3 ms·

Fire together, wire together refers to the connection between two neurons strengthening. Firing just before the recipient neuron fires strengthens the bond, an

by sdwr 5y ago

Fire together, wire together refers to the connection between two neurons strengthening. Firing just before the recipient neuron fires strengthens the bond, and firing afterwards/off tempo weakens the bond. It's an elegant concept, because it handles neural weights, a non-linear activation function, and clock speed with a simple, distributed rule.

HarHarVeryFunny 5y ago
Right, but first the "recipient" neuron needs to fire, which requires integrated synaptic inputs to cross some threshold, which requires input spikes to arrive close to the same time. This phase precession mechanism being discussed is what allows inputs arriving from different distances (i.e. with different signal travel times) to arrive close to the same time such that the recipient fires. Once it fires, then "fire together, wire together" can strengthen/weaken the synapses as appropriate.
- sdwr 5y ago
  After reading the article, I don't think that's what they're saying. My understanding is that place cells stand in for a literal location in space, and fire when they detect that location. The phase precession is how place cell A overlaps firing with place cell B when the individual is moving from location A to B, strengthening the connection (to create a mental link/memory between the two?)
  - HarHarVeryFunny 5y ago
    The article does discuss the place cell example (observed in rats), but basically as old news. What seems to be new (at least going by the Quanta article - I don't have access to Cell) is seeing phase precession in humans, and hints of it being a more universal mechanism also used for sequence learning, etc. In the place cell instance, it seems one effect of this mechanism might be for place cell firing to act as a predictive input for adjacent place cells (a pretty solid real-word prior - you can't be "here" unless you just came from somewhere adjacent!), and another might be to make prior-and-current place simultaneously available which could be used to learn direction of travel. If this is a general (or at least widespread) mechanism, not limited to place cell firing, then it opens up all sort of learning possibilities by bringing together (in time) inputs that would otherwise be asynchronous.

by sdwr 5y ago

HarHarVeryFunny 5y ago

Right, but first the "recipient" neuron needs to fire, which requires integrated synaptic inputs to cross some threshold, which requires input spikes to arrive close to the same time. This phase precession mechanism being discussed is what allows inputs arriving from different distances (i.e. with different signal travel times) to arrive close to the same time such that the recipient fires. Once it fires, then "fire together, wire together" can strengthen/weaken the synapses as appropriate.

sdwr 5y ago
After reading the article, I don't think that's what they're saying. My understanding is that place cells stand in for a literal location in space, and fire when they detect that location. The phase precession is how place cell A overlaps firing with place cell B when the individual is moving from location A to B, strengthening the connection (to create a mental link/memory between the two?)
- HarHarVeryFunny 5y ago
  The article does discuss the place cell example (observed in rats), but basically as old news. What seems to be new (at least going by the Quanta article - I don't have access to Cell) is seeing phase precession in humans, and hints of it being a more universal mechanism also used for sequence learning, etc. In the place cell instance, it seems one effect of this mechanism might be for place cell firing to act as a predictive input for adjacent place cells (a pretty solid real-word prior - you can't be "here" unless you just came from somewhere adjacent!), and another might be to make prior-and-current place simultaneously available which could be used to learn direction of travel. If this is a general (or at least widespread) mechanism, not limited to place cell firing, then it opens up all sort of learning possibilities by bringing together (in time) inputs that would otherwise be asynchronous.