Ilenna Jones
@ilennaj
Cellular/Molecular-turned-Computational Neuroscientist What do neurons even do?? | Neural Computation with Dendrites Biophysical Optimization | AI <-> Neuro Postdoctoral Research Fellow at the Harvard Kempner Institute www.ilenna.com
Then, to do what pharmacology cannot, we shuffled learned synapse locations after training, keeping every weight and the nonlinearity intact. Excitatory shuffling drops performance to LDA. Inhibitory shuffling drops it to chance. 9/
As for how placement pays off, inhibition tracks excitation tightly for non-preferred classes, so shunting holds the branch subthreshold. For the preferred class the tracking is looser, excitation escapes, crosses threshold, and is amplified. 8/
Clusters emerge on their own, on distal branches, for excitatory and inhibitory synapses. Remove the NMDAR-like nonlinearity and excitatory clustering falls, matching the APV experiments, but inhibitory clustering rises. 7/
It solves the task and approaches QDA performance with depth. Collapse it to one compartment and performance falls to LDA. Removing any one biological component drops it toward chance. 6/
Dendrinet is a feedforward network of neurons with binary-branching dendritic trees, sparse conductance-based excitatory and inhibitory synapses, shunting inhibition, and an NMDAR-proxy nonlinearity. Nothing is clustered by hand. Synapses relocate during training. 5/
So no single channel is informative. LDA gets ~35%. QDA gets 100%. Any above-chance performance has to be second-order, which is exactly what neighboring synapses on a shared nonlinear branch are positioned to do. 4/
We needed a task where placement could matter. In Permuted Covariance Classification, 200 input channels follow a block correlation structure, and the four classes differ only in which channels co-vary. Means and variances are matched across classes. 3/
ME: Daily notes, reading journals, and dictated thoughts... these are all voice preserved and never touched by AI. That's the part that's actually mine. AI: Linking nodes, surfacing open questions, and updating project records are all the AI's job. The AI provides the glue.