scholarly journals Neural Encoding of Attended Continuous Speech under Different Types of Interference

2018 ◽  
Vol 30 (11) ◽  
pp. 1606-1619 ◽  
Author(s):  
Andrea Olguin ◽  
Tristan A. Bekinschtein ◽  
Mirjana Bozic

We examined how attention modulates the neural encoding of continuous speech under different types of interference. In an EEG experiment, participants attended to a narrative in English while ignoring a competing stream in the other ear. Four different types of interference were presented to the unattended ear: a different English narrative, a narrative in a language unknown to the listener (Spanish), a well-matched nonlinguistic acoustic interference (Musical Rain), and no interference. Neural encoding of attended and unattended signals was assessed by calculating cross-correlations between their respective envelopes and the EEG recordings. Findings revealed more robust neural encoding for the attended envelopes compared with the ignored ones. Critically, however, the type of the interfering stream significantly modulated this process, with the fully intelligible distractor (English) causing the strongest encoding of both attended and unattended streams and latest dissociation between them and nonintelligible distractors causing weaker encoding and early dissociation between attended and unattended streams. The results were consistent over the time course of the spoken narrative. These findings suggest that attended and unattended information can be differentiated at different depths of processing analysis, with the locus of selective attention determined by the nature of the competing stream. They provide strong support to flexible accounts of auditory selective attention.

2021 ◽  
Author(s):  
Octave Etard ◽  
Rémy Ben Messaoud ◽  
Gabriel Gaugain ◽  
Tobias Reichenbach

AbstractSpeech and music are spectro-temporally complex acoustic signals that a highly relevant for humans. Both contain a temporal fine structure that is encoded in the neural responses of subcortical and cortical processing centres. The subcortical response to the temporal fine structure of speech has recently been shown to be modulated by selective attention to one of two competing voices. Music similarly often consists of several simultaneous melodic lines, and a listener can selectively attend to a particular one at a time. However, the neural mechanisms that enable such selective attention remain largely enigmatic, not least since most investigations to date have focussed on short and simplified musical stimuli. Here we study the neural encoding of classical musical pieces in human volunteers, using scalp electroencephalography (EEG) recordings. We presented volunteers with continuous musical pieces composed of one or two instruments. In the latter case, the participants were asked to selectively attend to one of the two competing instruments and to perform a vibrato identification task. We used linear encoding and decoding models to relate the recorded EEG activity to the stimulus waveform. We show that we can measure neural responses to the temporal fine structure of melodic lines played by one single instrument, at the population level as well as for most individual subjects. The neural response peaks at a latency of 7.6 ms and is not measurable past 15 ms. When analysing the neural responses elicited by competing instruments, we find no evidence of attentional modulation. Our results show that, much like speech, the temporal fine structure of music is tracked by neural activity. In contrast to speech, however, this response appears unaffected by selective attention in the context of our experiment.


1985 ◽  
Vol 16 (4) ◽  
pp. 260-266 ◽  
Author(s):  
Lee Ann Laraway

The purpose of this study was to determine whether there is a statistically significant difference between the auditory selective attention abilities of normal and cerebral-palsied individuals. Twenty-three cerebral-palsied and 23 normal subjects between the ages of 5 and 21 were asked to repeat a series of 30 items consisting of from 2 to 4 digits in the presence of intermittent white noise. Results of the study indicate that cerebral-palsied individuals perform significantly poorer than normal individuals when the stimulus is accompanied by noise. Noise was not a significant factor in the performance of the normal subjects regardless of age.


2019 ◽  
Vol 28 (4) ◽  
pp. 834-842
Author(s):  
Harini Vasudevan ◽  
Hari Prakash Palaniswamy ◽  
Ramaswamy Balakrishnan

Purpose The main purpose of the study is to explore the auditory selective attention abilities (using event-related potentials) and the neuronal oscillatory activity in the default mode network sites (using electroencephalogram [EEG]) in individuals with tinnitus. Method Auditory selective attention was measured using P300, and the resting state EEG was assessed using the default mode function analysis. Ten individuals with continuous and bothersome tinnitus along with 10 age- and gender-matched control participants underwent event-related potential testing and 5 min of EEG recording (at wakeful rest). Results Individuals with tinnitus were observed to have larger N1 and P3 amplitudes along with prolonged P3 latency. The default mode function analysis revealed no significant oscillatory differences between the groups. Conclusion The current study shows changes in both the early sensory and late cognitive components of auditory processing. The change in the P3 component is suggestive of selective auditory attention deficit, and the sensory component (N1) suggests an altered bottom-up processing in individuals with tinnitus.


Author(s):  
Julia Fritz ◽  
Gesine Dreisbach

The idea that conflicts are aversive signals recently has gained strong support by both physiological as well as psychological evidence. However, the time course of the aversive signal has not been subject to direct investigation. In the present study, participants had to judge the valence of neutral German words after being primed with conflict or non-conflict Stroop stimuli in three experiments with varying SOA (200 ms, 400 ms, 800 ms) and varying prime presentation time. Conflict priming effects (i.e., increased frequencies of negative judgments after conflict as compared to non-conflict primes) were found for SOAs of 200 ms and 400 ms, but absent (or even reversed) with a SOA of 800 ms. These results imply that the aversiveness of conflicts is evaluated automatically with short SOAs, but is actively counteracted with prolonged prime presentation.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Moritz Herbert Albrecht Köhler ◽  
Gianpaolo Demarchi ◽  
Nathan Weisz

AbstractBackgroundA long-standing debate concerns where in the processing hierarchy of the central nervous system (CNS) selective attention takes effect. In the auditory system, cochlear processes can be influenced via direct and mediated (by the inferior colliculus) projections from the auditory cortex to the superior olivary complex (SOC). Studies illustrating attentional modulations of cochlear responses have so far been limited to sound-evoked responses. The aim of the present study is to investigate intermodal (audiovisual) selective attention in humans simultaneously at the cortical and cochlear level during a stimulus-free cue-target interval.ResultsWe found that cochlear activity in the silent cue-target intervals was modulated by a theta-rhythmic pattern (~ 6 Hz). While this pattern was present independently of attentional focus, cochlear theta activity was clearly enhanced when attending to the upcoming auditory input. On a cortical level, classical posterior alpha and beta power enhancements were found during auditory selective attention. Interestingly, participants with a stronger release of inhibition in auditory brain regions show a stronger attentional modulation of cochlear theta activity.ConclusionsThese results hint at a putative theta-rhythmic sampling of auditory input at the cochlear level. Furthermore, our results point to an interindividual variable engagement of efferent pathways in an attentional context that are linked to processes within and beyond processes in auditory cortical regions.


2007 ◽  
Vol 44 (5) ◽  
pp. 711-727 ◽  
Author(s):  
Hilary Gomes ◽  
Martin Duff ◽  
Jack Barnhardt ◽  
Sophia Barrett ◽  
Walter Ritter

1953 ◽  
Vol 51 (2) ◽  
pp. 185-194 ◽  
Author(s):  
L. A. Allen ◽  
J. Grindley ◽  
Eileen Brooks

Chemical and bacteriological examination of muds from sources differing widely in the degree of pollution to which they were subject showed great differences in the contents of carbon, nitrogen and sulphide. These differences were not correlated with differences in the severity of faecal pollution. The amount of organic matter available for growth of micro-organisms in the mud of different depths was not reflected in the figures for organic carbon. A convenient index of this factor was obtained by measuring the volume of gas evolved during anaerobic digestion over a prolonged period of incubation. The rate of evolution was increased by the addition of an inoculum of digested sludge from a sewage works.Sulphate-reducing bacteria appeared to be of two different types. In samples of mud from fresh-water lakes much higher counts were usually obtained in a medium containing comparatively low concentrations of inorganic salts and of lactate than in a medium containing much higher concentrations of these constituents. In samples from locations where conditions were more saline the reverse was usually true.Counts of Bact. coli and of Strep, faecalis together probably constitute the best index of faecal pollution in the examination of samples of mud. These organisms are, however, largely confined to the surface layers.


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