Accurately measuring and quantifying the underlying interactions between brain areas is crucial for understanding the flow of information in the brain. Of particular interest in the field of electrophysiology is the analysis and characterization of the spectral properties of these interactions. Coherence and Granger-Geweke causality are well-established, commonly used methods for quantifying inter-areal interactions, and are thought to reflect the strength of inter-areal interactions. Here we show that the application of both methods to bidirectional systems with transmission delays is problematic, especially for coherence. Under certain circumstances, coherence can be completely abolished despite there being a true underlying interaction. This problem occurs due to interference caused in the computation of coherence, and is an artifact of the method. We motivate an understanding of the problem through computational modelling and numerical simulations. In addition, we have developed two methods that can recover the true bidirectional interactions in the presence of transmission delays.
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http://dx.doi.org/10.1016/j.neuroimage.2023.119998 | DOI Listing |
bioRxiv
December 2024
Center for Neural Science, New York University, New York, NY, USA.
Neocortex-wide neural activity is organized into distinct networks of areas engaged in different cognitive processes. To elucidate the underlying mechanism of flexible network reconfiguration, we developed connectivity-constrained macaque and human whole-cortex models. In our model, within-area connectivity consists of a mixture of symmetric, asymmetric, and random motifs that give rise to stable (attractor) or transient (sequential) heterogeneous dynamics.
View Article and Find Full Text PDFiScience
November 2024
Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
Neuronal oscillations are ubiquitous in brain activity at all scales and their synchronization dynamics are essential for information processing in neuronal systems. The underlying synaptic mechanisms, while mainly based on GABA- and glutamatergic neurotransmission, are influenced by neuromodulatory systems that have highly variable densities of neurotransmitter receptors and transporters across the cortical mantle. How they constrain the network structures of interacting oscillations has remained a central unaddressed question.
View Article and Find Full Text PDFCurr Biol
October 2024
Nash Family Department of Neuroscience, Lipschultz Center for Cognitive Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA. Electronic address:
Macaque ventral frontal cortex is composed of a set of anatomically heterogeneous and highly interconnected areas. Collectively, these areas have been implicated in many higher-level affective and cognitive processes, most notably the adaptive control of decision-making. Despite this appreciation, little is known about how subdivisions of ventral frontal cortex dynamically interact with each other during decision-making.
View Article and Find Full Text PDFbioRxiv
July 2024
Nash Family Department of Neuroscience, Lipschultz Center for Cognitive Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
Macaque ventral frontal cortex is comprised of a set of anatomically heterogeneous and highly interconnected areas. Collectively these areas have been implicated in many higher-level affective and cognitive processes, most notably the adaptive control of decision-making. Despite this appreciation, little is known about how subdivisions of ventral frontal cortex dynamically interact with each other during decision-making.
View Article and Find Full Text PDFSci Rep
June 2024
Department of psychological and cognitive sciences, Tsinghua University, Beijing, China.
Attention is often viewed as a mental spotlight, which can be scaled like a zoom lens at specific spatial locations and features a center-surround gradient. Here, we demonstrate a neural signature of attention spotlight in signal transmission along the visual hierarchy. fMRI background connectivity analysis was performed between retinotopic V1 and downstream areas to characterize the spatial distribution of inter-areal interaction under two attentional states.
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