Brain Flashcards
What is the anatomy of a neuron?
Synapse
Dendrites
Soma
Axon
What are the Neuron inputs?
Synapse and dendrites are inputs.
What are Neuron outputs?
Soma and Axon are transfer outs.
What is supervised learning?
Goal:: wire up synapses to achieve a desired output. We want the neuron only firing when it is supposed to- we want to fine tune it. Like the rat experiment.
What is unsupervised learning?
A system that is just trying to tune interesting detectors to something in the world. It doesn’t know if it’s something good or not.
What makes a neuron spike?
Other neurons that synapse to this neuron influence its voltage. (every cell naturally maintains a little bit of voltage to it) Other neurons can influence the voltage.
If voltage rises above a threshold, this causes a sudden spike.
Spikes travel down the axon and can influence other neurons. (neurons do a computation and then determine if there is a spike.
How does a neuron function?
The specialization that a neuron is that it has very large and long branches that come out of it which we call dendrites that carry information into the soma.
There’s a bunch of long branches which we call dendrites that carry information into the soma.
Coming out of the other end of the soma is the axon which is where information is transmitted out of the neuron
What is STDP- spike timing dependent plasticity
Thought to be one of the major ways neurons wire themselves up.
Does Not require the neurons to know anything about what is going on in the world or what they’re trying to do
It can happen in any synapse.
What are the motor cortex sensory inputs?
Unimodal regions are regions that respond to a single sensory input.
We also have somatosensory which have multi-purposes and can fill in for different things.- this is transmodal.
What happens when a presynaptic Spike comes just before a post synaptic Spike?
There’s an increase in syaptic weight.
What happens If the presynaptic spike comes just after a post synaptic Spike
Theres’s a decrease in the synaptic weight
What is important when a postsynaptic spike happens?
It means something interesting happens and we want to be sensitive to the early signal that this interesting thing happened
Discuss the regions of the Sensorimotor-Association Axis.
The yellow regions have a specific function and have been through evolution.
The purple regions are the association regions. (somewhat mysterious) there are various ways to make them light up. Used for learning association in the world.
What happens when you hook up neurons together?
An axon from another neuron can connect using a synapse to the dendrite of another neuron.
We can take info from neurons to be the inputs of another.
The dendrites are covered with synapses which are these little connections from axons from other neurons.
What happens when a neuron fires?
Other neurons that synapse to this neuron influence its voltage. (every cell naturally maintains a little bit of voltage to it) Other neurons can influence the voltage.
If voltage rises above a threshold, this causes a sudden spike.
Spikes travel down the axon and can influence other neurons. (neurons do a computation and then determine if there is a spike
