4) Sensation & Perception

Question 1

Sensation vs Perception

Answer 1

Sensation is the stimulation of sense organs

Perception is the mental representation after selecting / organizing / identifying / interpreting sensory input

Question 2

Transduction

Answer 2

process where sensors convert physical signals to neural signals

Question 3

Sensory Adaptation

Answer 3

gradual decline in sensitivity when stimulated long time

Question 4

How is sensory adaptation different from habituation?

Answer 4

can’t choose to pay attention to how our senses were before the decline in sensitivity

For habituation, brain filters out unnecessary info but we could pay attention to it if we wanted to

Question 5

When we first jump into a swimming pool, it feels cold. After 10 minutes, it doesn’t feel cold anymore. This is an example of

Answer 5

sensory adaptation

Question 6

describe the role of attention

Answer 6

flexible attention is important for survival & well-being

gotta pay attention in order to encode

Information we filtered out is still being processed even if we aren’t aware

Question 7

Selective Attention vs Inattentional Blindness

Answer 7

Selective attention
- Focus on specific things by choosing one sensory channel & tuning out others
- RAS and forebrain control this by activating regions in cerebral cortex

Typically leads to

Inattentional Blindness
- Fail to detect smt that’s right in front of you cuz too busy focusing on smt else
- change blindness is failing to detect obvious changes in environment

Question 8

Filter theory of attention

Answer 8

like a bottleneck that info goes through
- pay attention to important stuff

Question 9

Cocktail party effect

Answer 9

Ability to pick out important message (like our name) in random crowdy convos
Shows that our filter isn’t just on & off, brain is ready to act when it senses smt significant

Question 10

Bottom up processing

Answer 10

starting with perception of raw stimuli, then synthesizing into smt meaningful

Question 11

Top down processing

Answer 11

Start with our knowledge and expectations, imposing on raw stimuli

ex/ perceptual constancy, perceptual set

Question 12

Perceptual set

Answer 12

when our expectation influence our perception

an example of top down processing

Question 13

Parallel processing

Answer 13

ability to attend to many senses at a time

Question 14

What is the binding problem?

Answer 14

Things we perceive are processed and stored by diff regions in the brain

How does the brain put them all together?

May be due to rapid & coordinated activity

Explains many aspects off perception & attention

Question 15

Psychophysics

Answer 15

Study of relationship between perceptions & stimuli

absolute threshold, just noticeable difference, etc

Question 16

Absolute Threshold

Answer 16

lowest level of stimuli needed to be detected 50% of the time, starting from an intensity of 0

Question 17

Just noticeable difference

Answer 17

Smallest change in intensity of a stimulus that we can detect
NOT starting from 0!

Question 18

Signal Detection Theory

Answer 18

Stimuli are detected differently under diff conditions

Signal to noise ratio is important:
harder to detect as background noise increase

Question 19

Response bias

Answer 19

guessing when unsure

Question 20

Weber’s law

Answer 20

Change in a stimulus that will be just noticeable is a constant ratio of original stimulus

i.e. ratio of diff in intensity : background intensity

Question 21

Fechner’s Law

Answer 21

Describe relationship between stimulus magnitude and perceived magnitude

Perceived intensity increases proportionally to log of stimulus intensity

Curved graph!

ex/ light bulb

Question 22

Steven’s Law

Answer 22

Curved graph but says that diff stimuli causes diff changes in perceived intensity

Question 23

Ppl don’t notice that some days John wears a bit of makeup and other days he doesn’t. Sometimes he puts on a bit more than usual and some ppl (50%) notice. This is an example of

Fechner’s
Steven’s
Just noticeable difference
Absolute threshold
Weber’s

Answer 23

Absolute threshold

Question 24

Somatosensory System

Answer 24

responds to stimuli applied to skin

sense of touch, pain, temp

All types of nerve endings are spread unevenly throughout body

Mechanoreceptors
Specialized nerve endings on end of sensory nerves in skin

Free nerve endings
More plentiful

Question 25

Touch vs pain

Answer 25

touch travels faster and is localized more precisely

Question 26

Where does pain information go?

Answer 26

somatosensory cortex and limbic system

Question 27

pain

Answer 27

Personal, subjective experience

Influenced by culture, citation, attention, psychological variables

Intricately tied to emotion & cognition

Diff context changes how much pain they actually feel

Doesn’t always come from physical injuries

Question 28

What are the different types of pain receptors?

Answer 28

Nociceptors

1. Mechanical
   Respond to excess pressure, deformation, breaks in skin
2. Thermal
   Activated by different levels of temperature
3. Chemical
   Respond to chemicals like spice, venom, irritants, chemicals from changes in tissues
4. Polymodal
   Senses more than one type of pain stimuli

Question 29

Pain threshold

Answer 29

point when we perceive smt as painful

diff ppl have diff levels due to genetics

Question 30

What are the functions of pain expressions?

Answer 30

Evolved, not learned!

1. Protect from further harm
2. Alert others that we are hurt
3. May recruit empathy & care

Question 31

Explain the different theories of pain

Answer 31

Traditional theory (outdated)
- Pain results from transmission of pain signals from injury to brain
- Amount of pain = amount of tissue damage

Gate control theory
- Pain gate in spinal cord that can open and close to modulate pain experience
- psychological factors play important role

Question 32

Proprioception

Answer 32

body position

Question 33

Proprioireceptors

Answer 33

Sends info to somatosensory & motor cortex

1. Stretch receptors in muscles
2. Force receptors in tendons

Question 34

Gate Control Theory

Answer 34

• Pain gate in spinal cord that can open and close to modulate pain experience
• These factors play important role:

Physical
Open: extent of injury, activity level
Close: meds, counter stimulation like massage
Emotional
Open: anxiety, worry, depression
Close: positive emotions, relaxing
Cognitive
Open: focus on pain, boredom
Close: distraction, concentration, expectations, beliefs

Question 35

Traditional theory of pain

Answer 35

• outdated!
• Pain results from transmission of pain signals from injury to brain
• Amount of pain = amount of tissue damage
• Can’t explain headaches or phantom limb pain

Question 36

Vestibular sense

Answer 36

Balance

Cochlea & semicircular canals in ear filled with liquid helps us maintain balance

Sends info to
- parts of brain stem that control eye muscles & reflexes
- cerebellum for controlling body responses

Limited awareness of this sense cuz doesn’t go to cerebral cortex!

Question 37

Semicircular canals

Answer 37

3 fluidy canals in inner ear responsible for our sense of balance