Columnar arrangements of neurons with similar preference have been suggested as the fundamental processing units of the cerebral cortex. Within these columnar arrangements, feed-forward information enters at middle cortical layers whereas feedback information arrives at superficial and deep layers. This interplay of feedforward and feedback processing is at the core of perception and behavior. Here we provide in vivo evidence consistent with a columnar organization of the processing of sound frequency in the human auditory cortex. We measure submillimeter functional responses to sound frequency sweeps at high magnetic fields (7 tesla) and show that frequency preference is stable through cortical depth in primary auditory cortex. Furthermore, we demonstrate that-in this highly columnar cortex-task demands sharpen the frequency tuning in superficial cortical layers more than in middle or deep layers. These findings are pivotal to understanding mechanisms of neural information processing and flow during the active perception of sounds.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Dec 29 2015|
Bibliographical noteFunding Information:
This work was supported in part by Biomedical Technology Resource Centers, National Institute of Biomedical Imaging and Bioengineering Grant P41 EB015894. The 7-T magnet purchase was funded in part by the W. M. Keck Foundation, National Science Foundation Grant DBI-9907842, and National Institutes of Health Grant S10 RR1395. R.G. was supported by European Research Council Grant ERC-2010-AdG, 269853. E.F. was funded by The Netherlands Organisation for Scientific Research (NWO) VICI Grant 453-12-002. F.D.M. was funded by NWO VIDI Grant 864-13-012. M.M. was funded by NWO Rubicon Grant 446-12-010.