Concept
Population coding
Information carried across many noisy units rather than any single reliable one — which turns a wiring problem into a measurement problem, and sets the specification for most neural instruments.
From the EE side
From the neuro side
If the signal lives in the joint activity of thousands of cells, no amount of care spent on one electrode substitutes for having many of them. Most of the instrument engineering on this site follows from that one fact: channel count, multiplexing, and the power budget that limits both.
Nearby concepts
All topics under Population coding
- Neuropixels probes 2017 A CMOS shank carrying nearly a thousand recording sites with the amplifiers and multiplexers on the probe itself, which made recording hundreds of neurons at once routine.
- Cochlear implants 1991 An electrode array in the cochlea driven by a filter bank, which restores speech understanding using a couple of dozen channels where the ear has thousands.
- Functional MRI 1990 Imaging brain activity indirectly through the magnetic signature of blood oxygenation, which gave whole-brain maps of task-related activity without surgery or tracers.
- Two-photon microscopy 1990 Using the near-simultaneous arrival of two photons to confine fluorescence to a single focal point, which made optical recording deep in living tissue possible.
- Receptive fields in visual cortex 1962 Cortical cells respond not to spots of light but to oriented edges at particular positions, and to progressively more abstract features further along the pathway.
- The artificial neuron 1943 Stripping the neuron to a weighted sum and a threshold, which gave engineering a computing element built from biology and is still the unit inside every network built since.
- Electroencephalography 1929 Microvolt potentials measured at the scalp, which established that the brain has continuous electrical rhythms and states rather than only responses to stimuli.