EEG Spatiotemporal Patterns Underlying Self-other Voice Discrimination

Effects of observing own/others hand movement in different perspectives on mu rhythm suppression: an EEG study

BACKGROUND

Previous studies have reported that the sense of "self" is associated with specific brain regions and neural network activities. In addition, the mirror system, which functions when executing or observing an action, might contribute to differentiating the self from others and form the basis of the sense of self as a fundamental physical representation. This study investigated whether differences in mu suppression, an indicator of mirror system activity, reflect cognitions related to self-other discrimination.

METHODS

The participants were 30 of healthy college students. The participants observed short video clips of hand movements performed by themselves or actors from two perspectives (i.e., first-person and third-person). The electroencephalogram (EEG) mu rhythm (8-13 Hz) was measured during video observation as an index of mirror neuron system activity. EEG activity related to self-detection was analyzed using participants' hand movements as self-relevant stimuli.

RESULTS

The results showed that mu suppression in the 8-13-Hz range exhibited perspective-dependent responses to self/other stimuli. There was a significant self-oriented mu suppression response in the first-person perspective. However, the study found no significant response orientation in the third-person perspective. The results suggest that mirror system activity may involve self-other discrimination differently depending on the perspective.

CONCLUSIONS

In summary, this study examined the mirror system's activity for self and others using the EEG's mu suppression. As a result, it was suggested that differences in self and others or perspectives may influence mu suppression.

Neural adaptation to changes in self-voice during puberty

The human voice is a potent social signal and a distinctive marker of individual identity. As individuals go through puberty, their voices undergo acoustic changes, setting them apart from others. In this article, we propose that hormonal fluctuations in conjunction with morphological vocal tract changes during puberty establish a sensitive developmental phase that affects the monitoring of the adolescent voice and, specifically, self-other distinction. Furthermore, the protracted maturation of brain regions responsible for voice processing, coupled with the dynamically evolving social environment of adolescents, likely disrupts a clear differentiation of the self-voice from others' voices. This socioneuroendocrine framework offers a holistic understanding of voice monitoring during adolescence.

EEG Microstates in Social and Affective Neuroscience

Social interactions require both the rapid processing of multifaceted socio-affective signals (e.g., eye gaze, facial expressions, gestures) and their integration with evaluations, social knowledge, and expectations. Researchers interested in understanding complex social cognition and behavior face a "black box" problem: What are the underlying mental processes rapidly occurring between perception and action and why are there such vast individual differences? In this review, we promote electroencephalography (EEG) microstates as a powerful tool for both examining socio-affective states (e.g., processing whether someone is in need in a given situation) and identifying the sources of heterogeneity in socio-affective traits (e.g., general willingness to help others). EEG microstates are identified by analyzing scalp field maps (i.e., the distribution of the electrical field on the scalp) over time. This data-driven, reference-independent approach allows for identifying, timing, sequencing, and quantifying the activation of large-scale brain networks relevant to our socio-affective mind. In light of these benefits, EEG microstates should become an indispensable part of the methodological toolkit of laboratories working in the field of social and affective neuroscience.

Exploring the Association Between EEG Microstates During Resting-State and Error-Related Activity in Young Children

The error-related negativity (ERN) is a negative deflection in the electroencephalography (EEG) waveform at frontal-central scalp sites that occurs after error commission. The relationship between the ERN and broader patterns of brain activity measured across the entire scalp that support error processing during early childhood is unclear. We examined the relationship between the ERN and EEG microstates - whole-brain patterns of dynamically evolving scalp potential topographies that reflect periods of synchronized neural activity - during both a go/no-go task and resting-state in 90, 4-8-year-old children. The mean amplitude of the ERN was quantified during the -64 to 108 millisecond (ms) period of time relative to error commission, which was determined by data-driven microstate segmentation of error-related activity. We found that greater magnitude of the ERN associated with greater global explained variance (GEV; i.e., the percentage of total variance in the data explained by a given microstate) of an error-related microstate observed during the same -64 to 108 ms period (i.e., error-related microstate 3), and to greater anxiety risk as measured by parent-reported behavioral inhibition. During resting-state, six data-driven microstates were identified. Both greater magnitude of the ERN and greater GEV values of error-related microstate 3 associated with greater GEV values of resting-state microstate 4, which showed a frontal-central scalp topography. Source localization results revealed overlap between the underlying neural generators of error-related microstate 3 and resting-state microstate 4 and canonical brain networks (e.g., ventral attention) known to support the higher-order cognitive processes involved in error processing. Taken together, our results clarify how individual differences in error-related and intrinsic brain activity are related and enhance our understanding of developing brain network function and organization supporting error processing during early childhood.

Central Representation of Cervical Vestibular Evoked Myogenic Potentials

Sensitivity of vestibular system to sounds (SVSS) can be measureable by cervical vestibular evoked myogenic potentials (cVEMPs). The aim of this study is to investigate central representation of vestibular system sensitivity to sound. The research was conducted in 2022-2023 by searching English language databases. The criterion for selecting documents was their overlap with the aim of this work. The animals studies were not included. The saccule is stimulated by sounds, that are transmitted through air and bone conduction. Utricle and semicircular canals are activated only by the vibrations. The afferent nerve fibers of the vestibular system project to the temporal, frontal, parietal, primary visual cortex, insula and the cingulate cortex. There is a relationship between normal results of the cVEMPs and these parameters. Improved phonemes recognition scores and word recognition scores in white noise, the efficiency of auditory training, incraed amplitude of the auditory brainstem responses to 500 HZ tone burst. Learning the first words is not only based on the hearing and other senses participate. The auditory object is a three-dimensional imaging in people's minds, when they hear a word. The words expressed by a speaker create different auditory objects in people's minds. Each of these auditory objects has its own color, shape, aroma and characteristics. For the formation of the auditory objects, all senses and whole areas of the brain contribute. Like other senses, central representation of vestibular system sensitivity to sound are also involved in the formation of auditory objects.

Exploring the association between EEG microstates during resting-state and error-related activity in young children

The error-related negativity (ERN) is a negative deflection in the electroencephalography (EEG) waveform at frontal-central scalp sites that occurs after error commission. The relationship between the ERN and broader patterns of brain activity measured across the entire scalp that support error processing during early childhood is unclear. We examined the relationship between the ERN and EEG microstates - whole-brain patterns of dynamically evolving scalp potential topographies that reflect periods of synchronized neural activity - during both a go/no-go task and resting-state in 90, 4-8-year-old children. The mean amplitude of the ERN was quantified during the - 64 to 108 millisecond (ms) period of time relative to error commission, which was determined by data-driven microstate segmentation of error-related activity. We found that greater magnitude of the ERN associated with greater global explained variance (GEV; i.e., the percentage of total variance in the data explained by a given microstate) of an error-related microstate observed during the same - 64 to 108 ms period (i.e., error-related microstate 3), and to greater parent-report-measured anxiety risk. During resting-state, six data-driven microstates were identified. Both greater magnitude of the ERN and greater GEV values of error-related microstate 3 associated with greater GEV values of resting-state microstate 4, which showed a frontal-central scalp topography. Source localization results revealed overlap between the underlying neural generators of error-related microstate 3 and resting-state microstate 4 and canonical brain networks (e.g., ventral attention) known to support the higher-order cognitive processes involved in error processing. Taken together, our results clarify how individual differences in error-related and intrinsic brain activity are related and enhance our understanding of developing brain network function and organization supporting error processing during early childhood.

Bone conduction facilitates self-other voice discrimination

One's own voice is one of the most important and most frequently heard voices. Although it is the sound we associate most with ourselves, it is perceived as strange when played back in a recording. One of the main reasons is the lack of bone conduction that is inevitably present when hearing one's own voice while speaking. The resulting discrepancy between experimental and natural self-voice stimuli has significantly impeded self-voice research, rendering it one of the least investigated aspects of self-consciousness. Accordingly, factors that contribute to self-voice perception remain largely unknown. In a series of three studies, we rectified this ecological discrepancy by augmenting experimental self-voice stimuli with bone-conducted vibrotactile stimulation that is present during natural self-voice perception. Combining voice morphing with psychophysics, we demonstrate that specifically self-other but not familiar-other voice discrimination improved for stimuli presented using bone as compared with air conduction. Furthermore, our data outline independent contributions of familiarity and acoustic processing to separating the own from another's voice: although vocal differences increased general voice discrimination, self-voices were more confused with familiar than unfamiliar voices, regardless of their acoustic similarity. Collectively, our findings show that concomitant vibrotactile stimulation improves auditory self-identification, thereby portraying self-voice as a fundamentally multi-modal construct.

Breathing affects self-other voice discrimination in a bodily state associated with somatic passivity

A growing number of studies have focused on identifying cognitive processes that are modulated by interoceptive signals, particularly in relation to the respiratory or cardiac cycle. Considering the fundamental role of interoception in bodily self‐consciousness, we here investigated whether interoceptive signals also impact self‐voice perception. We applied an interactive, robotic paradigm associated with somatic passivity (a bodily state characterized by illusory misattribution of self‐generated touches to someone else) to investigate whether somatic passivity impacts self‐voice perception as a function of concurrent interoceptive signals. Participants' breathing and heartbeat signals were recorded while they performed two self‐voice tasks (self‐other voice discrimination and loudness perception) and while simultaneously experiencing two robotic conditions (somatic passivity condition; control condition). Our data reveal that respiration, but not cardiac activity, affects self‐voice perception: participants were better at discriminating self‐voice from another person’s voice during the inspiration phase of the respiration cycle. Moreover, breathing effects were prominent in participants experiencing somatic passivity and a different task with the same stimuli (i.e., judging the loudness and not identity of the voices) was unaffected by breathing. Combining interoception and voice perception with self‐monitoring framework, these data extend findings on breathing‐dependent changes in perception and cognition to self‐related processing.

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We combined psychophysics with robotics and voice‐morphing technology to evaluate the effect of breathing on self‐voice perception. Our results show that listeners better perceive their own voice during inspiration, an effect that is modulated by self‐related bodily processing. This extends previous findings documenting the effect of interoceptive signals on perception and suggests that the bodily self may serve as a scaffold for cognition.