A human intracranial study of long-range oscillatory coherence across a frontal–occipital–hippocampal brain network during visual object processing

doi:10.1073/pnas.0708418105

A human intracranial study of long-range oscillatory coherence across a frontal–occipital–hippocampal brain network during visual object processing

*Cognitive Neurophysiology Laboratory, Program in Cognitive Neuroscience and Schizophrenia, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962;
^†Program in Cognitive Neuroscience, Department of Psychology, City College of the City University of New York, North Academic Complex, 138th Street and Convent Avenue, New York, NY 10031;
^‡Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, 525 East 68th Street, New York, NY 10021;
^§Comprehensive Epilepsy Center, Long Island Jewish Medical Center, 270-05 76th Avenue, New Hyde Park, NY 11040; and
^¶Departments of Cell Biology and Anatomy and Neurology, New York Medical College, Basic Sciences Building, Room 217, Valhalla, NY 10595

Edited by Michael I. Posner, University of Oregon, Eugene, OR, and approved January 17, 2008 (received for review September 5, 2007)

Abstract

Visual object-recognition is thought to involve activation of a distributed network of cortical regions, nodes of which include the lateral prefrontal cortex, the so-called lateral occipital complex (LOC), and the hippocampal formation. It has been proposed that long-range oscillatory synchronization is a major mode of coordinating such a distributed network. Here, intracranial recordings were made from three humans as they performed a challenging visual object-recognition task that required them to identify barely recognizable fragmented line-drawings of common objects. Subdural electrodes were placed over the prefrontal cortex and LOC, and depth electrodes were placed within the hippocampal formation. Robust beta-band coherence was evident in all subjects during processing of recognizable fragmented images. Significantly lower coherence was evident during processing of unrecognizable scrambled versions of the same. The results indicate that transient beta-band oscillatory coupling between these three distributed cortical regions may reflect a mechanism for effective communication during visual object processing.

Footnotes

^‖To whom correspondence should be addressed. E-mail: foxe{at}nki.rfmh.org
Author contributions: P.S., S.M., and J.J.F. designed research; P.S., S.M., T.H.S., J.R.M., A.D.M., and J.J.F. performed research; P.S., S.M., J.R.M., and J.J.F. analyzed data; and P.S., S.M., T.H.S., A.D.M., D.C.J., P.K.S., and J.J.F. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/cgi/content/full/0708418105/DC1.