Week 4 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Sensation & transduction

A

Sensation: Stim of sense organ

Transduction: receptors convert physical from environment to signals for brain to interpret

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Perception

A

Interpretation of a sensation –> mental representation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Sensory adaptation

A

Sensitivity to prolonged stim tends to decline over time as one adapts to current conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Psychophysics

A

Study of how physical stim affect the senses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Absolute threshold

A

Minimal intensity needed to barely detect a stim 50% of the time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sensitivity

A

How responsive one is to faint stim

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Acuity

A

Differentiating btw two stim (e.g. two similar tones)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Just noticeable difference (JND)

A

Minimal change in a stim that can barely be detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Weber’s law

A

Amount of change needed for change to be noticed is constant ratio of the original stim

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Signal detection theory

A

Response to a stim depends on person’s sensitivity to stim and a person’s decision critereon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is light interpreted in the eye?
(keywords: cornea, pupil, iris, lens, accommodation, retina, photoreceptor cells, optic nerve)

A

1) Light passes through CORNEA (clear protective layer around eye)
2) Light passes through PUPIL (hole in the IRIS, the colored part of the eye that controls how much light is let in)
3) Light passes through LENS, which is shaped by eye muscles so the light is focused on the RETINA in a process called ACCOMMODATION (lens flatter for objects further away, lens more curved for objects nearby)
4) Retina lined with PHOTORECEPTOR CELLS called RODS and CONES
5) Signals from rods and cones transducted to brain via the OPTIC NERVE (OPTIC DISK is the beginning of the nerve in the eye)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Myopia vs hyperopia

A

Myopia/nearsighted - eyeball too long –> image focused in FRONT of retina

Hyperopia - eyeball too short –> image focused BEHIND retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Rods

A
  • Peripheral and night vision, brightness
  • More rods than cones (~120M rods)
  • Distributed evenly in retina except for area in the macula called the FOVEA
  • No rods in fovea –> reduced clarity in low light but increased sensitivity to light in periphery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cones

A
  • C words - “Clarity and Color”
  • ~6M cones; concentrated in the FOVEA but sparse in macula/retina –> we see things much clearer if we look right at them
  • 3 different cones for 3 different wavelengths: L-cones (long - red), M-cones (medium - green), S-cones (short - blue)
  • Missing cones –> color blindness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Trichromatic color theory

A

We perceive color by combining RGB wavelengths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Color-opponent system

A

Pairs of cone types work against each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What causes negative afterimages?

A

Opponent process theory: cones are together in opposing pairs: red/green, yellow/blue, black/white
- Cells stimulated by green inhibit the cells stimulated by red
- When changed, the previously inhibited red cells fire, while the green PREVIOUSLY-stimulated cells are tired and don’t fire –> we see red

18
Q

Neurological pathway from photoreceptor cells to brain

A

rods/cones –> bipolar cells –> retinal ganglion cells –> lateral geniculate nucleus (part of thalamus) –> area v1 –> other parts of the brain

NOTE: bunded RGCs form the optic nerve

19
Q

Dorsal vs ventral vision pathways + purpose

A

Dorsal: “where” – where an object is and its movement; upper pathway to parietal lobe

Ventral: “what”/”how” – shape and identity of an object; lower pathway to temporal lobe

Purpose: Neurons in area v1 only perceive small details like edge –> signals to regions farther from V1 respond to more complex features

20
Q

Visual agnosia vs prosopagnosia

A

Visual agnosia: inability to recognize objects

Prosopagnosia: inability to recognize faces

21
Q

Patient DF

A

Injured ventral stream –> couldn’t recognize objects

22
Q

Bottom-up processing

A

Sensory receptors pick up signals and send them to the brain

23
Q

Top-down processing

A

Perceiving things based on your prior knowledge of the world

24
Q

Monocular/pictorial depth cues

A
  • Can be seen w one eye
  • Linear perspective/vanishing point, light and shadow, interposition, relative height, relative size, texture gradient
25
Q

Binocular depth cues

A
  • Both eyes
  • RETINAL DISPARITY - two retinas have slightly different views of the world
  • CONVERGENCE - when a person perceives an object as close, eye muscles make the eyeballs turn in more – brain perceives
26
Q

Perceptual constancy

A

Even as aspects of sensory signals chance, our perception of it doesn’t

27
Q

Conceptual knowledge

A
  • When we perceive an object, we not only recognize what it looks like but also what it is/what it’s doing
  • Ex: when we see a car coming towards us we not only recognize it as a car but also that it’s metal, it could hurt us, it’s moving fast, etc
28
Q

Perceptual organization

A

Process of grouping or segregating features to organize objects

29
Q

Perceptual grouping rules

A

PSSCCC
- Proximity: objects grouped together are associated w each other
- Simplicity: simplest interpretation of objects
- Similarity: similarities in texture, shape, etc
- Continuity: tend to group objects w good continuation (edges or contours w same orientation)
- Closure: fill in missing gaps of visual scene
- Common fate: elements of a visual object moving together are perceived as parts of a single moving object

30
Q

Change blindness vs inattentional blindness

A

Change blindness: fail to notice change in visual scene

Inattentional blindness: fail to perceive objects not the focus of attention

31
Q

Muller-lyer illusion

A

Length of a line appears to be dependent on the orientation of arrows

32
Q

Carpentered world hypothesis

A

prev experience w corners plays role in the strength of muller-lyer illusion

33
Q

Point of subjective vs objective equality

A

Point of subjective equality: Point at which the two lines APPEAR equal

Point of objective equality: point at which the two lines are ACTUALLY equal

34
Q

How are sound waves interpreted as sound in the brain?
(keywords: pinna, auditory canal, eardrum, ossicles, cochlea, basilar membrane, inner hair cells)

A

1) The PINNA collects and channels sound waves into the AUDITORY CANAL, which funnels sound into the EARDRUM
2) The EARDRUM vibrates in response to the soundwaves
3) The OSSICLES (3 bones – hammer, anvil, and stirrup) amplify the vibrations to the COCHLEA
4) The COCHLEA converts the vibrations into neural impulses
- Cochlea divided by structure called BASILAR MEMBRANE – low frequency = tip moves, high frequency = base moves
- Basilar membrane moves up and down –> moves cochlear fluid –> stimulates INNER HAIR CELLS
5) INNER HAIR CELLS (specialized auditory receptor neurons located on basilar membrane) send signal to auditory nerve –> thalamus –> A1 (temporal lobe)
- Some evidence also suggests dorsal and ventral auditory streams

35
Q

McGurk effect

A

Speaker’s lip movements influence what sound is heard

36
Q

What are the physical dimensions of a soundwave

A

Frequency: pitch – measured in hz

Amplitude: intensity/loudness – measured in dB

Complexity: influences measure of timbre (quality that lets you differentiate btw note on piano vs guitar, etc) – mixture of soundwaves

37
Q

What are the different parts of the outer ear, middle ear, and inner ear?

A

Outer ear: pinna, auditory canal, eardrum

Middle ear: ossicles (hammer, anvil, stirrup)

Inner ear: cochlea (contains basilar membrane + inner hair cells), auditory nerve

38
Q

How is pitch signaled to the brain (2 “codes”)

A

Place code: brain uses relative activity of hair cells across whole membrane to determine pitch

Temporal code: brain uses timing of APs to determine pitch

39
Q

How is loudness signaled to the brain

A

Total amount of hair cell activity

40
Q

How is timbre signaled to the brain

A

Relative activity of hair cells

41
Q

How is location signaled to the brain

A

Binaural cues: sound arrives at one ear sooner than the other + sound will be more intense in one ear than the other

42
Q

Conductive vs sensorineural hearing loss

A

Conductive hearing loss: damaged eardrums or ossicles; can be corrected w surgery

Sensorineural: damage to inner ear; sensitivity and acuity decrease; hearing can help w sensitivity issues but not accuity