Importing

using NeuroAnalyzer

The following data formats are supported:

File Type	Extension	Notes
EDF	.edf
EDF+	.edf
Alice EDF	.edf
BDF	.bdf
BDF+	.bdf
GDF	.gdf
DigiTrack	.txt
BrainVision	.vhdr
CSV	.csv	channels × time or time × channels data tables are recognized automatically
EEGLAB	.set	preliminary support
FieldTrip	.mat	EEG, MEG, NIRS, events - preliminary support
FIFF	.fif or .fiff	preliminary support
Neuroscan	.cnt	continuous signal
Neuralink	.ncs	Continuously Sampled Channels (CSC)
Neurodata Without Borders	.nwb
Extensible Data Format	.xdf
NIRS	.nirs
SNIRF	.snirf
NIRX	.nirx
DuoMAG MEP	.ascii or .m
Thymatron	.png

import_recording() is a wrapper function that selects proper importing function based on file extension:

eeg = import_recording("files/eeg.edf")
info(eeg)

              Data type: EEG
            File format: EDF
            Source file: files/eeg.edf
         File size [MB]: 14.13
       Memory size [MB]: 61.2
                Subject:  528004  SIT 52, 20220831-122227-{d589f756-53fc-4f1b-915d-6e3b8c1560ad}
              Recording: EEGDigiTrack EEG-1042 (42-channel EEG Amplifier) V0.5 Rev. 41
        Recording notes: 
         Recording date: 31.08.22
         Recording time: 12:32:53
     Sampling rate (Hz): 256
Signal length [samples]: 308480
Signal length [seconds]: 1205.0
     Number of channels: 24
              Epochs ID: 
       Number of epochs: 1
 Epoch length [samples]: 308480
 Epoch length [seconds]: 1205.0
         Reference type: physical
         Line frequency: 50 Hz
                Markers: no
      Channel locations: yes
 Number of EEG channels: 19

Channels:
 ch     label           type        unit    bad     
 ------ --------------- ----------- ------- -------
 1      Fp1             EEG         μV      false   
 2      Fp2             EEG         μV      false   
 3      F3              EEG         μV      false   
 4      F4              EEG         μV      false   
 5      C3              EEG         μV      false   
 6      C4              EEG         μV      false   
 7      P3              EEG         μV      false   
 8      P4              EEG         μV      false   
 9      O1              EEG         μV      false   
 10     O2              EEG         μV      false   
 11     F7              EEG         μV      false   
 12     F8              EEG         μV      false   
 13     T3              EEG         μV      false   
 14     T4              EEG         μV      false   
 15     T5              EEG         μV      false   
 16     T6              EEG         μV      false   
 17     A1              REF         μV      false   
 18     A2              REF         μV      false   
 19     Fz              EEG         μV      false   
 20     Cz              EEG         μV      false   
 21     Pz              EEG         μV      false   
 22     EOG1            EOG         μV      false   
 23     EOG2            EOG         μV      false   
 24     ECG             ECG         mV      false   

By default, channel types (EEG, ECG, EOG, etc.) are recognized automatically based on channel labels. This may not work for some recordings with incorrect channel names. In such cases channel type detection can be disabled using detect_type::Bool parameter:

eeg = import_recording("files/eeg.edf")
eeg.header.recording[:channel_type]

24-element Vector{String}:
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "ref"
 "ref"
 "eeg"
 "eeg"
 "eeg"
 "eog"
 "eog"
 "ecg"

eeg = import_recording("files/eeg.edf"; detect_type = false)
eeg.header.recording[:channel_type]

24-element Vector{String}:
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"
 "eeg"

Importing EDF/EDF+:

eeg = import_edf("files/eeg-test-edf.edf")
eeg = import_edf("files/eeg-test-edfplus.edf")

Importing Alice4 EDF:

eeg = import_alice4("files/eeg-test-alice4.edf")

Importing BDF/BDF+:

eeg = import_recording("files/eeg-test-bdf.bdf")
eeg = import_recording("files/eeg-test-bdfplus.bdf")

Importing GDF:

eeg = import_recording("files/eeg-test-gdf_1.25.gdf")
eeg = import_recording("files/eeg-test-gdf_2.20.gdf")

Importing DigiTrack:

eeg = import_digitrack("files/eeg-test-digitrack.txt")

Importing BrainVision (at least two files must be available: .vhdr/.ahdr and .eeg):

eeg = import_recording("files/eeg-test-bv.vhdr")
eeg = import_recording("files/eeg-test-bv.ahdr")

Tip: BrainVision .eeg and .vmrk (markers, optional) files will be loaded using file names provided in .vhdr/.ahdr. All three files must be located in the same folder.

Importing CSV:

# channels × samples
eeg = import_csv("files/eeg-test_chxt.csv.gz")
# samples × channels
eeg = import_csv("files/eeg-test_txch.csv.gz")

Tip: Data shape will be automatically detected.

Importing SET:

eeg = import_set("files/eeg-test-eeglab.set")

Exporting

NeuroAnalyzer NEURO objects may be exported to CSV files:

export_csv(eeg, file_name = "files/eeg.csv")

Tip: By default, only signals are exported.

To export header, markers and channel positions:

export_csv(eeg,
           file_name = "files/eeg.csv",
           header = true,
           markers = true,
           locs = true)

Saving

NeuroAnalyzer NEURO objects are saved as HDF5 file.

All object structure (data, header, markers and channel positions) are stored in one same file.

Saving the object:

save(eeg, file_name = "files/eeg.hdf")

To overwrite, set overwrite=true:

save(eeg, file_name = "files/eeg.hdf", overwrite = true)

Tip: Filename extension must be .hdf

Loading

Loading NeuroAnalyzer NEURO object from HDF5:

eeg = load("files/eeg.hdf")