PSY 223 Intro Cog Exam 1

Question 1

Which scientific or medical fields were involved in the emergence of cognitive neuroscience?

Answer 1

Neuroscience: study of the structure and function of the nervous system

Neurology: causes and effects of diseases of the nervous system

Psychology: study of the mind and its implications for behavior

Question 2

Cognitive neuroscience: the neuroscience of cognitive processes

What does it Involve

Answer 2

Behavior: what someone does - external in this course, typically observable and measurable

Mind: element of a person that enables them to be aware of the world and their experiences, to think, and to feel - internal
Linking cognition to the brain

Cognitive Psychology: study of the cognitive processes of the mind and its implications for behavior

Question 3

What is the term for the primary cell in the brain?

Answer 3

Neuron

Question 4

Cognition:

Answer 4

the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses

Perceiving motion (basic), remembering a fact, having a conversation(more complex)

Question 5

Localization of function:

Answer 5

each function is localized to a brain region / each brain region has a specific function

Different brain regions are important for different functions

Question 6

Mass action:

Answer 6

each function can’t necessarily be localized to a specific brain region / each brain region isn’t specialized for a particular function

Question 7

Equipotentiality:

Answer 7

extreme form of mass action - all brain regions perform the same functions - not accurate

Question 8

How is each involved in neuronal communication? synapse, myelin sheath, node of Ranvier, dendrite, soma, axon, neurotransmitter, and Axon hillock

Answer 8

Synapse: site of communication between neurons - neurons close enough to pass chemical signal

Myelin Sheath: insulates the AP around axon so it doesn’t die out and speeds it up

Node of Ranvier: Action potentials are regenerated

Dendrite: receiving processes, i.e. receives input from other neurons

Soma: cell body

Axon: transmitting process, i.e. transmits a signal to other neurons

Neurotransmitter: a signal a neuron sends
Released from synaptic vesicles by presynaptic neuron (axon)
Bind to receptors on postsynaptic neuron (dendrite)
Can be excitatory or inhibitory

Axon hillock: origin of the action potential

Question 9

What does resting membrane potential refer to?

Answer 9

When the cell is at rest the inside is more negatively charged than the outside - resting membrane potential -70mv

The electrical potential difference across the plasma membrane when the cell is in a non-excited state.

​​At resting potential concentration of ions is kept constant through Na+/K+ pumps. When the threshold is reached, the Na+ gated channels are opened.
Sodium Potassium Pump: 3 sodium out and 2 potassium in

Question 10

What are the 4 steps of the action potential? For each step: What is it called? Is the membrane potential rising or falling? Is Na+ moving into the neuron, out of the neuron, or neither? Is K+ moving into the neuron, out of the neuron, or neither?

Answer 10

Depolarization Rising Phase - Na goes in making it positive

Overshoot - highest of AP favoring Na

Repolarization Falling Phase - K flows into cell making it negative back to RMP

Hyperpolarization undershoot - K keeps going in super negative below RMP

Restoration - back to RMP K close

Question 11

What is the “all-or-none” property of the action potential?

Answer 11

An AP either happens completely, or it does not happen at all

Question 12

Gyrus and Sulcus

Answer 12

Gyrus: raised surface (mountain) of the cerebrum

Sulcus: dips or folds (valley) between such structures

Folding of the cerebral cortex creates gyri and sulci which separate brain regions and increase the brain’s surface area and cognitive ability

Cerebrum largest part of the brain that starts and manages conscious thoughts; meaning, things that you actively think about or do. Cerebellum is a small part of your brain located at the bottom of this organ near the back of your head.

Question 13

Comparing methods

Spatial resolution:

Temporal resolution:

Answer 13

Spatial resolution: how resolved in space is the method, i.e. how specific is the spatial location of this method? - across neurons (for example, neuron vs. broad region of brain)

Temporal resolution: how resolved in time is the method, i.e. how specific is the timing of this method? - across time (for example, milliseconds vs. minutes)

Question 14

Changes in electrical activity in a neuron Integration across signals:
Two main types of postsynaptic potentials

EPSP:
IPSP:

Answer 14

1) EPSP: excitatory postsynaptic potential increase in membrane potential
- Could lead to an action potential if enough EPSPs summate across time from one neuron (temporal summation) or across space from multiple neurons (spatial summation)
- Leads to depolarization of neurons – excites post-syn. Neuron

2) IPSP: inhibitory postsynaptic potential decrease in membrane potential
- Leads to hyperpolarization of neurons – inhibits post-syn. Neuron

Question 15

Summation:

Temporal summation:

Spatial summation:

Answer 15

Temporal summation:
Rapid repeat EPSPs same location (EPSP lasts a while)
add and sum to produce AP

Spatial summation:
Simultaneous EPSPs in diff. parts of neuron
add and sum to produce AP

Simultaneous EPSP and IPSP in diff. parts of neuron
add and reduce chance of AP

Question 16

Single-cell recordings

temporal resolution and spatial resolution - good or bad

Analyze activity

Advantages/Disadvantages

Answer 16

Measures brain activity directly based on the electrical properties of communicating neurons so the potential mv (changes in electrical potential)

Have good temporal resolution and spatial resolution

The electrical potential difference between the inside and outside is the total membrane potential (mv)

Analyze activity
- changes in membrane potential
- number and rate of action potentials

Advantages: Most direct and precise way to record neural activity

Disadvantages: Inconvenience for participants - surgery is invasive

Question 17

EEG Electroencephalography

temporal resolution and spatial resolution - good or bad

Answer 17

Recording electrical activity across cells

Based on electrical signal from postsynaptic activity, recorded at the scalp

Measure brain activity directly based on the electrical properties of communicating neurons

Have poor spatial resolution but good temporal resolution

Question 18

MEG Magnetoencephalography

temporal resolution and spatial resolution - good or bad

Answer 18

Recording magnetic fields across cells

Based on magnetic signal generated from the electrical postsynaptic activity, recorded at the scalp

Measure brain activity indirectly based on the influence of electricity on magnetic fields

Have poor spatial resolution but good temporal resolution

Question 19

Intracranial EEG / Electrocorticography (ECoG)

temporal resolution and spatial resolution - good or bad

Answer 19

How does the electrical potential change over time, summed across neurons?

Recording electrical activity across cells

Good temporal resolution and spatial resolution (though not as good as single-cell recordings)

Question 20

Analyze Activity In EEG and MEG and ECoG

Answer 20

Event-related potential (ERP): average activity across events

Power: oscillations in EEG/MEG activity signal is a combination of oscillations at different frequencies, and power is defined by the strength of those frequencies
- always positive; related to amplitude (height of signal, sometimes taken from the center or mean)
- Greater electrical potential may reflect more synchronized neurons (spatial summation of excitatory postsynaptic potentials, EPSPs)

Oscillations: the rhythmic and/or repetitive electrical activity generated in the brain

Amplitude—distance between the resting position and the maximum displacement of the wave. Frequency—number of waves passing by a specific point per second.

Question 21

Positron Emission Tomography (PET)

temporal resolution and spatial resolution - good or bad

Answer 21

Tracks blood flowing to more active brain regions using a radioactive tracer

Take “images” based on molecules tied to blood flow, because more active brain regions require more blood

Studies “Where” and “What” pathways/streams

Good spatial resolution
Poor temporal resolution

Question 22

Functional magnetic resonance imaging (fMRI):

temporal resolution and spatial resolution - good or bad

Answer 22

Detect changes in oxygenated blood flow, which is correlated with changes in neural activity; based on tracking blood flowing to more active brain regions by taking advantage of blood’s magnetic properties. Active brain regions need blood with oxygen (oxygenated blood), oxygenated blood and deoxygenated blood have different magnetic properties.

Take “images” based on molecules tied to blood flow, because more active brain regions require more blood

Good spatial resolution
Poor temporal resolution

Question 23

Subtraction logic: PET and fMRI

Answer 23

How to determine which brain regions are involved in Cognitive Task A?

Look at activity for Task A because most of the brain needs blood most of the time

Task B: as similar as possible to Task A, except for the cognitive process of interest of Task A

Identify regions that are more during Task A than task B

Question 24

Permanent Lesions

Lesion:

Human causes of lesions:

Animal causes of lesions:

temporal resolution and spatial resolution - good or bad

Answer 24

Lesion: “a region in an organ or tissue which has suffered damage through injury or disease” → Lesions can identify if a brain region is necessary for a function: if someone is missing brain region A, and they can’t perform function B => brain region A is necessary for function B Lesion studies

Human causes of lesions: neurosurgery: brain region(s) removed to prevent some other problem (such as epilepsy) OR stroke, neurodegenerative disorders, head injuries, viral infection, tumors

Animal causes of lesions: destroy brain region(s), then have the animal perform a cognitive task

Good spatial resolution
Poor temporal resolution

Question 25

Reversible animal lesions

temporal resolution and spatial resolution - good or bad

In humans

Answer 25

Animals: more invasive and more common

pharmacological inactivation - block synaptic transmission

cryogenic depression (cooling)

optogenetic imaging - control neuronal function

Good spatial resolution
Good temporal resolution

In humans TMS

Question 26

Transcranial Magnetic Stimulation (TMS):

temporal resolution and spatial resolution - good or bad

double dissociation vs single dissociation

Answer 26

Creates reversible lesions in humans by creating a magnetic field that influences electrical properties of the brain - not an indirect measure of brain activity because it temporarily damages brain tissue (i.e., creates a lesion)

Creates a magnetic field in a specific area of the brain - magnetic field influences electrical activity, i.e. inhibits of the activity, in a specific area of the brain

Can assess cognitive function while the brain area is temporarily lesioned

Generally good spatial resolution: can have as good spatial resolution as fMRI → where in the brain that stimulation is being applied and what activity was like with and without the lesion

Generally good temporal resolution: can have as good temporal resolution as EEG

Can assess lesions to multiple brain regions in the same participant (double dissociation)

Single dissociation: affecting only one area of function

Question 27

Transduction:

Answer 27

“translation” of external, environmental stimuli into changes in neuronal signaling

Question 28

Sensation:

Answer 28

“neural processes that correspond most closely to the concept of detection”

Question 29

Perception:

Answer 29

internal experience of the external world

Question 30

Bottom-up
Top-down

Answer 30

Input signal → Transduction → Bottom-up processing: Integration across inputs → Top-down processing: Using pre-existing knowledge and context

Question 31

In what type of cell does transduction occur for vision?

Answer 31

Photoreceptors: where transduction takes place for vision translate light into neuronal signal

Rods: receptors for low light (night time) - Low acuity (spatial resolution)

Cones: receptors for high light intensity and different wavelengths (color) Cones and color - High acuity (spatial resolution)

Photoreceptor doesn’t just respond to light anywhere it depends on the location so on or off like photoreceptors respond to light in a particular part of space
A photoreceptor does not respond to light regardless of where the light is located with respect to the visual field

Question 32

Receptive field:

Intuition:

Answer 32

Receptive field: Sensory stimulus that induces maximal changes in a neuron’s membrane potential

Intuition: Bipolar cell needs input from several photoreceptors across space in the brain (spatial summation)

Question 33

On center/off center cell:

Answer 33

Off-center In center no light and On-center light in middle

ON-center bipolar cells are depolarized by small spot stimuli positioned in the receptive field center. OFF-center bipolar cells are hyperpolarized by the same stimuli. Both types are repolarized by light stimulation of the peripheral receptive field outside the center

Question 34

Simple cell

Complex cell

Answer 34

Simple Cell: Detects points of light in a single orientation in a certain part of the visual field relies on spatial summation from several LGN neurons with on-center receptive fields in slightly different visual locations

Complex cell: detect long bar of light in a single orientation in a certain part of the visual field
- relies on spatial summation from several simple cells, so responsive to light in a larger area than simple cells

Question 35

What is the visual field? Why is there a blindspot in the visual field?

Answer 35

Fovea / central retina: more densely populated with cones

Rods are more towards the periphery

Blind spot: at the optic disk, where the optic nerve fibers leave the eye - no photoreceptors

Visual field: “total area in which objects can be seen in the side (peripheral) vision as you focus your eyes on a central point”

Question 36

Retina: Order back of eye to front

Answer 36

Pigmented epithelium (back of eye)
Photoreceptors - rods and cones
Bipolar cells
Ganglion cells (light)
Light goes back of eye to photoreceptors

Question 37

How is information represented from eyes on the left and right side of the body to the left and right side of the brain?

Answer 37

Retinogeniculate Visual Pathway: conveys visuals info from retina to LGN(thalamus) → optic chiasm: where some nerve fibers cross from the left and right eyes => each side of the brain has visual information from the contralateral (opposite) visual hemifield

Question 38

Where is sensory information first processed in the cortex?

Answer 38

Once leave retina → optic nerve, optic chiasm, LGN, V1 or Primary visual cortex

Primary somatosensory cortex or V1 or primary visual cortex

Question 39

Retinotopy:

Answer 39

spatial relationships preserved from retina - mapping of visual input from the retina to neurons

Question 40

Cortical magnification:

Answer 40

Visual information presented near the center of the visual field is represented by larger areas of cortex, i.e. the majority of neurons in V1 have receptive fields from the center of the visual field (fovea). Thus, this central information is “magnified” → The number of neurons in the visual cortex responsible for processing the visual stimulus of a given size varies as a function of the location of the stimulus in the visual field.

Question 41

Define object recognition:

Answer 41

Matching representations of organized sensory input to stored representations in memory

Involves bottom-up processes (e.g. integrating lower level features) and top-down processes (e.g. knowledge, expectations, context)

Question 42

“Where” and “What” pathways/streams → The information leaving the visual cortex divides into 2 main streams of visual information

Answer 42

Dorsal: “where” (where in space are these features located?) determining the location of an object

Ventral: “what” (what do these features comprise?) determining the identity of an object

Inferior temporal cortex (IT) and the “what” pathway
- Matching representations of organized sensory input to stored representations in memory
- Involves bottom-up processes (e.g. integrating lower level features) and top-down processes (e.g. knowledge, expectations, context)

Question 43

What/Ventral: Main challenges of visual object recognition

Where does it end?

Feature Matching – object constancy

Feature Matching – object composition

Aperture Problem

Relative color

Answer 43

1) Where does it end? Object representations may assemble from “primitives”
- Hierarchical processing in visual system

2) Feature Matching – object constancy: Object is viewed as constant, despite changes in visual input
- M in different sizes is still an M

3) Feature Matching – object composition: Many objects are composed of the same collection of features
- R and P (vertical line and left facing curve)

4) Aperture Problem: integrate information from early visual brain regions into a coherent picture across larger regions of visual field

5) Relative color: what color are you seeing with solution V4

Question 44

What/Ventral: Understand how human visual object recognition can overcome the above problems, with:
1) distributed coding:

Where does it end?

Answer 44

Distributed coding: An object is “coded” not with APs from one neuron, but is distributed across several active neurons.

Population coding: Representation of a stimulus by the pattern of firing of a large number of neurons

Sparse coding: Representation of a stimulus by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent

Question 45

What/Ventral: Understand how human visual object recognition can overcome the above problems, with:
2) grouping the features together in principled ways: visual system groups features together in principled ways

feature matching

Answer 45

Similarity/Proximity: link alike items together
1) similarity: visual elements that are similar (e.g. same color) are likely to be grouped together
2) proximity: visual elements that are close together are likely to be part of the same object

Continuity/Closure: link items with missing pieces
3) continuity: edges are grouped together to avoid interruptions
4) closure: missing parts of an object are “filled in”

Question 46

What/Ventral: Understand how human visual object recognition can overcome the above problems, with:
3) expectations/pre-existing knowledge:

Aperture

Answer 46

Top-down processing

Question 47

Dorsal/Where: What information is represented in neurons in region MT?

Answer 47

Motion processing in region MT thanks to spatial summation

Neurons firing AP in response to light

Question 48

Localization of information in different coordinate systems: where/dorsal things are based to oneself and environment:
Egocentric localization

Answer 48

Egocentric localization: representation of space in a body or self-centered coordinate system; representation of space centered around one’s own location

Hemispatial Neglect: reduced awareness of stimuli on one side of space, even though there may be no sensory loss (what they are paying attention to so like only half of side - not a not seeing thing)

• neglect information on one half (hemi) of one’s space
• commonly on the opposite (contralateral) side to the parietal lobe lesion
• only ate food on the right side of her plate
• when looking at her left hand, she thought it was the doctor’s hand
• spoke about weakness on the right side of her body, even though this weakness was much more pronounced on the left side of her body

Question 49

Localization of information in different coordinate systems: where/dorsal things are based to oneself and environment:

Allocentric localization:

Answer 49

Representation of space in an environment-centered coordinate system; representation of space with respect to the environment

Place cells in the hippocampus: In a given environment, a place cell fires action potentials in a specific but objective place, i.e. independent of how the animal approaches it

Across cells, much of a given environment can be represented

Question 50

For each of audition, somatosensation (and vision):

Where does transduction of sensory information occur?

Answer 50

Audition: Sound = changes in (oscillatory) air pressure - Transduced occurs in the cochlea (inner ear) - goes from air to fluid. Transduction occurs in the cochlea via the inner hair cells on the basilar membrane swaying back and forth - hair cells moving at oscillation rate so by pitch

Somatosensation: sensory receptors in the peripheral nervous system

Vision: Photoreceptors

Question 51

For each of audition, somatosensation (and vision):

What are the receptive fields for each of the transducing sensory receptors?

Answer 51

Audition: Hair cells in cochlea

Somatosensation: Receptive field: Sensory stimulus that induces maximal changes in a neuron’s membrane potential correspond to different parts of the body - size and sensitivity vary by, body part, receptor type
Merkel and Meissner and Pacinian

Vision: Retina rods and cones

Question 52

For each of audition, somatosensation (and vision):

Where is sensory information first processed in the cortex?

Answer 52

Audition: primary auditory cortex (A1)

Somatosensation: primary somatosensory cortex (S1) = postcentral gyrus

Vision: primary visual cortex (V1)

Question 53

For each of audition, somatosensation (and vision):

What is the organization of information across neurons (both the term and what it means)?

Answer 53

Audition: Volley principle (100-4000 Hz): a group of neurons (“volley”) encodes the frequency, because no one neuron can fire action potentials quickly enough on its own

Somatosensation: Somatotopy: Different parts of S1 correspond to somatosensation in different body parts

Vision: Right eyes to LEFT LGN: visual info from the right half of the visual field of each eye is transmitted to the left side of the brain. Basically, optic nerve fibers from the RIGHT eye carry info from the right visual field to the left LGN→ LEFT BRAIN. Left Eye to RIGHT LGN: opposite of above

Question 54

For each of audition, somatosensation (and vision):

How is information integrated from both sides of the body to both sides of the brain?

Answer 54

Audition: superior olive (combine ears) - Sound localization in the horizontal plane

Somatosensation: crosses sides at medulla

Vision: opposite side of brain at the optic chiasm

Question 55

How do we sense/perceive each of the following:
Oscillatory changes in air pressure

Answer 55

Frequency (oscillations per second): perceived as pitch

Question 56

How do we sense/perceive each of the following:
different frequencies of oscillatory changes in air pressure

Answer 56

High Pitch = High frequency
Base of cochlea

Low Pitch = Low frequency
Apex of cochlea

Question 57

How do we sense/perceive each of the following:
different amplitudes of oscillatory changes in air pressure

Answer 57

height of signal
Intensity/amplitude: perceived as loudness

Question 58

What are the 3 properties of inner hair cells that allow for transduction of different sound frequencies?

Answer 58

Low frequencies (below 100 Hz): A neuron fires an action potential at a particular phase for a certain frequency (e.g. peak), so its timing is in sync with the wave

Volley principle (100-4000 Hz): a group of neurons (“volley”) encodes the frequency, because no one neuron can fire action potentials quickly enough on its own

Tonotopy (100-20000 Hz): sound causes maximum vibration for hair cells at one location on the basilar membrane in the cochlea, which varies in width and height

Question 59

What are 3 different types of somatosensory receptors?

Answer 59

1.mechanoreceptors: receptive to mechanical forces, such as pressure, texture, vibration, stretch
2.thermoreceptors: receptive to heat and cold
3.nociceptors: receptive to sensory processes signaling (risk of) tissue damage, which can trigger pain response

Question 60

What are 4 ways the receptive fields of somatosensory mechanoreceptors can vary?

Answer 60

1.location of the body part it covers
2.size of the body part it covers
3.the type of stimulus it is sensitive to
4.for frequency-sensitive mechanoreceptors, the optimal frequency of vibration

Question 61

Define adaptation (with respect to receptor responses)

Answer 61

important to account for adaptation: “decreased response to a stimulus as a result of recent exposure to it”

Question 62

Sound localization - combining info across ears is helpful with this

Answer 62

Horizontal: Relies on the differential timing of information from the left and right ears
Vertical: Relies on reflections from the pinna

Question 63

Top-down auditory processing

Answer 63

More nerves go to the cochlea from the brainstem than from the cochlea to the brainstem

Question 64

Superior olive:

Pinna:

Answer 64

Superior olive: Sound localization in the horizontal plane
Pinna: Sound localization in the vertical plane

Question 65

Audition

Sound

Answer 65

Audition – act, sense or power of hearing sound

Sound- series of pressure waves in air (or other medium)

Question 66

Summary: Transduction in the ear

Different frequencies of bbbbbbbbbbb (pitch) and bbbbbbbbb (amplitude) are encoded based on the properties of the inner hair cells

Answer 66

Sound corresponds to changes in air pressure

Sound is transduced via vibrations in the inner hair cells on the basilar membrane of the cochlea

Different frequencies of sound (pitch) and loudness (amplitude) are encoded based on the properties of the inner hair cells

Question 67

Define somatotopy (as it relates to motor movements, not somatosensation)

Answer 67

Different parts of M1 correspond to planning and control of movements in different body parts
Like S1, each side of brain corresponds to the contralateral side of the body
Like S1, not consistent with anatomical order or size
However, not the same mapping as S1

Question 68

Beyond somatotopy, what else informs when a neuron will fire the most action potentials in M1?

Answer 68

Neurons in M1 are active prior to a movement, during motor preparation

Individual neurons in M1 fire the most action potentials during planning of movement of a particular body part AND movement of that body part in a specific direction

Number of AP varies with movement - across neurons diff rate at which they fire AP but each neuron has a different body part with a specific body part

Vector has direction and and magnitude
Translate neuronal activity into a vector:
direction = direction with greatest response rate
magnitude = response rate

Population coding

Question 69

What 2 types of stimuli cause a mirror neuron to fire the most action potentials?

Answer 69

Exist in motor cortex regions outside of M1, including premotor cortex

Fire the most action potentials in response to
1) a specific action or set of actions performed by the self or
2) the same (set of) action(s) as in 1, but performed by another

Some seem to fire more action potentials in response to specific actions performed by another; some respond to a wider range of actions

These actions usually consist of a series of individual movements

Hypothesized roles beyond motor movement remain controversial

Question 70

contribute to motor movements: Cerebellum

Answer 70

Cerebellum: Motor coordination

motor sequences requiring precise aim and timing

fine-tuning of movements

Question 71

contribute to motor movements: Basal ganglia

Answer 71

Basal ganglia: Regulating motor activity, such as starting and stopping action

Question 72

contribute to motor movements: Supplementary motor cortex

Answer 72

most active just before a rapid series of movements
e.g. push, turn, then pull a mechanical key, playing piano or guitar

Question 73

contribute to motor movements: Premotor cortex

Answer 73

primarily active during preparations for a movement (e.g. grab a cup)
somewhat active during the actual movement

Question 74

Summary: Movements in primary motor cortex (M1)

Answer 74

Neurons in a region of M1 will fire the most action potentials when planning the movement of a specific body part

An individual neuron within a region of M1 will fire the most action potentials when planning the movement of a specific body part in a specific direction - each neuron diff direction of movement

Recording from multiple neurons at once, it is possible to predict the planned motor movement of a body part

Question 75

Ascending BLANK information and descending BLANK information are severed

Answer 75

somatosensory

Motor