Class 7,8,9,10 Flashcards
(125 cards)
1
Q
Olfactory receptor neurons are __
A
bipolar: one dendrite out to the nasal cavity
2
Q
Each dendrite has ~____ cilia in __
A
10-15 tips (cilia) in a layer of mucus
3
Q
Cilia have __
A
have places for chemicals to bind onto
4
Q
Olfactory receptors synapse onto
A
mitral cells in glomeruli (sing. glomerulus)
5
Q
Olfactory receptors of the same type synapse onto the same
A
glomerulus
6
Q
Ascending olfactory pathway
A
(Side notes - • Olfactory information does not pass through the thalamus • Unique to olfaction • Largely ipsilateral projections)
7
Q
Axial Slice
A
Horizontal slice that is angled
8
Q
Sniffing vs. Smelling
A
- Differential involvement of cortical regions based on stage of olfaction
- Sniffing rate can affect the rate of smell detection and clearance
9
Q
olfactory system is able to pick up on molecules released from __ which can modulate __
A
tears, arousal
(men did not find picture of women as attractive if they were smelling tears)
10
Q
What is the role of olfaction?
A
rotten food
detection of danger
some form of communication/social bonds modulated by olfactory system
11
Q
The five basic tastes that we recognize
A
• Sweet • Sour • Salty • Bitter • Umami (orig: うま味 pleasant taste)
12
Q
Taste buds are on __ are __
A
papillae, are groups of taste receptors
13
Q
Different sizes of __ on the tongue in ___
A
papillae, different regions
14
Q
Taste buds contain a combination of __ cells
A
recptor
Receptors are activated differently depending on the receptor type
15
Q
Cranial nerves VII and IX carry information from ___ to the (____) brainstem
information then reaches ___
A
taste receptors
(nucleus of solitary tract)
thalamus in ventral posterior nucleus
than to the Primary gustatory cortex
16
Q
Primary gustatory cortex is ___
A
insula and operculum
17
Q
One goal of olfaction is to help with __
A
finding food and determining whether it is good to eat
18
Q
Disorders of olfaction have been associated with
A
reduced food intake and enjoyment
- General reduction in quality of life can be seen in some patients
- This effect appears to lessen with prolonged duration of the disorder
19
Q
Somatosensation
(& the three systems)
A
Sensations from the body: Greek soma (the body) + sensation
Three systems involved:
- Exteroceptive (external stimuli)
- Proprioceptive (position of body)
- Interoceptive (condition within the body)
20
Q
Types of sensations:
A
- Mechanical stimuli (touch)
- Thermal stimuli (temperature)
- Nociceptive stimuli (pain)
21
Q
Types of cutaneous (___) receptors
A
(skin)
Merkel cells, Meissner’s corpuscles, Pacinian corpuscle, Ruffini corpuscle, Free nerve endings
22
Q
Merkel cells
A
(Merkel’s discs)
• Sustained touch, slow to adapt
23
Q
Meissner’s corpuscles
A
Light touch, fast to adapt
24
Q
Pacinian corpuscle
A
Sudden deep pressure, fast to adapt
25
Ruffini corpuscle
Stretching of skin, slow to adapt
26
Free nerve endings
* Thermoreceptors
* Nociceptors
27
Fast vs Slow Adapting receptors
28
Receptive Fields
Sizes of receptive fields vary depending on the type of receptor and location on body
* Larger receptive fields = detecting change over wider area, less precise
* Smaller receptive fields = detecting change over small area, very precise
29
Cell bodies of touch receptors
30
Reflex Circuits
Actions that are completed without neural control directly from the brain
* Sensory information carried to spinal cord **via afferent fiber**
* Usually (but not always) at least one **interneuron** within spinal cord connects sensory neuron to motor
* **Efferent fiber** (motor neuron) sends signal to muscle to respond
31
Dorsal-column medial-lemniscus system
Fine touch, vibration, two-point discrimination, proprioception
(Ascending somatosensory pathway)
32
Anterolateral system
Temperature, pain
| (Ascending somatosensory pathway)
33
Primary Somatosensory Cortex
S1
* Mapped based on part of body that receives tactile input (touch, temperature, pain, etc.)
* Representation of body parts proportional to density of touch receptors
* This mapping is also upside-down in cortex
34
Bimodal Neurons
Receive somatosensory and visual information
• After learning to use a tool, the corresponding visual receptive field expands to include the too
35
The rubber hand illusion
Processing of both visual and touch information during the RHI involves several brain regions implicated in visuotactile integration
36
Deffinition of Pain
“an unpleasant sensory and emotional experience associated with actual and potential tissue damage, or described in terms of tissue damage, or both”
37
Three Part process of pain
Sensory-discriminative (e.g. S1)
Affective-motivational (e.g. amygdala)
Cognitive-evaluative (e.g. insula)
38
Pain pathways are coded by __ and ascends by\_\_
Descending pathways can modulate\_\_\_ by the ___ which includes/is contributed by \_\_
free nerve endings, Ascends via anterolateral tracts
the ascending input, PAG
* Cognitive contributions to pain modulation
* Opioids (e.g. morphine) act on this descending pathway
39
Role of the Ossicles
to Amplification of sound pressure onto oval window
Ossicles act like levers to increase pressure onto smaller space (Oval window is much smaller than tympanic membrane)
40
The Ossicles
MIS (Mallleus, Incus, Stapies)
41
The cochlea chambers
scala vestibuli, scala media, scala tympani.
Scala vestibuli and scala tympani are continuous
42
Hair cells arranged into\_\_ inner hair cells and ___ outer hair cells
single row of inner hair cells and 3 rows of outer hair cells
43
hair cells total
18000-23000
44
hair cells synapse onto
spiral ganglion cells
• Cell bodies make up spiral ganglion • Axons form auditory nerve
45
Movement of basilar membrane due to __ results in \_\_\_
sound results in the bending of stereocilia
46
Changes in the membrane potential of the hair cell are the result of __ which results in \_\_
the opening of K+ channels located at the tip of the stereocilia
K+ influx into the cell from the surrounding endolymph results in depolarization, the opening of Ca2+ channels and the release of neurotransmitter onto spiral ganglion neurites
47
Most spiral ganglion cells receive input from
a single inner hair cell at a particular location on the basilar membrane
48
Spiral ganglion cells generate __ in response to \_\_
action potentials in response to the sound of a specific frequency: the **neuron’s characteristic frequency**
49
Location of Spiral Ganglion
50
Two main properties determine how the basilar membrane responds to sound
Width and stiffness
The basilar membrane is organized according to a place code for frequency – a **tonotopic map**
51
Place code
the location of the response along the basilar membrane codes the frequency of a tone
52
Temporal code
the frequency of action potentials matches the frequency of a tone
53
Volly
accomplished by groups of neurons
(Volley theory states that groups of neurons of the auditory system respond to a sound by firing action potentials slightly out of phase with one another so that when combined, a greater frequency of sound can be encoded and sent to the brain to be analyzed.)
54
Each ear projects to
both hemispheres
55
Coincidence detectors
Cells in brainstem respond to small timing differences
help determine location of sound
56
medial superior olive (MSO) is where
the first stage of comparison is made
57
Inferior colliculus in audition
Relays information up to the thalamus
Also aids in processing info of aversive stimuli (startle response)
58
Auditory cortex in audition
Medial geniculate nucleus projects to primary auditory cortex (A1) • Brodmann Area 41
* A1 cortical neurons are sharply frequency tuned
* Form **tonotopic map**
* Frequency-defined receptive field
59
Auditory Pathway
60
Core of Auditory Cortex
(A1, rostral, rostro-temporal regions):
simple sound features
• Input from MGN
61
Belt and parabelt of Auditory Cortex
increasing levels of complexity in sounds
62
Rostral to Caudal in auditory cortex
**What to Where**
* *Rostral** regions more responsive to **sound identity**
* *Caudal** regions responsive to **sound location**
63
Moving outward from A1 involves
more and more complex percepts
* Selectivity for voices
* Sensitivity to pitch
64
Retna cell Layers
65
M cells
motion detection
66
Rods
have pigment \_\_
sensitive to \_\_\_
detets \_\_
Located\_\_
rhodopsin
* Sensitive to small amounts of light
* Saturated when there is a lot of bright light
* Detects black and white
* Located in the periphery of retina
* Many rods connect to one ganglion cell
67
Cones
## Footnote
have pigment \_\_
sensitive to \_\_\_
detets \_\_
Located\_\_
photopsin
* Sensitive to large amounts of light
* Detects colour
• Three different kinds (Blue, green red)
Located in the fovea (center) of retina
Few cones connect to one ganglion cell
68
Blue cones
Short wavelengths
69
Green Cones
Medium wavelength
70
Red Cones
Long wavelength
71
Ganglion Cells
Innervate the \_\_\_
Types \_\_
* Innervate the lateral geniculate nucleus (LGN)
* Many different kinds of ganglion cells (ex. M and P cells)
72
M cells
Ganglion Cells
(Parasol):
• Coarse detection, motion, B&W, large
receptive fields
73
P cells
Ganglion Cells
(Midget):
• Details, colour, small receptive fields
74
Receptive Field is \_\_
• Area of visual space where a neuron maximally fires
75
Ganglion cells have ___ receptive fields which are good for \_\_\_
center-surround structure
* Well suited for detecting contrasts, like edges or borders
* On-center, off-surround vs. off-center, onsurround
76
Retna to brain pathway
• Contralateral organization of visual pathways
• Information from right visual field is directed to the primary visual cortex of the left hemisphere, and vice versa
(Not the right eye!)
77
Tectopulvinar pathway \_\_
senitive to \_\_
imput from \_\_
Orientation of \_\_\_
Retina -\> superior colliculus -\> pulvinar nuclei -\> visual cortex
* Sensitive to motion and novelty
* Receives input from M cells
* 10 % of optic fibers
* Orientation of peripheral stimuli
* Eye movement
78
Geniculostriate pathway
## Footnote
senitive to \_\_
imput from \_\_
Retina -\> Lateral Geniculate Nucleus -\> V1
• 90% of optic nerves
* Sensitive to colour and fine-grained detail
* Receives input from P and M cells
79
LGN
layers \_\_
The Lateral Geniculate Nucleus
has six layers: receives inputs from both eyes
(but from the same visual field)
* Ipsilateral eye projects to layers 2, 3, 5
* Contralateral eye projects to layers 1, 4, 6
80
Ipsilateral eye projects to layers
2 3 5
81
Contralateral eye projects to layers
1 4 6
82
Layers 1 and 2 of LGN
Magnocellular layers
* **Receive inputs from M ganglion cells** in retina
* Primarily input from **rods**
* **Large cells** (magno = big)
83
Layers 3-6 og LGN
Parvocellular layers
Receive **inputs from P ganglion** cells in retina
* Primarily input from **cones**
* **Small cells** (parvo = small)
84
Retinotopic Map
Spatial layout of information from the retina is preserved along the geniculostriate pathway
85
Two paths within LGN
Magnocellular Pathway and Parvocellular Pathway
86
Magnocellular Pathway
* Colour-insensitive
* Large receptive fields
* Fast, transient
* **More sensitive at low contrast/ low spatial frequency**
## Footnote
**MOTION**
87
Parvocellular Pathway
* Colour-sensitive
* Small receptive fields
* Slow, sustained
• **More sensitive at high contrast/ high spatial frequency**
**OBJECT RECONITION**
88
Primary Visual Cortex ( ) Computes \_\_
\_\_ stop
\_\_ intergration
(V1)
Computes **simple features** such as (Orientation • Ocular dominance • Spatial location • Colour • Spatial frequency)
* First stop in cortex
* Binocular integration
89
Representations in V1
Receptive Fields are \_\_
\_ detect location and orientation
\_detect orientation
\_ detect orientation and length
RFs are not just spots of light, but now bars in different orientations
• Simple cells detect location and orientation
• Complex cells detect orientation (no on/off
regions)
• Hyper-complex cells detect orientation and
length
90
Simple cells detect
Location and Orenration
91
Complex Cells organize
orientation (no on/off regions)
92
Hyper complex cells detect
orientation and length
93
Organization of V1
Hypercollums and Subcollums
94
Hypercolumns
groups of cells tuned to respond to stimulation at a certain spatial location
95
Subcolumns for
specific orientations and input from different eyes
96
higher up you go in (visual) processing \_\_
Neuronal preferences grow increasingly more complex
Receptive fields increase in size
97
Subcolumns (in V1)
for specific orientations and input from different eyes
98
Contextual modulation
Activity of a neuron in visual cortex for a certain stimulus can be modulated based on what surrounds the stimulus
99
Figure/ground segregation
a cell will respond more strongly to its preferred stimulus when it is part of the figure than the background
100
Blindsight is \_\_
due to\_\_
* Variant of cortical blindness • Due to extensive damage to V1
* Some patients show preservation of visual discernment • However, they are not aware they can ‘see’
101
V1 Nessaey For
conscious visual awareness
102
Ventral visual stream
**The WHAT path**
* Processing of complex objects
* Selective responses for certain objects
103
Must solve problems of Ventral stream
* Scale invariance
* Orientation
* Brightness (light/dark)
104
Must solve problems of Doral stream
• Spatial relations • Motion perception
105
Dorsal visual stream
WHERE
• Tracks objects as they move • Spatial perception and action
106
Testing invariance of recognition
Reconsize as same thing dsipire varing formats
* Form-cue invariance
* Adaptation: reduction of activity due to repetition
107
Adaptation
reduction of activity due to repetition
108
Role of LOC in invariance
(Lateral occipital cortex) -**reconizes shape of object but not depth**
seems to reconize invarance is a certine type of way
**identical - lower pattern of activity**
109
Damage to parietal lobe impairs
spatial tasks
110
Damage to temporal lobe impairs
object discrimination
111
Double dissociation
weather functions are independent
112
Lessioning studies and Landmark discrimination task & Object discrimination task
113
Damage to the ventral stream causes
Visual agnosia
114
Apperceptive agnosia
• Problem forming percepts
• Can perceive *parts but not meaningful whole*
• Cannot see integrated object (integrative visual
agnosia)
* Varying degrees of perceptual problems (depending on extent of lesion)
* **Deficit in copying forms** • Trouble integrating parts into a whole • Problems with perceptual constancy
115
Damage to the ventral stream
Associative agnosia
116
Associative agnosia
• **Can perceive meaningful whole but not link to knowledge**
* **Problem accessing semantic information**
* Can see integrated object but don’t know what it is
***Can copy complex objects but cannot identify them***
• Perceptual grouping intact
Can copy objects but *cannot recall from memory*
117
differences in activity for spatial task
inferior parietal
118
differences in activity for object change
lateral occipital areas
119
Apperceptive agnosia damage
Diffuse damage across occipital regions
120
Associative agnosia damage
Damage at border of occipital and temporal regions
121
Optic ataxia
lack of coordination between visual input and hand movements
(Damage to the dorsal stream)
* Recognition of objects but cannot use that info to guide actions
* Can see objects, but cannot reach for them
122
Paitent DF and card slot
lateral ocipital lesion
123
Extrastriate areas include
* Extrastriate body area (EBA)
* Parahippocampal place area (PPA)
* Visual word form area (VWFA)
* Lateral occipital cortex (LOC)
* Fusiform face area (FFA)
124
Prosopagnosia is \_\_
intact \_\_
result of \_\_
* Inability to perceive individual faces
* Can perceive other objects
* Intact semantic information
* Can process holistically aside from faces
* Can be result of damage to fusiform face area (FFA) • Either right or bilateral
125
Is the FFA only for faces?
No
FFA shows sensitivity to objects that one has expertise with
• Greebles!
• Parts of greebles have fixed spatial
relationships
