Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex.

Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex.
Hear Res. 2017 Sep 11;:
Authors: Weisz N, Lithari C
Abstract
Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what extent within auditory cortex different modulation frequencies elicit aSSRs at a homogenous source or whether the localization of the aSSR is topographically organized in a systematic manner. The latter would be suggested by previous neuroimaging works in monkeys and humans showing a periodotopic organization within and across distinct auditory fields. However, the sluggishness of the signal from these neuroimaging works prohibit inferences with regards to the fine-temporal features of the neural response. In the present study, we employed amplitude-modulated (AM) sounds over a range between 4 and 85 Hz to elicit aSSRs while recording brain activity via mag...

Source: Hearing Research - September 11, 2017 Category: Audiology Authors: Weisz N, Lithari C Tags: Hear Res Source Type: research