The default network (DN) has been consistently associated with self-related cognition, but also to bodily state monitoring and autonomic regulation. We hypothesized that these two seemingly disparate functional roles of the DN are functionally coupled, in line theories proposing selfhood is grounded neural internal organs, such as heart. measured magnetoencephalograhy responses evoked by heartbeats while human participants freely mind-wandered. When interrupted a visual stimulus at random...

Several recent studies have demonstrated that the bottom-up signaling of a visual stimulus is subserved by interareal gamma-band synchronization, whereas top-down influences are mediated alpha-beta band synchronization. These processes may implement control processing if and mediating rhythms coupled via cross-frequency interaction. To test this possibility, we investigated Granger-causal among awake macaque primary area V1, higher V4, parietal 7a during attentional task performance....

A fundamental feature of the temporal organization neural activity is phase-amplitude coupling between brain rhythms at different frequencies, where amplitude a higher frequency varies according to phase lower frequency. Here, we show that this rule extends brain-organ interactions. We measured both infra-slow (~0.05Hz) rhythm intrinsically generated by stomach - gastric basal using electrogastrography, and spontaneous dynamics with magnetoencephalography during resting-state eyes open....

This technical paper offers a critical re-evaluation of (spectral) Granger causality measures in the analysis biological timeseries. Using realistic (neural mass) models coupled neuronal dynamics, we evaluate robustness parametric and nonparametric causality. Starting from broad class generative (state-space) show how their Volterra kernels prescribe second-order statistics response to random fluctuations; characterised terms cross-spectral density, cross-covariance, autoregressive...

Abstract Top-down modulation of sensory processing is a critical neural mechanism subserving numerous important cognitive roles, one which may be to inform lower-order systems the current ‘task at hand’ by conveying behavioral context these systems. Accumulating evidence indicates that top-down cortical influences are carried directed interareal synchronization oscillatory neuronal populations, with recent results pointing beta-frequency oscillations as particularly for processing. However,...

The quantification of covariance between neuronal activities (functional connectivity) requires the observation correlated changes and therefore multiple observations. strength such correlations may itself undergo moment-by-moment fluctuations, which might e.g. lead to fluctuations in single-trial metrics as reaction time (RT), or co-fluctuate with correlation activity other brain areas. Yet, quantifying relation co-fluctuations is precluded by fact that are not defined per single...

Abstract A framework is presented for quantifying functional network organization in the brain by spectral analysis based on autoregressive modeling. Local field potentials (LFPs), simultaneously recorded from distributed sites cerebral cortex of monkeys, are treated as signals generated local neuronal assemblies. During delay period a visual pattern discrimination task, oscillatory assembly activity manifested LFPs beta‐frequency range (14–30 Hz). Coherence has shown that these oscillations...

Hearing spoken words can enhance the recognition of visual object categories. Yet, mechanisms that underpin this facilitation are incompletely understood. Recent proposals suggest alter processes by activating category-specific representations in sensory regions. Here, we tested hypothesis neural oscillations serve as a mechanism to activate language-generated representations. Participants performed cue-picture matching task where cues were either words, their native or second language,...

There is a current interest in quantifying time-varying connectivity (TVC) based on neuroimaging data such as fMRI. Many methods have been proposed, and are being applied, revealing new insight into the brain's dynamics. However, given that ground truth for TVC brain unknown, many concerns remain regarding accuracy of proposed estimates. Since there exist it difficult to assess differences between studies. In this paper, we present tvc_benchmarker, which Python package containing four...

Through statistical learning (SL), cognitive systems may discover the underlying regularities in environment. Testing human adults (<i>n</i> = 35, 21 females), we document, context of a classical visual SL task, divergent rhythmic EEG activity interstimulus delay periods within patterns versus between (i.e., pattern transitions). Our findings reveal increased oscillatory beta band (∼20 Hz) at triplet transitions that indexes learning: it emerges with repetitions; and importantly, is highly...

Abstract Several recent studies have demonstrated that the bottom-up signaling of a visual stimulus is subserved by interareal gamma-band synchronization, whereas top-down influences are mediated alpha-beta band synchronization. These processes may implement control processing if and mediating rhythms coupled via cross-frequency interaction. To test this possibility, we investigated Granger-causal among awake male macaque primary area V1, higher V4 parietal 7a during attentional task...

Contextual information triggers predictions about the content ("what") of environmental stimuli to update an internal generative model surrounding world. However, visual dynamically changes across time, and temporal predictability ("when") may influence impact on processing. In this magnetoencephalography (MEG) study, we investigated how processing feature specific is affected by ("when"). Participants (N = 16) were presented with four consecutive Gabor patches (entrainers) constant spatial...

Abstract There is a current interest in quantifying brain dynamic functional connectivity (DFC) based on neuroimaging data such as fMRI. Many methods have been proposed, and are being applied, revealing new insight into the brain’s dynamics. However, given that ground truth for DFC unknown, many concerns remain regarding accuracy of proposed estimates. Since there exists it difficult to assess differences between studies. Here, we evaluate five different together represent wide spectrum...

Visual perception depends on prior experience. Previous encounters with visual objects allow an organism to form expectations about future encounters, and use those tune the system more efficiently process expected inputs. This paper explores proposition that expectation involves top-down modulation of neurons in low-level areas cortex anticipation stimuli. It reports evidence occurs within task-specific coherent oscillatory networks a macaque monkey, this is related stimulus processing efficiency.

Abstract Top-down modulation of sensory processing is a critical neural mechanism subserving number important cognitive roles. Principally, top-down influences appear to inform lower-order systems the current ‘task at hand’, and thus may convey behavioral context these systems. Accumulating evidence indicates that cortical are carried by directed interareal synchronization oscillatory neuronal populations. An question currently under investigation laboratories whether information conveyed...

Abstract One of the most central cognitive functions is attention. Its neuronal underpinnings have primarily been studied during conditions sustained Much less known about dynamics underlying processes shifting attention in space, as compared to maintaining it on one stimulus, and deploying a particular stimulus. Here, we use ECoG investigate four rhythms across large parts left hemisphere two macaque monkeys task that allows investigation deployment shifting. Shifting involved strong...

Abstract Predictive processing has been proposed as a fundamental cognitive mechanism to account for how the brain interacts with external environment via its sensory systems. In vision, contextual information triggers predictions about content (“ what ”) of environmental stimuli update an internal generative model surrounding world. However, visual dynamically changes across time, and temporal predictability when may influence impact on processing. this magnetoencephalography (MEG) study,...

Visual perception depends on prior experience. Previous encounters with visual objects allow an organism to form expectations about future encounters, and use those tune the system more efficiently process expected inputs. This paper explores proposition that expectation involves top-down modulation of neurons in low-level areas cortex anticipation stimuli. It reports evidence occurs within task-specific coherent oscillatory networks a macaque monkey, this is related stimulus processing efficiency.

Optimal human behavior depends on the expectancy of future events based perceptual analysis an individual's present situation using knowledge gained from past experience. This article explores proposition that neural processes underlying analysis, retrieval, and are all integrated through coordination large-scale networks cerebral cortex. It is proposed created when local expressing likely associated with coordinated as part totality relations concerning situation.

Abstract Statistical learning (SL) is taken to be the main mechanism by which cognitive systems discover underlying regularities of environment. We document, in context a classical visual SL task, divergent rhythmic EEG activity during anticipation stimuli within patterns versus pattern transitions. Our findings reveal differential pre-stimulus oscillatory beta band (∼20 Hz) that indexes learning: it emerges with increased repetitions, and importantly, highly correlated behavioral outcomes....