The journal Scientific Reports publishes online on November 17, 2016, another paper from the Brainlab. The paper is entitled Timing predictability enhances regularity encoding in the human subcortical auditory pathway, and co-authored by Natàlia Gorina-Careta, Katarzina Zarnowiec, Jordi Costa-Faidella and Carles Escera.
Using the frequency-following response (FFR) as a proxy of subcortical auditory function, in this paper we show that regularity encoding is boosted by timing predictability in the human subcortical auditory system. This results confirm that regularity encoding is a pervasive property of the entire auditory hierarchy, and that timing predictability helps anticipate upcoming stimuli.
The full abstract reads as follows:
The encoding of temporal regularities is a critical property of the auditory system, as short-term neural representations of environmental statistics serve to auditory object formation and detection of potentially relevant novel stimuli. A putative neural mechanism underlying regularity encoding is repetition suppression, the reduction of neural activity to repeated stimulation. Although repetitive stimulation per se has shown to reduce auditory neural activity in animal cortical and subcortical levels and in the human cerebral cortex, other factors such as timing may influence the encoding of statistical regularities. This study was set out to investigate whether temporal predictability in the ongoing auditory input modulates repetition suppression in subcortical stages of the auditory processing hierarchy. Human auditory frequency–following responses (FFR) were recorded to a repeating consonant–vowel stimuli (/wa/) delivered in temporally predictable and unpredictable conditions. FFR amplitude was attenuated by repetition independently of temporal predictability, yet we observed an accentuated suppression when the incoming stimulation was temporally predictable. These findings support the view that regularity encoding spans across the auditory hierarchy and point to temporal predictability as a modulatory factor of regularity encoding in early stages of the auditory pathway.
Full reference. Gorina-Careta, N., Zarnowiec, K., Costa-Faidella, J., & Escera, C. (2016). Timing predictability enhances regularity encoding in the human subcortical auditory pathway. Scientific Reports, 6:37405. doi: 10.1038/srep37405.