Steady State Depression
Summarize the last supplied train responses relative to the first response; a sampled tail is not proof that a true steady state was reached, and facilitation yields negative depression.
Description
Response trains can depress or facilitate relative to their first response.
Response trains can depress or facilitate relative to their first response. A mean over a chosen tail provides a simple end-of-train ratio.
The tool returns tailMeanMagnitude (tail mean magnitude); steadyStateFirstRatio (steady state first ratio); fractionalDepression (fractional depression). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use Steady State Depression
Use Steady State Depression when you already have responseMagnitudes, tailResponses and want tailMeanMagnitude, steadyStateFirstRatio, fractionalDepression. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use Steady State Depression and understand its results
- Enter responseMagnitudes, tailResponses using the field table below. Match the units, ordering and data boundaries described in the calculation.
- Run the tool after checking the stated bounds and matching paired observations or categories. A malformed request gives a tool error rather than a usable measurement.
- Read tailMeanMagnitude, steadyStateFirstRatio, fractionalDepression. Use the calculation and interpretation below to distinguish amounts, ratios, signs and decision flags where applicable.
- Review the supplied parameters and assumptions before using the result in a report or comparing it with another observation.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| responseMagnitudes | Response magnitudes | list of number | Required |
| tailResponses | Tail responses | integer | Required |
Use nonnegative magnitudes with a positive first response. The positive integer tail length must exclude that first response.
ratio = mean(last k responses)/first; depression = 1−ratio The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"responseMagnitudes": [
10,
8,
6,
4,
4
],
"tailResponses": 2
},
"output": {
"tailMeanMagnitude": 4,
"steadyStateFirstRatio": 0.4,
"fractionalDepression": 0.6
}
}Limitations and assumptions
A ratio above one gives negative depression. The tool does not prove that the selected tail is a steady state or fit a mechanism.
Numerical inputs must be finite. The tool checks its declared input shape and calculation constraints; those checks do not verify the quality, calibration or representativeness of the supplied observations.
Alternative or Complementary methods
Paired Pulse Ratio: Distinguish mean paired-trial second/first ratios from ratio of mean response magnitudes; use consistently baseline-corrected nonnegative amplitudes. Recovery Time Constant Depression: Fit log(1−recovered fraction) against recovery interval to estimate exponential recovery tau; this model assumes an asymptotic recovery fraction of one.
Methodological background: Synapses and short-term synaptic dynamics.1
References
-
Synapses and short-term synaptic dynamics — Gerstner et al.; Neuronal Dynamics
Similar or alternative tools
- Paired Pulse Ratio
Distinguish mean paired-trial second/first ratios from ratio of mean response magnitudes; use consistently baseline-corrected nonnegative amplitudes.
- Recovery Time Constant Depression
Fit log(1−recovered fraction) against recovery interval to estimate exponential recovery tau; this model assumes an asymptotic recovery fraction of one.