Mind V. Brain Flashcards
Dualism
Philosophy of mind
The idea that there is no physical basis for consciousness
Mind and body are two different things
Descartes
Philosopher– dualism
Physicalism
Everything has a foundation in the physical world
Francis Crick– cofounder of DNA double helix; first thought tRNA as adaptor molecule (1950s, 69s, 70s)
Wrote “Astonishing Hypothesis”: observation– biochemical reactions in brain
What does the brain do?
- Receives signals
- Processes information
- Sends signals
Brain v computer
Electrons move faster through copper than human tissue
However, brain is 1 billion times better: each cell can make its own decisions ( a computer cannot process that much info at once because on, ya certain number if chords can make their own decisions
How?
1. Modular–many compounds that all come together (if one part breaks you can replace that one part)
2. Connected– all parts are interconnected
Plasticity: form/shape new connections, lose old ones
Individuality: impossible to map the brain out because it is a little different
Human brain
You use all of your brain
People are either left brained or right brained
100 billion neurons
There are 1,000-10,000 synapses for a “typical” neuron (so 1,000,000(1,00010,000))= number or synapses
Neurons multiply at a rate of 250,000 neurons/minute during pregnancy
Done growing when you are 18 but can still make new connections
Brain uses 20% of your body’s energy (glucose=only source of energy hat brain uses)
Cerebrospinal fluid
Functions:
- buoyancy
- protection (absorbs shock)
- chemical stability (can hold onto some oxygen/glucose)
- pressure regulation (should have 150 mL usually, if brain swells can decrease fluid)
Right and left hemispheres of the brain
Control opposite side of body
Look similar but have very different neurons/neurochemistry, even between individuals
Connected at corpus callosum– tight bundle of nerve fibers that send signals between left and right
Corpus callosum
tight bundle of nerve fibers that send signals between left and right
Ventricles
Empty space in your head where fluid goes
Efficient exchange of info
Alzheimer’s– more ventricles, less neuronal tissue
Hindbrain and brain stem
Basic vital functions: breathing, heartbeat; relays signals
Cerebellum
Motor control Doesn't initiate movement but does regular,tell coordination, precision, and timing Motor learning (muscle memory) Usually where neurodegenerative diseases end, lose functions, and die
Midbrain
Control vision, hearing, sleep/wake cycle, temperature regulation, reward/addiction, and movement
Substantia Nigra– Parkinson’s
Main dooaminergic losing neurons
Dopamine v serotonin
Dopamine pathways functions:
- reward (motivation)
- pleasure, euphoria
- motor function (fine tuning)
- compulsion
Serotonin pathways functions:
- mood
- memory processing
- sleep
- cognition
Forebrain
Thalamus: relay signals between cerebrum and midbrain (sensory and motor); levels if consciousness (sleeping or unconsciousness)
Hypothalamus: master regulator of hormones in body
Thalamus
Forebrain
relay signals between cerebrum and midbrain (sensory and motor)
Levels of consciousness (sleeping or unconsciousness)
Hypothalamus
Forebrain
Master regulator of hormones opinion body
Frontal lobe
Tons of conscious thinking About 90% of dopamine in cerebrum is here Morality Thinking about words Long term memory
Parietal lobe
Takes in sensory info and gives us a higher sense of where we are (directions, spacially aware)
Occipital lobe
Dedicated to vision
Damage -> hallucinations
Temporal lobe
Important for long term visual memory and for language comprehension
PET scan
Position emission tomography
Requires tracer molecules (dyes)
Radioactive elements
-carbon (glucose) or oxygen-- can pass through blood brain barrier
Difficult to do
Maps brain activityFunctioning magnetic resonance imaging
Uses radio waves to analyze blood flow (increased blood flow=more active)
No tracer molecules
Map blood flow in the brain during different activities
Patients can do different things
Memory
Process in which info is encoded, stored, and retrieved
Short-term memory
7 thoughts that are held for 15-30 seconds
As time goes by, 1 by 1 the neurotransmitters are depleted and go away
Working memory
Temporarily storing and processing info
Long term memory
Data stored for long periods of time (hours to a lifetime)
3 types of long term memory
- Implicit
- Explicit
- Emotional memory
Implicit long term memory
procedural memory that refers to the use of objects
Brain: amygdala and cerebellum
Riding a bike; driving a car
Explicit long term memory
All memories that are consciously available (no idea where in the brain those memories are formed)
Episodic:recalling specific events in time with supporting info
Sematic: factual info that is context-independent
Mice-Morris water maze
Emotional memory
Can be implicit or explicit
Conscious thoughts recalling specific events that elicit strong emotions
Converting short to long term memory
- Synaptic consolidation: new connections become resistant (not immune) to interference
- Maintenance: new connections need many retrievals–space repetition with intervals of time in between learning and review sessions
- Sleep: when brain converts working to long term; reinforces connections of that day
Short to long term memory @ molecular level
Aplysias– sea slug with rudimentary nervous system
System learned that he didn’t like being shocked through training
Means there must be something on basic (molecular/cellular) level causing this
Long term potentiation
Long lasting enhanced signal transmission between two neurons
Improves ability of pre-synaptic neurons to communicate with post-synaptic neurons
Continued release of neurotransmitters
Closest candidate for the molecular basis of cognition and memory
1. More receptor proteins on dendrites–makes signal stronger
2. Presynaptic cell releases more neurotransmitters–makes signal stronger; can keep adding like this
Long term memory
Send signal to nucleus
New protein synthesis brings it back to synapse
