'Baseline correct the data.
Parameters
baseline : tuple or list of length 2
The time interval to apply rescaling / baseline correction.
If None do not apply it. If baseline is (a, b)
the interval is between "a (s)" and "b (s)".
If a is None the beginning of the data is used
and if b is None then b is set to the end of the interval.
If baseline is equal to (None, None) all the time
interval is used.
mode : None | \'ratio\' | \'zscore\' | \'mean\' | \'percent\' | \'logratio\' | \'zlogratio\'
Do baseline correction with ratio (power is divided by mean
power during baseline) or zscore (power is divided by standard
deviation of power during baseline after subtracting the mean,
power = [power - mean(power_baseline)] / std(power_baseline)),
mean simply subtracts the mean power, percent is the same as
applying ratio then mean, logratio is the same as mean but then
rendered in log-scale, zlogratio is the same as zscore but data
is rendered in log-scale first.
If None no baseline correction is applied.
verbose : bool, str, int, or None
If not None, override default verbose level (see :func:`mne.verbose`).
Returns
inst : instance of AverageTFR
The modified instance.'

@verbose
def apply_baseline(self, baseline, mode='mean', verbose=None):

    self.data = rescale(self.data, self.times, baseline, mode, copy=False)
    return self
