DOI: 10.5061/dryad.xd2547dw5
title: RDK-IAPS paradigm EEG, target vs distractor

description: It has been suggested that the visual system samples attended information
 rhythmically. Does rhythmic sampling also apply to distracting
 information? How do attended information and distracting information
 compete temporally for neural representations? We recorded
 electroencephalography (EEG) from participants who detected instances of
 coherent motion in a random dot kinematogram (RDK; the target), overlayed
 on different categories (pleasant, neutral, and unpleasant) of affective
 images from the International Affective System (IAPS) (the distractor).
 The moving dots were flickered at 4.29 Hz whereas the IAPS pictures were
 flickered at 6 Hz. The time course of EEG spectral power at 4.29 Hz was
 taken to index the temporal dynamics of target processing. The spatial
 pattern of the EEG spectral power at 6 Hz was similarly extracted and
 subjected to a moving-window MVPA decoding analysis to index the temporal
 dynamics of processing pleasant, neutral, or unpleasant distractor
 pictures. We found that (1) both target processing and distractor
 processing exhibited rhythmicity at ∼1 Hz and (2) the phase difference
 between the two rhythmic time courses were related to task performance,
 i.e., relative phase closer to π predicted a higher rate of coherent
 motion detection whereas relative phase closer to 0 predicted a lower rate
 of coherent motion detection. These results suggest that (1) in a
 target-distractor scenario, both attended and distracting information were
 sampled rhythmically and (2) the more target sampling and distractor
 sampling were separated in time within a sampling cycle, the less
 distraction effects were observed, both at the neural and the behavioral
 level.
description: EEG data was recorded using a 32-channel MR-compatible EEG
 recording system (Brain Products, Germany). The system was synchronized to
 the internal clock of the scanner to facilitate the subsequent scanner
 noise removal. Thirty-one Ag/AgCl electrodes were located on the scalp
 according to the 10–20 system via an elastic cap. One additional electrode
 was located on the participant’s upper back to record the
 electrocardiogram (ECG). Electrode FCz was used as the reference during
 recording. Impedances were kept below 20kΩ for all scalp electrodes and
 below 50kΩ for the ECG electrode, as suggested by the manufacturer. EEG
 data was digitized at 16-bit resolution and sampled at 5kHz with a 0.1-
 250 Hz (3dB-point) bandpass filter applied online (Butterworth, 18
 dB/octave roll off). The digitized data was transferred to a laptop
 computer via a fiber-optic cable. Artifact removal from
 electroencephalogram (EEG) data, specifically magnetic gradient and
 cardioballistic artifacts, was conducted using the Brain Vision Analyzer
 2.0 software (Brain Products GmbH). The elimination of magnetic gradient
 artifacts was based on an algorithm initially proposed by (Allen et al.,
 2000). The process involves the creation of an artifact template through
 averaging EEG data over 41 consecutive fMRI volumes, which was
 subsequently subtracted from the EEG recordings. Additionally,
 cardioballistic artifacts were removed by employing a technique developed
 by (Allen et al., 1998), in which R peaks were detected via the EKG
 electrode, and a corrective template were computed from 21 successive
 heart beats and subtracted from the EEG data.
 Subsequent to scanner artifact removal, data was downsampled to
 500 Hz and exported into EEGLab software. The data underwent further
 filtering using a 0.1 to 40 Hz band-pass Butterworth filter. Independent
 Components Analysis (ICA) was applied to remove components associated with
 eye blinks, horizontal eye movements, and residual cardioballistic
 artifacts. The data were then converted to the average
 reference.
description: # Title: RDK-IAPS paradigm EEG, target vs distractor * **Author(s):**
 Changhao Xiong, Nathan Petro * **Affiliation:** Department of Biomedical
 Engineering, University of Florida and Boys Town National Research
 Hospital * **Contact Information:**
 [nathan.petro@boystown.org](mailto:nathan.petro@boystown.org) * **Access
 this dataset on Dryad:**
 [https://doi.org/10.5061/dryad.xd2547dw5](https://doi.org/10.5061/dryad.xd2547dw5) ### Dataset Summary This dataset contains Electroencephalography (EEG) data recorded during a visual attention task. In the experiment, participants were required to process a central Random Dot Kinematogram (RDK) as the target, while ignoring a peripheral emotional image from the International Affective Picture System (IAPS) serving as a distractor. The data can be used to investigate the neural mechanisms related to visual attention and motion perception under emotional distraction. --- ## Description of the data and file structure This section details how the data is organized to allow other researchers to understand and reuse it. ### 1. File Naming Convention The data is organized into individual `.mat` files for each participant, following this naming convention: `XXXssVEPICA3.mat` * `XXX`: Represents the participant ID, where `XXX` is a three-digit number. ### 2. .MAT File Structure and Content Each `.mat` file contains a MATLAB `struct` variable named `EEG`, which is compatible with the EEGLAB toolbox. The fields are output from the EEGLAB directly and defined as follows: * **`EEG.data`**: A 3D matrix of size `[channels x time points x trials]`, containing the EEG voltage values in microvolts. * **`EEG.srate`**: The sampling rate in Hertz (Hz). * **`EEG.chanlocs`**: A `1 x 31` struct array with electrode information (e.g., `.labels` for channel names, and `.X`, `.Y`, `.Z` for coordinates). * **`EEG.nbchan`**: The number of channels. * **`EEG.pnts`**: The number of time points per trial (epoch). * **`EEG.trials`**: The total number of trials. * **`EEG.times`**: A `1 x [EEG.pnts]` array for the time vector of each trial in milliseconds (ms), relative to stimulus onset (0 ms). * **`EEG.event`**: A `1 x [number of events]` struct array that logs experimental event markers. Data for reproducing the main result has been defined here. The rest of the fields in the .mat file are description attributes. ### 3. Experimental Paradigm & Event Codes **Task Description**: Participants were instructed to fixate on a central cross and report coherent motion of the dots while ignoring the simultaneously presented IAPS picture. ## Human subjects data I received explicit consent from participants to publish the de-identified data in the public domain. The data is after preprocessing, and the identification information is not contained.