Adverse Listening Conditions and Memory Load Drive a Common Alpha Oscillatory Network

“4, top row; bottom row shows the same data being plotted onto brain areas as outlined in the automatic anatomical labeling atlas; Tzourio-Mazoyer et al., 2002).”

“Offline, the data were analyzed using MATLAB and the FieldTrip toolbox (Oostenveld et al., 2011).”

“At the second or group level, we submitted the individual z-maps to a massed cluster-based permutation t test (testing for significant differences from zero, two-sided, dependent samples, with 1000 iterations; as outlined by Maris and Oostenveld, 2007).”

“The alpha enhancement attributable to more severe acoustic degradation was found to be additive to the alpha enhancement attributable to more stored items: acoustic degradation (a perceptual challenge) and memory load (a capacity challenge) both draw on a neural system subserving “functional inhibition” (Klimesch et a…”

“Noise vocoding is an effective technique to manipulate the spectral detail while preserving the temporal envelope of the speech signal (Drullman, 1995; Shannon et al., 1995) and render it more or less intelligible in a graded and controlled way, depending on the number of bands used.”

“The alpha enhancement attributable to more severe acoustic degradation was found to be additive to the alpha enhancement attributable to more stored items: acoustic degradation (a perceptual challenge) and memory load (a capacity challenge) both draw on a neural system subserving “functional inhibition” (Klimesch et a…”

“As illustrated in Figure 4, the significant cluster extends into the SMG and the temporoparietal junction (TPJ), both being hotspots in verbal working memory (Paulesu et al., 1993; Jacquemot et al., 2003; Jacquemot and Scott, 2006; Obleser and Eisner, 2009).”

“…to overcome this and other inherent limitations when interpreting sensor-space topographies (Lopes da Silva, 2004), alpha activity during delay was projected to source space using an adaptive spatial filter in the frequency domain [dynamic imaging of coherent sources (DICS); Gross et al., 2001].”

“Enhanced alpha oscillations have become a welldocumented neural substrate of increased cognitive effort, in line with a functional, inhibitory role of alpha in controlling or gating local circuits of neural activity (Klimesch et al., 2007; Jensen and Mazaheri, 2010; Foxe and Snyder, 2011; Weisz et al., 2011).”

“…a function of memory load has been demonstrated unanimously in the Sternberg task, in which items have to be briefly retained in short-term memory, and higher memory load is known to elicit longer response times (Jensen et al., 2002; Leiberg et al., 2006; Nenert et al., 2012; Sander et al., 2012).”

“Several have found that greater effort is associated with increased total alpha power at electrode locations over posterior scalp (e.g., Obleser et al., 2012; Wisniewski et al., 2017; Wöstmann et al., 2017).”

“…reason for the current lack of observable PSD effects lies in the more complex stimulus characteristics (i.e. a mix of three simultaneous sound streams instead of a single stream used in previous work) and consequent potential variability in rehearsal strategies across trials and participants.”

“Specifically, the areas of interest in such alpha increases are central-parietal [4,27] and occipital-parietal [28].”

“Previous research has shown when listeners attend to speech in background noise, or speech that has been spectrally degraded, changes in attention and memory load are reflected in alpha power (Dimitrijevic et al. 2017; Obleser et al. 2012; Paul et al. 2021; Wöstmann et al. 2015).”

“Indeed, the location of the effect suggested by the gradiometer topographies is in line with previous MEG findings [30] and current fMRI results, showing changes in the lateralization of parietal, cingulated, and superior frontal nodes toward the right hemisphere, and also with past studies indicating that the parieta…”

“However, Obleser et al. (2012) showed a potentiation of alpha power when working memory load was high and distinctness was low.”

“In this investigation, we now want to extend our evaluation of rASR by evaluating its capabilities to correct muscle artifacts (electromyogenic artifacts, EMG) in the EEG data while preserving the power of the alpha frequency band (8-13 Hz), commonly related neural inhibitory processes and especially pronounced during…”

“Other research investigating alpha power and listening effort that were not included in the current review also show inconsistent effects of auditory task demand (Obleser et al. 2012; Petersen et al. 2015; Ala et al. 2022).”

“…the amplitude of neural alpha oscillations (∼7–13 Hz) in the magneto-/electroencephalogram (M/EEG) is suggested to be a sensitive marker of cognitive resources allocated to a task: alpha power increases with higher memory load (Jensen et al., 2002; Tuladhar et al., 2007; Obleser et al., 2012).”

“difficult—but still audible—listening conditions [9, 10].”

“…psychophysiological measures such as pupillometry (e.g., Kuchinsky et al. 2013), eye-movement tracking (e.g., BenDavid et al. 2011), galvanic skin response (e.g., Mackersie et al. 2015), or electroencephalography frequency bands (e.g., Obleser et al. 2012) can be used to explore listening effort.”

“…to executive functioning, working memory, attention, etc. (Adank, 2012; Davis and Johnsrude, 2003; Erb and Obleser, 2013; Grossman et al., 2002; McCoy et al., 2005; Obleser et al., 2012; Peelle et al., 2010; Piquado et al., 2010; Vaden et al., 2013; Wild et al., 2012; Wingfield and Grossman, 2006).”

“Alpha power (power of neural oscillations between 8 and 12 Hz) as a potential neural marker of effort and demand has been studied extensively (Foxe and Snyder, 2011; Klimesch, 2012; Obleser et al., 2012; Strauß et al., 2014; Wostmann et al., 2015; Petersen et al., 2015; Dimitrijevic et al., 2019; Magosso et al., 2019;…”

“, Obleser and Weisz, 2011) as well as cognitive load (Obleser et al., 2012; Hunter, 2020), indicating that alpha power indexes allocation of cognitive resources during listening.”

“Related to task performance, phase-related changes and suppression of alpha activity have been shown to predict successful speech intelligibility in quiet and noise (Obleser et al. 2012; Strauß et al. 2015; Weisz et al. 2011).”

“Pupil size and parietal alpha power, derived from the electroencephalogram (EEG), were chosen, since both measures been shown to provide important insights in auditory experiments, e.g., focusing on listening effort (e.g., Kraus et al., 2023b; Obleser et al., 2012).”

“…visually presented letters and numbers ( Jensen et al., 2002; Klimesch et al., 1999; Schack & Klimesch, 2002), shapes ( Herrmann et al., 2004; Johnson et al., 2011), spatial information ( Bastiaansen et al., 2002), and auditory stimuli ( Lim et al., 2015; Obleser et al., 2012; Vogt et al., 1998).”

“Relevant to the RRT, alpha-band activity has also been observed to increase with memory load (Obleser et al., 2012), though the scalp topography of alpha activity may shift toward frontal electrode sites when re fl ecting the maintenance of memory contents as working memory is updated (Manza et al.,…”

“For the auditory serial recall task, recordings of spoken German digits were used (Obleser et al., 2012).”

“Neurophysiological methods such as electroencephalographic (EEG) responses (Obleser et al., 2012; Miles et al., 2017) and pupil dilation (e.g., Ohlenforst et al., 2017a; 1Hörzentrum Oldenburg gGmbH, Oldenburg, Germany 2Medizinische Physik, Department für Medizinische Physik und Akustik, Fakultät…”

“Increased alpha power is associated with increased difficulty and subjective listening effort (Dimitrijevic et al., 2019; W ¨ ostmann et al., 2015; Obleser et al., 2012), we hypothesized that when a large temporal mismatch between two listening sides is present, CI users employ more cognitive…”

“Neural oscillatory alpha power is sensitive to listening demands, likely reflecting top-down attentional modulation (Dimitrijevic et al., 2017; Herrmann et al., 2023; Kraus et al., 2023b; Obleser et al., 2012; Paul et al., 2021; Petersen et al., 2015; Weisz et al., 2011; Wöstmann et al., 2015).”

“Alpha activity during resting-state primarily serves the physiological function of inhibiting cortical areas associated with primary processes, as extensively described (Jensen & Mazaheri, 2010; Obleser et al., 2012; van Dijk et al., 2008).”

“It has been shown DNR reduces adverse effects of noise on memory for speech, helps the hearing aid user in noisy conditions, and prevents cognitive load during auditory processing [3,4].”

“…electroencephalography (EEG) (Alhanbali et al., 2019; Bernarding et al., 2012, 2017; Fiedler et al., 2021; Haro et al., 2022; Miles et al., 2017; Obleser et al., 2012), event-related potentials (ERPs) (Obleser & Kotz, 2011), functional near-infrared spectroscopy (fNIRS) (Rovetti et al., 2019;…”

“The set of numbers (adapted from Obleser et al. 2012) comprised the numbers 1 to 9, which were spoken by a female voice and adjusted to a duration of 500 ms each.”

“Selective attention modulates the entrainment of low-frequency ( 1 – 8 Hz) cortical activity to the envelope of the attended speech stream [12, 27, 31].”

“Alphaoscillationsare themostdominantfeatureoftheEEGsignal,andenhancedalphaisoften associatedwithreducedattentiontoexternalstimuliandincreasedmind-wandering 84 – 90 .”

“Thus, our results suggest that durations are itemized in working memory like any other mental events.”

“Nevertheless, studies examining listening effort using various methods have consistently reported that acoustically degrading speech (e.g., Obleser et al., 2012; Winn et al., 2015) and decreasing the signal-to-noise ratio between speech and competing sounds (e.g., Wendt et al., 2016; Wiggins et…”

“For instance, it would be of interest to compare S PEECH A DJUSTER -elicited preferences with listening effort metrics based on pupillometry [30, 31], EEG [32, 33] or self-reports [34, 35].”

“In detail, we applied a two-level statistical approach (Obleser et al., 2012): On the first (single-subject) level, we used an independent samples regression t-test, to regress time-frequency representations (–0.5 to 1.5 s relative to S1 onset; 1–20 Hz; all 22 electrodes) of single-trial phase…”

“These results add to previous research showing the IPL's involvement in auditory processing (Gaab et al., 2006; Husain et al., 2006; Jacquemot et al., 2003; Kiefer et al., 2008; Obleser et al., 2012).”

“In addition, cognitive factors such as working-memory capacity have been identified as important contributors to successful auditory learning and compensation strategies (Tremblay and Backer 2016; Obleser et al. 2012).”

“Methods of assessing LE can be divided into physiological, subjective and performance-based procedures: Common physiological procedures are electroencephalography [3, 4], pupillometry [5, 6] and skin conductance [7].”

“Alpha power has been widely associated with cognitive effort during challenging listening conditions (e.g., Dimitrijevic et al., 2017; Dimitrijevic et al., 2019; Obleser et al., 2012; Paul et al., 2021; Petersen et al., 2015).”

“…work has shown similar patterns across alpha and theta bands in response to task difficulty manipulations in the context of effortful listening (Obleser et al., 2012; Cartocci et al., 2018; Petersen et al., 2015), we opted to average the mean power across the two frequency bands to derive a…”

“There is a possibility that in the present task, used in the reference to Obleser et al. (2012), the stimuli are more represented in numerical compared to verbal in working memory.”

“When the stimulus’s difficulty level reached more severe, the EEG alpha band power started to decrease (Hunter, 2022; Li et al., 2020; Obleser & Weisz, 2012; Obleser et al., 2012).”

“Therefore, to test for a potential interaction effect of speech type and SNR in source data, we conducted a follow-up region of interest (ROI) analysis on those voxels belonging to both the significant clusters of each factor (Obleser et al. 2012).”

“While some have found enhanced alpha power when hearing degraded speech (Becker et al., 2013; Obleser et al., 2012; Wöstmann et al., 2015), others have found the opposite effect (Hauswald et al., 2022; Miles et al., 2017).”

“g (Obleser et al., 2012)), putatively protecting the tobe-remembered information against interference.”

“…2015; Ding et al., 2016; Doelling et al., 2014; Peelle et al., 2013), whereas Alpha activity has been more consistently linked to attention control and the regulation of relevant and irrelevant information (Klimesch, 2012; Obleser et al., 2012; Wöstmann et al., 2017; Dimitrijevic et al., 2017).”

“…in different contexts); (2) t-values were subsequently z-transformed to account for different trial numbers in the cleaned data (as described in Obleser et al., 2012); (3) non-parametrical Monte Carlo cluster-based permutation tests with 2000 randomizations for 1600 ms after the onset of the…”

“It has been demonstrated that the cognitive effort related to challenging listening situations interferes with resources required for memory load and selective attention capacities [10].”

“Studies have demonstrated that alpha activity indexes speech intelligibility, with suppressed alpha power reflecting successful comprehension and increased power reflecting greater listening e ff ort [25], [27], [28], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45].”

“…oscillations between 8–12 Hz) as a potential neural marker of effort and demand has been studied extensively (Foxe and Snyder, 2011; Klimesch, 2012; Obleser et al., 2012; Strauß et al., 2014; Wostmann et al., 2015; Petersen et al., 2015; Dimitrijevic et al., 2019; Magosso et al., 2019; Price et…”

“…letters and numbers (Jensen et al., 2002; Klimesch et al., 1999; Schack & Klimesch, 841 2002), shape information (Herrmann et al., 2004; Johnson et al., 2011), spatial information 842 (Bastiaansen et al., 2002), and auditory stimuli (Lim et al., 2015; Obleser et al., 2012; Vogt et al., 843 1998).”

“The SMG has previously been observed to be crucial for stimulus maintenance in auditory working memory (van Dijk et al., 2010; Obleser et al., 2012 for increased alpha power in SMG during auditory working memory; Paulesu et al., 1993).”

“During adverse listening conditions, higher cognitive load has been linked to an increase in the power of the neural alpha activity (Obleser et al., 2012).”