scholarly journals Neural correlates of perceptual switching while listening to bistable auditory streaming stimuli

2019 ◽  
Author(s):  
NC Higgins ◽  
DF Little ◽  
BD Yerkes ◽  
KM Nave ◽  
A Kuruvilla-Mathew ◽  
...  

AbstractUnderstanding the neural underpinning of conscious perception remains one of the primary challenges of cognitive neuroscience. Theories based mostly on studies of the visual system differ according to whether the neural activity giving rise to conscious perception occurs in modality-specific sensory cortex or in associative areas, such as the frontal and parietal cortices. Here, we search for modality-specific conscious processing in the auditory cortex using a bistable stream segregation paradigm that presents a constant stimulus without the confounding influence of physical changes to sound properties. ABA_ triplets (i.e., alternating low, A, and high, B, tones, and _ gap) with a 700 ms silent response period after every third triplet were presented repeatedly, and human participants reported nearly equivalent proportions of 1- and 2-stream percepts. The pattern of behavioral responses was consistent with previous studies of visual and auditory bistable perception. The intermittent response paradigm has the benefit of evoking spontaneous perceptual switches that can be attributed to a well-defined stimulus event, enabling precise identification of the timing of perception-related neural events with event-related potentials (ERPs). Significantly more negative ERPs were observed for 2-streams compared to 1-stream, and for switches compared to non-switches during the sustained potential (500-1000 ms post-stimulus onset). Further analyses revealed that the negativity associated with switching was independent of switch direction, suggesting that spontaneous changes in perception have a unique neural signature separate from the observation that 2-streams has more negative ERPs than 1-stream. Source analysis of the sustained potential showed activity associated with these differences originating in anterior superior temporal gyrus, indicating involvement of the ventral auditory pathway that is important for processing auditory objects.Significance StatementWhen presented with ambiguous stimuli, the auditory system takes the available information and attempts to construct a useful percept. When multiple percepts are possible from the same stimuli, however, perception fluctuates back and forth between alternating percepts in a bistable manner. Here, we examine spontaneous switches in perception using a bistable auditory streaming paradigm with a novel intermittent stimulus paradigm, and measure sustained electrical activity in anterior portions of auditory cortex using event-related potentials. Analyses revealed enhanced sustained cortical activity when perceiving 2-streams compared to 1-stream, and when a switch occurred regardless of switch direction. These results indicate that neural responses in auditory cortex reflect both the content of perception and neural dynamics related to switches in perception.

2019 ◽  
Vol 14 (10) ◽  
pp. 1073-1086 ◽  
Author(s):  
Sebastian Schindler ◽  
Gregory A Miller ◽  
Johanna Kissler

Abstract In the age of virtual communication, the source of a message is often inferred rather than perceived, raising the question of how sender attributions affect content processing. We investigated this issue in an evaluative feedback scenario. Participants were told that an expert psychotherapist, a layperson or a randomly acting computer was going to give them online positive, neutral or negative personality feedback while high-density EEG was recorded. Sender attribution affected processing rapidly, even though the feedback was on average identical. Event-related potentials revealed a linear increase with attributed expertise beginning 150 ms after disclosure and most pronounced for N1, P2 and early posterior negativity components. P3 and late positive potential amplitudes were increased for both human senders and for emotionally significant (positive or negative) feedback. Strikingly, feedback from a putative expert prompted large P3 responses, even for inherently neutral content. Source analysis localized early enhancements due to attributed sender expertise in frontal and somatosensory regions and later responses in the posterior cingulate and extended visual and parietal areas, supporting involvement of mentalizing, embodied processing and socially motivated attention. These findings reveal how attributed sender expertise rapidly alters feedback processing in virtual interaction and have implications for virtual therapy and online communication.


2004 ◽  
Vol 100 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Wolfgang Heinke ◽  
Ramona Kenntner ◽  
Thomas C. Gunter ◽  
Daniela Sammler ◽  
Derk Olthoff ◽  
...  

Background It is an open question whether cognitive processes of auditory perception that are mediated by functionally different cortices exhibit the same sensitivity to sedation. The auditory event-related potentials P1, mismatch negativity (MMN), and early right anterior negativity (ERAN) originate from different cortical areas and reflect different stages of auditory processing. The P1 originates mainly from the primary auditory cortex. The MMN is generated in or in the close vicinity of the primary auditory cortex but is also dependent on frontal sources. The ERAN mainly originates from frontal generators. The purpose of the study was to investigate the effects of increasing propofol sedation on different stages of auditory processing as reflected in P1, MMN, and ERAN. Methods The P1, the MMN, and the ERAN were recorded preoperatively in 18 patients during four levels of anesthesia adjusted with target-controlled infusion: awake state (target concentration of propofol 0.0 microg/ml), light sedation (0.5 microg/ml), deep sedation (1.5 microg/ml), and unconsciousness (2.5-3.0 microg/ml). Simultaneously, propofol anesthesia was assessed using the Bispectral Index. Results Propofol sedation resulted in a progressive decrease in amplitudes and an increase of latencies with a similar pattern for MMN and ERAN. MMN and ERAN were elicited during sedation but were abolished during unconsciousness. In contrast, the amplitude of the P1 was unchanged by sedation but markedly decreased during unconsciousness. Conclusion The results indicate differential effects of propofol sedation on cognitive functions that involve mainly the auditory cortices and cognitive functions that involve the frontal cortices.


2006 ◽  
Vol 18 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Joel S. Snyder ◽  
Claude Alain ◽  
Terence W. Picton

A general assumption underlying auditory scene analysis is that the initial grouping of acoustic elements is independent of attention. The effects of attention on auditory stream segregation were investigated by recording event-related potentials (ERPs) while participants either attended to sound stimuli and indicated whether they heard one or two streams or watched a muted movie. The stimuli were pure-tone ABA-patterns that repeated for 10.8 sec with a stimulus onset asynchrony between A and B tones of 100 msec in which the A tone was fixed at 500 Hz, the B tone could be 500, 625, 750, or 1000 Hz, and was a silence. In both listening conditions, an enhancement of the auditory-evoked response (P1-N1-P2 and N1c) to the B tone varied with f and correlated with perception of streaming. The ERP from 150 to 250 msec after the beginning of the repeating ABA-patterns became more positive during the course of the trial and was diminished when participants ignored the tones, consistent with behavioral studies indicating that streaming takes several seconds to build up. The N1c enhancement and the buildup over time were larger at right than left temporal electrodes, suggesting a right-hemisphere dominance for stream segregation. Sources in Heschl's gyrus accounted for the ERP modulations related to f-based segregation and buildup. These findings provide evidence for two cortical mechanisms of streaming: automatic segregation of sounds and attention-dependent buildup process that integrates successive tones within streams over several seconds.


2014 ◽  
Vol 28 (2) ◽  
pp. 73-81 ◽  
Author(s):  
Xue Du ◽  
Glenn Hitchman ◽  
Qing-Lin Zhang ◽  
Jiang Qiu

Previous studies pay more attention to the cognitive control in classical cognitive conflict task but the time-course of the expectation violation in a social comparison context remains unknown. Event-related potentials (ERPs) were recorded to explore the electrophysiological correlates of expectation violation by using a reward feedback paradigm in a social comparison context. Results showed that: Expectation incongruent stimuli (EIS) elicited a more positive ERP deflection (P400-700) than did expectation congruent stimuli (ECS) between 400 and 700 ms. Furthermore, dipole source analysis revealed that the generator of P400-700 was localized near the posterior cingulate gyrus (PCC), which might be involved in the monitoring and controlling of reward expectation conflict (expectation violation). EIS also elicited a more negative ERP deflection (N1000-1500) than did ECS between 1,000 and 1,500 ms. The generator of N1000-1500 was localized near the parahippocampal gyrus, which might be related to unpleasant emotions induced by a lack of reward feedback.


2019 ◽  
Author(s):  
Geoffrey Valentine ◽  
Margarita Zeitlin ◽  
Chu-Hsuan Kuo ◽  
Lee Osterhout

Abstract Background Scalp-recorded event-related potentials (ERPs) are poorly suited for certain types of source analysis. For example, it is often difficult to precisely assess whether two ERP waveforms were produced by similar neural sources, especially when the waveforms share the same polarity and a similar scalp topography and temporal dynamics. We report here an alternative method to establishing independence of neural sources grounded in the principle of superposition, which stipulates that electrical fields summate where they intersect in time and space. We assessed the independence of two frequently reported positive waves in the ERP literature, the P300 (elicited by unexpected stimuli) and P600 (elicited by syntactic anomalies). Subjects read sentences that contained a word that was either non-anomalous, unexpected in one feature (capitalized, different font, different font color, or ungrammatical), or unexpected in two features (capitalized and different font style, capitalized and different font color, or capitalized and ungrammatical). Thus, in the double anomaly condition, the similarity between a shared feature (i.e., capitalization) and a second feature was systematically manipulated across conditions from larger degree (i.e., font style) to lesser degree (i.e., ungrammatical) of feature similarity. Results We quantified the degree of source independence for the features of interest by applying a novel Additivity Index, which compares ERPs elicited by the doubly anomalous words to composite waveforms formed by mathematically summing the ERP response to singly anomalous words. The degree of source independence is reflected by the degree of summation, with Additivity scores ranging from 0 (completely non-independent) to 1 (completely independent). The computed Additivity Index values varied with feature similarity in the predicted direction: similar features demonstrated lower Additivity Index values, or lower degrees of independence. On the other hand, dissimilar features manifested robust additivity, resulting in larger AI values. Conclusion We quantified the degree to which the P600 and P300 effects are neurally distinct across stimulus features with varying degrees of similarity by computing a continuous measure of independence via the Additivity Index. These findings indicate that the Additivity Index provides a valid and general method for quantifying the neural independence of scalp-recorded brain potentials.


2019 ◽  
Author(s):  
Dan Xiang ◽  
Joseph Dien ◽  
Donald J. Bolger

AbstractThe visual word form area or VWFA has been of special interest for studies of reading and dyslexia and yet there are conflicting models regarding its function. Here we put the Local Combination Detector, Lexicon, and Interactive accounts to the test, using a combination of event-related potentials and functional magnetic resonance imaging. We do so using both pseudoword and reversed radical false word manipulations with Chinese characters, making use of its special properties. We recorded event-related potentials with 68 channels while twenty native Chinese speakers were making rhyme and meaning judgments on single Chinese characters and BOLD signals were collected in a 3T magnet using multi-plane EPI with a further fifteen native Chinese speakers. The word N170 showed a prolongation for reversed radical false characters while the VWFA also showed an effect of reversal, albeit only for pseudocharacters. Furthermore, an N450 rhyming effect was observed in the phonological task compared to the semantic task, but only via an interaction with reversal. The source analysis of the N450 co-registered with a Supplementary Motor Area activation. The combination of these observations suggests that the ventral orthographic pathway is partially order insensitive and that full phonological encoding occurs relatively late, supporting and expanding a model of dyslexia. Overall, they best support a version of the Lexicon account of the VWFA.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257380
Author(s):  
Marcel Franz ◽  
Barbara Schmidt ◽  
Holger Hecht ◽  
Ewald Naumann ◽  
Wolfgang H. R. Miltner

Several theories of hypnosis assume that responses to hypnotic suggestions are implemented through top-down modulations via a frontoparietal network that is involved in monitoring and cognitive control. The current study addressed this issue re-analyzing previously published event-related-potentials (ERP) (N1, P2, and P3b amplitudes) and combined it with source reconstruction and connectivity analysis methods. ERP data were obtained from participants engaged in a visual oddball paradigm composed of target, standard, and distractor stimuli during a hypnosis (HYP) and a control (CON) condition. In both conditions, participants were asked to count the rare targets presented on a video screen. During HYP participants received suggestions that a wooden board in front of their eyes would obstruct their view of the screen. The results showed that participants’ counting accuracy was significantly impaired during HYP compared to CON. ERP components in the N1 and P2 window revealed no amplitude differences between CON and HYP at sensor-level. In contrast, P3b amplitudes in response to target stimuli were significantly reduced during HYP compared to CON. Source analysis of the P3b amplitudes in response to targets indicated that HYP was associated with reduced source activities in occipital and parietal brain areas related to stimulus categorization and attention. We further explored how these brain sources interacted by computing time-frequency effective connectivity between electrodes that best represented frontal, parietal, and occipital sources. This analysis revealed reduced directed information flow from parietal attentional to frontal executive sources during processing of target stimuli. These results provide preliminary evidence that hypnotic suggestions of a visual blockade are associated with a disruption of the coupling within the frontoparietal network implicated in top-down control.


2015 ◽  
Author(s):  
Javier Sanchez-Lopez ◽  
Juan Silva-Pereyra ◽  
Thalia Fernandez

Background. Research on sports has revealed that behavioral responses and event-related brain potentials (ERP) are better in expert than in novice athletes for sport-related tasks. Focused attention is essential for optimal athletic performance across different sports but mainly in combat disciplines. During combat, long periods of focused attention (i.e., sustained attention) are required for a good performance. Few investigations have reported effects of expertise on brain electrical activity and its neural generators during sport-unrelated attention tasks. The aim of the present study was to assess the effect of expertise (i.e., skilled and novice martial arts athletes) analyzing the ERP during a sustained attention task (Continuous Performance Task; CPT) and the cortical three-dimensional distribution of current density, using the sLORETA technique. Methods. CPT consisted in an oddball-type paradigm presentation of five stimuli (different pointing arrows) where only one of them (an arrow pointing up right) required a motor response (i.e., target). CPT was administered to skilled and novice martial arts athletes while EEG were recorded. Amplitude ERP data from target and non-target stimuli were compared between groups. Subsequently, current source analysis for each ERP component was performed on each subject. sLORETA images were compared by condition and group using Statistical Non-Parametric Mapping analysis. Results. Skilled athletes showed significant amplitude differences between target and non-target conditions in early ERP components (P100 and P200) as opposed to the novice group; however, skilled athletes showed no significant effect of condition in N200 but novices did show a significant effect. Current source analysis showed greater differences in activations in skilled compared with novice athletes between conditions in the frontal (mainly in the Superior Frontal Gyrus and Medial Frontal Gyrus) and limbic (mainly in the Anterior Cingulate Gyrus) lobes. Discussion. These results are supported by previous findings regarding activation of neural structures that underlie sustained attention. Our findings may indicate a better-controlled attention in skilled athletes, which suggests that expertise can improve effectiveness in allocation of attentional resources during the first stages of cognitive processing during combat.


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