L1 Intro to Perception

Question 1

What is the origin of the word ‘Perceive’?

Answer 1

per - means “in front of”

ceive - (capere - latin) means “to capture”

Question 2

Why is it critical for animals to sense?

Answer 2

Without sensory, we would not be able to react and respond to various forms of energy in the environment.

We would not be able to respond to significant objects and events and therefore could not survive.

Question 3

What are our 5 input senses?

Answer 3

Sound, Smell, Sight, Temperature, Touch

Question 4

Why is perception a part of psychology?

Answer 4

Perception is the foundation for everything else:

Memory, learning, motor skills, emotion, motivation, social psychology, personality and pathology.

Question 5

What are the ‘two different worlds we live in’?

Answer 5

The Perceptual World and Physical World

What we hear, see, smell taste and touch depends on the physical world but that also entirely dependent for us on our sensory apparatus and nervous system (perceptual world).

Question 6

What are the 5 classifications of the senses?

Answer 6

Sense,

Stimulus,

Sensory Structure,

Receptor,

Cortex

Question 7

What is sensory information processed by to give us perception?

Answer 7

Our Brain

Question 8

What is proprioception?

Answer 8

The position of your body in space.

Tells you where your body is.

Question 9

1. What is ‘The Fallacy of our Percepts?’
2. What is the psychological answer?

Answer 9

1. How can we know anything if our senses are subjective and constantly changing?
2. If we can determine how perception changes under various conditions, then we should be able to predict these changes and therefore understand perception.

Question 10

Describe the physical process of the eye and how it creates vision.

Answer 10

The info comes in through pupil,

then projected upside down and a little blurry on the fovea,

then you have optic nerve fibres which go to the receptor cells (rods and cones).

Question 11

Where is the ‘blind spot’ in the eye?

Answer 11

Where the optic nerve meets the back of the retina.

(Just to the right of the fovea)

Question 12

What is the area of vision around the ‘central viewing area’ called?

Answer 12

The periphery.

Question 13

Why do we not know we have a blind spot in our vision?

Answer 13

Our brain ‘guesses’ and fills it in for us.

Question 14

Why are there lots of cones at 0 degrees in the centre of the Fovea?

Answer 14

Cones are how we see colour and sharp clarity and is most sensitive to daylight levels of wavelength (560nm).

It is in the fovea because that is where we can actually focus (centre of vision).

Question 15

What is the difference between Rods and Cones?

Answer 15

Rods are responsible for vision at low light levels (scotopic vision). No colour vision. Low Spatial Acuity.

Cones are active at higher light levels (photopic vision). Capable of colour vision. High Spatial Acuity.

Question 16

What is the part of the eye that is responsible for our focused vision (point of central focus)?

Answer 16

The Fovea

Question 17

What does a ‘bi-lateral representation of the cortex’ mean?

Answer 17

We have a similar structure on either side of the brain.

Question 18

What is Psychophysics?

Answer 18

The branch of psychology that deals with the relations between physical stimuli and mental phenomena.

Question 19

What is a Threshold in Psychophysics?

Answer 19

A border or boundary

Question 20

What is an Absolute Threshold in Psychophysics?

Answer 20

The minimum amount of energy needed to detect a stimulus.

There might be light around, but there isn’t enough to detect a person or see things.

Question 21

What is the current idea of threshold in psychometric function?

Answer 21

That the threshold is a continuous function, gradually increasing in as a sigmoid (S-shaped).

(50 may be where we start to see something (estimate of the absolute threshold for the object))

Question 22

For measuring perception, what were the 3 psychophysical methods proposed by Fechner (1860)?

Answer 22

Method of Adjustment

Method of Limits

Method of Constant Stimuli

Question 23

Describe the Method of Adjustment for measuring perception.

Answer 23

Ask the observer to adjust the intensity until they can barely detect the stimulus.

Question 24

Describe the Method of Limits for measuring perception.

Answer 24

The experimenter adjusts intensity up (or down) until the observer changes their response.

Question 25

Describe the Method of Constant Stimuli for measuring perception.

Answer 25

Observers view several preset stimulus intensities (in random order) and judge whether each is perceived or not.

(Most popular method)

Question 26

What is sensitivity in comparison to the psychophysical function?

Answer 26

Sensitivity is the inverse of threshold.

sensitivity = 1/threshold (1 over threshold)

Question 27

What is the difference threshold?

(JND-just noticeable difference)

Answer 27

The minimum change in a stimulus in order for the change to be perceivable

Question 28

What are the three different types of absorption spectra for cones?

Answer 28

Short Wavelengths (Blue)

Medium Wavelengths (Green)

Long Wavelengths (Red)

Question 29

Name and describe the two types of colour vision deficiency.

Answer 29

Deuteranopes: complete lack of green (medium wave) cones

Protanopes: complete lack of red (long wave) cones

Question 30

Which gender is more likely to have colour vision deficiency?

Answer 30

Men

Question 31

What is an Ishihara colour plate do?

Answer 31

Tests for colour blindness.

Question 32

What is the part of the brain responsible for vision called?

Answer 32

Primary Visual Area or Striate Cortex

Question 33

What is the retina?

Answer 33

A layer at the back of the eyeball that contains cells sensitive to light.

These trigger nerve impulses that pass via the optic nerve to the brain, where the visual image is formed.

Question 34

What was the classic idea for ‘threshold’?

Answer 34

That there was absolutely no reaction until it hit the threshold then it rocketed straight to 100% perceptible.