README.md

metadata

license: pddl
tags:
  - eeg
  - medical
  - clinical
  - classification
  - ocd
  - flanker

Gruendler2009: EEG Obsessive-Compulsive Disorder Estimation Dataset with Flanker Task

The dataset Gruendler2009 originates from an EEG experiment that examined the relationship between obsessive–compulsive (OC) symptomatology and error-related brain activity. Participants were 46 undergraduate students selected based on their scores on the Obsessive–Compulsive Inventory-Revised (OCI-R), with groups categorized as high or low OC (a score of 21 being the boundary).

The experiment consisted of a flanker task to elicit ERNs from motor errors in a response conflict paradigm. Specifically, participants were shown a 5-letter string like "QQQQQ" or "QQOQQ". Within a 1-second time-window, they then had to press a left or right button, depending on the letter in the middle of the string. The assignment of which button to press for a given middle letter was swapped between blocks of experiments.

The EEG data were recorded using a 64-channel EEG + 2-channel EOG + 1-channel EKG setup. Demographic and psychometric data (including the Beck Depression Inventory) were collected to control for confounds.

Paper

Gründler, T. O., Cavanagh, J. F., Figueroa, C. M., Frank, M. J., & Allen, J. J. (2009). Task-related dissociation in ERN amplitude as a function of obsessive–compulsive symptoms. Neuropsychologia, 47(8-9), 1978-1987.

DISCLAIMER: We (DISCO) are NOT the owners or creators of this dataset, but we merely uploaded it here, to support our's (EEG-Bench) and other's work on EEG benchmarking.

Dataset Structure

• data/ contains the annotated EEG experiment data in .cnt format.
• DMDX_Codes_Flankers_Only.rtf (more compact) and Flankers_Letters_Task_Babcock.rtf (more verbose) provide descriptions of the experiments.
• Info.xlsx contains various information about the subjects (identified by the ID column), such as sex, age, Beck Depression Inventory (BDI), Obsessive-Compulsive Inventory (OCI), Speilberger Trait Anxiety Inventory (TAI), Speilberger State Anxiety Inventory (SAI) and Carver & White BIS/BAS scales.
• scripts/ contains MATLAB scripts that might provide further information about the data.

Filename Format

[PID]flankers.cnt      (or [PID]flankers_ready.cnt)

where PID is the participant's ID as used in Info.xlsx's ID column.

NOTE that the flankers_ready.cnt files may have been preprocessed, while the flankers.cnt may be the original raw EEG files.

Fields in each File

A .cnt file can be read in python as follows:

import mne
raw = mne.io.read_raw_cnt(filepath)

Now, raw.get_data(units='uV') yields a numpy array of shape (#channels, time_len) in micro-Volt units.

Some general info can be inspected with raw.info, such as the sampling rate (raw.info["sfreq"]).

The channel names (in their correct order) can be seen via raw.ch_names.

Events can be read with

events_list, events_dict = mne.events_from_annotations(raw)

where events_dict contains the mapping of the original event types (like "126") to event IDs in [1,2,..., num_event_types], the latter of which are used in events_list.

events_list is a list of events, ordered by time. Each entry e = [timestamp, (not important), event ID] consists of the time of the event onset timestamp that refers to the time_len dimension in the raw.get_data() EEG array, as well as the event-ID.

(See the https://mne.tools/stable/generated/mne.io.Raw.html documentation for more details.)

(Inferred) Meaning of the Event Types

The meaning of the following event types should be inferrable from DMDX_Codes_Flankers_Only.rtf and Flankers_Letters_Task_Babcock.rtf:

• 50: A fixation cross/asterisk is shown on the monitor in front of the participant
• 110: A message "WRONG" is displayed, indicating that the participant did not press a button in time (or also that the participant pressed the wrong button, but I'm not 100% sure about that)

• 111: Letters "KKKKK" are shown on the screen, and the participant is asked to press the left button when "K" is the center letter and the right button when "R" is the center letter.
• 112: Letters "KKRKK" are shown on the screen, and the participant is asked to press the left button when "K" is the center letter and the right button when "R" is the center letter.
• 113: Letters "RRKRR" are shown on the screen, and the participant is asked to press the left button when "K" is the center letter and the right button when "R" is the center letter.
• 114: Letters "RRRRR" are shown on the screen, and the participant is asked to press the left button when "K" is the center letter and the right button when "R" is the center letter.

• 121: Letters "MMMMM" are shown on the screen, and the participant is asked to press the left button when "M" is the center letter and the right button when "N" is the center letter.
• 122: Letters "MMNMM" are shown on the screen, and the participant is asked to press the left button when "M" is the center letter and the right button when "N" is the center letter.
• 123: Letters "NNMNN" are shown on the screen, and the participant is asked to press the left button when "M" is the center letter and the right button when "N" is the center letter.
• 124: Letters "NNNNN" are shown on the screen, and the participant is asked to press the left button when "M" is the center letter and the right button when "N" is the center letter.

• 125: Letters "MMMMM" are shown on the screen, and the participant is asked to press the left button when "N" is the center letter and the right button when "M" is the center letter.
• 126: Letters "MMNMM" are shown on the screen, and the participant is asked to press the left button when "N" is the center letter and the right button when "M" is the center letter.
• 127: Letters "NNMNN" are shown on the screen, and the participant is asked to press the left button when "N" is the center letter and the right button when "M" is the center letter.
• 128: Letters "NNNNN" are shown on the screen, and the participant is asked to press the left button when "N" is the center letter and the right button when "M" is the center letter.

• 131: Letters "FFFFF" are shown on the screen, and the participant is asked to press the left button when "F" is the center letter and the right button when "E" is the center letter.
• 132: Letters "FFEFF" are shown on the screen, and the participant is asked to press the left button when "F" is the center letter and the right button when "E" is the center letter.
• 133: Letters "EEFEE" are shown on the screen, and the participant is asked to press the left button when "F" is the center letter and the right button when "E" is the center letter.
• 134: Letters "EEEEE" are shown on the screen, and the participant is asked to press the left button when "F" is the center letter and the right button when "E" is the center letter.

• 135: Letters "FFFFF" are shown on the screen, and the participant is asked to press the left button when "E" is the center letter and the right button when "F" is the center letter.
• 136: Letters "FFEFF" are shown on the screen, and the participant is asked to press the left button when "E" is the center letter and the right button when "F" is the center letter.
• 137: Letters "EEFEE" are shown on the screen, and the participant is asked to press the left button when "E" is the center letter and the right button when "F" is the center letter.
• 138: Letters "EEEEE" are shown on the screen, and the participant is asked to press the left button when "E" is the center letter and the right button when "F" is the center letter.

• 141: Letters "QQQQQ" are shown on the screen, and the participant is asked to press the left button when "Q" is the center letter and the right button when "O" is the center letter.
• 142: Letters "QQOQQ" are shown on the screen, and the participant is asked to press the left button when "Q" is the center letter and the right button when "O" is the center letter.
• 143: Letters "OOQOO" are shown on the screen, and the participant is asked to press the left button when "Q" is the center letter and the right button when "O" is the center letter.
• 144: Letters "OOOOO" are shown on the screen, and the participant is asked to press the left button when "Q" is the center letter and the right button when "O" is the center letter.

• 145: Letters "QQQQQ" are shown on the screen, and the participant is asked to press the left button when "O" is the center letter and the right button when "Q" is the center letter.
• 146: Letters "QQOQQ" are shown on the screen, and the participant is asked to press the left button when "O" is the center letter and the right button when "Q" is the center letter.
• 147: Letters "OOQOO" are shown on the screen, and the participant is asked to press the left button when "O" is the center letter and the right button when "Q" is the center letter.
• 148: Letters "OOOOO" are shown on the screen, and the participant is asked to press the left button when "O" is the center letter and the right button when "Q" is the center letter.

• 151: Letters "VVVVV" are shown on the screen, and the participant is asked to press the left button when "V" is the center letter and the right button when "U" is the center letter.
• 152: Letters "VVUVV" are shown on the screen, and the participant is asked to press the left button when "V" is the center letter and the right button when "U" is the center letter.
• 153: Letters "UUVUU" are shown on the screen, and the participant is asked to press the left button when "V" is the center letter and the right button when "U" is the center letter.
• 154: Letters "UUUUU" are shown on the screen, and the participant is asked to press the left button when "V" is the center letter and the right button when "U" is the center letter.

• 155: Letters "VVVVV" are shown on the screen, and the participant is asked to press the left button when "U" is the center letter and the right button when "V" is the center letter.
• 156: Letters "VVUVV" are shown on the screen, and the participant is asked to press the left button when "U" is the center letter and the right button when "V" is the center letter.
• 157: Letters "UUVUU" are shown on the screen, and the participant is asked to press the left button when "U" is the center letter and the right button when "V" is the center letter.
• 158: Letters "UUUUU" are shown on the screen, and the participant is asked to press the left button when "U" is the center letter and the right button when "V" is the center letter.

• 161: Letters "TTTTT" are shown on the screen, and the participant is asked to press the left button when "T" is the center letter and the right button when "I" is the center letter.
• 162: Letters "TTITT" are shown on the screen, and the participant is asked to press the left button when "T" is the center letter and the right button when "I" is the center letter.
• 163: Letters "IITII" are shown on the screen, and the participant is asked to press the left button when "T" is the center letter and the right button when "I" is the center letter.
• 164: Letters "IIIII" are shown on the screen, and the participant is asked to press the left button when "T" is the center letter and the right button when "I" is the center letter.

• 165: Letters "TTTTT" are shown on the screen, and the participant is asked to press the left button when "I" is the center letter and the right button when "T" is the center letter.
• 166: Letters "TTITT" are shown on the screen, and the participant is asked to press the left button when "I" is the center letter and the right button when "T" is the center letter.
• 167: Letters "IITII" are shown on the screen, and the participant is asked to press the left button when "I" is the center letter and the right button when "T" is the center letter.
• 168: Letters "IIIII" are shown on the screen, and the participant is asked to press the left button when "I" is the center letter and the right button when "T" is the center letter.

License

By the original authors of this work, this work has been licensed under the PDDL v1.0 license (see LICENSE.txt).