scholarly journals Decoding the neural dynamics of free choice in humans

PLoS Biology ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. e3000864
Author(s):  
Thomas Thiery ◽  
Anne-Lise Saive ◽  
Etienne Combrisson ◽  
Arthur Dehgan ◽  
Julien Bastin ◽  
...  
Keyword(s):  
Free Choice ◽  
Temporal Dynamics ◽  
Motor Planning ◽  
Decision Task ◽  
Neural Activation ◽  
Deliberation Process ◽  
High Gamma ◽  
Planning Processes ◽  
Eeg Recordings ◽  
Parietal Cortices

How do we choose a particular action among equally valid alternatives? Nonhuman primate findings have shown that decision-making implicates modulations in unit firing rates and local field potentials (LFPs) across frontal and parietal cortices. Yet the electrophysiological brain mechanisms that underlie free choice in humans remain ill defined. Here, we address this question using rare intracerebral electroencephalography (EEG) recordings in surgical epilepsy patients performing a delayed oculomotor decision task. We find that the temporal dynamics of high-gamma (HG, 60–140 Hz) neural activity in distinct frontal and parietal brain areas robustly discriminate free choice from instructed saccade planning at the level of single trials. Classification analysis was applied to the LFP signals to isolate decision-related activity from sensory and motor planning processes. Compared with instructed saccades, free-choice trials exhibited delayed and longer-lasting HG activity during the delay period. The temporal dynamics of the decision-specific sustained HG activity indexed the unfolding of a deliberation process, rather than memory maintenance. Taken together, these findings provide the first direct electrophysiological evidence in humans for the role of sustained high-frequency neural activation in frontoparietal cortex in mediating the intrinsically driven process of freely choosing among competing behavioral alternatives.

scholarly journals Decoding the neural dynamics of free choice in humans

2019 ◽  
Author(s):  
Thomas Thiery ◽  
Anne-Lise Saive ◽  
Etienne Combrisson ◽  
Arthur Dehgan ◽  
Julien Bastin ◽  
...  
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Free Choice ◽  
Temporal Dynamics ◽  
Motor Planning ◽  
Decision Task ◽  
Neural Activation ◽  
List Type ◽  
High Gamma ◽  
Eeg Recordings

SummaryHow do we choose a particular action among equally valid alternatives? Non-human primate findings have shown that decision-making implicates modulations in unit firing rates and local field potentials (LFPs) across frontal and parietal cortices. Yet the electrophysiological brain mechanisms that underlie free choice in humans remain ill defined. Here, we address this question using rare intracerebral EEG recordings in surgical epilepsy patients performing a delayed oculomotor decision task. We find that the temporal dynamics of high gamma (HG, 60-140 Hz) neural activity in distinct frontal and parietal brain areas robustly discriminate free choice from instructed saccade planning at the level of single trials. Classification analysis was applied to the LFP signals to isolate decision-related activity from sensory and motor planning processes. Compared to instructed saccades, free choice trials exhibited delayed and longer-lasting HG activity. The temporal dynamics of these sustained decision-related responses distinguished deliberation-related from working memory processes. Taken together, these findings provide the first direct electrophysiological evidence in humans for the role of sustained high-frequency neural activation in fronto-parietal cortex in mediating the intrinsically driven process of freely choosing among competing behavioral alternatives.HighlightsFirst intracerebral recordings in humans performing an oculomotor decision-making taskMachine learning analytics unravel underlying spectral and temporal brain dynamicsFree choice trials exhibit sustained fronto-parietal high gamma (HG) activity during the delayMaking a decision and maintaining it in working memory are associated with distinct sustained HG dynamics

scholarly journals Canard solutions in neural mass models: consequences on critical regimes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elif Köksal Ersöz ◽  
Fabrice Wendling
Keyword(s):  
Temporal Dynamics ◽  
Spatial Scales ◽  
Singular Perturbation Theory ◽  
Geometric Singular Perturbation Theory ◽  
Critical Transitions ◽  
Intracerebral Eeg ◽  
Neural Mass ◽  
Mesoscopic Level ◽  
Eeg Recordings ◽  
Physiological Background

AbstractMathematical models at multiple temporal and spatial scales can unveil the fundamental mechanisms of critical transitions in brain activities. Neural mass models (NMMs) consider the average temporal dynamics of interconnected neuronal subpopulations without explicitly representing the underlying cellular activity. The mesoscopic level offered by the neural mass formulation has been used to model electroencephalographic (EEG) recordings and to investigate various cerebral mechanisms, such as the generation of physiological and pathological brain activities. In this work, we consider a NMM widely accepted in the context of epilepsy, which includes four interacting neuronal subpopulations with different synaptic kinetics. Due to the resulting three-time-scale structure, the model yields complex oscillations of relaxation and bursting types. By applying the principles of geometric singular perturbation theory, we unveil the existence of the canard solutions and detail how they organize the complex oscillations and excitability properties of the model. In particular, we show that boundaries between pathological epileptic discharges and physiological background activity are determined by the canard solutions. Finally we report the existence of canard-mediated small-amplitude frequency-specific oscillations in simulated local field potentials for decreased inhibition conditions. Interestingly, such oscillations are actually observed in intracerebral EEG signals recorded in epileptic patients during pre-ictal periods, close to seizure onsets.

scholarly journals Dynamic Alterations in Neural Networks Supporting Aversive Learning in Children Exposed to Trauma: Neural Mechanisms Underlying Psychopathology

2020 ◽  
Author(s):  
Stephanie N. DeCross ◽  
Kelly Sambrook ◽  
Margaret Sheridan ◽  
Nim Tottenham ◽  
Katie A McLaughlin
Keyword(s):  
Functional Connectivity ◽  
Temporal Dynamics ◽  
Longitudinal Design ◽  
Region Of Interest ◽  
Posterior Cingulate Cortex ◽  
Parahippocampal Gyrus ◽  
Functional Coupling ◽  
Neural Activation ◽  
Aversive Learning ◽  
Frontal Pole

Altered aversive learning represents a potential mechanism through which childhood trauma (CT) might influence risk for psychopathology. This study examines the temporal dynamics of neural activation and patterns of functional connectivity during aversive learning in children with and without CT, and evaluates whether these neural patterns mediate the association of CT with psychopathology in a longitudinal design. 147 children (aged 8-16 years, 77 with CT) completed a fear conditioning procedure during an fMRI scan. Dynamic patterns of neural activation were examined in whole-brain and region-of-interest analyses; functional connectivity was assessed with generalized psychophysiological interaction analyses. We evaluated whether the associations between CT and psychopathology symptoms at baseline and two-year follow-up were mediated by neural activation and connectivity during aversive learning. Children exposed to trauma displayed blunted patterns of neural activation over time during CS+>CS- in right amygdala and during CS->CS+ in right hippocampus and frontal pole. Additionally, during CS+>CS-, CT was associated with elevated functional connectivity of right amygdala with fronto-parietal regions and reduced connectivity with hippocampus, posterior parahippocampal gyrus, and posterior cingulate cortex. The longitudinal association between CT and later externalizing symptoms was mediated by blunted activation in right amygdala and insula. Reduced amygdala-hippocampal connectivity mediated the association of CT with transdiagnostic anxiety symptoms. CT is associated with poor threat-safety discrimination and altered functional coupling between salience and default mode network regions during aversive learning. These altered neural dynamics during learning may be key mechanisms linking CT with internalizing and externalizing psychopathology.

scholarly journals High similarity between EEG from subcutaneous and proximate scalp electrodes in patients with temporal lobe epilepsy

2018 ◽  
Vol 120 (3) ◽  
pp. 1451-1460 ◽  
Author(s):  
Sigge Weisdorf ◽  
Sirin W. Gangstad ◽  
Jonas Duun-Henriksen ◽  
Karina S. S. Mosholt ◽  
Troels W. Kjær
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Temporal Dynamics ◽  
Real Life ◽  
High Similarity ◽  
Time Frequency ◽  
Scalp Eeg ◽  
Eeg Recordings ◽  
The Impact

Subcutaneous recording using electroencephalography (EEG) has the potential to enable ultra-long-term epilepsy monitoring in real-life conditions because it allows the patient increased mobility and discreteness. This study is the first to compare physiological and epileptiform EEG signals from subcutaneous and scalp EEG recordings in epilepsy patients. Four patients with probable or definite temporal lobe epilepsy were monitored with simultaneous scalp and subcutaneous EEG recordings. EEG recordings were compared by correlation and time-frequency analysis across an array of clinically relevant waveforms and patterns. We found high similarity between the subcutaneous EEG channels and nearby temporal scalp channels for most investigated electroencephalographic events. In particular, the temporal dynamics of one typical temporal lobe seizure in one patient were similar in scalp and subcutaneous recordings in regard to frequency distribution and morphology. Signal similarity is strongly related to the distance between the subcutaneous and scalp electrodes. On the basis of these limited data, we conclude that subcutaneous EEG recordings are very similar to scalp recordings in both time and time-frequency domains, if the distance between them is small. As many electroencephalographic events are local/regional, the positioning of the subcutaneous electrodes should be considered carefully to reflect the relevant clinical question. The impact of implantation depth of the subcutaneous electrode on recording quality should be investigated further. NEW & NOTEWORTHY This study is the first publication comparing the detection of clinically relevant, pathological EEG features from a subcutaneous recording system designed for out-patient ultra-long-term use to gold standard scalp EEG recordings. Our study shows that subcutaneous channels are very similar to comparable scalp channels, but also point out some issues yet to be resolved.

scholarly journals Dynamics of the cerebral blood flow response to brief neural activity in human visual cortex

2019 ◽  
Vol 40 (9) ◽  
pp. 1823-1837 ◽  
Author(s):  
Jung Hwan Kim ◽  
Amanda J Taylor ◽  
Danny JJ Wang ◽  
Xiaowei Zou ◽  
David Ress
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Visual Cortex ◽  
Temporal Dynamics ◽  
Oxygen Metabolism ◽  
Late Time ◽  
Neural Activation ◽  
Hemodynamic Response Function ◽  
Time Dynamics ◽  
Human Visual Cortex

The blood oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal depends on an interplay of cerebral blood flow (CBF), oxygen metabolism, and cerebral blood volume. Despite wide usage of BOLD fMRI, it is not clear how these physiological components create the BOLD signal. Here, baseline CBF and its dynamics evoked by a brief stimulus (2 s) in human visual cortex were measured at 3T. We found a stereotypical CBF response: immediate increase, rising to a peak a few second after the stimulus, followed by a significant undershoot. The BOLD hemodynamic response function (HRF) was also measured in the same session. Strong correlations between HRF and CBF peak responses indicate that the flow responses evoked by neural activation in nearby gray matter drive the early HRF. Remarkably, peak CBF and HRF were also strongly modulated by baseline perfusion. The CBF undershoot was reliable and significantly correlated with the HRF undershoot. However, late-time dynamics of the HRF and CBF suggest that oxygen metabolism can also contribute to the HRF undershoot. Combined measurement of the CBF and HRF for brief neural activation is a useful tool to understand the temporal dynamics of neurovascular and neurometabolic coupling.

Neural Activation During the STROOP Task in Bipolar Disorder Patients and Their Unaffected Relatives

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
F. Pompei ◽  
M. Haldane ◽  
M. Kempton ◽  
J. Jogia ◽  
P. Girardi ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Genetic Predisposition ◽  
Neural Activation ◽  
List Type ◽  
Significant Group ◽  
Significant Group Difference ◽  
Colour Word ◽  
Behavioural Performance ◽  
Parietal Cortices ◽  
Cluster Level

Aims:To examine potential similarities in neural activation during the STROOP colour word test (SCWT) in patients with Bipolar Disorder (BD) and their unaffected first degree relatives of BD patients as an expression of genetic predisposition.Methods:39 remitted BD patients were compared to 46 of their healthy relatives and to 42 controls. fMRI data were collected on a 1.5 T GE Signa MR system using a blocked periodic design and analysed in SPM5.Results:There was no statistically significant group difference in the behavioural performance. At the corrected cluster level threshold of p< 0.001 controls showed more activation than:a.BD patients in the caudate, the inferior (BA 47), middle and superior frontal gyri (BA 8, 6, 46), the parietal cortices (BA 7, 40), the precuneus and occipital cortices (BA 7, 19).b.Relatives in the caudate and cingulate cortex (BA 24, 31!). No other contrasts were significant.Conclusion:These findings suggest that changes in neural activation during response inhibition may reflect genetic predisposition to BD.

Forming Tool Use Representations: A Neurophysiological Investigation into Tool Exposure

2011 ◽  
Vol 23 (10) ◽  
pp. 2920-2934 ◽  
Author(s):  
John Christopher Mizelle ◽  
Teresa Tang ◽  
Nikta Pirouz ◽  
Lewis A. Wheaton
Keyword(s):  
Learning Strategies ◽  
Tool Use ◽  
Motor Planning ◽  
Hemispheric Dominance ◽  
Neural Activation ◽  
The Novel ◽  
Beta Band ◽  
Related Information ◽  
Direct Exposure ◽  
Indirect Exposure

Prior work has identified a common left parietofrontal network for storage of tool-related information for various tasks. How these representations become established within this network on the basis of different modes of exposure is unclear. Here, healthy subjects engaged in physical practice (direct exposure) with familiar and unfamiliar tools. A separate group of subjects engaged in video-based observation (indirect exposure) of the same tools to understand how these learning strategies create representations. To assess neural mechanisms engaged for pantomime after different modes of exposure, a pantomime task was performed for both tools while recording neural activation with high-density EEG. Motor planning–related neural activation was evaluated using beta band (13–22 Hz) event-related desynchronization. Hemispheric dominance was assessed, and activation maps were generated to understand topography of activations. Comparison of conditions (effects of tool familiarity and tool exposure) was performed with standardized low-resolution brain electromagnetic tomography. Novel tool pantomime following direct exposure resulted in greater activations of bilateral parietofrontal regions. Activations following indirect training varied by tool familiarity; pantomime of the familiar tool showed greater activations in left parietofrontal areas, whereas the novel tool showed greater activations at right temporoparieto-occipital areas. These findings have relevance to the mechanisms for understanding motor-related behaviors involved in new tools that we have little or no experience with and can extend into advancing theories of tool use motor learning.

scholarly journals Dynamics of the functional link between area MT LFPs and motion detection

2015 ◽  
Vol 114 (1) ◽  
pp. 80-98 ◽  
Author(s):  
Jackson E. T. Smith ◽  
Vincent Beliveau ◽  
Alan Schoen ◽  
Jordana Remz ◽  
Chang'an A. Zhan ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Field Potential ◽  
Wide Band ◽  
Detection Performance ◽  
Common Input ◽  
Spike Response ◽  
Functional Link ◽  
Area Mt ◽  
Temporal Area ◽  
High Gamma

The evolution of a visually guided perceptual decision results from multiple neural processes, and recent work suggests that signals with different neural origins are reflected in separate frequency bands of the cortical local field potential (LFP). Spike activity and LFPs in the middle temporal area (MT) have a functional link with the perception of motion stimuli (referred to as neural-behavioral correlation). To cast light on the different neural origins that underlie this functional link, we compared the temporal dynamics of the neural-behavioral correlations of MT spikes and LFPs. Wide-band activity was simultaneously recorded from two locations of MT from monkeys performing a threshold, two-stimuli, motion pulse detection task. Shortly after the motion pulse occurred, we found that high-gamma (100–200 Hz) LFPs had a fast, positive correlation with detection performance that was similar to that of the spike response. Beta (10–30 Hz) LFPs were negatively correlated with detection performance, but their dynamics were much slower, peaked late, and did not depend on stimulus configuration or reaction time. A late change in the correlation of all LFPs across the two recording electrodes suggests that a common input arrived at both MT locations prior to the behavioral response. Our results support a framework in which early high-gamma LFPs likely reflected fast, bottom-up, sensory processing that was causally linked to perception of the motion pulse. In comparison, late-arriving beta and high-gamma LFPs likely reflected slower, top-down, sources of neural-behavioral correlation that originated after the perception of the motion pulse.

scholarly journals Reaching and grasping with the tongue: Shared motor planning between hand actions and articulatory gestures

2018 ◽  
Vol 71 (10) ◽  
pp. 2129-2141 ◽  
Author(s):  
Lari Vainio ◽  
Kaisa Tiippana ◽  
Mikko Tiainen ◽  
Aleksi Rantala ◽  
Martti Vainio
Keyword(s):  
Hand Movement ◽  
Precision Grip ◽  
Motor Planning ◽  
Action Planning ◽  
Hand Movements ◽  
Vowel Production ◽  
Power Grip ◽  
Production Processes ◽  
Manual Responses ◽  
Planning Processes

Research has shown connections between articulatory mouth actions and manual actions. This study investigates whether forward–backward hand movements could be associated with vowel production processes that programme tongue fronting/backing, lip rounding/spreading (Experiment 1), and/or consonant production processes that programme tongue tip and tongue dorsum actions (Experiment 2). The participants had to perform either forward or backward hand movement and simultaneously pronounce different vowels or consonants. The results revealed a response benefit, measured in vocal and manual reaction times, when the responses consisted of front vowels and forward hand movements. Conversely, back vowels were associated with backward hand movements. Articulation of rounded versus unrounded vowels or coronal versus dorsal consonants did not produce the effect. In contrast, when the manual responses of forward–backward hand movements were replaced by precision and power grip responses, the coronal consonants [t] and [r] were associated with the precision grip, whereas the dorsal consonant [k] was associated with the power grip. We propose that the movements of the tongue body, operating mainly for vowel production, share the directional action planning processes with the hand movements. Conversely, the tongue articulators related to tongue tip and dorsum movements, operating mainly for consonant production, share the action planning processes with the precision and power grip, respectively.

scholarly journals Cue-related Temporal Factors Modulate Movement-related Beta Oscillatory Activity in the Human Motor Circuit

2016 ◽  
Vol 28 (7) ◽  
pp. 1039-1051 ◽  
Author(s):  
Elizabeth Heinrichs-Graham ◽  
David J. Arpin ◽  
Tony W. Wilson
Keyword(s):  
Premotor Cortex ◽  
Motor Planning ◽  
Oscillatory Activity ◽  
Planning Time ◽  
Motor Circuit ◽  
Cortical Motor ◽  
Temporal Factors ◽  
Human Motor ◽  
Study Participants ◽  
Parietal Cortices

In humans, there is a strong beta (15–30 Hz) event-related desynchronization (ERD) that begins before movement, which has been tentatively linked to motor planning operations. The dynamics of this response are strongly modulated by whether a pending movement is cued and the inherent parameters of the cue. However, previous studies have focused on the information content of cues and not on parameters such as the timing of the cue relative to other events. Variations in such timing are critical, as they directly impact the amount of time that participants have to plan pending movements. In this study, participants performed finger-tapping sequences during magnetoencephalography, and we manipulated the amount of time (i.e., “long” vs. “short”) between the presentation of the to-be-executed sequence and the cue to initiate the sequence. We found that the beta ERD was stronger immediately after the cue to move in the contralateral postcentral gyrus and bilateral parietal cortices during the short compared with long planning time condition. During movement execution, the beta ERD was stronger in the premotor cortex and the SMA in the short relative to long condition. Finally, peak latency in the SMA significantly correlated with RT, such that the closer the peak beta ERD was to the cue to move, the quicker the participant responded. The results of this study establish that peri-movement beta ERD activity across the cortical motor circuit is highly sensitive to cue-related temporal factors, with a direct link to motor performance.

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