Context Sensitivity across Multiple Time scales with a Flexible Frequency Bandwidth. (21st July 2021)

• Record Type: Journal Article
• Authors: Regev, Tamar I; Markusfeld, Geffen; Deouell, Leon Y; Nelken, Israel
• Is Part Of: Cerebral cortex. Volume 32:Number 1(2022)
• Page Start: 158
• Page End: 175
• Publication Date: 2021-07-21
• Subjects: adaptation -- computational modeling -- EEG -- ERP -- human auditory cortex; Cerebral cortex -- Periodicals; Brain -- Periodicals; 612.825
• DOI: 10.1093/cercor/bhab200
• Languages: English
• ISSNs: 1047-3211

Abstract

Abstract: Everyday auditory streams are complex, including spectro-temporal content that varies at multiple timescales. Using EEG, we investigated the sensitivity of human auditory cortex to the content of past stimulation in unattended sequences of equiprobable tones. In 3 experiments including 82 participants overall, we found that neural responses measured at different latencies after stimulus onset were sensitive to frequency intervals computed over distinct timescales. Importantly, early responses were sensitive to a longer history of stimulation than later responses. To account for these results, we tested a model consisting of neural populations with frequency-specific but broad tuning that undergo adaptation with exponential recovery. We found that the coexistence of neural populations with distinct recovery rates can explain our results. Furthermore, the adaptation bandwidth of these populations depended on spectral context—it was wider when the stimulation sequence had a wider frequency range. Our results provide electrophysiological evidence as well as a possible mechanistic explanation for dynamic and multiscale context-dependent auditory processing in the human cortex.