Sensation And Perception

Question 0

What is sensation?

Answer 0

• The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment (direct information and send it to the brain).

Question 1

What is prosopagnosia?

Answer 1

• Face blindness

Question 2

What is perception?

Answer 2

• The process of organizing and interpreting sensory information, enables us to recognize meaningful objects and events.

Question 3

What is bottom- up processing?

Answer 3

• Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.
• Gives things meaning
• Organization into perception

Question 4

What is top- up processing?

Answer 4

• Information processing- guided by higher- level mental processes, as when we construct perceptions drawing on our experience and expectations.

Question 5

What is transduction?

Answer 5

• Converting one form of energy into another in your brain

Question 6

What is psychophysics?

Answer 6

-The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

Question 7

What are 3 things that all of our senses do?

Answer 7

• Receive sensory stimulation
• Transform stimulation into neural impulses
• Deliver neural information to the brain

Question 8

What is an absolute threshold?

Answer 8

• Awareness of a faint stimuli - the minimum stimulation necessary to detect a particular light, sound, pressure, taste, or odour 50% of the time

Question 9

What is signal detection theory?

Answer 9

• Predicts when we will detect weak signals (measured as our ratio of “hits” to “false alarms”)
  Ex: Exhausted parents will notice the faintest whimper from a newborn’s cradle while failing to notice louder, unimportant sounds

Question 10

What is subliminal stimuli ?

Answer 10

• Stimuli you cannot detect 50% of the time

- Below one’s absolute threshold for conscious awareness

Question 11

What is priming?

Answer 11

• The activation (often unconsciously) of certain associations, predisposing one’s perception, memory, or responses
  (i. e flashing an image and then replacing it with a masking stimulus that interrupts the brain’s processing before conscious perception).

Question 12

What is the difference threshold?

Answer 12

• Minimum difference a person can detect between any two stimuli, 50 % of the time
• Increases w/ the size of the stimulus (ex: you likely wouldn’t notice if 1oz was added to 100oz, but would notice if 1oz was added to 10oz.

Question 13

What does Weber’s law state?

Answer 13

• To be perceived as different, two stimuli must differ by a constant minimum proportion (%) rather than a constant amount
  (I.e 2 lights must differ in intensity by 8%, 2 objects by 2%, and 2 tones by 0.3%).

Question 14

What is sensory adaptation?

Answer 14

• When we are exposed to a constant stimulus, we become less aware of it because our nerve cells fire less frequently.

Question 15

What is a perceptual set?

Answer 15

• A set of mental tendencies and assumptions that greatly affects (top-down) about what we perceive- hear, taste, smell.
  Ex: “Gear up” vs. “Cheer up”.

Question 16

What are context effects?

Answer 16

-The fact that a given stimulus may trigger radically different perceptions partly bc of our differing set, but also bc of immediate context.
Ex: when we hear “eel on the wagon” the brain perceives “wheel” instead.

Question 17

What can vision be defined as?

Answer 17

• Stimulus output

- Electromagnetic radiation

Question 18

What is an electromagnetic radiation wavelength?

Answer 18

• Packets of electromagnetic eradication, oscillating- the degree of oscillation determines the wavelength
  
  • more oscillation= shorter wavelength
  • wavelength determines whether or not our eyes can detect it

Question 19

Describe wavelength and amplitude.

Answer 19

• Wavelength of light - determines the hue that we will experience (Hue= colour)
• Amplitude of wavelength- determines the brightness of the colour
  
  • High amplitude, brighter colour
  • Low amplitude, duller colour

Question 20

What does the eye do?

Answer 20

• Detects and transduces electromagnetic radiation (light)

Question 21

What is transduction?

Answer 21

• Conversion of one form of energy into another

Question 22

What is the role of the cornea?

Answer 22

• Protects the eye
• Bends the light and focuses it on a smaller area
• Gets light into the pupil

Question 23

What is the pupil?

Answer 23

• Hole through which the light gets through

- No light can go into the eye and bounce back out

Question 24

What is the iris? What does it do?

Answer 24

• The iris is the coloured part of the eye that surrounds the pupil.
• When there’s a lot of light, it will contract and become overwhelmed. When there’s not a lot of light, it will dilate.

Question 25

What is the lens? What does it do?

Answer 25

• Lens is located behind the iris and the pupil
• It can change- flatten (looking at things far away) or curve (for looking at things close up)
• Does the focusing

Question 26

What is the retina?

Answer 26

• Layers of tissue/ cells that detect and organize light, radiation, etc before they send that information to the brain
• Contains photoreceptors

Question 27

What are photoreceptors? And what do they do?

Answer 27

• Rods and cones
  
  • Rods are responsible for black and white vision and are more sensitive overall. They are located mostly in the periphery.
  • Cones are responsible for colour vision and are mostly in the centre of the retina (aka the fovea).

Question 28

What is the blind spot?

Answer 28

• A hole in your retina where there are no receptor cells
  
  • The brain has no direct information here about a small area of your visual field, it only has indirect info from the other eye. Your brain fills in info by making its best guess based on the adjacent areas of the retina.

Question 29

What does interposition mean?

Answer 29

• If one object partially blocks another, we perceive it as being closer

Question 30

What does linear perspective mean?

Answer 30

• Parallel lines seem to converge in the distance

- The more they converge, the farther they seem

Question 31

What does the brain assume when looking at shadowing/ shading?

Answer 31

• That light comes from above

- We can infer depth based on the shading

Question 32

What does relaxive motion mean?

Answer 32

• Objects that are closer are perceived as moving faster through our visual field

Question 33

What is the Young- Helmholtz Trichromatic theory?

Answer 33

• Any colour can be create by combining the light waves of the 3 primary colours (Red, Green, Blue).
• Theory was that the brain works the same way when perceiving colour
• Hypothesized that the retina will have 3 different types of colour sensitive cells
• Wasn’t an entirely correct theory, as sometimes yellow seems purple, and people can be missing comes but still perceive yellow

Question 34

How does colour blindness arise?

Answer 34

• Missing red, green (or both) rods

(Red and green rods both look similar)

Question 35

What does opponent process theory state?

Answer 35

• Opponent retinal processes enable colour vision
  Ex: some cells are stimulated by green and inhibited by red and vice versa.
  Red and green= opponents
  Blue and yellow= opponents
  Black and white= opponents

Question 36

What are monocular cues?

Answer 36

• Relative height
  - Things that are higher in your visual field tend to be perceived as father away
• Relative size
  • If we assume two objects are similar inside, then the one that takes up the least amount of retinal space will be perceived as farther away

Question 37

What are binocular cues?

Answer 37

Retinal disparity:

• The object of focus: the greater the disparity between two objects, the closer it is
• The more lateral the retinal image is, the closer the object is (I.e 3D Images)