Unit 2: Perception + Sensation

Question 1

What are the two ways that all allow us to perceive 3D images even though only a 2D image is projected onto our retina?

Answer 1

(1) Monocular Depth Cues

(2) Binocular Depth Cues

Question 2

What are two types of binocular depth cues?

Answer 2

(1) Eye convergence-the closer something is, the closer our eyes are directed toward each other
(2) Binocular Disparity-the further away something is the less the image changes between eyes

Question 3

What are the types of monocular depth cues

Answer 3

(1) Motion Parallax-objects move by quicker when you are closer to them (requires the image already to be 3D i.e. not a picture)
(2) Pictorial Cues
(3) Lighting + shading- tells concave vs. convex

Question 4

Give examples of the types of pictorial cues.

Answer 4

(1) Linear perspective- at further distances, parallel lines appear to converge
(2) Texture gradient-decreases for objects far away in an image
(3) Relative image size-uses our past experiences
(4) Atmospheric Perspective-objects farther away appear hazier
(5) Interposition- objects closer block more of our view

Question 5

What is perceptual constancy and shape constancy?

Answer 5

Perceptual constancy is our ability to maintain our perception of the size of something regardless of how it it changing on our retina, due to the fact that we know what size it is.
Similarly, we know the shape of common things and so if their shape is changed on our retina we know that it is still the same form (i.e a door opening will appear long and distorted rather than the regular rectangle that it is).

Question 6

What are the 5 Gestalt principles?

Answer 6

(1) Law of similarity-grouping of similar things
(2) Law of continuation-assuming object continue on the path they were on
(3) Law of proximity- groups things in close proximity together
(4) Law of closure-closing things in based on recognized shape
(5) Figure-Ground-can separate objects from their background

Question 7

What is the opponent process theory?

Answer 7

The idea that cones are linked together in opposing pairs of colours such that activity of one inhibits the other: blue/yellow, red/green, and black/white.
Example. you dont see a yellowy blue colour

Question 8

What are our 3 types of cones and how do they work together to allow us to see colour?

Answer 8

Red, green, and blue cones. Each are sensitive to those specific wavelengths of light, and the different firing patterns of these photoreceptors give us the wide array of colours: example, equal stimulation of red and green cones allow us to see yellow.

Question 9

What are the 4 auditory illusions?

Answer 9

(1) Speech to song illusion
(2) Tritone Paradox (can tell ascending/descending)
(3) Phantom word illusion-when 2 people speaking sound like 2 words
(4) Phoneme restoration effect-brain fills in the gaps

Question 10

Define Consciousness.

Answer 10

An awareness of ones surroundings and of whats in ones mind at a given moment, includes wake fullness and awareness.

Question 11

What are the 2 criteria of consciousness?

Answer 11

(1) Awareness- Monitoring of info from environment and own thoughts
(2) Wake fullness- degree of ones alertness reflecting whether a person is awake or asleep

Question 12

Define mindfullness.

Answer 12

A heightened awareness of the present moment

Question 13

Define attention.

Answer 13

The focus of ones consciousness.

Question 14

What is selective attention?

Answer 14

The ability to choose what you focus on, while ignoring background/unimportant details.

Question 15

What is the cocktail party effect?

Answer 15

The ability to filter out background auditory stimuli and then refocus attention when you hear your name.

Question 16

What is the perceptual load model?

Answer 16

When we do not notice potential distractions because something consumes all of our attentional capacity. Each sense uses some of attentional capacity, explaining why we turn the radio down when looking for something.

Question 17

What is a circadian rhythm?

Answer 17

A 24hr rhythm that regulates many bodily functions, including the sleep and wake cycle.
This can also be known as our “biological clock” and it occurs in our super chiasmatic nucleus(SCN): apart of the hypothalamus

Question 18

Explain how the SCN regulates the sleep/wake cycle.

Answer 18

• The SCN can suppress activity in the pineal gland, responsible for secreting melatonin. So when SCN activity is high, we say awake, and when it is low, melatonin is high and we can sleep more.
• Cells in the SCN run themselves on a biological clock (24.4) so if light is gone, they can still run themselves slightly differing from a 24 hour clock.

Question 19

What are the sleep stages and what are the corresponding brain waves?

Answer 19

(1) Awake/alert- beta waves
(2) Relaxed/drowsy- alpha waves
(3) Stage 1- theta waves
(4) Stage 2- sleep spindles
(5) Stage 3- Delta waves (slow wave sleep)
(6) Stage 4- Delta waves (slow wave sleep)
(7) REM sleep- similar to awake waves

Question 20

Explain how we cycle through the sleep cycles.

Answer 20

Stage 1-4-REm and then back up 4,3,2, REM. Stage 1 is not reached again

• As the night progresses we spend less time in slow wave sleep, and more time in REM sleep.
• Babies spend about 50% of their sleep in REM, whereas adults typically 20%

Question 21

When you have “sleep debt”/sleep deprivation how does it affect your performance?

Answer 21

It affects your mental capacity (cognitive skill), but not really your physical skills.

Question 22

What are the 3 theories that are used to explain why we sleep?

Answer 22

(1) Restoration Theory-Repair damages, remove waste. You can have internal and external damages from sleep deprivation
(2) Memory Consolidation Theory-learning and memory is strengthened, to recall memories we require a slow wave sleep cycle the night after.
(3) Evolutionary Theory-inactivity promotes survival

Question 23

What is insomnia?

Answer 23

Difficulty falling or staying asleep consecutively for 2 plus weeks. Treatment: increased levels of GABA.

Question 24

What is sleep apnea?

Answer 24

When one stops breathing during sleep: involves waking up a lot during sleep because of stop breathing, and involves extreme sleep deprivation. Treatment: device that stops blockage.

Question 25

Explain sleep walking.

Answer 25

Occurs during slow wave sleep, not REM sleep.

Question 26

Explain narcolepsy.

Answer 26

The tendency to fall asleep at odd times due to issues with sleep and wake cycle (the orexin neurotransmitter helps one to stay away and people with narcolepsy have very low levels of this).

Question 27

What is hyper insomnia?

Answer 27

Sleeping 10 plus hours ever day for 2plus weeks