Disruption of the Prefrontal Cortex Improves Implicit Contextual Memory-Guided Attention: Combined Behavioral and Electrophysiological Evidence

2019 ◽  
Vol 30 (1) ◽  
pp. 20-30 ◽  
Author(s):  
Mario Rosero Pahi ◽  
Juliana Cavalli ◽  
Frauke Nees ◽  
Herta Flor ◽  
Jamila Andoh
Keyword(s):  
Prefrontal Cortex ◽  
Brain Activity ◽  
Learning Task ◽  
Contextual Learning ◽  
Learning Performance ◽  
Oscillatory Activity ◽  
Beta Band ◽  
Top Down ◽  
Contextual Memory ◽  
Electrical Brain Activity

Abstract Many studies have shown that the dorsolateral prefrontal cortex (DLPFC) plays an important role in top-down cognitive control over intentional and deliberate behavior. However, recent studies have reported that DLPFC-mediated top-down control interferes with implicit forms of learning. Here we used continuous theta-burst stimulation (cTBS) combined with electroencephalography to investigate the causal role of DLPFC in implicit contextual memory-guided attention. We aimed to test whether transient disruption of the DLPFC would interfere with implicit learning performance and related electrical brain activity. We applied neuronavigation-guided cTBS to the DLPFC or to the vertex as a control region prior to the performance of an implicit contextual learning task. We found that cTBS applied over the DLPFC significantly improved performance during implicit contextual learning. We also noted that beta-band (13–19 Hz) oscillatory power was reduced at fronto-central channels about 140 to 370 ms after visual stimulus onset in cTBS DLPFC compared with cTBS vertex. Taken together, our results provide evidence that DLPFC-mediated top-down control interferes with contextual memory-guided attention and beta-band oscillatory activity.

scholarly journals An Analysis of the External Validity of EEG Spectral Power in an Uncontrolled Outdoor Environment during Default and Complex Neurocognitive States

2021 ◽  
Vol 11 (3) ◽  
pp. 330
Author(s):  
Dalton J. Edwards ◽  
Logan T. Trujillo
Keyword(s):  
External Validity ◽  
Spectral Power ◽  
Brain Activity ◽  
Outdoor Environment ◽  
Oscillatory Activity ◽  
Brain State ◽  
Beta Band ◽  
Eeg Spectral Power ◽  
Eeg Power ◽  
Human Participants

Traditionally, quantitative electroencephalography (QEEG) studies collect data within controlled laboratory environments that limit the external validity of scientific conclusions. To probe these validity limits, we used a mobile EEG system to record electrophysiological signals from human participants while they were located within a controlled laboratory environment and an uncontrolled outdoor environment exhibiting several moderate background influences. Participants performed two tasks during these recordings, one engaging brain activity related to several complex cognitive functions (number sense, attention, memory, executive function) and the other engaging two default brain states. We computed EEG spectral power over three frequency bands (theta: 4–7 Hz, alpha: 8–13 Hz, low beta: 14–20 Hz) where EEG oscillatory activity is known to correlate with the neurocognitive states engaged by these tasks. Null hypothesis significance testing yielded significant EEG power effects typical of the neurocognitive states engaged by each task, but only a beta-band power difference between the two background recording environments during the default brain state. Bayesian analysis showed that the remaining environment null effects were unlikely to reflect measurement insensitivities. This overall pattern of results supports the external validity of laboratory EEG power findings for complex and default neurocognitive states engaged within moderately uncontrolled environments.

Auditory modulation of oscillatory activity in extra-striate visual cortex and its contribution to audio–visual multisensory integration: A human intracranial EEG study

2012 ◽  
Vol 25 (0) ◽  
pp. 198
Author(s):  
Manuel R. Mercier ◽  
John J. Foxe ◽  
Ian C. Fiebelkorn ◽  
John S. Butler ◽  
Theodore H. Schwartz ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Multisensory Integration ◽  
Multisensory Processing ◽  
Brain Activity ◽  
Visual Stimuli ◽  
Additive Model ◽  
Oscillatory Activity ◽  
Time Frequency ◽  
Electrical Brain Activity ◽  
Sensory Cortices

Investigations have traditionally focused on activity in the sensory cortices as a function of their respective sensory inputs. However, converging evidence from multisensory research has shown that neural activity in a given sensory region can be modulated by stimulation of other so-called ancillary sensory systems. Both electrophysiology and functional imaging support the occurrence of multisensory processing in human sensory cortex based on the latency of multisensory effects and their precise anatomical localization. Still, due to inherent methodological limitations, direct evidence of the precise mechanisms by which multisensory integration occurs within human sensory cortices is lacking. Using intracranial recordings in epileptic patients () undergoing presurgical evaluation, we investigated the neurophysiological basis of multisensory integration in visual cortex. Subdural electrical brain activity was recorded while patients performed a simple detection task of randomly ordered Auditory alone (A), Visual alone (V) and Audio–Visual stimuli (AV). We then performed time-frequency analysis: first we investigated each condition separately to evaluate responses compared to baseline, then we indexed multisensory integration using both the maximum criterion model (AV vs. V) and the additive model (AV vs. A+V). Our results show that auditory input significantly modulates neuronal activity in visual cortex by resetting the phase of ongoing oscillatory activity. This in turn leads to multisensory integration when auditory and visual stimuli are simultaneously presented.

scholarly journals Brain–Heart Interaction During Transcutaneous Auricular Vagus Nerve Stimulation

2021 ◽  
Vol 15 ◽  
Author(s):  
Kathrin Machetanz ◽  
Levan Berelidze ◽  
Robert Guggenberger ◽  
Alireza Gharabaghi
Keyword(s):  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Heart Function ◽  
Brain Activity ◽  
Gamma Band ◽  
Cortical Activation ◽  
Oscillatory Activity ◽  
Beta Band ◽  
Rr Intervals

ObjectivesTranscutaneous auricular vagus nerve stimulation (taVNS) modulates brain activity and heart function. The induced parasympathetic predominance leads to an increase of heart rate variability (HRV). Knowledge on the corresponding cortical activation pattern is, however, scarce. We hypothesized taVNS-induced HRV increases to be related to modulation of cortical activity that regulates the autonomic outflow to the heart.Materials and MethodsIn thirteen healthy subjects, we simultaneously recorded 64-channel electroencephalography and electrocardiography during taVNS. Two taVNS stimulation targets were investigated, i.e., the cymba conchae and inner tragus, and compared to active control stimulation in the anatomical vicinity, i.e., at the crus helicis and outer tragus. We used intermitted stimulation bursts of 25 Hz applied at a periodicity of 1 Hz. HRV was estimated with different time-domain methodologies: standard deviation of RR (SDNN), the root mean squares of successive differences (RMSSD), the percentage of RR-intervals with at least 50 ms deviation from the preceding RR-interval (pNN50), and the difference of consecutive RR intervals weighted by their mean (rrHRV).ResultsThe stimulation-induced HRV increases corresponded to frequency-specific oscillatory modulation of different cortical areas. All stimulation targets induced power modulations that were proportional to the HRV elevation. The most prominent changes that corresponded to HRV increases across all parameters and stimulation locations were frontal elevations in the theta-band. In the delta-band, there were frontal increases (RMSSD, pNN50, rrHRV, SDNN) and decreases (SDNN) across stimulation sites. In higher frequencies, there was a more divers activity pattern: Outer tragus/crus helicis stimulation increased oscillatory activity with the most prominent changes for the SDNN in frontal (alpha-band, beta-band) and fronto-parietal (gamma-band) areas. During inner tragus/cymba conchae stimulation the predominant pattern was a distributed power decrease, particularly in the fronto-parietal gamma-band.ConclusionNeuro–cardiac interactions can be modulated by electrical stimulation at different auricular locations. Increased HRV during stimulation is correlated with frequency-specific increases and decreases of oscillatory activity in different brain areas. When applying specific HRV measures, cortical patterns related to parasympathetic (RMSSD, pNN50, rrHRV) and sympathetic (SDNN) modulation can be identified. Thus, cortical oscillations may be used to define stimulation locations and parameters for research and therapeutic purposes.

scholarly journals Significance of GABAA Receptor for Cognitive Function and Hippocampal Pathology

2021 ◽  
Vol 22 (22) ◽  
pp. 12456
Author(s):  
Yuya Sakimoto ◽  
Paw Min-Thein Oo ◽  
Makoto Goshima ◽  
Itsuki Kanehisa ◽  
Yutaro Tsukada ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Gabaa Receptor ◽  
Neuronal Excitability ◽  
Autism Spectrum ◽  
Contextual Learning ◽  
Learning Performance ◽  
Inhibitory Synapses ◽  
Gamma Aminobutyric Acid ◽  
Contextual Memory ◽  
Spatiotemporal Information

The hippocampus is a primary area for contextual memory, known to process spatiotemporal information within a specific episode. Long-term strengthening of glutamatergic transmission is a mechanism of contextual learning in the dorsal cornu ammonis 1 (CA1) area of the hippocampus. CA1-specific immobilization or blockade of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor delivery can impair learning performance, indicating a causal relationship between learning and receptor delivery into the synapse. Moreover, contextual learning also strengthens GABAA (gamma-aminobutyric acid) receptor-mediated inhibitory synapses onto CA1 neurons. Recently we revealed that strengthening of GABAA receptor-mediated inhibitory synapses preceded excitatory synaptic plasticity after contextual learning, resulting in a reduced synaptic excitatory/inhibitory (E/I) input balance that returned to pretraining levels within 10 min. The faster plasticity at inhibitory synapses may allow encoding a contextual memory and prevent cognitive dysfunction in various hippocampal pathologies. In this review, we focus on the dynamic changes of GABAA receptor mediated-synaptic currents after contextual learning and the intracellular mechanism underlying rapid inhibitory synaptic plasticity. In addition, we discuss that several pathologies, such as Alzheimer’s disease, autism spectrum disorders and epilepsy are characterized by alterations in GABAA receptor trafficking, synaptic E/I imbalance and neuronal excitability.

Propagation of EEG Activity in the Beta and Gamma Band during Movement Imagery in Humans

2005 ◽  
Vol 44 (01) ◽  
pp. 106-113 ◽  
Author(s):  
J. Ginter ◽  
M. Kamiński ◽  
P. J. Durka ◽  
G. Pfurtscheller ◽  
C. Neuper ◽  
...  
Keyword(s):  
Brain Activity ◽  
Hand Movement ◽  
Specific Information ◽  
Beta Band ◽  
Directed Transfer Function ◽  
Left Hand ◽  
Electrical Brain Activity ◽  
Movement Imagery ◽  
Short Time

Summary Objectives: The objective of the paper was the determination of electrical brain activity propagation in sensorimotor areas during hand movement imagery. Methods: Right-hand and left-hand movement imagination was studied in three subjects. The 10-channel Multivariate Autoregressive Model (MVAR) was fitted to EEG signals recorded from subsets of electrodes overlying central and related brain areas. By means of the Short-time Directed Transfer Function (SDTF) the propagation of brain activity as a function of frequency and time was found. Results: During imagery the relation between propagations in gamma and beta bands changed significantly for electrodes overlying sensorimotor areas, namely the increase in gamma was accompanied by the decrease in the beta band. Conclusions: The hypothesis was put forward that these kinds of changes in flow of electrical brain activity are connected with the specific information processing.

Inducing Neuroplasticity through Intracranial Theta Burst Stimulation in the Human Sensorimotor Cortex

2021 ◽  
Author(s):  
Jose L Herrero ◽  
Alexander Smith ◽  
Akash Mishra ◽  
Noah Markowitz ◽  
Ashesh D Mehta ◽  
...  
Keyword(s):  
Sensorimotor Cortex ◽  
Brain Activity ◽  
Activity Patterns ◽  
Oscillatory Activity ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Beta Band ◽  
Sensorimotor Network ◽  
Intracranial Electrodes ◽  
Theta Burst

The progress of therapeutic neuromodulation greatly depends on improving stimulation parameters to most efficiently induce neuroplasticity effects. Intermittent Theta Burst stimulation (iTBS), a form of electrical stimulation that mimics natural brain activity patterns, has proved to efficiently induce such effects in animal studies and rhythmic Transcranial Magnetic Stimulation studies in humans. However, little is known about the potential neuroplasticity effects of iTBS applied through intracranial electrodes in humans. This study characterizes the physiological effects of intracranial iTBS in humans and compare them with alpha frequency stimulation, another frequently used neuromodulatory pattern. We applied these two stimulation patterns to well-defined regions in the sensorimotor cortex, which elicited contralateral hand muscle contractions during clinical mapping, in epilepsy patients implanted with intracranial electrodes. Treatment effects were evaluated using oscillatory coherence across areas connected to the treatment site, as defined with cortico-cortical evoked potentials. Our results show that iTBS increases coherence in the beta frequency band within the sensorimotor network indicating a potential neuroplasticity effect. The effect is specific to the sensorimotor system, the beta-band and the stimulation pattern, and outlasted the stimulation period by ~3 minutes. The effect occurred in 4/7 subjects depending on the build-up of the effect during iTBS treatment and other patterns of oscillatory activity related to ceiling effects within the beta-band and to pre-existent coherence within the alpha-band. By characterizing the neurophysiological effects of iTBS within well-defined cortical networks, we hope to provide an electrophysiological framework that allows clinicians/researchers to optimize brain stimulation protocols which may have translational value.

scholarly journals Neural markers for Musical Creativity in Jazz Improvisation and Classical Interpretation

2021 ◽  
Author(s):  
Shama Sarwat Rahman ◽  
Kim Christensen ◽  
Henrik Jeldtoft Jensen ◽  
Peter Vuust ◽  
Joydeep Bhattacharya
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Brain Activity ◽  
Activity Patterns ◽  
Anterior Cingulate ◽  
List Type ◽  
Actual Performance ◽  
Electrical Brain Activity ◽  
Musical Creativity ◽  
Increased Activity

AbstractTwo main types of musical creativity in the western canon are improvisation and interpretation. With improvisation, the fundamental structure of the melody, chords, rhythm and tempo of a piece can be modified, while with interpretation, the focus is on the emotional dynamics. Here we characterise electrical brain activity from professional jazz and classical pianists, whilst they were engaged in these different creative tasks with musical excerpts from both genres. Multivariate EEG was recorded during two phases of each task, mental planning and actual performance. Subsequently neuronal activity patterns were source localised with standardised low resolution electromagnetic tomography (sLORETA). For each musical performance, we obtained both subjective (self-rated) and objective (blind, expert-rated) measures of musical creativity. Across both tasks and genre backgrounds, within the first and middle 4 second segments of the performance phase, for musical performances that were judged highly creative objectively by external expert music assessors, we observed an increased activation in the anterior cingulate and medial prefrontal cortex (Brodmann area, BA32), suggesting a maintenance of executive control, and integrating motoric and emotional communication during creativity. Across genre backgrounds, within the performance phase for the interpretation task compared to the improvisation task, there was an increased activity in the insula (BA 13), suggesting a convergent creative task from the linked goal-orientated conscious error-monitoring and audio-visual integration functions. Genre profession also gave rise to differences across phases; jazz pianists presented a decreased parietal (BA7) activity during improvisation tasks suggesting a role for defocussed attention and for classical pianists, both tasks were associated with occipitotemporal (BA 37) activity which is involved in semantic/ metaphorical processing suggesting a close adherence to the visual score. These 3 areas relate the cognitive demands of the creative musical task to the demands of the corresponding genre of music.HighlightsEEG activity associated to musical creativity types: Improvisation and InterpretationIncreased activity in Insula (BA 13) for Interpretation suggest convergent creativityDecreased Precuneus (BA7) activity for Improvisation suggest defocussed attentionIncreased activity in medial prefrontal cortex (BA32) in highly creative performance

scholarly journals Dual brain stimulation enhances interpersonal learning through spontaneous movement synchrony

2020 ◽  
Author(s):  
Yafeng Pan ◽  
Giacomo Novembre ◽  
Bei Song ◽  
Yi Zhu ◽  
Yi Hu
Keyword(s):  
Brain Stimulation ◽  
Information Transfer ◽  
Interactive Learning ◽  
Brain Activity ◽  
Body Movement ◽  
Learning Task ◽  
Brain Regions ◽  
Learning Performance ◽  
Spontaneous Movement ◽  
Movement Synchrony

Abstract Social interactive learning denotes the ability to acquire new information from a conspecific—a prerequisite for cultural evolution and survival. As inspired by recent neurophysiological research, here we tested whether social interactive learning can be augmented by exogenously synchronizing oscillatory brain activity across an instructor and a learner engaged in a naturalistic song-learning task. We used a dual brain stimulation protocol entailing the trans-cranial delivery of synchronized electric currents in two individuals simultaneously. When we stimulated inferior frontal brain regions, with 6 Hz alternating currents being in-phase between the instructor and the learner, the dyad exhibited spontaneous and synchronized body movement. Remarkably, this stimulation also led to enhanced learning performance. These effects were both phase- and frequency-specific: 6 Hz anti-phase stimulation or 10 Hz in-phase stimulation, did not yield comparable results. Furthermore, a mediation analysis disclosed that interpersonal movement synchrony acted as a partial mediator of the effect of dual brain stimulation on learning performance, i.e. possibly facilitating the effect of dual brain stimulation on learning. Our results provide a causal demonstration that inter-brain synchronization is a sufficient condition to improve real-time information transfer between pairs of individuals.

scholarly journals Unmixing Oscillatory Brain Activity by EEG Source Localization and Empirical Mode Decomposition

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Sofie Therese Hansen ◽  
Apit Hemakom ◽  
Mads Gylling Safeldt ◽  
Lærke Karen Krohne ◽  
Kristoffer Hougaard Madsen ◽  
...  
Keyword(s):  
Empirical Mode Decomposition ◽  
Source Localization ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Motor Evoked Potential ◽  
Region Of Interest ◽  
Oscillatory Activity ◽  
Electrical Brain Activity ◽  
Mode Decomposition ◽  
Oscillatory Brain Activity

Neuronal activity is composed of synchronous and asynchronous oscillatory activity at different frequencies. The neuronal oscillations occur at time scales well matched to the temporal resolution of electroencephalography (EEG); however, to derive meaning from the electrical brain activity as measured from the scalp, it is useful to decompose the EEG signal in space and time. In this study, we elaborate on the investigations into source-based signal decomposition of EEG. Using source localization, the electrical brain signal is spatially unmixed and the neuronal dynamics from a region of interest are analyzed using empirical mode decomposition (EMD), a technique aimed at detecting periodic signals. We demonstrate, first in simulations, that the EMD is more accurate when applied to the spatially unmixed signal compared to the scalp-level signal. Furthermore, on EEG data recorded simultaneously with transcranial magnetic stimulation (TMS) over the hand area of the primary motor cortex, we observe a link between the peak to peak amplitude of the motor-evoked potential (MEP) and the phase of the decomposed localized electrical activity before TMS onset. The results thus encourage combination of source localization and EMD in the pursuit of further insight into the mechanisms of the brain with respect to the phase and frequency of the electrical oscillations and their cortical origin.

scholarly journals Pre-stimulus beta-band activity is a signature of statistical learning

2020 ◽  
Author(s):  
Louisa Bogaerts ◽  
Craig G. Richter ◽  
Ayelet N. Landau ◽  
Ram Frost
Keyword(s):  
Statistical Learning ◽  
Time Window ◽  
Stimulus Presentation ◽  
Learning Performance ◽  
Predictive Processing ◽  
Oscillatory Activity ◽  
Beta Band ◽  
Behavioral Learning ◽  
Primary Means ◽  
Highly Correlated

AbstractStatistical learning (SL) is taken to be the main mechanism by which cognitive systems discover the underlying regularities of the environment. We document, in the context of a classical visual SL task, divergent rhythmic EEG activity during the anticipation of stimuli within patterns versus pattern transitions. Our findings reveal differential pre-stimulus oscillatory activity in the beta band (∼20 Hz) that indexes learning: it emerges with increased pattern repetitions, and importantly, it is highly correlated with behavioral learning outcomes. These findings hold the promise of converging on an online measure of learning regularities and provide important theoretical insights regarding the mechanisms of SL and prediction.Significance StatementSL has become a major theoretical construct in cognitive science, providing the primary means by which organisms learn about regularities in the environment. As such it is a critical building block for basic and higher-order cognitive functions.Here we identify for the first time a spectral neural index in the time window prior to stimulus presentation, which evolves with increased pattern exposure, and is predictive of learning performance.The manifestation of learning that is revealed not in stimulus processing but in anticipatory moments of the learning episode, makes a direct link between the fields of statistical learning and predictive processing, and suggests a possible mechanistic account of visual SL.

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