Stimulus onset quenches neural variability: a widespread cortical phenomenon.
Level 5 - mechanism / opinion, no new human data
Animal electrophysiology study (Level 5 by CEBM rules).
PubMed 20173745 · doi:10.1038/nn.2501
What was done
The authors analyzed neural variability across 13 extracellular recording datasets and one intracellular recording dataset across seven cortical areas spanning all four cortical lobes in monkeys and cats. Measurements included intracellular membrane potentials, single-unit spiking, and correlated population spiking captured with 96-electrode arrays under awake, behaving, and anesthetized states.
What was found
The abstract reports no exact numerical values or effect sizes. Qualitatively, stimulus onset caused a decline in trial-to-trial neural variability across all 14 datasets and all stimuli tested. This decline occurred regardless of whether the stimulus altered the mean firing rate, and was observed across membrane potentials, individual neuron spiking, and correlated population activity in awake, behaving, and anesthetized animals.
Why it matters
This study demonstrates that stimulus-induced quenching of response variability is a widespread, generalized feature of cortical processing rather than an area-specific or state-dependent artifact.
Limits
The abstract does not report quantitative effect sizes, variance ratios, or the total number of animals and recorded neurons. The data are derived entirely from non-human animal models (cats and monkeys).
Cited by
- supports When an animal or person performs a perceptual or behavioral task, initial neural recordings show high background noise, which transitions to a significantly higher signal-to-noise ratio as the task is repeated.