Delta-alpha/beta coupling as a signature of visual working memory in the prefrontal cortex

Mohammad Aliramezani; Ashkan Farrokhi; Christos Constantinidis; Mohammad Reza Daliri

doi:10.1016/j.isci.2024.110453

Delta-alpha/beta coupling as a signature of visual working memory in the prefrontal cortex

iScience. 2024 Jul 3;27(8):110453. doi: 10.1016/j.isci.2024.110453. eCollection 2024 Aug 16.

Authors

Mohammad Aliramezani¹, Ashkan Farrokhi¹, Christos Constantinidis², Mohammad Reza Daliri^{1

3}

Affiliations

¹ School of Cognitive Sciences (SCS), Institute for Research in Fundamental Sciences (IPM), Tehran 19568-36613, Iran.
² Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA.
³ Department of Biomedical Engineering, School of Electrical Engineering, Iran University of Science and Technology (IUST), Tehran 16846-13114, Iran.

Abstract

Executive functions, particularly visual working memory, depend on the prefrontal cortex (PFC). Phase-amplitude coupling (PAC) has been proposed as a measure of synchronized brain oscillations. To study the neural correlates of working memory in cross-frequency interactions, local field potential (LFP) recordings were made in the PFC of two macaque monkeys. PAC analysis revealed that the delta band (1-5 Hz) phase modulated the alpha-beta band (8-33 Hz) amplitude throughout task epochs, in both the pre- and post-training stages. The elevation of δ-αβ PAC in the fixation period during post-training was a signature of task learning. Interestingly, the δ-αβ PAC was not enhanced in error trials compared to correct trials, and the subject's performance was strictly dependent on the orchestration of the delta phase. Furthermore, contrary to the dorsoventral functional specialization of PFC, spatial and shape stimuli induced the same pattern of PAC in PFC subdivisions.

Keywords: Biological sciences; Cell; Neuroscience.