Concept
Noise
The floor set by physics beneath every measurement and every signal — the thing instrument designers fight, and that nervous systems seem in places to exploit.
From the EE side
From the neuro side
Thermal noise is the same in an op-amp and in a pipette seal, which is why electrophysiology is fundamentally an instrumentation problem. What is stranger is how often biology looks less like it is suppressing noise than putting it to work.
Nearby concepts
All topics under Noise
- 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.
- 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.
- The patch clamp 1976 A glass pipette sealed against a membrane made the current through single ion channels measurable, turning channels from inference into instrument readings.
- Microelectrode arrays 1972 Photolithographed electrode grids traded single-channel resolution for many cells at once, which is what turned single-unit recording into population dynamics.
- Efficient coding 1961 The proposal that sensory systems are built to remove redundancy from their input, which turns "why is the retina wired this way" into an information-theory question.
- The voltage clamp 1949 A feedback amplifier that holds membrane potential at a commanded value and reports the current needed to do it, which is what turned excitability into a measurable quantity.
- 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.