A5033414200- Neural dynamics and brain function
- EEG and Brain-Computer Interfaces
- Functional Brain Connectivity Studies
- Neuroscience and Neural Engineering
- Visual perception and processing mechanisms
- Photoreceptor and optogenetics research
- Neuroscience and Neuropharmacology Research
- Action Observation and Synchronization
- Neural and Behavioral Psychology Studies
- Neural Networks and Applications
- Memory and Neural Mechanisms
- Blind Source Separation Techniques
- Neurobiology of Language and Bilingualism
- Wireless Body Area Networks
- Neurobiology and Insect Physiology Research
- Advanced Memory and Neural Computing
- stochastic dynamics and bifurcation
- Mental Health Research Topics
- Language, Metaphor, and Cognition
- Molecular Communication and Nanonetworks
- Advanced Chemical Sensor Technologies
- Digital Communication and Language
- Genetics and Neurodevelopmental Disorders
- Language and cultural evolution
- Child and Animal Learning Development
University of Amsterdam
2016-2025
Netherlands Institute for Neuroscience
2015-2024
Radboud University Nijmegen
2015-2024
Universidad Autónoma de Chile
2011-2018
Amsterdam University of the Arts
2012
Pontificia Universidad Católica de Chile
2004-2008
Clínica MEDS (Chile)
2005
University of Chile
2001
University of Padua
1993
University of Pisa
1967
We present a micromachined 252-channel ECoG (electrocorticogram)-electrode array, which is made of thin polyimide foil substrate enclosing sputtered platinum electrode sites and conductor paths. The array subtends an area approximately 35 mm by 60 designed to cover large parts hemisphere macaque monkey's cortex. Eight omnetics connectors are directly soldered the foil. This leads compact assembly size enables chronic implantation allows free movements animal between recording sessions. 1 in...
Theta rhythms govern rodent sniffing and whisking, human language processing. Human psychophysics suggests a role for theta also in visual attention. However, little is known about areas its attentional modulation. We used electrocorticography (ECoG) to record local field potentials (LFPs) simultaneously from V1, V2, V4, TEO of two macaque monkeys performing selective attention task. found ≈4-Hz rhythm within both the V1-V2 V4-TEO region, synchronization between them, with predominantly...
Rhythms occur both in neuronal activity and behavior. Behavioral rhythms abound at frequencies or below 10 Hz. Neuronal cover a very wide frequency range, the phase of low-frequency often rhythmically modulates strength higher-frequency rhythms, particularly gamma-band synchronization (GBS). Here, we study stimulus-induced GBS awake monkey areas V1 V4 relation to specific form spontaneous behavior, namely microsaccades (MSs), small fixational eye movements. We found that MSs ∼3.3 The...
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....
This paper reports a dynamic causal modeling study of electrocorticographic (ECoG) data that addresses functional asymmetries between forward and backward connections in the visual cortical hierarchy. Specifically, we ask whether employ gamma-band frequencies, while preferentially use lower (beta-band) frequencies. We addressed this question by empirical cross spectra using neural mass model equipped with superficial deep pyramidal cell populations-that source connections, respectively....
Gamma-band activity in visual cortex has been implicated several cognitive operations, like perceptual grouping and attentional selection. So far, it studied primarily under well-controlled fixation conditions using stimuli, isolated bars or patches of grating. If gamma-band is to subserve its purported functions outside the laboratory, should be present during natural viewing conditions. We recorded neuronal with a 252-channel electrocorticographic (ECoG) grid covering large parts left...
Significance When a visual stimulus repeats multiple times, cortical neurons show decreasing firing rate responses, yet neither perception nor stimulus-related behavior is compromised. We that repetition leads to increased neuronal gamma-band (∼40–90 Hz) synchronization within and between early higher areas. The enhanced likely maintains effective signaling in the face of dwindling rates. also gamma rhythm increases for spikes general those putative interneurons, whereas it decreases...
Cognitive functions are subserved by rhythmic neuronal synchronization across widely distributed brain areas. In 105 area pairs, we investigated functional connectivity (FC) through coherence, power correlation, and Granger causality (GC) in the theta, beta, high-beta, gamma rhythms. Between rhythms, spatial FC patterns were largely independent. Thus, rhythms defined distinct interaction networks. Importantly, networks of coherence GC not explained distributions strengths Those networks,...
Abstract Circuits of excitatory and inhibitory neurons generate gamma-rhythmic activity (30–80 Hz). Gamma-cycles show spontaneous variability in amplitude duration. To investigate the mechanisms underlying this variability, we recorded local-field-potentials (LFPs) spikes from awake macaque V1. We developed a noise-robust method to detect gamma-cycle amplitudes durations, which showed weak but positive correlation. This correlation, joint amplitude-duration distribution, is well reproduced...
During visual stimulation, neurons in cortex often exhibit rhythmic and synchronous firing the gamma-frequency (30-90 Hz) band. Whether this phenomenon plays a functional role during processing is not fully clear remains heavily debated. In article, we explore function of gamma-synchronization context predictive efficient coding theories. These theories hold that sensory utilize statistical regularities natural world order to improve efficiency neural code, optimize inference stimulus causes...
Using high-density electrocorticographic recordings – from awake-behaving monkeys and dynamic causal modelling, we characterised contrast dependent gain control in visual cortex, terms of synaptic rate constants intrinsic connectivity. Specifically, used neural field models to quantify the balance excitatory inhibitory influences; both strength spatial dispersion horizontal connections. Our results allow us infer that increasing increases sensitivity or superficial pyramidal cells inputs...
Neuronal gamma-band synchronization (25-80 Hz) in visual cortex appears sustained and stable during prolonged stimulation when investigated with conventional averages across trials. However, recent studies macaque have used single-trial analyses to show that both power frequency of gamma oscillations exhibit substantial moment-by-moment variation. This has raised the question whether these apparently random variations might limit functional role for neural processing. Here, we studied...
Selective attention depends on goal-directed and stimulus-driven modulatory factors, each relayed by different brain rhythms. Under certain circumstances, stress-related states can change the balance between factors. However, neuronal mechanisms underlying these changes remain unclear. In this study, we explored how psychosocial stress modulate rhythms during an attentional task a task-free period. We recorded EEG ECG activity of 42 healthy participants subjected to either Trier Social...
Cognitive functioning requires coordination between brain areas. Between visual areas, feedforward gamma synchronization improves behavioral performance. Here, we investigate whether similar principles hold across regions and frequency bands, using simultaneous electrocorticographic recordings from 15 areas of two macaque monkeys during performance a selective attention task. Short reaction times (RTs), suggesting efficient interareal communication, occurred when occipital V1, V2, V4, DP...
Significance The greatest proportion of brain activity is endogenously generated. brain’s endogenous highly structured and affects sensory coding, behavior, perception. observation across spatial scales suggests that it plays a role in the maintenance formation networks. correlation spontaneous functional MRI signals has demonstrated existence multiple intrinsic networks, previously observed during controlled cognitive paradigms. prevalence reliability networks have generated intense...
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...