EEG Alpha Power and Pupil Diameter Reflect Endogenous Auditory Attention Switching and Listening Effort

Auditory attention describes a listeners focus on an acoustic source while they ignore other competing sources that might be present. In an environment with multiple talkers and background noise (i.e. the cocktail party effect), auditory attention can be difficult, requiring the listener to expend measurable cognitive effort. A listener will naturally interrupt sustained attention on a source when switching towards another source during conversation. This change in attention is potentially even more taxing than maintaining sustained attention due to the limits of human working memory, and this additional effort required has not been well studied. In this work, we evaluated an attention decoder algorithm for detecting the change in attention and investigated cognitive effort expended during attentional switching and sustained attention. Two variants of endogenous attention switching were explored: the switches either had in-the-moment decision making or a pre-defined attentional switch time. A least-squares, EEG-based, attention decoding algorithm achieved 64.1% accuracy with a 5-second correlation window and illustrated smooth transitions in the attended talker prediction through switches in sustained attention at approximately half of the analysis window size (2.2 seconds). The expended listening effort, as measured by simultaneous electroencephalography (EEG) and pupillometry, was also a strong indicator of switching. Specifically, centrotemporal alpha power [F(2, 18) = 7.473, P = 0.00434] and mean pupil diameter [F(2, 18) = 9.159, P = 0.0018] were significantly different for trials that contained a switch in comparison to sustained trials. We also found that relative attended and ignored talker locations modulate the EEG alpha topographic response. This alpha lateralization was found to be impacted by the interaction between experimental condition and whether the measure was computed before or after the switch [F(2,18) = 3.227, P = 0.0634]. These results suggest that expended listening effort is a promising feature that should be pursued in a decoding context, in addition to speech and location-based features.

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EEG alpha power and coherence time courses in a sustained attention task

First International IEEE EMBS Conference on Neural Engineering, 2003. Conference Proceedings. ◽

10.1109/cne.2003.1196761 ◽

2003 ◽

Cited By ~ 12

Author(s):

S.P. Kelly ◽

P. Dockree ◽

R.B. Reilly ◽

I.H. Robertson

Keyword(s):

Sustained Attention ◽

Coherence Time ◽

Alpha Power ◽

Attention Task ◽

Time Courses ◽

Eeg Alpha

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Auditory attention switching with listening difficulty: Behavioral and pupillometric measures

10.31234/osf.io/2ubyj ◽

2019 ◽

Author(s):

Daniel McCloy ◽

Eric Larson ◽

Adrian K.C. Lee

Keyword(s):

Auditory Attention ◽

Stream Segregation ◽

Self Report ◽

Attention Switching ◽

Listening Effort ◽

Sound Sources ◽

Experimental Conditions ◽

Switching Attention ◽

Crowded Environments ◽

Target Detection Task

Pupillometry has emerged as a useful tool for studying listening effort. Past work involving listeners with normal audiological thresholds has shown that switching attention between competing talker streams evokes pupil dilation indicative of listening effort [McCloy et al (2017), J. Acoust. Soc. Am 141(4):2440]. The current experiment examines behavioral and pupillometric data from a two-stream target detection task requiring attention-switching between auditory streams, in two participant groups: audiometrically normal listeners who self-report difficulty localizing sound sources and/or understanding speech in reverberant or acoustically crowded environments, and their age-matched controls who do not report such problems. Three experimental conditions varied the number and type of stream segregation cues available. Participants who reported listening difficulty showed both behavioral and pupillometric signs of increased effort compared to controls, especially in trials where listeners had to switch attention between streams, or trials where only a single stream segregation cue was available.

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Cortical alpha oscillations in cochlear implant users reflect subjective listening effort during speech-in-noise perception

PLoS ONE ◽

10.1371/journal.pone.0254162 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254162

Author(s):

Brandon T. Paul ◽

Joseph Chen ◽

Trung Le ◽

Vincent Lin ◽

Andrew Dimitrijevic

Keyword(s):

Cochlear Implant ◽

Cochlear Implants ◽

Inferior Frontal Gyrus ◽

Alpha Power ◽

Listening Effort ◽

Left Inferior Frontal Gyrus ◽

Alpha Oscillations ◽

Speech In Noise ◽

Eeg Alpha ◽

Cortical Regions

Listening to speech in noise is effortful for individuals with hearing loss, even if they have received a hearing prosthesis such as a hearing aid or cochlear implant (CI). At present, little is known about the neural functions that support listening effort. One form of neural activity that has been suggested to reflect listening effort is the power of 8–12 Hz (alpha) oscillations measured by electroencephalography (EEG). Alpha power in two cortical regions has been associated with effortful listening—left inferior frontal gyrus (IFG), and parietal cortex—but these relationships have not been examined in the same listeners. Further, there are few studies available investigating neural correlates of effort in the individuals with cochlear implants. Here we tested 16 CI users in a novel effort-focused speech-in-noise listening paradigm, and confirm a relationship between alpha power and self-reported effort ratings in parietal regions, but not left IFG. The parietal relationship was not linear but quadratic, with alpha power comparatively lower when effort ratings were at the top and bottom of the effort scale, and higher when effort ratings were in the middle of the scale. Results are discussed in terms of cognitive systems that are engaged in difficult listening situations, and the implication for clinical translation.

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Effect of Directional Microphone Technology in Hearing Aids on Neural Correlates of Listening and Memory Effort: An Electroencephalographic Study

Trends in Hearing ◽

10.1177/2331216520948410 ◽

2020 ◽

Vol 24 ◽

pp. 233121652094841

Author(s):

Axel H. Winneke ◽

Michael Schulte ◽

Matthias Vormann ◽

Matthias Latzel

Keyword(s):

Hearing Aids ◽

Speech Intelligibility ◽

Memory Performance ◽

Span Task ◽

Alpha Power ◽

Memory Retention ◽

Listening Effort ◽

Directional Microphone ◽

Spatial Noise ◽

Eeg Alpha

The aim of the study was to compare the effect of different spatial noise-processing algorithms in hearing aids on listening effort and memory effort on a subjective, behavioral, and neurophysiological level using electroencephalography (EEG). Two types of directional microphone (DM) technologies for spatial noise processing were chosen: one with a wide directionality (wide DM) and another with a narrower directionality (narrow DM) to accentuate the speech source. Participants with a severe hearing loss were fitted with hearing aids and participated in two EEG experiments. In the first one, participants listened to sentences in cafeteria noise and were asked to rate the experienced listening effort. The second EEG experiment was a listening span task during which participants had to repeat sentence material and then recall the final words of the last four sentences. Subjective listening effort was lower with narrow than wide DM and EEG alpha power was reduced for the narrow DM. The results of the listening span task indicated a reduction in experienced memory effort and better memory performance. During the memory retention phase, EEG alpha level for the narrow relative to the wide DM was reduced. This effect was more pronounced during linguistically difficult sentences. This study extends previous findings, as it reveals a benefit for narrow DM in terms of cognitive performance and memory effort also on a neural level, and when speech intelligibility is almost 100%. Together, this indicates that a narrow and focused DM allows for a more efficient neurocognitive processing than a wide DM.

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Distinct neural variables underlie subjective reports of attention

10.1101/2020.01.23.916841 ◽

2020 ◽

Author(s):

Stephen Whitmarsh ◽

Christophe Gitton ◽

Veikko Jousmäki ◽

Jérôme Sackur ◽

Catherine Tallon-Baudry

Keyword(s):

Steady State ◽

Tactile Stimulation ◽

Subjective Experience ◽

Pupil Diameter ◽

Cognitive Effort ◽

Source Analysis ◽

Alpha Power ◽

Subjective Ratings ◽

Stimulus Processing ◽

Alpha Oscillations

AbstractAttention is subjectively experienced as a unified cognitive effort. This unitary experience of attention contrasts with the diversity of neural and peripheral correlates of attention. While the effects of attention on stimulus-evoked responses, alpha oscillations and pupil diameter, are well-known the relationship between these indices and the subjective experience of attention, has not yet been assessed. Participants performed a sustained (10 s to 30 s) attention task in which rare (10%) targets were detected within continuous tactile stimulation (16 Hz). Trials were followed by attention ratings on an 8-point Likert scale. Steady-state evoked fields (SSEFs) in response to tactile stimulation, as measured by magnetoencephalography, provided an objective measure of sensory processing. Beamformer source analysis of somatosensory alpha power was used as a measure of cortical excitability, while pupillometry provided a peripheral index of arousal. Attention ratings correlated negatively with contralateral somatosensory alpha power, and positively with pupil diameter. The effect of pupil diameter on attention ratings extended into the following trial, reflecting a sustained aspect of attention related to vigilance. The effect of alpha power did not carry over to the next trial, and furthermore mediated the effect of pupil diameter on attention ratings. Variation in SSEF power reflected stimulus processing under the influence of alpha oscillations, but were not readily expressed through subjective ratings of attention. Together, our results show that both alpha power and pupil diameter are reflected in the subjective experience of attention, albeit on different time spans, while continuous stimulus processing might not be metacognitively accessible.1Significance StatementAttention is subjectively experienced as a unified cognitive effort, in contrast with a diversity of neural and peripheral measures shown to correlate with attention. We present the first comprehensive study on the complex inter-relationship between the most common bio-physiological indices of attention, and their association with the subjective experience of attention. We show that the subjective experience of attention correlates negatively with cortical alpha oscillations, and positively with pupil diameter. The latter reflected a sustained aspect of attention, spanning several tens of seconds, related to vigilance. Alpha power, representing cortical control, fluctuated faster and mediated the effect of pupil diameter on attention. Tactile steady-state power reflected stimulus processing, also under the influence of alpha oscillations, but did not contribute much to subjective ratings of attention.

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