A ubiquitous spectrolaminar motif of local field potential power across the primate cortex?

This is a commentary on a recently published paper. Mendoza-Halliday, Major et al., 2024 (“The Paper”) advocates a local field potential (LFP)-based approach to functional identification of cortical layers during “laminar” multielectrode recordings in nonhuman primates (NHPs). The broader goal is to substantiate the hypothesis of a ubiquitous spectrolaminar motif in NHP neocortex: gamma range activity originates in the upper layers and reflects feedforward activity, while alpha-beta activity originates in the lower layers and reflects feedback activity. In an impressive scientific effort, the authors analyze “laminar” data (simultaneous recordings from all cortical layers) collected from 14 cortical areas in 2 prior macaque studies and compare them to marmoset, mouse, and human data. Despite This Paper’s strengths, and its potential for scientific impact, a series of concerns that are fundamental to the analysis and interpretation of field potential signals, question its scientific foundations. The Paper also overstates the strength and prevalence of the spectrolaminar motif it advocates, and it understates key strengths and nuances of prior work.