Mapping brain function during naturalistic viewing using high-density diffuse optical tomography

Andrew K Fishell,Joseph P Culver,Tracy M Burns-Yocum,Adam T Eggebrecht,Karla M Bergonzi

doi:10.1038/s41598-019-45555-8

Abstract

Naturalistic stimuli, such as movies, more closely recapitulate “real life” sensory processing and behavioral demands relative to paradigms that rely on highly distilled and repetitive stimulus presentations. The rich complexity inherent in naturalistic stimuli demands an imaging system capable of measuring spatially distributed brain responses, and analysis tools optimized for unmixing responses to concurrently presented features. In this work, the combination of passive movie viewing with high-density diffuse optical tomography (HD-DOT) is developed as a platform for naturalistic brain mapping. We imaged healthy young adults during free viewing of a feature film using HD-DOT and observed reproducible, synchronized cortical responses across a majority of the field-of-view, most prominently in hierarchical cortical areas related to visual and auditory processing, both within and between individuals. In order to more precisely interpret broad patterns of cortical synchronization, we extracted visual and auditory features from the movie stimulus and mapped the cortical responses to the features. The results demonstrate the sensitivity of HD-DOT to evoked responses during naturalistic viewing, and that feature-based decomposition strategies enable functional mapping of naturalistic stimulus processing, including human-generated speech.

Highlights

Optical neuroimaging techniques enable functional brain imaging in naturalistic settings unavailable to imaging modalities with highly constrained imaging environments such as functional magnetic resonance imaging[1,2]
The central goal of the present work is to evaluate the functional mapping performance of naturalistic movie viewing combined with a large field-of-view high-density diffuse optical tomography (HD-DOT) system in healthy young adults
If HD-DOT is sensitive to complex, multi-modal cortical responses associated with naturalistic viewing, we hypothesize that highly reproducible, synchronized, cortical responses will be measurable across regions related to both sensory and higher-order cognitive processing

Summary

Introduction

Optical neuroimaging techniques enable functional brain imaging in naturalistic settings unavailable to imaging modalities with highly constrained imaging environments such as functional magnetic resonance imaging (fMRI)[1,2]. In addition to social interactions and natural movements, naturalistic imaging paradigms have included free viewing of movies and television shows[19,20,21]. Naturalistic viewing simultaneously and reliably engages multiple cortical processing systems, including those related to processing the movie’s auditory/visual content and narrative structure[19,20]. These systems are spatially distributed across the cortex, underscoring the need for a large field-of-view to capture the multi-modality responses. If HD-DOT is sensitive to complex, multi-modal cortical responses associated with naturalistic viewing, we hypothesize that highly reproducible, synchronized, cortical responses will be measurable across regions related to both sensory (auditory/visual) and higher-order cognitive (e.g. linguistic) processing

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Conclusion