48

what the two different types of memory in the brain

Answer 48

iconic memory echoic memory

Question 49

what are the different types of attention

Answer 49

selective divided focussed sustained

Question 50

what are the processes of memory

Answer 50

encoding - input of information to memory storage - retaining information in memory retrieval - recovery of information from memory

Question 51

what is sensory memory also called

Answer 51

ultra-short memory

Question 52

what is short term memory often referred to as

Answer 52

working memory

Question 53

how long soes sensory memory last

Answer 53

2 seconds

Question 54

what are the two different memory's that come under sensory memory

Answer 54

iconic echoic

Question 55

what are the different memory's that come under long term memory

Answer 55

semantic episodic motor programmes

Question 56

what is situation awareness

Answer 56

the synthesis of an accurate and up-to-date mental model of one's environment

Question 57

what can claustrophobia be defined as

Answer 57

an abnormal fear of being in an enclosed space

Question 58

what can reduce the feeling of discomfort

Answer 58

good lighting and ventilation

Question 59

what is the fear of heights called

Answer 59

acrophobia