Terms for Weeks 7 to 12 Flashcards Preview

PSYC 271, Brain & Behaviour > Terms for Weeks 7 to 12 > Flashcards

Flashcards in Terms for Weeks 7 to 12 Deck (91)
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1
Q

What does wavelength play an important role in?

A

the perception of colour

2
Q

What does intensity play an important role in?

A

the perception of brightness

3
Q

Convergence

A

eyes turn inwards slightly; greatest when inspecting close up

4
Q

Binocular disparity

A

difference in the position of the same image on two retinas; greater for close objects; depth perception cue

5
Q

Duplexity theory

A

cones and rods mediate different kinds of vision

6
Q

Photopic vision

A

cone-mediated; predominates in good lighting; high-acuity; coloured perceptions

7
Q

Scotopic vision

A

rod-mediated; lacks detail and colour; predominates in dim light

8
Q

Retina-geniculate-striate system

A

all signals from the left visual field reach the right primary visual cortex AND all signals from the right visual field reach the left primary visual cortex

9
Q

Two parallel channels of communication flow that run through each lateral geniculate nucleus

A
  1. Parvocellular

2. Magnocellular

10
Q

On-center cells

A

Respond to lights shone in the central region of their receptive fields with “on” firing AND to lights shone in the periphery of their receptive fields with inhibition followed by “off” firing when light is turned off

11
Q

Off-center cells

A

Opposite of on-center cells
Respond with inhibition and “off” firing in response to lights in the center of their receptive fields AND with “on” firing to lights in the periphery of their receptive fields

12
Q

Simple cortical cells

A

Receptive fields are divided into static “on” and “off” regions…
All monocular…
Respond best to straight-line stimuli in a specific orientation…
Receptive fields are rectangular

13
Q

Complex cortical cells

A
Larger receptive fields...
Not divided into “on” “off” regions...
Many are binocular (respond to stimulation of either eye)...
Can respond to movement...
Respond best to straight line stimuli...
Rectangular receptive fields
14
Q

Component theory (aka trichromatic theory)

A

3 different kinds of colour receptors (cones);
Some are sensitive to short wavelengths, some to medium, some to long;
Came from idea that any colour can be made by mixing together of three different wavelengths

15
Q

Opponent-process theory

A

Came from idea that complementary colours cannot exist together & afterimage;
Two different classes of cells in the visual system for encoding colour and another for encoding brightness

16
Q

Blindsight

A

ability to respond to visual stimuli in a scotoma (area of blindness) with no conscious awareness of them

17
Q

Dorsal stream

A

respond to spatial stimuli;
“Where” objects;
“Control of behaviour” - directs behavioural interactions with objects

18
Q

Ventral stream

A

respond to characteristics of objects;
“What” objects;
“Conscious perception” - mediates the conscious perception of objects

19
Q

Prosopagnosia

A

visual agnosia for faces

20
Q

Ocular dominance columns

A

inputs carrying information from the left and right eye are initially kept separate in the primary visual cortex
Ex; A light shone in the left eye will fire off neurons in the left-eye ocular dominance columns but not in the right-eye ocular dominance columns and vice versa

21
Q

Orientation columns

A

small chunks of primary visual cortex that have the same orientation preference

22
Q

“Blobs”

A

in center of the ocular dominance columns - contain neurons responsive to colour

23
Q

Ocular dominance plasticity

A

Occurs most readily in critical period and refers to the shift in ocular dominance
Ex; when one eye is not fully functional and more parts of the primary visual cortex start to respond to the other

24
Q

Amblyopia

A

impairment of the visual cortex to process information

25
Q

Binding problem

A

how does the brain bind together activity in widely distributed cortical areas into one perceptual conscious image?

26
Q

Primary sensory cortex

A

input is mostly contralateral; receives input from the thalamic relay nuclei

27
Q

Secondary sensory cortex

A

input is from both sides of body; receives input from primary sensory cortex or other areas of secondary sensory cortex

28
Q

Association cortex

A

prefrontal and posterior parietal cortex (contains bimodal neurons); receives input from more than one sensory system

29
Q

Fourier analysis

A

mathematical procedure for breaking down complex waves into their component sine waves

30
Q

Missing fundamental

A

the pitch of a complex sound may not be directly related to the frequency of any of the sound’s components

31
Q

The auditory system is largely ___________

A

tonotopic

32
Q

Anterior auditory pathway

A

involved in identifying sounds; “what”

33
Q

Posterior auditory pathway

A

involved in location sounds; “where”

34
Q

Two major somatosensory pathways:

A
  1. Dorsal-column medial-lemniscus system

2. Anterolateral system

35
Q

Anterolateral system

A

tends to carry information about pain & temperature

36
Q

Dorsal-column medial-lemniscus system

A

tends to carry information about touch & proprioception (awareness of position & movement of body)

37
Q

The human primary somatosensory cortex is _____________

A

somatotopic

38
Q

Astereognosia

A

inability to recognize objects by touch

39
Q

Asomatognosia

A

failure to recognize parts of one’s own body

  • Usually unilateral (affecting only left side of body)
  • Associated with damage to the right temporal and posterior parietal lobe
  • Commonly a component of contralateral neglect
40
Q

Anterior cingulate cortex

A

most frequently linked to pain

41
Q

Descending pain control

A

pain can be suppressed by cognitive & emotional factors

42
Q

Cross modal perception

A

Perception resulting from interactions between two or more sensory modalities

43
Q

The angular gyrus

A

particularly important for sensory integration across modalities and cross modal perception

44
Q

Synesthesia

A

A perceptual phenomenon in which stimulation of one sensory modality elicits a simultaneous and involuntary perceptual experience within another sensory modality
Most well researched form: grapheme-color synesthesia

45
Q

In the sensory systems, information mainly flows up through the hierarchy, whereas in the sensorimotor system, information flows _______

A

down

46
Q

Ballistic movements

A

Brief, “all-or-none”, high-speed movements that are not normally influenced by sensory feedback

47
Q

Sensorimotor association cortex consists of two major areas:

A
  1. Posterior parietal association cortex

2. Dorsolateral prefrontal association cortex

48
Q

Posterior parietal association cortex

A

Involved in perception of spatial location and guidance of voluntary behaviour
Associated with apraxia and contralateral neglect

49
Q

Apraxia

A

disorder of voluntary movement, difficult making specific movements when requested to do so, but can do so unconsciously

50
Q

Contralateral neglect

A

Inability to respond to stimuli on the side of the body opposite (contralateral) to the side of a brain lesion

51
Q

Dorsolateral prefrontal association cortex

A

Involved in evaluation of external stimuli and decision to initiate complex voluntary motor responses

52
Q

Secondary motor cortex

A

Thought to be involved in the programming of specific patterns of movements

53
Q

Mirror neurons

A

Fire when an individual performs a goal-oriented movement or when they observe the same goal-oriented movement
First discovered in monkeys and provide a possible mechanism for social cognition

54
Q

Primary motor cortex

A

Each site in the primary motor cortex receives sensory feedback from receptors in the muscles and joints that the site influences
Major point of convergence of cortical sensorimotor signals

55
Q

Two important sensorimotor structures that interact with different levels of the hierarchy and coordinate & modulate its activities:

A
  1. Cerebellum

2. Basal ganglia

56
Q

Cerebellum

A

Contains more than half of the brain’s neurons
Thought to correct ongoing movements that deviate from their intended course
Believed to play a major role in motor learning - sequences of movements

57
Q

Basal ganglia

A

play a role in the modulation of motor output, like the cerebellum
Thought to also be involved in a variety of cognitive function (i.e., habit learning)

58
Q

Dorsolateral motor pathways

A

Motor neurons activated project to distal muscles (i.e., finger muscles)

59
Q

Ventromedial motor pathways

A

Motor neurons activated project to proximal muscles of the trunk and limbs (i.e., shoulders)

60
Q

Fast muscle fibers

A

have few blood vessels (more pale)

61
Q

Slow muscle fibers

A

have more blood vessels (more red)

62
Q

Case of H.M.

A

Removal of medial portions of temporal lobes (including most of hippocampus & amygdala) to treat epilepsy

Treatment was called a bilateral medial temporal lobectomy

Led to the discovery of two categories of long term memory: explicit & implicit

Lost almost total ability to form new long-term memories -tests demonstrated that he had intact implicit memory

Intact short-term memory and intact remote, long-term memory

63
Q

Explicit memory

A

conscious long-term memories

64
Q

Implicit memory

A

long-term memory without conscious awareness

65
Q

Major structures of the medial temporal lobes:

A
  1. Hippocampus
  2. Amygdala
  3. Medial temporal cortex
  4. CA1 subfield (in hippocampus)
66
Q

Repetition priming tests assess…

A

implicit memory

67
Q

Explicit long-term memories fall into two categories:

A
  1. Episodic

2. Semantic

68
Q

Episodic memory

A

explicit memories for particular events of one’s life

Aka autobiographical memory

69
Q

Semantic memory

A

explicit memories for general facts or information

70
Q

Korsakoff’s syndrome

A

Disorder of memory common in people who have consumed large amounts of alcohol;
Attributable to brain damage associated with thiamine deficiency;
Characterized by a variety of sensory and motor problems (i.e., extreme confusion, personality changes, etc.)

71
Q

Hebb’s theory of memory consolidation

A

Memories of experiences are stored in the short-term by neural activity circulating in closed circuits

Theses circulating patterns are susceptible to disruption but eventually they induce structural changes in the involved synapses which provide stable long-term storage

72
Q

Reconsolidation

A

each time a memory is retrieved from long-term it is temporarily unstable in short-term memory, until it is reconsolidated

73
Q

Delayed nonmatching-to-sampling test

A

Used with rats and monkeys;
Provided a means of testing the assumption that the amnesia resulting from medial temporal lobe damage is entirely the consequence of hippocampal damage

74
Q

Radial arm maze and Morris water maze

A

Demonstrated that the hippocampus plays a role in spatial processing

75
Q

Jennifer Aniston cells (aka concept cells)

A

found in the medial temporal lobe, respond to ideas of concepts (highly selective & invariant)

76
Q

Infereotemporal cortex & memory

A

important role in storing memories of visual input

77
Q

Amygdala & memory

A

memory for emotional significance of experiences

78
Q

Prefrontal cortex & memory

A

plays a role in memory for tasks that involve a series of responses

79
Q

Cerebellum & memory

A

plays a role in memory of learned sensorimotor skills

80
Q

Striatum & memory

A

plays a role in habit formation memory (memory that develops over many trials)

81
Q

Altering memories in PTSD patients

A

Reduce fear/stress associated with traumatic memories;
Trigger recall of memory to put it in an unstable state;
Administer drug that will blunt the hormonal and autonomic response to reliving the emotional experience

82
Q

Engram

A

brain cells that are altered in some way after learning

83
Q

Hebbian learning rule essentially says…

A
  • Neurons that fire together wire together; neurons that are out of sync lose their link
  • Neurons that are active together increase the strength of their synapses
  • Neurons that reactivate together form cell assemblies
84
Q

Cell assembly

A

Theoretical memory mechanism;
Groups of neurons that serve a common function such as forming and storing a memory;
Reactivation of the cell assembly allows the conscious recall of the memory

85
Q

Long-term potentiation, aka LTP

A

high probability of concurrent pre and postsynaptic activity (synaptic strengthening)

the enduring facilitation of synaptic transmission that occurs following activation of synapses by high-intensity, high-frequency stimulation of presynaptic neurons

86
Q

Long-term depression, aka LTD

A

low probability of concurrent pre and postsynaptic activity (synaptic weakening)

opposite of LTP and occurs in response to prolonged low-frequency stimulation of presynaptic neurons

87
Q

LTP only develops if…

A

the firing of the presynaptic neuron is followed by the firing of the postsynaptic neuron

88
Q

The co-occurrence of firing in presynaptic and postsynaptic cells is recognized as the __________ ______ in LTP

A

critical factor

89
Q

Hebb’s postulate for learning

A

assumption that co-occurrence is a physiological necessity for learning and memory

90
Q

The _____ receptor is prominent at the synapses at which LTP is commonly studied

A

NMDA

91
Q

Metaplasticity

A

refers to the fact that LTP and/or LTD induction can be modulated by prior synaptic activity