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. Amplitude-modulated
(AM) sounds were presented to healthy human participants in a frequency oddball paradigm
to investigate deviance-related responses along the auditory hierarchy in the ranges
of FFR, MLR and LLR. AM frequency deviants modulated the FFR, the Na and Nb components
of the MLR, and the LLR eliciting the MMN. These findings demonstrate that it is possible
to elicit deviance-related responses at three different levels (FFR, MLR and LLR) in one
single recording protocol, highlight the involvement of the whole auditory hierarchy in deviance
detection and have implications for cognitive and clinical auditory neuroscience. Moreover,
the present protocol provides a new research tool into clinical neuroscience so that the
functional integrity of the auditory novelty system can now be tested as a whole in a range of
clinical populations where the MMN was previously shown to be defective