The development and structure of the HEALthy Brain and Child Development (HBCD) Study EEG protocol

Abstract

The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. Electroencephalography (EEG) is one of two brain imaging modalities central to the HBCD Study. EEG records electrical signals from the scalp that reflect electrical brain activity. In addition, the EEG signal can be synchronized to the presentation of discrete stimuli (auditory or visual) to measure specific cognitive processes with excellent temporal precision (e.g., event-related potentials; ERPs). EEG is particularly helpful for the HBCD Study as it can be used with awake, alert infants, and can be acquired continuously across development. The current paper reviews the HBCD Study's EEG/ERP protocol: (a) the selection and development of the tasks (Video Resting State, Visual Evoked Potential, Auditory Oddball, Face Processing); (b) the implementation of common cross-site acquisition parameters and hardware, site setup, training, and initial piloting; (c) the development of the preprocessing pipelines and creation of derivatives; and (d) the incorporation of equity and inclusion considerations. The paper also provides an overview of the functioning of the EEG Workgroup and the input from members across all steps of protocol development and piloting.

Keywords: Auditory oddball; EEG; Face processing; HBCD; Infants; Longitudinal cohort; Protocols; Resting EEG; Visual evoked potentials.

Fig. 1

Schematic of the first set of HBCD Study visits. EEG is collected at Visits 3 and 4.

Fig. 2

Representation of EEG signal collected during the Video Resting State Task as power spectra for relative power in the 2–50 Hz in the occipital (OZ) cluster. The black line represents the average across all participants and the lines in color represent each individual.

Fig. 3

Sequencing of stimuli sounds, /ba/ or /da/, in the MMN task. The ISI noted is used in Visit 3. The ISI is 600 ms for later visits.

Fig. 4

Selected ERP Waveforms for the Auditory Oddball (MMN/MMR) and Visual Evoked Potential (VEP) tasks. A) Auditory Oddball task ERP plots by condition for the Deviant, Standard, and their difference wave (Deviant – Standard) and B) their topography during the 200–400 ms time window. Note that only standard stimuli immediately preceding a deviant syllable were used. C) ERP plots for the VEP with the N1, P1, and N2 components labeled, and D) their topography during their respective time windows.

Fig. 5

Visual representation of the stimuli used in the VEP task.

Fig. 6

Schematic of the Faces task used in Visits 3, 4, and 6, depicting the Face/Object block. The attention getter is one of several toys, paired with a sound, displayed by a research assistant to return infant gaze to the screen. Trials advance by RA button press when infant is attending to the screen.

Fig. 7

Selected ERP Waveforms for the Face Processing task: A) ERP plots by condition for the Upright faces during the Inverted faces block, Objects, Inverted faces, and Upright faces during the Object block with the P1, N290, and P400 components labeled. Also displayed are the difference waves between Upright – Inverted and Upright – Object as dashed lines and B) their topography during the N290 time window (200–300 ms).

Fig. 8

Conceptual schematic of the data flow used by HBCD to move EEG data from the collection site to the central storage and processing servers.