9.2 - Human Performance and Limitations

Question 1

What is the anatomy of the eye

Answer 1

1: Cornea
2: Iris and Pupil
3: Lens
4: Retina
5: Fovea

Question 2

What is the Cornea

Answer 2

The clear window at the front of the eye which allows light enter.

Question 3

How much of the focusing ability is the cornea responsible for?

Answer 3

70 - 80%

Question 4

What is the Iris and Pupil

Answer 4

The Iris (coloured part of the eye) controls the amount of light by varying the size of the pupil (the dark centre)

Question 5

What factor can the Iris adjusted by

Answer 5

5:1

Question 6

How does the lens focus

Answer 6

Ciliary muscles in the lens change their shape to adjust the level of focus. This is called accommodation

Question 7

What does the Retina contain

Answer 7

Rods and Cones

Question 8

How do the cones function

Answer 8

They function in good light, can detect fine detail and are colour sensitive, allowing the eye to distinguish about 1000 shades of colour

Question 9

How do the Rods function

Answer 9

Rods cannot detect colour and are poor at distinguishing fine detail but good at detecting movement

Question 10

How does the eye prevent an image falling into the blind spot

Answer 10

Constant rapid eye movement (saccades)

Question 11

What is the Fovea

Answer 11

A small depression at the centre of the retina that is responsible for Central vision

Question 12

How many nerve cells leading from the retina to the visual cortex

Answer 12

1.2 million

Question 13

How many nerve cells in the inner ear

Answer 13

50’000

Question 14

How many times more sensitive is the eye than the nose

Answer 14

24 times more sensitive is

Question 15

How is Hypermetropia (long sightedness) caused

Answer 15

By a shorter than normal eyeball

Question 16

Where is the image formed in an aye with Hypermetropia

Answer 16

Behind the retina

Question 17

How is Myopia caused

Answer 17

By a longer than normal eyeball

Question 18

Where is the image formed in an eye with Myopia

Answer 18

In front of the retina

Question 19

What is Presbyopia

Answer 19

Loss of lens flexibility with age

Question 20

What is Glaucoma

Answer 20

Build up in pressure of the fluid in the eye

Question 21

What are cataracts

Answer 21

Clouding of the lens

Question 22

What is Astigmatism

Answer 22

A misshapen cornea

Question 23

What can excessive light cause

Answer 23

Increased Glare, especially for older people

Question 24

What is Colour Vision Deficiency

Answer 24

Colour Blindness

Question 25

What is the most common type of colour blindness

Answer 25

Red and green

Question 26

What document controls the standards for vision

Answer 26

Regulation CAP 562 Leaflet H60

Question 27

What are the functions of the ear

Answer 27

1: Detecting sounds 2: monitoring balance and acceleration

Question 28

What are the 3 divisions of the ear

Answer 28

1: Outer ear 2: Middle ear 3: Inner ear

Question 29

What does the outer ear do

Answer 29

Directs sound down the auditory canal to the ear drum

Question 30

How long does the acoustic or aural reflex reduce noise levels

Answer 30

About 15 mins

Question 31

How is air in the middle ear refreshed

Answer 31

By the eustachian tube

Question 32

How are vibrations transmitted from the ear drum

Answer 32

The Ossicles

Question 33

What is the Ossicles made up of

Answer 33

1: Hammer 2: Anvil 3: Stirrup

Question 34

When must employers provided hearing protection and hearing protection zones

Answer 34

When normal speech cannot be heard clearly at 1 meter

Question 35

When must employers assess the risk to workers health and provide training due to noise levels

Answer 35

If ambient noise is above where normal speech cannot be heard at 2 meters

Question 36

What happens if the a noise exposure limit value that must never be exceeded is reached

Answer 36

Work must cease until a solution is provided

Question 37

What is noise dose

Answer 37

A term that describes a combination of a noise’s duration and intensity

Question 38

What is Time Weighted Average

Answer 38

Exposure to any sound over 80dB and measured over 8 hours as an average

Question 39

What TWA noise level is considered hazardous and potentially damaging to the inner ear

Answer 39

Noise above 85dB for 8 hours

Question 40

What level does ear plugs attenuate noise

Answer 40

Upto 20dB

Question 41

What level does ear defenders attenuate noise

Answer 41

Upto 40dB

Question 42

What is the naturally deteriorating of the hearing that can start from age 30

Answer 42

Presbycusis

Question 43

Information processing is the process of what

Answer 43

1: Receiving information through the senses 2: Analysing information 3: Deriving meaning from information 4: Storing information

Question 44

What are the memory stores known as

Answer 44

1: Iconic Memory 2: Echoic Memory

Question 45

What does Iconic Memory do

Answer 45

Provides a smooth stream of visual information to the brain which can be extracted over an extended period in the visual short term memory

Question 46

What does Echoic Memory do

Answer 46

Registers sound

Question 47

How long is visual information stored in the Iconic memory

Answer 47

Upto half a second

Question 48

How long are sounds stored in the Echoic memory

Answer 48

Upto two seconds

Question 49

What are the forms of attention

Answer 49

1: Selective 2: Divided 3: Focussed 4: Sustained

Question 50

What is selective Attention

Answer 50

When a person is monitoring several sources of input but focuses on the source that seem more important

Question 51

What is divided attention

Answer 51

When a person is required to do more than one thing at the same time

Question 52

What is focussed attention

Answer 52

When a person’s attention is channeled towards a single source and avoiding distractions

Question 53

What is Sustained Attention

Answer 53

The ability to maintain concentration and remain already over long periods of time

Question 54

How is attention influenced

Answer 54

By arousal level and stress

Question 55

What is the definition of perception

Answer 55

The process of assembling sensations into a useable mental representation of the world

Question 56

What are the processes of memory

Answer 56

1: Encoding 2: Storage 3: Retrieval

Question 57

What is the process of getting information into outlet brains

Answer 57

Encoding

Question 58

How is the encoded information put into storage in the brain

Answer 58

Three stages 1: Sensory memory 2: Short term memory or working memory 3: Long term memory

Question 59

How long does sensory memory hold information

Answer 59

Upto a couple of seconds. Know as ultra short term memory stores

Question 60

How much information can the short term memory hold and for how long

Answer 60

5-9 items for 10-20 seconds

Question 61

How long can long term memory hold information

Answer 61

It’s continuous storage of information and has no limits

Question 62

What are the types of long term memory

Answer 62

1: Semantic Memory 2: Episodic Memory

Question 63

What is Semantic memory

Answer 63

It’s the store of general, factual knowledge

Question 64

What is Episodic memory

Answer 64

The memory of specific events such as past experiences, people, events and objects

Question 65

What is the memory process

Answer 65

1: Encoding 2: Storage 2: Retrieval 4: Decision

Question 66

What is Situation awareness

Answer 66

The synthesis of an accurate and Upto date mental model of one’s environment and state

Question 67

What is the fear of enclosed spaces

Answer 67

Claustrophobia

Question 68

What is the fear of heights

Answer 68

Acrophobia

Question 69

What is a motor programme

Answer 69

A organised series of movements, made up of subroutines that are run together in order to

Question 70

What is neuroplasticity

Answer 70

The continual changes that take place in the brain as you experience and adapt to your surroundings