Baseline Correct ERP Data

Subtracts the mean amplitude of a pre-stimulus baseline period from each epoch. This is an essential preprocessing step before ERP measurement.

Usage

eegERPbaseline(
  x,
  baseline = c(-200, 0),
  epoch_start = 0,
  assay_name = NULL,
  output_assay = "baseline_corrected"
)

Arguments

x

A PhysioExperiment object with epoched (3D) EEG data.

baseline

Baseline period in milliseconds as c(start, end). For example, c(-200, 0) for 200ms pre-stimulus baseline. Default is c(-200, 0).

epoch_start

Start time of the epoch in milliseconds relative to stimulus onset. Default is 0 (epoch starts at stimulus).

assay_name

Input assay name (default: first assay).

output_assay

Output assay name (default: "baseline_corrected").

Value

Modified PhysioExperiment with baseline-corrected data in output_assay. Creates a new 3D assay (time x channels x epochs) where each epoch has had the mean of its baseline period subtracted.

References

Luck, S. J. (2014). An Introduction to the Event-Related Potential Technique (2nd ed.). MIT Press.

See also

eegERPdetect(), eegERPmeasure(), eegEpoch(), eegFilter()

Examples

if (FALSE) { # \dontrun{
pe <- make_eeg_erp(n_epochs = 40, sr = 250)
result <- eegERPbaseline(pe, baseline = c(-200, 0), epoch_start = -200)
} # }