Overcoming the methodological challenges of developmental fNIRS

Lauren Emberson, Judit Gervain, Laura Pirazzoli, Sarah Lloyd-Fox, Ioulia Kovelman

Duration: 180 min

Capacity: 30

Level: Introductory

Experimental Demo

Requirements: None

Synopsis: fNIRS is a neuroimaging modality that is uniquely suited to investigating early developmental populations (neonates, infants, young children). However, these populations have unique challenges even in the fNIRS community. In this mini-course, researchers interested in conducting developmental studies will gain the methodological knowledge necessary to conducting successful and rigorous studies with developmental populations. The course will be run by a team of established developmental cognitive neuroscientists with decades of fNIRS experience. The team has expertise across different ages (neonates to childhood) and domains of study (vision, language, learning, social) and collecting fNIRS both in the lab and in the field. Topics will include experimental designs appropriate for each stage of early development, how to cap effectively at different ages, effective techniques for participant recruitment including communication with parents from diverse backgrounds, how to deal with motion and other sources of noise, techniques available for spatial localization of probes, and current methods for ROI identification, and relatedly, statistical analyses. All of these topics will be tackled in a hands-on, seminar-style fashion including demos with developmentally-specialized equipment and videos of actual experiments. Finally, given an experimental question chosen by the attendees, students will work with the instructors to apply the methodological skills covered in this course.

Course structure:

  • Experimental design: Introduce designs have been found to maximize both experimenter power and participant compliance. How do experimental designs (e.g., ISI length) vary across early developmental populations? How to maintain infant/child attention throughout the experiment. Stimuli will be demonstrated and shared. We will present designs that are effective with infants and ones that are effective with toddlers and highlight the key differences between these designs.
  • Recruitment: Recruitment techniques will be discussed along with how to communicate with parents. Special attention will be paid to the challenges of recruitment in global settings as well as with participants from disadvantaged groups in the developed world (e.g., low SES, recent immigrants).
  • Probe placement/Capping: What are the procedures for successful capping in each of these age ranges? How to purchase or modify your fNIRS equipment to increase your success. Videos of capping in a number of populations, along with caps brought from the instructors’ labs, will provide practical knowledge.
  • Techniques for probe localization: In these populations, spatial location of probes is particularly challenging as standard methods (e.g., 3D digitizers) are not practically useable. Methods of standardizing and evaluating cap placement as well as the cutting-edge techniques of video-based co-registration will be introduced.
  • ROI selection and head-size/age: Issues of ROI selection and comparisons across ages and differing head sizes will be addressed. The interrelationship between ROI selection and statistical analyses will be addressed.
  • Motion and other sources of noise: Instructors will address how to minimize motion but also how to identify and remove motion artifacts. Short channel and other sources of physiological noise will be addressed. 

We have assembled a team of established developmental cognitive neuroscientists with a breadth of experience in both population (neonates, infants, young children) and domain of study (vision, language, learning, social). This mini-course will be seminar-style where topics will be introduced using hands-on demonstrations, videos from the instructors’ labs and presentation of experiments/stimuli. The seminar-style of the course will allow instructors to give tailored information/feedback to the attendees based on their experimental foci. The course will culminate with the group workshopping an experiment: Given an experimental question chosen by the attendees, the students will work in small groups, each with one of the instructors, to design an experiment with special attention to the methodological details covered in this course.

Learning objectives: The goal of this mini-course is to augment the general fNIRS training with specific skills necessary for conducting successful and rigorous research with early developmental populations (Experimental design, recruitment, probe placement, probe localization, ROI selection, sources of noise in the signal).