xcp_d.utils.confounds.load_motion
- xcp_d.utils.confounds.load_motion(confounds_df, TR, motion_filter_type=None, band_stop_min=None, band_stop_max=None, motion_filter_order=4)[source]
Load the six basic motion regressors (three rotations, three translations).
- Parameters:
confounds_df (pandas.DataFrame) – The confounds DataFrame from which to extract the six basic motion regressors.
TR (
float
) – Repetition time of the BOLD run, in seconds.motion_filter_type ({None, “lp”, “notch”}) – Type of filter to use for removing respiratory artifact from motion regressors.
If None, no filter will be applied.
If the filter type is set to “notch”, frequencies between
band_stop_min
andband_stop_max
will be removed with a notch filter. In this case, bothband_stop_min
andband_stop_max
must be defined.If “lp”, frequencies above
band_stop_min
will be removed with a Butterworth filter. In this case, onlyband_stop_min
must be defined. If “lp” or “notch”, that filtering will be done in this function. Otherwise, no filtering will be applied.band_stop_min (
float
or None) – Lower frequency for the motion parameter filter, in breaths-per-minute (bpm). Motion filtering is only performed ifmotion_filter_type
is not None. If used with the “lp”motion_filter_type
, this parameter essentially corresponds to a low-pass filter (the maximum allowed frequency in the filtered data). This parameter is used in conjunction withmotion_filter_order
andband_stop_max
.Here is a list of recommended values, based on participant age:
Age Range (years)
Recommended Value
< 1
30
1 - 2
25
2 - 6
20
6 - 12
15
12 - 18
12
19 - 65
12
65 - 80
12
> 80
10
When
motion_filter_type
is set to “lp” (low-pass filter), another commonly-used value for this parameter is 6 BPM (equivalent to 0.1 Hertz), based on Gratton et al.[1].band_stop_max (
float
or None) – Upper frequency for the motion parameter filter, in breaths-per-minute (bpm). Motion filtering is only performed ifmotion_filter_type
is not None. This parameter is only used ifmotion-filter-type
is set to “notch”. This parameter is used in conjunction withmotion_filter_order
andband_stop_min
.Here is a list of recommended values, based on participant age:
Age Range (years)
Recommended Value
< 1
60
1 - 2
50
2 - 6
35
6 - 12
25
12 - 18
20
19 - 65
18
65 - 80
28
> 80
30
motion_filter_order (
int
) – Number of filter coefficients for the motion parameter filter. Motion filtering is only performed ifmotion_filter_type
is not None. This parameter is used in conjunction withband_stop_max
andband_stop_min
.
- Returns:
motion_confounds_df – The six motion regressors. The three rotations are listed first, then the three translations.
- Return type:
References