Biology subjects

Rytikova, A. M.

Publications and source records attributed to Rytikova, A. M..

2 recordsLinked to original sources

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↗