Increased subcortical neural responses to repeating auditory stimulation in children with autism spectrum disorder.

Recent research has highlighted atypical reactivity to sensory stimulation as a core symptom in children with autism spectrum disorder (ASD). However, little is known about the dysfunctional neurological mechanisms underlying these aberrant sensitivities. Here we tested the hypothesis that the ability to filter out auditory repeated information is deficient in children with ASD already from subcortical levels, yielding to auditory sensitivities.

Deviance-Related Responses along the Auditory Hierarchy: Combined FFR, MLR and MMN Evidence.

The mismatch negativity (MMN) provides a correlate of automatic auditory discrimination in human auditory cortex that is elicited in response to violation of any acoustic regularity. Recently, deviance-related responses were found at much earlier cortical processing stages as reflected by the middle latency response (MLR) of the auditory evoked potential, and even at the level of the auditory brainstem as reflected by the frequency following response (FFR). However, no study has reported deviance-related responses in the FFR, MLR and long latency response (LLR) concurrently in a single recording protocol.

Regularity encoding and deviance detection of frequency modulated sweeps: human middle- and long-latency auditory evoked potentials.

Fast encoding of frequency modulated (FM) sweeps is crucial for communication. In humans, FM sweeps deviating from the acoustic regularity elicit the mismatch negativity (MMN) evoked potential. Yet, direction sensitivity to FM sweeps is found in animals' primary auditory cortex, upstream of MMN sources found in humans.

Detection of simple and pattern regularity violations occurs at different levels of the auditory hierarchy.

Auditory deviance detection in humans is indexed by the mismatch negativity (MMN), a component of the auditory evoked potential (AEP) of the electroencephalogram (EEG) occurring at a latency of 100-250 ms after stimulus onset. However, by using classic oddball paradigms, differential responses to regularity violations of simple auditory features have been found at the level of the middle latency response (MLR) of the AEP occurring within the first 50 ms after stimulus (deviation) onset. These findings suggest the existence of fast deviance detection mechanisms for simple feature changes, but it is not clear whether deviance detection among more complex acoustic regularities could be observed at such early latencies.

Is fast auditory change detection feature specific? An electrophysiological study in humans.

Recent oddball studies showed that auditory change detection responses exist in the first 50 ms after sound onset, upstream of mismatch negativity (MMN). We examined if these early responses could be elicited by feature-specific changes, meaning changes in the value of one attribute of a stimulus, regardless of whether other attributes of the stimulus are changing or not. We used a multifeature paradigm with four types of deviants: frequency, duration, intensity, and interaural time difference.