moabb.datasets.Nakanishi2015#

class moabb.datasets.Nakanishi2015(subjects=None, sessions=None)[source]#

Bases: BaseDataset

[source]

Dataset Snapshot

Nakanishi2015

A comparison study of canonical correlation analysis based methods for detecting steady-state visual evoked potentials. This study performed a comparison of existing CCA-based SSVEP detection methods using a 12-class SSVEP dataset recorded from 10 subjects in a simulated online BCI experiment.

SSVEP, 12 classes

AuthorsMasaki Nakanishi, Yijun Wang, Yu-Te Wang, Tzyy-Ping Jung

πŸ‡ΊπŸ‡Έβ€‚University of California San Diego, USΒ·2015Β·wangyj@semi.ac.cn
SSVEP Code: Nakanishi2015 9 subjects 1 session 8 ch 256 Hz 12 classes 4.0 s trials Unknown

Class Labels: 9.25, 11.25, 13.25, 9.75, 11.75, 13.75, 10.25, 12.25, ...

Overview

SSVEP Nakanishi 2015 dataset.

This dataset contains 12-class joint frequency-phase modulated steady-state visual evoked potentials (SSVEPs) acquired from 10 subjects used to estimate an online performance of brain-computer interface (BCI) in the reference study

Benchmark Context

WithinSession

Included in 1 MOABB benchmark table(s). Scores are across available pipelines (WithinSession accuracy).

Sample frame: 9 subjects Γ— 1 sessions

  • SSVEP all classes 6 pipelinesMax 87.22 Β· Median 80.99 Β· Mean 58.46 Β· Std 39.49

Citation & Impact

Stimulus Protocol
../_images/Nakanishi2015.svg

4s task window per trial Β· 12-class ssvep paradigm Β· 1 runs/session across 1 sessions

HED Event Tags
HED tags12/12 events annotated

Source: MOABB BIDS HED annotation mapping.

Experimental-stimulus
12
Label
12
Sensory-event
12
Visual-presentation
12
9.25
Sensory-eventExperimental-stimulusVisual-presentationLabel
11.25
Sensory-eventExperimental-stimulusVisual-presentationLabel
13.25
Sensory-eventExperimental-stimulusVisual-presentationLabel
9.75
Sensory-eventExperimental-stimulusVisual-presentationLabel
11.75
Sensory-eventExperimental-stimulusVisual-presentationLabel
13.75
Sensory-eventExperimental-stimulusVisual-presentationLabel
10.25
Sensory-eventExperimental-stimulusVisual-presentationLabel
12.25
Sensory-eventExperimental-stimulusVisual-presentationLabel
14.25
Sensory-eventExperimental-stimulusVisual-presentationLabel
10.75
Sensory-eventExperimental-stimulusVisual-presentationLabel
12.75
Sensory-eventExperimental-stimulusVisual-presentationLabel
14.75
Sensory-eventExperimental-stimulusVisual-presentationLabel

HED tree view

Tree Β· 9.25
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 11.25
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 13.25
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 9.75
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 11.75
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 13.75
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 10.25
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 12.25
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 14.25
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 10.75
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 12.75
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Tree Β· 14.75
β”œβ”€ Sensory-event
β”œβ”€ Experimental-stimulus
β”œβ”€ Visual-presentation
└─ Label
Channel Summary
Total channels8
EEG8 (EEG)
Montagestandard_1020
Sampling256 Hz
ReferenceCMS/DRL
Notch / line60 Hz

This diagram is automatically generated from MOABB metadata. Please consult the original publication to confirm the experimental protocol details.

SSVEP Nakanishi 2015 dataset.

This dataset contains 12-class joint frequency-phase modulated steady-state visual evoked potentials (SSVEPs) acquired from 10 subjects used to estimate an online performance of brain-computer interface (BCI) in the reference study [1].

References

[1]

Masaki Nakanishi, Yijun Wang, Yu-Te Wang and Tzyy-Ping Jung, β€œA Comparison Study of Canonical Correlation Analysis Based Methods for Detecting Steady-State Visual Evoked Potentials,” PLoS One, vol.10, no.10, e140703, 2015. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0140703

from moabb.datasets import Nakanishi2015
dataset = Nakanishi2015()
data = dataset.get_data(subjects=[1])
print(data[1])

Dataset summary

#Subj

9

#Chan

8

#Classes

12

#Trials / class

15

Trials length

4.15 s

Freq

256 Hz

#Sessions

1

Participants

  • Population: healthy

  • Age: 28 years

  • BCI experience: not specified

Equipment

  • Amplifier: Biosemi ActiveTwo

  • Electrodes: EEG

  • Montage: standard_1020

  • Reference: CMS/DRL

Preprocessing

  • Bandpass filter: 6-80 Hz

  • Steps: downsampling, bandpass filtering

  • Notes: Zero-phase forward and reverse IIR filtering was implemented using the filtfilt() function in MATLAB. Data epochs were extracted with a 135-ms latency delay considering the visual system delay.

Data Access

Experimental Protocol

  • Paradigm: ssvep

  • Feedback: none

  • Stimulus: flickering

__init__(subjects=None, sessions=None)[source]#

Initialize function for the BaseDataset.

property all_subjects#

Full list of subjects available in this dataset (unfiltered).

convert_to_bids(path=None, subjects=None, overwrite=False, format='EDF', verbose=None, generate_figures=False)[source]#

Convert the dataset to BIDS format.

Saves the raw EEG data in a BIDS-compliant directory structure. Unlike the caching mechanism (see CacheConfig), the files produced here do not contain a processing-pipeline hash (desc-<hash>) in their names, making the output a clean, shareable BIDS dataset.

Parameters:
  • path (str | Path | None) – Directory under which the BIDS dataset will be written. If None the default MNE data directory is used (same default as the rest of MOABB).

  • subjects (list of int | None) – Subject numbers to convert. If None, all subjects in subject_list are converted.

  • overwrite (bool) – If True, existing BIDS files for a subject are removed before saving. Default is False.

  • format (str) – The file format for the raw EEG data. Supported values are "EDF" (default), "BrainVision", and "EEGLAB".

  • verbose (str | None) – Verbosity level forwarded to MNE/MNE-BIDS.

  • generate_figures (bool) – If True, generate interactive neural signature HTML figures in {bids_root}/derivatives/neural_signatures/. Requires plotly (pip install moabb[interactive]). Default is False.

Returns:

bids_root – Path to the root of the written BIDS dataset.

Return type:

pathlib.Path

Examples

>>> from moabb.datasets import AlexMI
>>> dataset = AlexMI()
>>> bids_root = dataset.convert_to_bids(path='/tmp/bids', subjects=[1])

See also

CacheConfig

Cache configuration for get_data().

moabb.datasets.bids_interface.get_bids_root

Return the BIDS root path.

Notes

Added in version 1.5.

data_path(subject, path=None, force_update=False, update_path=None, verbose=None)[source]#

Get path to local copy of a subject data.

Parameters:
  • subject (int) – Number of subject to use

  • path (None | str) – Location of where to look for the data storing location. If None, the environment variable or config parameter MNE_DATASETS_(dataset)_PATH is used. If it doesn’t exist, the β€œ~/mne_data” directory is used. If the dataset is not found under the given path, the data will be automatically downloaded to the specified folder.

  • force_update (bool) – Force update of the dataset even if a local copy exists.

  • update_path (bool | None Deprecated) – If True, set the MNE_DATASETS_(dataset)_PATH in mne-python config to the given path. If None, the user is prompted.

  • verbose (bool, str, int, or None) – If not None, override default verbose level (see mne.verbose()).

Returns:

path – Local path to the given data file. This path is contained inside a list of length one, for compatibility.

Return type:

list of str

download(subject_list=None, path=None, force_update=False, update_path=None, accept=False, verbose=None)[source]#

Download all data from the dataset.

This function is only useful to download all the dataset at once.

Parameters:
  • subject_list (list of int | None) – List of subjects id to download, if None all subjects are downloaded.

  • path (None | str) – Location of where to look for the data storing location. If None, the environment variable or config parameter MNE_DATASETS_(dataset)_PATH is used. If it doesn’t exist, the β€œ~/mne_data” directory is used. If the dataset is not found under the given path, the data will be automatically downloaded to the specified folder.

  • force_update (bool) – Force update of the dataset even if a local copy exists.

  • update_path (bool | None) – If True, set the MNE_DATASETS_(dataset)_PATH in mne-python config to the given path. If None, the user is prompted.

  • accept (bool) – Accept licence term to download the data, if any. Default: False

  • verbose (bool, str, int, or None) – If not None, override default verbose level (see mne.verbose()).

get_additional_metadata(subject: str, session: str, run: str) None | DataFrame[source]#

Load additional metadata for a specific subject, session, and run.

This method is intended to be overridden by subclasses to provide additional metadata specific to the dataset. The metadata is typically loaded from an events.tsv file or similar data source.

Parameters:
  • subject (str) – The identifier for the subject.

  • session (str) – The identifier for the session.

  • run (str) – The identifier for the run.

Returns:

A DataFrame containing the additional metadata if available, otherwise None.

Return type:

None | pd.DataFrame

get_block_repetition(paradigm, subjects, block_list, repetition_list)[source]#

Select data for all provided subjects, blocks and repetitions.

subject -> session -> run -> block -> repetition

See also

BaseDataset.get_data

Parameters:
  • subjects (List of int) – List of subject number

  • block_list (List of int) – List of block number

  • repetition_list (List of int) – List of repetition number inside a block

Returns:

data – dict containing the raw data

Return type:

Dict

get_data(subjects=None, cache_config=None, process_pipeline=None)[source]#

Return the data corresponding to a list of subjects.

The returned data is a dictionary with the following structure:

data = {'subject_id' :
            {'session_id':
                {'run_id': run}
            }
        }

subjects are on top, then we have sessions, then runs. A sessions is a recording done in a single day, without removing the EEG cap. A session is constitued of at least one run. A run is a single contiguous recording. Some dataset break session in multiple runs.

Processing steps can optionally be applied to the data using the *_pipeline arguments. These pipelines are applied in the following order: raw_pipeline -> epochs_pipeline -> array_pipeline. If a *_pipeline argument is None, the step will be skipped. Therefore, the array_pipeline may either receive a mne.io.Raw or a mne.Epochs object as input depending on whether epochs_pipeline is None or not.

Parameters:
  • subjects (List of int) – List of subject number

  • cache_config (dict | CacheConfig) – Configuration for caching of datasets. See CacheConfig for details.

  • process_pipeline (Pipeline | None) – Optional processing pipeline to apply to the data. To generate an adequate pipeline, we recommend using moabb.utils.make_process_pipelines(). This pipeline will receive mne.io.BaseRaw objects. The steps names of this pipeline should be elements of StepType. According to their name, the steps should either return a mne.io.BaseRaw, a mne.Epochs, or a numpy.ndarray(). This pipeline must be β€œfixed” because it will not be trained, i.e. no call to fit will be made.

Returns:

data – dict containing the raw data

Return type:

Dict

property metadata: DatasetMetadata | None[source]#

Return structured metadata for this dataset.

Returns the DatasetMetadata object from the centralized catalog, or None if metadata is not available for this dataset.

Returns:

The metadata object containing acquisition parameters, participant demographics, experiment details, and documentation. Returns None if no metadata is registered for this dataset.

Return type:

DatasetMetadata | None

Examples

>>> from moabb.datasets import BNCI2014_001
>>> dataset = BNCI2014_001()
>>> dataset.metadata.participants.n_subjects
9
>>> dataset.metadata.acquisition.sampling_rate
250.0