Chapter 2: Cognitive Neuroscience Flashcards
Be able to understand the basics of neurons, and how they work to guide thinking and behavior
Why can a stim machine make your muscles twitch without getting your brain involved?
The brain acts as an electric current which makes your muscles move (this is a major simplification but you get it) but the stim machine acts as that electrical current instead
what is the neuron doctrine?
The idea that the brain does not have an moving parts that allow us to see it working, but it does have trillions of elections instead
the brain send information using specialized cells called neurons electrochemically.
when neurons send a signal electrically, it is going what type of distance?
longer distance
when neurons send a signal chemically it is going what type of distance?
shorter
neurotransmitters are what type of neural communication?
chemical
what are some examples of neurotransmitters?
-serotonin
-norepinephrine
-dopamine
-GABA
-acetylcholine
-glutamate
-endorphins
what are the basic 4 parts of neuroanatomy?
- dendrite
- soma
- axon
- axon terminal
make sure you can label ;)
hehe
what is the dendrite responsible for?
receiving chemical information (ie neurotransmitters)
what is the soma responsible for
processing information
what is the axon responsible for?
sending electrical signalst
the axon is protected by the…
myelin sheath
what is the axon terminal responsible for?
sending chemical information out
what are sensory receptors?
receptor cells (think the 5 senses) that send information from the body to the brain
“what does the brain need to know about the body?”
“oh shit we just stubbed our toe,, tell the brain!”
what are motor neurons?
behaviors that leave the brain and tell the body what to do
“Jump around in pain!!”
are also involved in your breathing, blinking, and sitting upright
what are interneurons?
they connect neurons to other neurons they communicate between sensory and motor neurons
“the body said we stubbed our toe, that means we should jump around in pain, hey sensory neurons, tell the body to jump around in pain”
neurons are organized into what two systems?
-central nervous system
-peripheral nervous system
what does the central nervous system made up of? What do those parts do?
-brain neurons: involved in high level processing (cognition)
-spine neurons: involved in low level processing (ie. patellar reflex)
what is the peripheral nervous system made up of, and what do those parts do?
-sensory neurons: afferent signals (signals coming in)
-motor neurons: efferent signals (signals going out)
the neuron send messages as an…
action potential
action potential
-requires substantial stimulation to happen
-is an electrical burst that travels down the axon (1/1000 second)
-once it reaches the terminal, chemicals are released for the next cell to pick up on
fun fact, coordinating the electrical quality of the cells was won what prize?
1932 nobel prize
How does a sensory neuron communicate if a stimulus is extra strong?
they fire over repeatedly
all AP’s are a ________ voltage of______
similar, +40 mv
what is the firing rate for
1. no contact
2. soft touch
3. hard poke
- 1 AP per 2 seconds (.5 Hz)
- 5 AP per second (5 Hz)
- 20 AP per second (20 Hz)
what is the basil firing rate?
the rate at which an action potential fires when there is no contact being had
1 AP per 2 seconds (.5 Hz)
what are the types of neuron group activation (aka brain waves)
-asynchronous firing
-synchronous firing
what is asynchronous firing?
-neurons fire whenever they need to
-random neural responses
what is synchronous firing?
-neurons fire together
-oscillatory neuronal responses
-classified by frequency of oscillation
when does synchronous firing occcur
SLEEP! It can also happen while awake but we think about it with sleep more often
what are the types of synchronous firing brain waves?
gamma waves: when the mind is problem solving
beta: when the mind is active but not really processing anything crazy
alpha: peaceful relaxation
theta: drowsy (I AM A THETA)
Delta: full sleep
what is transcranial magnetic stimulation?
when a pulsing magnet is placed outside of the skull and used to stimulate or disrupt cortical action potential
surprisingly non-invasive
what is faradays law and how does it relate to transcranial magnetic stimulation?
the magnetism interacts with electrical activity which is why it can disrupt action potentials
in 2018 a man played his guitar while undergoing brain surgery, how was this possible? Why would a doctor want to do this?
- the brain does not have pain receptors
- doctors do it so that they can test out motor function while operating so they wont be surprised by any slip up after the surgery
Explain Purdon 2013 and it’s relevance?
Studied how chemicals disrupt the brain.
Patients were tasked with pushing a button while undergoing propofol, a general anesthetic to measure their consciousness
kind of a basic way of measuring how the brain is impacted
Other than pressing a button, what is another way to measure how anesthesia impacts the brain?
EEG tracking
What does EEG tracking during anesthesia tell us about the brain?
-delta and alpha waves increase during anesthesia
-dela waves overwhelm all other waves
what is neural specialization?
-each neuron fires for it’s own specific reasons
ex.) you have a neuron that fires only when you see your grandmother
what is sparse coding?
the idea that you have small groups of two to three cells that are tasked with doing very specific functions
tied to the concept of neural specialization
roughly how many neurons are needed for vision?
2-10
what determines the job of a specific neuron?
- experience
- location
what is experience dependent neurofunctioning?
changes in the brain’s structure and function that occur in response to individual experiences and environmental interactions.
the purpose of neurons is developed and decided based on individualized experience
Explain Blackmore, 1970
-studied feature detection cell development
-researchers raised kittens in a tube with horizontal stripes. When the kittens were taken out of the tube, they were shown horizontal stripes again, and their neurons in the visual cortex DID fire. However when shown vertical lines, the kittens showed bad visual placement indicating they were not processing the lines
they did however recover after several hours
this just shows how the function of neurons is dependent on what they have experienced.
what is localization?
where the function of a neuron is dependent on it’s location in the brain
what is cortical equipotentiality?
believed in the 1800’s, the idea that the brain has no “specialized regions” and that any part of the brain can do any thing
what ruined the idea of cortical equipotentiality?
Patient Tan
Who was patient Tan?
A man who had suffered brain damage to his Brocas area who could only speak the word “Tan”
he exposed the idea that different parts in the brain were responsible for different functions like the brocas area
what is the modern and classic way that we discover what part of the brain does what?
- Brain Damage (classic)
- Brain imaging (modern)
what is double dissociation?
a method used to determine if similar functions are localized independently
commonly done with case studies
ex.
-patient 1 can do A but not B
- patient B can do B but not A
-therefore A and B must be controlled separately
name each of the main parts of the brain and their responsibilities:
frontal- decision making, high level processing
parietal- senses and attention
temporal- auditory processing
occipital- visual processing
cerebellum- fine and advanced motor skills
what is the inferior temporal cortex? (fusiform gyrus) How can we use it to illustrate double dissociation?
We know it is involved in handling visual recognition tasks, but we “don’t know” if it is used in both facial AND object recognition
so we can use the Boston naming task and general questioning to figure out if someone can do one and not the other or if they can’t do both
what are the fancy words for not being able to recognize objects and faces?
facial recognition- prosopagnosia
object recognition- visual agnosia
what are some more examples of recognition specialization?
- parahippocampal place area: responsible for differentiating images of outdoors and indoors
- what is the extrastriate body area (EBA): responds to images of bodies and body parts
what is an example of functional brain imaging?
fMri -magnetic resonance images
how does the fmri work?
- oxygen molecule responds to magnetism (paramagnetic)
- more active parts of the brain use more oxygen for approx. 3 to 8 seconds
- Oxygen concentration is measured and mapped as voxels (3D pixels) using magnets
what is distributed cognitive processing
the idea that not everything is explicitly specialized, but rather they are parts of a larger cognitive networks which work together to perform actions
example:
the hippocampus is the memory center of the brain but it is not the only piece you need other parts for memory processing
sometimes we overemphasize…
specialization
what is a neural network?
connections between regions by axons (direct physical connections)
think about the picture of the really long axon that spanned like all of the brain
what are the two types of neural pathways?
functional and structural pathways
what are structural pathways?
pathways that connect the Left and Right hemispheres of the brain through the corpus collosum
what are functional pathways?
pathways that connect different areas of the brain
ie.
a neuron that connects the motor to the sensory area
what is the connectome?
a project that attempted to create a roadmap of all neural pathways within the human mind
however it is totally theoretical brain wiring diagram created using MRI track weighted imaging and functional connectivity
how do we map the structure of the brain?
MRI track weighted imaging (TW)
what is MRI track weighted imaging
tracks the movement of water molecules with oxygen across the axons, and tracks how axons physically link different parts of the brain
how do we map function of the brain?
fmri functional connectivity (FC)
what is fmri functional connectivity?
uses temporal (timing) dependencies between two different brain regions,,
if region A and B are both active and inactive at similar times, they may have functional connectivity
what is the functional connectivity method (different from the fmri way)
uses a seed location and a test location to associate function in different parts of the brain
the seed location is a location with a known function and the test location is a location with possible correlation
then the relationship is measured over time to determine their functional connectivity
what are the 6 common networks with high functional connectivity?
- visual network
-vision and visual perception
-primary visual cortex
area of the brain: back occipital lobe - somato-motor network
-movement and touch
-somatosensory cortex
area of the brain: the side kind of parietal area - dorsal attention network
-direct attention to visual stimulus and spatial locations
area of the brain: kinda all over mostly in the parietal but some in the frontal and some in the occipital - executive control network
-working memory and higher level cognition
area of the brain: mostly frontal, but some in the parietal and some in the occipital
