Alpha-Beta and Gamma Rhythms Subserve Feedback and Feedforward Influences among Human Visual Cortical Areas

• Published in: Neuron (Cambridge, Mass.) Vol. 89; no. 2; pp. 384 - 397
• Main Authors: Michalareas, Georgios, Vezoli, Julien, van Pelt, Stan, Schoffelen, Jan-Mathijs, Kennedy, Henry, Fries, Pascal
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 20.01.2016; Elsevier Limited
• Subjects: Alpha Rhythm - physiology; Animals; Beta Rhythm - physiology; Bias; Feedback; Feedback, Physiological - physiology; Female; Gamma Rhythm - physiology; Human subjects; Humans; Investigations; Macaca; Male; Sensors; Visual Cortex - physiology; Visual Pathways - physiology; Visual Perception - physiology
• ISSN: 0896-6273; 1097-4199; 1097-4199
• DOI: 10.1016/j.neuron.2015.12.018

Primate visual cortex is hierarchically organized. Bottom-up and top-down influences are exerted through distinct frequency channels, as was recently revealed in macaques by correlating inter-areal influences with laminar anatomical projection patterns. Because this anatomical data cannot be obtained in human subjects, we selected seven homologous macaque and human visual areas, and we correlated the macaque laminar projection patterns to human inter-areal directed influences as measured with magnetoencephalography. We show that influences along feedforward projections predominate in the gamma band, whereas influences along feedback projections predominate in the alpha-beta band. Rhythmic inter-areal influences constrain a functional hierarchy of the seven homologous human visual areas that is in close agreement with the respective macaque anatomical hierarchy. Rhythmic influences allow an extension of the hierarchy to 26 human visual areas including uniquely human brain areas. Hierarchical levels of ventral- and dorsal-stream visual areas are differentially affected by inter-areal influences in the alpha-beta band. •Gamma mediates forward and alpha-beta feedback influences among human visual areas•Human inter-areal directed influences correlate with macaque laminar connectivity•Rhythmic inter-areal influences establish a hierarchy of 26 human visual areas•Alpha-beta influences differentially affect ventral- and dorsal-stream visual areas Michalareas et al. show that in human visual cortex influences along feedforward projections predominate in the gamma band, whereas influences along feedback projections predominate in the alpha-beta band. These influences constrain a functional hierarchy in agreement with macaque anatomical hierarchy.