<p>Shedding Light On The Human Auditory Cortex: A Review Of The Advances In Near Infrared Spectroscopy (NIRS)</p>

Abstract

Imaging the auditory cortex can prove challenging using neuroimaging methodologies due to interfering noise from the scanner in fMRI and the low spatial resolution of EEG. Optical imaging provides a new and exciting option for exploring this key cortical area. This review presents a brief history of optical imaging, followed by an exploration of how advances in optical imaging technologies have increased the understanding of the functions and processes within the auditory cortex. In particular, the benefits and limitations of using functional near infrared spectroscopy (fNIRS) on complex populations such as infants and individuals with hearing loss are explored, along with suggestions for future research developments.

The Benefit of Cross-Modal Reorganization on Speech Perception in Pediatric Cochlear Implant Recipients Revealed Using Functional Near-Infrared Spectroscopy

“…The purpose of this study was to explore the relationship between speech understanding and cortical responses in children with CIs and normally-hearing (NH) subjects. These were measured using functional near-infrared spectroscopy (fNIRS), a CI-safe, and child-friendly optical neuroimaging technique (Sevy et al, 2010 ; Quaresima et al, 2012 ; Saliba et al, 2016 ; Harrison and Hartley, 2019 ). Specifically, in the temporal cortex, we examined three different factors that may correlate with speech perception in CI recipients: responsiveness to visual speech, auditory speech, and non-speech sounds.…”

Brightening the Study of Listening Effort with Functional Near-Infrared Spectroscopy: A Scoping Review

“…It has higher spatial resolution than EEG (10-20 mm for fNIRS compared to 5-9 cm for EEG), so it is a comparably better choice for localizing cortical activity. 82 The locations of source and detectors on the scalp can also be digitized and converted to coordinates in MNI space and/or coregistered to fMRI brain atlases for better visualizations of localized activity. Certain fNIRS systems can also interface with other imaging modalities to provide a more thorough, multimodal assessment of neural activity.…”

“…They can be used for longer imaging sessions up to approximately 1 hour and can be easily implemented for repeated measures designs. 82 An additional benefit for fNIRS systems is that they are relatively robust to motion artifacts, so they can be used in paradigms that involve substantial participant movement. 70 Wearable fNIRS systems are portable and can be used in more naturalistic settings outside the lab.…”

Use of Functional Near-Infrared Spectroscopy to Predict and Measure Cochlear Implant Outcomes: A Scoping Review

“…fNIRS is increasingly used for functional brain-imaging research in adults and children, including CI recipients, because it is quiet, non-invasive, and CI-compatible [68][69][70][71][72][73][74][75]. fNIRS uses near infrared light and as such is unaffected by electrical or magnetic artefacts.…”

“…There have been a number of reviews regarding the use of fNIRS in auditory/language research [70,81], and more specifically, the use of fNIRS in deaf or CI-using populations [73,82]. However, to the best of our knowledge, no literature is available that specifically reviews work assessing the relationship between fNIRS cortical measures and behavioral outcomes in CI users.…”