title: Frontal midline θ power as an index of listening effort.
abstract: Attempts to identify physiological correlates of listening effort have mainly focused on peripheral measures (e.g. pupillometry) and auditory-evoked/event-related potentials. Although nonauditory studies have suggested that sustained time-frequency electroencephalographic (EEG) features in the θ-band (4-7 Hz) are correlated with domain-general mental effort, little work has characterized such features during effortful listening. Here, high-density EEG data was collected while listeners performed a sentence-recognition task in noise, the signal-to-noise ratio (SNR) of which varied across blocks. Frontal midline θ (Fmθ), largely driven by sources localized in or near the medial frontal cortex, showed greater power with decreasing SNR and was positively correlated with self-reports of effort. Increased Fmθ was present before speech onset and during speech presentation. Fmθ power also differed across SNRs when including only trials in which all words were recognized, suggesting that the effects were unrelated to performance differences. Results suggest that frontal cortical networks play a larger role in listening as acoustic signals are increasingly masked. Further, sustained time-frequency EEG features may usefully supplement previously used peripheral and event-related potential measures in psychophysiological investigations of effortful listening.
authors.affiliation: a711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH, USA bBall Aerospace Technologies Ball Aerospace and Technologies Corp., Fairborn, OH, USA cDOD Hearing Center of Excellence, Lackland Air Force Base, TX, USA.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Wisniewski
authors.forename: Eric R
authors.initials: ER
authors.lastname: Thompson
authors.forename: Nandini
authors.initials: N
authors.lastname: Iyer
authors.forename: Justin R
authors.initials: JR
authors.lastname: Estepp
authors.forename: Max N
authors.initials: MN
authors.lastname: Goder-Reiser
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Sullivan
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008297:Male; D055815:Young Adult