EEG Microstate Duration
Measure target-state contiguous EEG label run durations and sample coverage; recording-edge partial runs are included and absence gives empty durations with zero coverage.
Description
Microstate duration summarizes consecutive samples carrying a target label.
Microstate duration summarizes consecutive samples carrying a target label. Coverage describes the fraction of all labelled samples in that state.
The tool returns targetRunDurationsMs (target run durations ms); meanTargetDurationMs (mean target duration ms); targetCoverageFraction (target coverage fraction). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use EEG Microstate Duration
Use EEG Microstate Duration when you already have stateLabels, sampleRateHz, targetState and want targetRunDurationsMs, meanTargetDurationMs, targetCoverageFraction. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use EEG Microstate Duration and understand its results
- Enter stateLabels, sampleRateHz, targetState 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 targetRunDurationsMs, meanTargetDurationMs, targetCoverageFraction. 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 |
|---|---|---|---|
| stateLabels | State labels | list of number | Required |
| sampleRateHz | Sample rate hz | number | Required |
| targetState | Target state | integer | Required |
Include initial and terminal runs, convert run lengths to milliseconds and return their mean. No target runs gives an empty list, zero mean and zero coverage.
runMs = 1000×runSamples/sampleRate; coverage = targetSamples/totalSamples The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"stateLabels": [
1,
1,
2,
2,
2,
1
],
"sampleRateHz": 100,
"targetState": 1
},
"output": {
"targetRunDurationsMs": [
20,
10
],
"meanTargetDurationMs": 15,
"targetCoverageFraction": 0.5
}
}Limitations and assumptions
Boundary runs may be censored by the recording edges. Labels are supplied; no EEG clustering or smoothing occurs.
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
EEG Microstate Occurrence: Count observed transitions into a target EEG microstate per recording second, excluding the initial partial run; this differs from mean run duration and coverage. EEG Asymmetry Index: Compute epoch-paired ln(right power)−ln(left power) and its average; electrodes, band selection, referencing and artifact rejection are caller responsibilities.
Methodological background: EEG alpha map series: brain micro-states by space-oriented adaptive segmentation.1
References
-
EEG alpha map series: brain micro-states by space-oriented adaptive segmentation — Lehmann, Ozaki and Pal; Electroencephalography and Clinical Neurophysiology
Similar or alternative tools
- EEG Microstate Occurrence
Count observed transitions into a target EEG microstate per recording second, excluding the initial partial run; this differs from mean run duration and coverage.
- EEG Asymmetry Index
Compute epoch-paired ln(right power)−ln(left power) and its average; electrodes, band selection, referencing and artifact rejection are caller responsibilities.