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).”

“The technique has been used widely in behavioral and brain imaging studies previously (Scott et al., 2000, 2006; Faulkner et al., 2001; Davis and Johnsrude, 2003; Obleser et al., 2007).”

“conductor (Nolte, 2003), and the lead field was calculated at each point in a grid with a 1 cm resolution.”

“Specifically, working memory (Pichora-Fuller et al., 1995; Rudner et al., 2011) and selective attention capacities (ShinnCunningham and Best, 2008; Kerlin et al., 2010) are affected by acoustic degradation.”

“…recent functional imaging studies have pointed out that suppression of BOLD activity (often reported to be anticorrelated with alpha power, Laufs et al., 2003; Sadaghiani et al., 2010) in cingulate areas (i.e., the “default” network, as well as in the TPJ) is pivotal to successful working…”

“The technique has been used widely in behavioral and brain imaging studies previously (Scott et al., 2000, 2006; Faulkner et al., 2001; Davis and Johnsrude, 2003; Obleser et al., 2007).”

“For source localization, we chose a procedure used in various previous studies localizing oscillatory power (Medendorp et al., 2007; Haegens et al., 2010; Hipp et al., 2011; Obleser and Weisz, 2012).”

“2), alpha power in the delay phase emerged mainly from posterior parietal cortex, in line with the often reported posterior alpha network (Foxe et al., 1998; Laufs et al., 2006).”

“The signal space separation method (SSS; Taulu et al., 2004) was applied to suppress external noise.”

“…imaging studies have pointed out that suppression of BOLD activity (often reported to be anticorrelated with alpha power, Laufs et al., 2003; Sadaghiani et al., 2010) in cingulate areas (i.e., the “default” network, as well as in the TPJ) is pivotal to successful working memory performance…”

“This is important because we did not aim at manipulating speech intelligibility per se but first and foremost aimed at manipulating the perceptual uncertainty and the concomitant effort evoked by degraded speech (Pisoni, 2000; Burkholder et al., 2005; Pichora-Fuller and Singh, 2006).”

“Acoustic degradation elicits perceptual uncertainty (Burkholder et al., 2005), which is likely to perpetuate into memory storage phases and interfere with resources required for memory load (Rabbitt, 1968; Wingfield et al., 2005; Piquado et al., 2010).”

“, 2011) and selective attention capacities (ShinnCunningham and Best, 2008; Kerlin et al., 2010) are affected by acoustic degradation.”

“2), alpha power in the delay phase emerged mainly from posterior parietal cortex, in line with the often reported posterior alpha network (Foxe et al., 1998; Laufs et al., 2006).”

“The technique has been used widely in behavioral and brain imaging studies previously (Scott et al., 2000, 2006; Faulkner et al., 2001; Davis and Johnsrude, 2003; Obleser et al., 2007).”

“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).”

“Obleser and Eisner (2009) have argued that the SMG should operate on a postcategorical “abstract” code, in line with its important role in the “phonological store” concept (Jacquemot and Scott, 2006; Buchsbaum and D’Esposito, 2008).”

“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.”

“For source localization, we chose a procedure used in various previous studies localizing oscillatory power (Medendorp et al., 2007; Haegens et al., 2010; Hipp et al., 2011; Obleser and Weisz, 2012).”

“In vocoding, the bands were equally spaced using the Greenwood formula (as implemented by Rosen et al., 1999); the filter center frequencies were linearly spaced on the log-frequency axis.”

“…of BOLD activity (often reported to be anticorrelated with alpha power, Laufs et al., 2003; Sadaghiani et al., 2010) in cingulate areas (i.e., the “default” network, as well as in the TPJ) is pivotal to successful working memory performance (Anticevic et al., 2010, 2011; Reas et al., 2011).”

“With respect to the comparably low number of trials per experimental cell, please note that all analyses were run as parametric analyses (Obleser et al., 2008).”

“Arguably the most important difference between visuospatial and auditory tasks is the dependence on the unfolding of time (Shamma, 2001): more so than in vision, the time required for encoding six digits (or, more realistically, an ongoing conversation) will trigger a neural cascade of encoding and…”

“This is important because we did not aim at manipulating speech intelligibility per se but first and foremost aimed at manipulating the perceptual uncertainty and the concomitant effort evoked by degraded speech (Pisoni, 2000; Burkholder et al., 2005; Pichora-Fuller and Singh, 2006).”

“These additional challenges might draw on neural resources that will in turn be lacking for other cognitive tasks (Heinrich and Schneider, 2011; Obleser and Weisz, 2012).”

“Specifically, working memory (Pichora-Fuller et al., 1995; Rudner et al., 2011) and selective attention capacities (ShinnCunningham and Best, 2008; Kerlin et al., 2010) are affected by acoustic degradation.”

“Importantly, the alpha-change pattern also showed a significant interaction, best characterized as an “expansive” (i.e., nonlinear) response function (Miller and Troyer, 2002; Duong and Freeman, 2008; Fig.”

“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).”

“For source localization, we chose a procedure used in various previous studies localizing oscillatory power (Medendorp et al., 2007; Haegens et al., 2010; Hipp et al., 2011; Obleser and Weisz, 2012).”

“Beamformer methods are known to encounter difficulties in resolving correlated sources, for example, from simultaneously active bilateral auditory cortex (Dalal et al., 2006).”

“Obleser and Eisner (2009) have argued that the SMG should operate on a postcategorical “abstract” code, in line with its important role in the “phonological store” concept (Jacquemot and Scott, 2006; Buchsbaum and D’Esposito, 2008).”

“The technique has been used widely in behavioral and brain imaging studies previously (Scott et al., 2000, 2006; Faulkner et al., 2001; Davis and Johnsrude, 2003; Obleser et al., 2007).”

“This is important for the auditory neuroscience of degraded hearing and aging, and functional MRI studies of listening to degraded speech have pointed in this direction before (Sharp et al., 2004; Harris et al., 2009).”

“…of BOLD activity (often reported to be anticorrelated with alpha power, Laufs et al., 2003; Sadaghiani et al., 2010) in cingulate areas (i.e., the “default” network, as well as in the TPJ) is pivotal to successful working memory performance (Anticevic et al., 2010, 2011; Reas et al., 2011).”

“Accordingly, alpha enhancement as 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 e…”

“The present data concur with these suggestions and emphasize how intertwined speech perception and verbal working memory are, particularly when coping with degraded input (Eisner et al., 2010).”

“Accordingly, alpha enhancement as 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 e…”

“This is important for the auditory neuroscience of degraded hearing and aging, and functional MRI studies of listening to degraded speech have pointed in this direction before (Sharp et al., 2004; Harris et al., 2009).”

“Acoustic degradation elicits perceptual uncertainty (Burkholder et al., 2005), which is likely to perpetuate into memory storage phases and interfere with resources required for memory load (Rabbitt, 1968; Wingfield et al., 2005; Piquado et al., 2010).”

“Accordingly, alpha enhancement as 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 e…”

“These additional challenges might draw on neural resources that will in turn be lacking for other cognitive tasks (Heinrich and Schneider, 2011; Obleser and Weisz, 2012).”

“Acoustic degradation elicits perceptual uncertainty (Burkholder et al., 2005), which is likely to perpetuate into memory storage phases and interfere with resources required for memory load (Rabbitt, 1968; Wingfield et al., 2005; Piquado et al., 2010).”

“…of BOLD activity (often reported to be anticorrelated with alpha power, Laufs et al., 2003; Sadaghiani et al., 2010) in cingulate areas (i.e., the “default” network, as well as in the TPJ) is pivotal to successful working memory performance (Anticevic et al., 2010, 2011; Reas et al., 2011).”

“Importantly, the alpha-change pattern also showed a significant interaction, best characterized as an “expansive” (i.e., nonlinear) response function (Miller and Troyer, 2002; Duong and Freeman, 2008; Fig.”

“…of BOLD activity (often reported to be anticorrelated with alpha power, Laufs et al., 2003; Sadaghiani et al., 2010) in cingulate areas (i.e., the “default” network, as well as in the TPJ) is pivotal to successful working memory performance (Anticevic et al., 2010, 2011; Reas et al., 2011).”

“Alpha rhythms reflects the cognitive system’s pre-stimulus preparation for incoming stimuli, enabling efficient processing (Babiloni et al., 2006), and have been associated with both WM load and processing of acoustically degraded stimuli (Obleser et al., 2011).”

“Obleser et al. (2012) used magnetoencephalography to compare the effects of increasing memory load during an explicit memory task and during degraded speech understanding.”

“…found modulations in alpha power in a variety of auditory tasks prompted by degraded spectral detail (Obleser and Weisz, 2012), missing temporal expectations (Wilsch et al., 2014), working memory load (Leiberg et al., 2006; Obleser et al., 2012), or syntactic complexity (Meyer et al., 2013).”