Unit 4

Question 1

Explain the difference between bottom-up and top-down perception

Answer 1

Bottom-up: What we perceive based on sensory inputs ex: You would perceive this “13” as a straight line next to a squiggle line”
Top-Down: The influence of context, previous experience and biases on the way we perceive a stimulus ex: You would perceive this “13” as a 13 because you know your numbers or as “B” if I put it in the context “A 13 C” (hard to show digitally lol)

Question 2

What is a perpetual set?

Answer 2

Mental predispositions or biases that influence what we perceive. They are often learned and greatly impact our perception of the world

Question 3

Give an example of how perceptual sets influence your perception

Answer 3

“other race effect”: It is easier to recognize ppl of our own ethnic/cultural background bc of our learned experiences

Question 4

What are our perceptions based on?

Answer 4

Sensation and our expectations

Question 5

Give an example of how your brain builds unique tactile experiences using only 4 sensations

Answer 5

wet = change in temp and pressure
hot stove = high temp and high pain

Question 5

Give an example of how senses can work together

Answer 5

Taste + smell from environment or food) = flavour

Question 5

How is touch info organized in the brain

Answer 5

It is processed in the somatosensory cortex with areas of high sensitivity/fine detail (acuity) having the most space dedicated to them

Question 6

What are the 4 major sensations that the skin detects?

Answer 6

-pressure
-temperature
-vibration
-pain
*Each has a different receptor

Question 7

What is mirror-touch synesthesia?

Answer 7

When you feel touch on your body after seeing it on someone elses

Question 8

What is the rubber hand illusion

Answer 8

You only let someone see a rubber hand
you touch both the rubber hand and their hand
eventually they feel sensation in their hand when you only touch the rubber hand

Question 9

What is proprioception?

Answer 9

A sense of the body’s position in space.
It comes from sensory receptors in different areas of your body ex: joints and tendons.
Your sense of balance is an important part of proprioception.

Question 10

What is your sense of balance controlled by?

Answer 10

Your vestibular system
-semicircular canals in your inner ear are filled with fluid and send signals to the area of your brain dedicated to vestibular function.
-vision feedback also helps

Question 11

What is kinesthesis?

Answer 11

Perception of the movement of the limbs

Question 12

What 2 types of perception allow us to coordinate our body movements in the world?

Answer 12

Proprioception
Kinesthesis

Question 13

What is interoception?

Answer 13

Perception of internal organs (done by the insular cortex)

Question 14

What are association areas?

Answer 14

Parts of the cortex where senses merge to enchance perception

Question 15

How do blind ppl use the visual cortex?

Answer 15

to read braille!!
Born-blind ppl also use it to do auditory tasks so their auditory cortex can be used to locate sound in space

Question 16

How do we tell the direction of a sound

Answer 16

-visually
-sounds arrive at ears at diff times
-head makes “sound shadow” so there is different loudness in diff ears

Question 17

When do we tend to perceive sound the most accurately?

Answer 17

When the source is something we can see

Question 18

What determines frequency and amplitude perception?

(Frequency theory and Place theory)

Answer 18

Frequency: Where the basilar membrane of the cilia is stimmed (wider end = low frequencies, high-mid = stiffer tip) and which part of the cochlea it is sent by (for mid-high only)

Amplitude: Based on frequency of stims

Question 19

What are the limits of human frequency and amplitude perception

Answer 19

F: 20-20k Hz (times/sec)
A: Up to 120 db without damage

Question 20

What is the point of colour and size constancy

Answer 20

Helps us to ensure that colours and sizes of objects appear the same in different lightings and at different distances ex: you don’t think your far away friend was shrunk and you don’t think your bedsheets turned gray in the lower lighting.

Question 21

What is the ponzo illusion?

Answer 21

The one with the train track looking things where one line looks like its bigger (Hard to describe in words but you get it)

Question 22

Why does your brain need to take your body and eye movements into account?

Answer 22

SO you can dissociate body movement from movement in the environment

Question 23

Explain Gestalt Psychology

Answer 23

He has principles which are a set of rules the visual system uses to distinguish figures from a background ex: connectedness, proximity, closure, ect.
Some things challenge this system ex: WWF logo

Question 24

What is Akinetopsia?

Answer 24

the inability to see motion.
happens with a damaged dorsal pathway

Question 25

What is phiphenomena?

Answer 25

Apparent motion. (separate lights or images appear as one fluid movement)

Question 26

What are the ventral and dorsal pathways

Answer 26

ventral = what. (in between occipital and temporal lobes)
dorsal = where (in parietal lobe)

Question 27

What is the occipital lobe?

Answer 27

Primary visual cortex

Question 28

What is prosopagnosia

Answer 28

Inability to recognize faces (me lol)

Question 29

What normally happens when you see the face of someone you recognize?

Answer 29

Specific neural pathways are reactivated

Question 30

What connects your eyes to your brain?

Answer 30

The optic nerve

Question 31

Where does light hit your eyes?

Answer 31

In the back. (your retina)

Question 32

a)When you see something in your central vision, where does the information from each eye go (brain hemisphere).

b)What about when something is on your right a bit?

c)What about when something is in your right peripheral?

Answer 32

a)Travels ispsilaterally

b) Both eyes send info to the left hemisphere

c) Right eye sends info to the left hemisphere

Question 33

What are feature detectors?

Answer 33

Regions in our brain that determine the basic building blocks of vision ex: edges, angles, colours, movement.
Higher regions then allow us to represent whole objects
(Hierachial analysis)

Question 34

What lobes are involved in hierachial analysis?

Answer 34

Occipital and sometimes temporal

Question 35

If we only processed vision in the occipital lobe could we still perceive visual stimuli?

Answer 35

NO!

Question 36

What is a large portion of our brain used for?

Answer 36

vision

Question 37

What is pyschophysics?

Answer 37

The relationship between physical characteristics in our environment and our experience of them

Question 38

What is absolute threshold?

Answer 38

minimum amount of stimulation needed to detect a stimulus 50% of the time

Question 39

What is signal detection theory

Answer 39

A way to account for bias when measuring absolute threshold. It involves measuring when there is no stimulus to determine the false alarm rate.

Question 40

What are some examples of sensory/perceptual adaptation

Answer 40

Nose-blindness
“First-sip feeling”
Light and Dark adaptation
Fixed visual stimuli would also disappear if our eyes weren’t constantly moving

Question 41

Explain the difference between sensory and perceptual adaptation

Answer 41

Sensory: Constant stims will disappear after a while. This helps us to reduce noise in our environment and become more sensitive to changes in our surroundings
Perceptual: Decreased brain response due to unchanging stimuli

Question 42

When might perception not equal reality?

Answer 42

-Colour constancy
-McGurk Effect
-Whole perception
-Sensory processing sensitiivty (some ppl process it more deeply)

Question 43

Explain the differences between sensation, perception and transduction

Answer 43

Sensation: When a sensory organ detects a stimulus
Transduction: When the sensory info is turned to an electric signal
Perception: When the brain processes the electrical signals and determines what it “thinks” about the environment