Neurobiology
Neural Networks in the Brain
Spreading-activation model: proposes that the activation of any one concept initiates a spread of activity to nearby concepts in the network, which primes those concepts so they become temporarily more retrievable than they were before.
- ex. Sky, ocean, blueberries, sapphires all linked to “blue”
Modern brain theories posit that memories for concepts are stored in overlapping neural circuits in the cerebral cortex. And thus priming occurs because the activation of the circuit for one concept activates the part of the circuit for another.
Retrieval of one memory causes activation to spread out to the nearby nodes representing related memories. In neurobiology we think of neurons as being arranged in networks. The more distant the connection between neurons, the longer it should take for one neuron to activate another, and the less likely it would be for that one neuron to activate the other.
In other words, information is not coded in a single molecule, synapse, or neuron. Information is coded in networks and patterns of neuronal activity.
Creativity can be thought of as networks that spread far wider, and making connections that neurons in another individual does not.
Long-Term Potentiation
Long-term potentiation (LTP) is a process involving persistent strengthening of synapses that leads to a long-lasting increase in signal transmission between neurons. It is an important process in the context of synaptic plasticity. LTP recording is widely recognized as a cellular model for the study of memory.
LTP is like a marriage bond, connections are stronger between the presynpatic and postsynaptic neurons.
Long Term Potentiation - the biomolecular process that your neurons go through as you learn
- how connections between neurons are strengthened through repeated pairing/firing
- neurons that fire together, wire together (using LTP)
Our brain cells communicate with one another via synaptic transmission - one brain cell releases a chemical (neurotransmitter) that the next brain cell absorbs. This communication process is known as “neuronal firing.” When brain cells communicate frequently, the connection between them strengthens. Messages that travel the same pathway in the brain over & over begin to transmit faster and faster. With enough repetition, they become automatic. That’s why we practice things like hitting a golf ball - with enough practice, we can go on automatic pilot.
A dendritic spine is a small membranous profusion from a neuron’s dendrite that typically receives input from a single axon at the synapse.
The more the spines are stimulated, the bigger, more stable, and longer lived they become (in contrast with smaller, immature spines, which are more transient). These large, so-called mushroom or stubby spines are thought to be one of the physical correlates of memory.
Repeated long-term potentiation causes spines to become larger and heartier.
Synapses are strengthened and maintained in stages: Changes in synaptic strength that support LTP evolve in stages that can be identified by the unique molecular processes that support each stage.
Lasting synaptic changes depend on a temporally ordered sequence of molecular events
- Generation, Stabilization, Consolidation, Maintenance
To create permanent memories through this system, emphasize occasional activation of neural pathways. Occasional activation signals a host of maintenance molecular processes.