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Frontal Alpha Asymmetry

Source: R/eeg-clinical.R
eegAsymmetry.Rd

Computes frontal alpha asymmetry indices from paired electrode sites. For each pair (right, left), band power is computed via FFT and the asymmetry index is calculated as log(power_right) - log(power_left). Positive values indicate greater right-hemisphere alpha (typically associated with greater left-hemisphere cortical activity).

Usage

eegAsymmetry(x, pairs = NULL, band = c(8, 13), assay_name = NULL)

Arguments

x

A PhysioExperiment object with EEG data.

pairs

A list of character vectors of length 2, each specifying a (right, left) electrode pair. Defaults to list(c("F4", "F3"), c("F8", "F7")).

band

Numeric vector of length 2 specifying the frequency band in Hz (default: c(8, 13) for alpha).

assay_name

Name of the input assay. If NULL, the default assay is used.

Value

A data.frame with columns:

pair

Character label for the electrode pair.

left_channel

Character name of the left electrode.

right_channel

Character name of the right electrode.

left_power

Numeric band power for the left electrode.

right_power

Numeric band power for the right electrode.

asymmetry_index

Numeric asymmetry: log(right) - log(left).

References

Nuwer, M. R., et al. (1999). IFCN standards for digital recording of clinical EEG. Electroencephalography and Clinical Neurophysiology, 106(3), 259-261.

See also

eegSpikeDetect(), eegQEEG(), eegSlowing()

Examples

if (FALSE) { # \dontrun{
pe <- make_eeg(n_time = 5000, n_channels = 19, sr = 500)
asym <- eegAsymmetry(pe)
print(asym)
} # }