Biology subjects

Fadeev, K. A.

Publications and source records attributed to Fadeev, K. A..

5 recordsLinked to original sources

bioRxiv2026

Top-down attention modulates auditory sustained responses but not the neural processing advantage for vowels

Temporal and spectral regularities characteristic of vowels are preferentially encoded by the auditory system, giving rise to a prolonged enhancement of a negative electromagnetic response in the auditory cortex - sustained negativity (SN). However, it remains unclear how sustained attention to the auditory stream interacts with this intrinsically enhanced processing. Here, we used MEG to examine SN and its differential response to vowel-like acoustic patterns versus spectrally complex noise, while modulating subjects attention to the auditory stimulation. Four stimulus types (600 ms duration; vowel-like sounds with and without pitch, periodic non-vowel sounds, and aperiodic noise) were presented to 30 adults during passive listening and an active gap-detection task. In 16% of randomly selected trials, a 50-ms silent gap was inserted into the stimuli, which served as a target. The number of non-target trials between successive targets ranged from 1 to 10, with the highest probability corresponding to an interval of six trials. Only non-target trials were analyzed. Analysis of reaction times and omission errors indicated that target expectancy increased with the number of trials since the previous target. Task-related attention enhanced an early orienting-related negativity ([~]50-150 ms) across all stimulus types, irrespective of target expectancy. It also accelerated the processing of periodicity in non-vocal sounds but did not affect the processing of vowels. In contrast, the later segment of the SN (150-600 ms) was strongly modulated by proximity to the previous target, decreasing immediately after target events and increasing as the likelihood of target occurrence rose. Despite these attentional and expectancy-related modulations, the enhanced neural processing of periodic vowels relative to noise remained stable. These findings indicate that sustained attention modulates both early and late SN responses and accelerates the extraction of periodicity in non-vocal sounds, yet does not alter the neural advantage conferred by vowel-related regularities.

neuroscience↗

bioRxiv2025

Vowel-like patterns modulate auditory P100m response but not its association with language abilities in children with ASD

BackgroundThe P100/P100m component of auditory event-related potentials/fields is considered a potential biomarker of atypical arousal and language abnormalities in children with ASD. When elicited by complex speech-like sounds with regular temporal or frequency structure, P100/P100m may be influenced by sustained negativity (SN), which can reduce its amplitude due to opposing current polarity. MethodsUsing MEG, we investigated how acoustic regularities affect P100m latency and amplitude differences between TD children and those with ASD. MEG was recorded in 35 ASD and 39 TD boys (7-12 years) in response to control sounds (non-periodic, non-vowels) and stimuli with temporal regularity (periodic non-vowels), frequency regularity (non-periodic vowels), or both (periodic vowels). P100m was estimated using distributed source localization. ResultsIn both groups, P100m amplitude and latency decreased in response to acoustic regularities, accompanied by a proportional increase in SN. No group differences were observed in P100m latency, amplitude, or their modulation by stimulus characteristics. In ASD, P100m latency variability was increased, and higher P100m amplitudes in the left auditory cortex were negatively associated with cumulative language and intellectual abilities. ConclusionsIn children, changes in P100m in response to acoustic regularities are most parsimoniously explained by an enhancement of SN with opposite polarity. No consistent relationship was found between P100m parameters or their modulation by acoustic regularities and ASD diagnosis. However, variations in cortical maturation and/or habituation processes, which affect the left-hemispheric P100m, may be relevant to cognitive and language functioning in children with ASD.

neuroscience↗

bioRxiv2024

Attenuated processing of vowels in the left hemisphere predicts speech-in-noise perception deficit in children with autism

BackgroundDifficulties with speech-in-noise perception in autism spectrum disorders (ASD) may be associated with impaired analysis of speech sounds, such as vowels, which represent the fundamental phoneme constituents of human speech. Vowels elicit early (< 100 ms) sustained processing negativity (SPN) in the auditory cortex that reflects the detection of an acoustic pattern based on the presence of formant structure and/or periodic envelope information (f0) and its transformation into an auditory "object". MethodsWe used magnetoencephalography (MEG) and individual brain models to investigate whether SPN is altered in children with ASD and whether this deficit is associated with impairment in their ability to perceive speech in the background of noise. MEG was recorded while boys with ASD and typically developing boys passively listened to sounds that differed in the presence/absence of f0 periodicity and formant structure. Word-in-noise perception was assessed in the separate psychoacoustic experiment using stationary and amplitude modulated noise with varying signal-to-noise ratio. ResultsSPN was present in both groups with similarly early onset. In children with ASD, SPN associated with processing formant structure was reduced predominantly in the cortical areas lateral to and medial to the primary auditory cortex, starting at [~] 150 - 200 ms after the stimulus onset. In the left hemisphere, this deficit correlated with impaired ability of children with ASD to recognize words in amplitude-modulated noise, but not in stationary noise ConclusionsThese results suggest that perceptual grouping of vowel formants into phonemes is impaired in children with ASD and that, in the left hemisphere, this deficit contributes to their difficulties with speech perception in fluctuating background noise.

neuroscience↗

bioRxiv2022

Different hemispheric lateralization for periodicity and formant structure of vowels in the auditory cortex and its changes between childhood and adulthood

The spectral formant structure and periodicity pitch are the major features that determine the identity of vowels and the characteristics of the speaker. However, very little is known about how the processing of these features in the auditory cortex changes during development. To address this question, we independently manipulated the periodicity and formant structure of vowels while measuring auditory cortex responses using MEG in children aged 7-12 years and adults. We analyzed the sustained negative shift of source current associated with these vowel properties, which was present in the auditory cortex in both age groups despite differences in the transient components of the auditory response. In adults, the sustained activation associated with formant structure was lateralized to the left hemisphere early in the auditory processing stream requiring neither attention nor semantic mapping. This lateralization was not yet established in children, in whom the right hemisphere contribution to formant processing was strong and decreased during or after puberty. In contrast to the formant structure, periodicity was associated with a greater response in the right hemisphere in both children and adults. These findings suggest that left-lateralization for the automatic processing of vowel formant structure emerges relatively late in ontogenesis and pose a serious challenge to current theories of hemispheric specialization for speech processing.

neuroscience↗

bioRxiv2019

Late ERP amplitude for self-face perception positively associated with heartbeat perception accuracy

Perception of yourself involves the integration of information from various sources. In a number of studies, it was found that the perception of ones own face is accompanied by an increase in the accuracy of perception of heartbeats and the amplitude of brain potentials caused by heart beats. In this study, subjects had to do a heartbeat count test to determine the accuracy of the interception. Then, the subjects were presented with the faces of an unknown person, a friend and the subjects own face. The simultaneous registration of EEG was organized. We analyzed the relationship between the amplitude of the evoked potentials when viewing these faces and the accuracy of interoception. It was found that the amplitude of the late EP component (850 - 1106 ms) has a positive correlation with IAcc in the central and right parietal and occipital areas when perceiving ones own face. According to the localization of distributed sources of activity, it was found that the connection is localized in the right anterior upper temporal cortex. Thus, the association between exteroceptive perception of ones own face and IAcc occurs in the late period of EP. Moreover it is localized in the right temporal region of the cortex, associated with multisensory integration and recognition of personal information.

neuroscience↗