Cognitive Neuroscience Flashcards
Cognitive neuroscience
involves study of physiological basis of cognition
- nervous system + individual units
Nerve net
interconnections of neurons in a highway type of format making it a continuous network
Neuron doctrine
the idea that individual nerve cells with GAPS between them transmit the signals (aren’t continuous with other cells)
Neurons
cells specialized to create, receive, and transmit information in the nervous system through electrical and chemical means
Cell body
like the eyeball body of the neuron ykwim keeping the cell alive that main ball part
axon
the stringy thing protruding from the cell body filled with fluid that transmits electrical signals to other neurons
TRANSMITTING INFO
dendrites
multiple branches from the cell body RECEIVING INFORMATION from other neurons
RECEIVING INFO
Action potential
- no big or small - fires or it doesn’t!
- electrical impulse used for signalling purposes
Microelectrodes
placed near axon and pick up electrical signal
Low intensity action potentials
slow firing
High intensity
Rapid firing
synapse
space between axon of one neuron and dendrite of other neuron
Feature detectors
neurons taht only fire for a particular “favourite stimulus”
- tune themselves based on what’s in environment
Cats raised in tubes with ONLY vertical lines didn’t have feature detectors for horizontal lines -> nothing fires when they see horizontal lines
Eg: i know damn well i have feature detectors that fire when i see sanemi hes sooooo 😍 😍 😍 LIKE i have feature detectors for the curved lines of his chest and the lines of his scars, not his whole being, I have SPECIFICITY CODING FOR THAT!!!
Experience dependent plasticity
brain anticipates what stimuli it has to prepare for in the future
Feature detectors
neurons tuned to respond in specific low-level stimulus properties
- Okay i know i joke about having feature detectors for sanemi but low key he’s too complex for me too loll
- feature detectors -> respond to lines and shapes simple things
Hierarchical processing
the way your brain ascends from lower (simple) to higher levels of the brain when perceiving an object
- you perceive the most simple forms first, before making your way up to seeing/perceiving the whole picture
Mirror neurons
the neurons responsible for monkey see monkey do
- specialized for emulating what other people are experiencing, doing, feeling
- fire when you watch someone do an action AND when you do the action yourself wow -> evolutionary adaptation -> preheat the oven; pre-learn an activity
empathy is likely due to what type of neurons
mirror
Specificity coding
representation of a specific stimulus by firing of specifically tuned neurons specialized to respond to specific stimulus
- specific neurons for specific people!??!?!?
- okay I definitely have special neuron for sanemi
Specificity coding
representation of a specific stimulus by firing of specifically tuned neurons specialized to respond to specific stimulus
- okay I definitely have special neuron for sanemi
Population coding
Representation of a PARTICULAR object by the pattern of firing of large number of neurons
- same neurons fire for detecting a human face but at different rates depending on WHO it is
sparse coding
when a particular object is represented by a pattern of firing of only a SMALLER (sparse) group of neurons while the others mostly remain silent
Differences in coding/types of representation by neural firing:
feature detectors
specificity coding
population coding
Sparse coding
feature detectors - neurons for specific SIMPLE stimuli like lines
specificity coding - single specific neurons for specific stimulus (like specific neuron for specific person)
population coding - a large group of neurons fire in different patterns for different stimuli/objects (same neurons fire for detecting human but different pattern depending on who)
sparse coding - a small group of neurons fire in different patters for different stimuli/objects while the other neurons remain mostly silent
Localization of function
the idea that specific functions are served by particular areas of the brain
Eg: occipital lobe FOR visual input
Hierarchial processing elaboration: seeing jewels
see lines of jewels -> see shapes of jewels -> see jewels cute cat face -> recognize that this is my cat jewels
occipital lobe -> frontal lobe/top parts of the brain
-> get the visual information -> then identify what this visual information IS -> make sense of what this is
Cerebral cortex
casing of brain - 3 mm layer that covers brain - contains mechanisms responsible for most of our COGNITIVE FUNCTIONS
where is Broca’s area located (lobe) and what does it do
frontal lobe
forming and speaking words
where is Wernicke’s area (what lobe) and what is it responsible for
temporal lobe
comprehending language
Double dissociations
when damage to one part of the brain causes one function to be impaired while another function is maintained
And vice versa (the inverse) when that other part of the brain is damaged
- basically the idea that some parts of the brain are ONLY responsible for certain functions, and not others
- if one part of the brain is damaged, that part’s corresponding specific function won’t work, but other functions related to undamaged parts still work
- confusing for no reason istg
the presence of double associations prove _______
localization of function
Action potentials are measured by _________ during single-cell recordings
electrodes
area in the lower region of the temporal lobe containing neurons sensitive to/responsible for face detection
FFA - Fusiform Face Area
Single-cell recordings
measure activity (action potentials) of single neurons to identify which neuron matches with which cognitive process through inserting a micro-electrode right by the neuron
- super precise looking at a single neuron directly to hopefully detect what it’s responsible for detecting
Fusiform Face Area is responsible for detecting and sensitive to the stimuli of:
faces
MRI - Magnetic Resonance Imaging
Uses Magnetic fields and radio WAVES to get anatomical pics of body tissue (much larger areas than cell-recordings)
fMRI - functional Magnetic Resonance Imaging
MRI application that measures changes in the BOLD signal (Blood-Oxygen-Dependent-Signal) correlated with cognitive activity
how does detecting changes in the BOLD signal (blood-oxygen-level-dependent) help us get a map/“image” of cognitive activity?
When neurons become active they use more oxygen which they take from blood, hence the properties of the surrounding blood changes
(Active neurons refill on oxygen from blood -> seeing how the blood properties change gives us insight to how much cognitive activity is happening in a specific brain region)
what does BOLD stand for and what does this BOLD signal tell us
Blood Oxygen Level Dependent
- tells us the CHANGEs in average activity of specific voxels -> eg: more firing for this action in this area; less firing for this action in another area
voxels
3D pixel like representations of LEVELS of neuron activity on the brain -> eg: red part on fMRI shows the most activation in response to a stimuli while the yellow part around it shows slightly less activation
- can see brain activity on the structure of a brain at a larger scale
1 voxel on an fMRI would represent:
a CLUMP of neurons within a specific region in the brain
Parahippocampal Place Area (PPA) responds to ___________, and is located in between which cortexes?
places - indoor and outdoor places/locations
Eg: person with damage to this area can see grass, trees, and benches, but they fail to realize this is a park -> can’t comprehend the environment around them
Temporal + occipital
the Extrastriate Body Area (EBA) responds to ________, and is located in which lobe/cortex?
pictures of or parts of bodies
- helps identifying the stickman is indeed a representation of a person
occipital
Stimulus category in Distributed representation
- these parts of the brain light up in response to these stimuli, so these areas must be associated with these process
hashtags to group stimuli - which region of the brain was activated the most in respond to this type of stimuli
example of distributed representation
when listening to someone talk, multiple parts of the brain light up
- the stimuli of talking and listening can be processed in different/multiple ways depending on the situation
definition and personal example of DISTRIBUTED REPRESENTATION
the idea that complex behaviours involved coordinated activity across different parts of the brain -> multiple regions and network activated to do one behaviour
eg: playing piano:
- visual cortex for seeing piano, keys, and sight reading
- temporal lobe for hearing and really listening to the music
- amygdala for feeling emotions in response to the music
- motor cortex in the frontal lobe making your fingers move
location of function and distributed representation
the idea that specific parts of the brain are connected to specific functions, but at the same time, multiple specific parts of the brain can ALSO be connected to one function
- it can be ultra specific (location of function) one part for one function l
- or it can be a group effort (distributed representation): different parts working together to create one function
PET
Positron Emission Tomography - type of functional brain imaging
How do PET scans work?
injection of radioactive 2-DG (similar to glucose) that is taking out by ACTIVE cells
-> see what cells in which part of the brain are in need of the food during a specific function/in response to specific stimulus
-> give food to the cells to see what cells take it
TMS
Transcranial Magnetic Stimulation
How does TMS (Transcranial Magnetic Stimulation) work?
Uses magnetic field and electrical current to modulate brain activity at certain sites -> see what happens if you turn this part of the brain off -> damn person can’t do this function anymore -> therefore this part of brain must relate to this function
virtual lesion
used in Transcranial magnetic stimulation - temporarily deactivating/impairing a part of the brain to ETHICALLY see what function that part relates to
-> make causal inference
virtual lesion
used in Transcranial magnetic stimulation - temporarily deactivating/impairing a part of the brain to ETHICALLY see what function that part relates to
-> make causal inference
rTMS (repetitive TMS) is used to:
produce longer lasting changes in neuron activity - shut down parts for longer
Principles of Neural Networks
- complex structural pathways called networks is the brain info highway
- functional pathways WITHIN structural pathways
- operate dynamically - always moving
- resting state - all parts of brain still active when no cognitive activity -> this is why there is no logic in dream logic
Neural network principles simplified (4):
- Structural highway neural network
- Functional pathways within this serving diff functions
- Dynamic operation - network be moving
- Brain still active during resting states (hence dreams/daydreaming)
Default mode network (DMN) and what is it associated with
Network of brain regions that are active at rest - associated with mind-wandering
what is mind-wandering and what are some reasons for mind-wandering (2):
Withdrawing to an internal headspace/daydreaming/letting your thoughts take you wherever you’re just chilling - thinking about things NOT in the immediate environment
- Adaptive - mental rest
- Practicing retrieving memories
the amount of time someone spends mind-wandering or daydreaming can be dependent on how active their ________________ (3) is.
Default Mode Network
3 types of Connectivity
- Structural
- Functional
- Resting-state functional
structural connectivity
Physical connections within brain - how the wiring is connected
functional connectivity
the extent to which multiple areas are correlated for one function (kind of like distributed representation)
Seed location
the brain area associated with a specific task
- the first location you look at for accessing functional connectivity through an fMRI scan
measuring the resting-state fMRI at another location
test location
to know the degree of functional connectivity with an fMRI scan you have to:
calculate the CORRELATION between seed (og place) and test (other place) location responses - see how connected these two areas of the brain are
Functional Network
more than one area of the brain coming together with another area to make a function happen
Visual functional network responsible for vision.
Somato-motor functional network responsible for ________ and ________.
Dorsal Attention: ________________ (2).
somato-motor: movement and touch
dorsal: attention to visual and spatial
Executive control functional network is responsible for ___________ (3).
Executive control functional network: higher level cognitive tasks -> memory and attention
Salience
attending to SURVIVAL relevant events in the environment
- basically attention catching
- it’s attention catching for a reason
Salience
attending to SURVIVAL relevant events in the environment
- basically attention catching
- it’s attention catching for a reason
Default Mode Functional Network
Mind wandering, personal life story, social functions, internal emotional states
basically introspecting, reflecting, daydreaming, making connections for social reasons (be entertaining and interact or whatever)
DTI stands for
Diffusion Tensor Imaging
Diffusion Tensor Imaging uses
MRI tech to map out major structural pathways in the brain - (eg: bundles of axons)
DTI which is __________, is also know as TWI which is ___________.
Diffusion Tensor Imagining
Track Weighted Imaging
DTI which is __________, is also know as TWI which is ___________.
Diffusion Tensor Imagining
Track Weighted Imaging
Track Weighted Imaging or Diffusion Tensor Imaging is useful for:
Identifying and understanding differences in structural connectivity between different brain regions
- more axons in this area
- more clusters of whatever in this area
- why is this?
