MEG-PLAN: a clinical and technical protocol for obtaining magnetoencephalography data in minimally verbal or nonverbal children who have autism spectrum disorder

Abstract

Background: Neuroimaging research on individuals who have autism spectrum disorder (ASD) has historically been limited primarily to those with age-appropriate cognitive and language performance. Children with limited abilities are frequently excluded from such neuroscience research given anticipated barriers like tolerating the loud sounds associated with magnetic resonance imaging and remaining still during data collection. To better understand brain function across the full range of ASD there is a need to (1) include individuals with limited cognitive and language performance in neuroimaging research (non-sedated, awake) and (2) improve data quality across the performance range. The purpose of this study was to develop, implement, and test the feasibility of a clinical/behavioral and technical protocol for obtaining magnetoencephalography (MEG) data. Participants were 38 children with ASD (8-12 years) meeting the study definition of minimally verbal/nonverbal language. MEG data were obtained during a passive pure-tone auditory task.

Results: Based on stakeholder feedback, the MEG Protocol for Low-language/cognitive Ability Neuroimaging (MEG-PLAN) was developed, integrating clinical/behavioral and technical components to be implemented by an interdisciplinary team (clinicians, behavior specialists, scientists, and technologists). Using MEG-PLAN, a 74% success rate was achieved for acquiring MEG data, with a 71% success rate for evaluable and analyzable data. Exploratory analyses suggested nonverbal IQ and adaptive skills were related to reaching the point of acquirable data. No differences in group characteristics were observed between those with acquirable versus evaluable/analyzable data. Examination of data quality (evaluable trial count) was acceptable. Moreover, results were reproducible, with high intraclass correlation coefficients for pure-tone auditory latency.

Conclusions: Children who have ASD who are minimally verbal/nonverbal, and often have co-occurring cognitive impairments, can be effectively and comfortably supported to complete an electrophysiological exam that yields valid and reproducible results. MEG-PLAN is a protocol that can be disseminated and implemented across research teams and adapted across technologies and neurodevelopmental disorders to collect electrophysiology and neuroimaging data in previously understudied groups of individuals.

Keywords: Applied behavior analysis; Autism spectrum disorder; Compliance; Imaging methodology; Intellectual disability; Magnetoencephalography; Minimally verbal; Nonverbal.

Fig. 1

MEG Protocol for Low-language/cognitive Ability Neuroimaging (MEG-PLAN)

Fig. 2

Sample practice plan and accompanying materials to support family preparation for MEG visit. a (top) Sample practice plan provided to families prior to MEG visit. Plan describes the background justification for why the procedures are necessary, how to describe the procedure to the child, and step-by-step instructions for practice and desensitization. b (bottom) Sample materials provided to parents to support practice plan. In this case, a laminated picture of a face is provided with practice wires (waxed/plastic string) and samples of the paper tape used to affix the coils (“wires”) to the face. Additional pieces of paper tape are provided to allow for additional practice and desensitization

Fig. 3

Sample visual supports used in MEG-PLAN. a (top left) Sample first-then board used to communicate behavioral expectations and/or the next step in the schedule, followed by the reinforcer the participant would earn for completion of the step. b (bottom left) Sample pages from a picture book. This book was reviewed with the participant and parent to familiarize them with the MEG process. It was also sometimes used as a visual schedule for each step in the MEG visit process. c (right side) Sample visual schedule that breaks down behaviors, such as digitizing, into smaller, discrete steps

Fig. 4

Three phases of MEG-PLAN implementation and the interdisciplinary team members needed for each phase

Fig. 5

Test-retest of pure-tone (M50) latency and amplitude. Legend: Test-retest of pure-tone (M50) latency and amplitude determination in eight minimally verbal/nonverbal children on the autism spectrum confirms the feasibility of the MEG-PLAN approach as well as the reliability of latency measures

Fig. 6

a Left and right superior temporal gyrus (STG) dipoles placed and left and right Heschl’s gyrus. b Left and right STG auditory source waveforms from an 8-year-old male. Left and right STG M50 responses are observed (left M50 field map shown). c Mean M50 latency values for each group with standard error bars. d Mean M50 amplitude values for each group with standard error bars