scholarly journals On-scalp MEG SQUIDs are sensitive to early somatosensory activity unseen by conventional MEG

2019 ◽  
Author(s):  
Lau M. Andersen ◽  
Christoph Pfeiffer ◽  
Silvia Ruffieux ◽  
Bushra Riaz ◽  
Dag Winkler ◽  
...  
Keyword(s):  
Brain Activity ◽  
Activity Patterns ◽  
Signal Strength ◽  
Classification Performance ◽  
Discrimination Accuracy ◽  
Sensor Coverage ◽  
Non Invasive ◽  
Spatio Temporal ◽  
Sensor Density ◽  
The Right

AbstractMagnetoencephalography (MEG) has a unique capacity to resolve the spatio-temporal development of brain activity from non-invasive measurements. Conventional MEG, however, relies on sensors that sample from a distance (20-40 mm) to the head due to thermal insulation requirements (the MEG sensors function at 4 K in a helmet). A gain in signal strength and spatial resolution may be achieved if sensors are moved closer to the head. Here, we report a study comparing measurements from a seven-channel on-scalp SQUID MEG system to those from a conventional (in-helmet) SQUID MEG system.We compared spatio-temporal resolution between on-scalp and conventional MEG by comparing the discrimination accuracy for neural activity patterns resulting from stimulating five different phalanges of the right hand. Because of proximity and sensor density differences between on-scalp and conventional MEG, we hypothesized that on-scalp MEG would allow for a more high-resolved assessment of these activity patterns, and therefore also a better classification performance in discriminating between neural activations from the different phalanges.We observed that on-scalp MEG provided better classification performance during an early post-stimulus period (15-30 ms). This corresponded to electroencephalographic (EEG) response components N16 and P23, and was an unexpected observation as these components are usually not observed in conventional MEG. They indicate that on-scalp MEG opens up for a richer registration of the cortical signal, allowing for sensitivity to what are potentially sources in the thalamo-cortical radiation and to quasi-radial sources.We had originally expected that on-scalp MEG would provide better classification accuracy based on activity in proximity to the P60m component compared to conventional MEG. This component indeed allowed for the best classification performance for both MEG systems (60-75%, chance 50%). However, we did not find that on-scalp MEG allowed for better classification than conventional MEG at this latency. We believe this may be due to the limited sensor coverage in the recording, in combination with our strategy for positioning the on-scalp MEG sensors. We discuss how sensor density and coverage as well as between-phalange source field dissimilarities may influence our hypothesis testing, which we believe to be useful for future benchmarking measurements.

scholarly journals Neural alignment predicts learning outcomes in students taking an introduction to computer science course

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Meir Meshulam ◽  
Liat Hasenfratz ◽  
Hanna Hillman ◽  
Yun-Fei Liu ◽  
Mai Nguyen ◽  
...  
Keyword(s):  
Computer Science ◽  
Learning Outcomes ◽  
Brain Activity ◽  
Activity Patterns ◽  
Real Life ◽  
Final Exam ◽  
Neural Representations ◽  
Real Life Setting ◽  
The Right ◽  
Mri Study

AbstractDespite major advances in measuring human brain activity during and after educational experiences, it is unclear how learners internalize new content, especially in real-life and online settings. In this work, we introduce a neural approach to predicting and assessing learning outcomes in a real-life setting. Our approach hinges on the idea that successful learning involves forming the right set of neural representations, which are captured in canonical activity patterns shared across individuals. Specifically, we hypothesized that learning is mirrored in neural alignment: the degree to which an individual learner’s neural representations match those of experts, as well as those of other learners. We tested this hypothesis in a longitudinal functional MRI study that regularly scanned college students enrolled in an introduction to computer science course. We additionally scanned graduate student experts in computer science. We show that alignment among students successfully predicts overall performance in a final exam. Furthermore, within individual students, we find better learning outcomes for concepts that evoke better alignment with experts and with other students, revealing neural patterns associated with specific learned concepts in individuals.

scholarly journals Prefrontal High Gamma in ECoG tags periodicity of musical rhythms in perception and imagination

2019 ◽  
Author(s):  
S. A. Herff ◽  
C. Herff ◽  
A. J. Milne ◽  
G. D. Johnson ◽  
J. J. Shih ◽  
...  
Keyword(s):  
Auditory Processing ◽  
Right Hemisphere ◽  
Brain Activity ◽  
Activity Patterns ◽  
Superior Temporal Gyrus ◽  
Gamma Activity ◽  
Rhythm Perception ◽  
High Gamma ◽  
The Right ◽  
Musical Rhythms

AbstractRhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope-tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners, to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACC) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelation of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms’ structure as opposed to mere auditory phenomena. The ACC approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.

scholarly journals fMRI single trial discovery of spatio-temporal brain activity patterns

2016 ◽  
Vol 38 (3) ◽  
pp. 1421-1437 ◽  
Author(s):  
Michele Allegra ◽  
Shima Seyed-Allaei ◽  
Fabrizio Pizzagalli ◽  
Fahimeh Baftizadeh ◽  
Marta Maieron ◽  
...  
Keyword(s):  
Brain Activity ◽  
Activity Patterns ◽  
Single Trial ◽  
Spatio Temporal

scholarly journals The structured flow on the brain's resting state manifold

2022 ◽  
Author(s):  
Jan Fousek ◽  
Giovanni Rabuffo ◽  
Kashyap Gudibanda ◽  
Hiba Sheheitli ◽  
Viktor Jirsa ◽  
...  
Keyword(s):  
Resting State ◽  
Brain Activity ◽  
Activity Patterns ◽  
Predictive Coding ◽  
Network Connectivity ◽  
High Amplitude ◽  
Characteristic Functional ◽  
Spatio Temporal ◽  
Generative Mechanism ◽  
Task Conditions

Spontaneously fluctuating brain activity patterns emerge at rest and relate to brain functional networks involved in task conditions. Despite detailed descriptions of the spatio-temporal brain patterns, our understanding of their generative mechanism is still incomplete. Using a combination of computational modeling and dynamical systems analysis we provide a complete mechanistic description in terms of the constituent entities and the productive relation of their causal activities leading to the formation of a resting state manifold via the network connectivity. We demonstrate that the symmetry breaking by the connectivity creates a characteristic flow on the manifold, which produces the major empirical data features including spontaneous high amplitude co-activations, neuronal cascades, spectral cortical gradients, multistability and characteristic functional connectivity dynamics. The understanding of the brain's resting state manifold is fundamental for the construction of task-specific flows and manifolds used in theories of brain function such as predictive coding.

scholarly journals Processing of Targets in Smooth or Apparent Motion Along the Vertical in the Human Brain: An fMRI Study

2010 ◽  
Vol 103 (1) ◽  
pp. 360-370 ◽  
Author(s):  
Vincenzo Maffei ◽  
Emiliano Macaluso ◽  
Iole Indovina ◽  
Guy Orban ◽  
Francesco Lacquaniti
Keyword(s):  
Apparent Motion ◽  
Visual Motion ◽  
Brain Activity ◽  
Activity Patterns ◽  
Vertical Motion ◽  
Constant Speed ◽  
Lingual Gyrus ◽  
Fmri Study ◽  
Smooth Motion ◽  
The Right

Neural substrates for processing constant speed visual motion have been extensively studied. Less is known about the brain activity patterns when the target speed changes continuously, for instance under the influence of gravity. Using functional MRI (fMRI), here we compared brain responses to accelerating/decelerating targets with the responses to constant speed targets. The target could move along the vertical under gravity (1 g), under reversed gravity (−1 g), or at constant speed (0 g). In the first experiment, subjects observed targets moving in smooth motion and responded to a GO signal delivered at a random time after target arrival. As expected, we found that the timing of the motor responses did not depend significantly on the specific motion law. Therefore brain activity in the contrast between different motion laws was not related to motor timing responses. Average BOLD signals were significantly greater for 1 g targets than either 0 g or −1 g targets in a distributed network including bilateral insulae, left lingual gyrus, and brain stem. Moreover, in these regions, the mean activity decreased monotonically from 1 g to 0 g and to −1 g. In the second experiment, subjects intercepted 1 g, 0 g, and −1 g targets either in smooth motion (RM) or in long-range apparent motion (LAM). We found that the sites in the right insula and left lingual gyrus, which were selectively engaged by 1 g targets in the first experiment, were also significantly more active during 1 g trials than during −1 g trials both in RM and LAM. The activity in 0 g trials was again intermediate between that in 1 g trials and that in −1 g trials. Therefore in these regions the global activity modulation with the law of vertical motion appears to hold for both RM and LAM. Instead, a region in the inferior parietal lobule showed a preference for visual gravitational motion only in LAM but not RM.

Non-invasive detection and identification of brain activity patterns in the developing fetus

2007 ◽  
Vol 118 (9) ◽  
pp. 1940-1946 ◽  
Author(s):  
Hari Eswaran ◽  
Naim I. Haddad ◽  
Bashir S. Shihabuddin ◽  
Hubert Preissl ◽  
Eric R. Siegel ◽  
...  
Keyword(s):  
Brain Activity ◽  
Activity Patterns ◽  
Non Invasive ◽  
Detection And Identification

scholarly journals Методика пространственно-временного анализа электрической активности головного мозга

2020 ◽  
Vol 46 (11) ◽  
pp. 39
Author(s):  
А.Е. Руннова ◽  
М.О. Журавлев ◽  
А.Р. Киселёв ◽  
А.О. Сельский
Keyword(s):  
Wavelet Transform ◽  
Electrical Activity ◽  
Continuous Wavelet Transform ◽  
Temporal Dynamics ◽  
Brain Activity ◽  
Activity Patterns ◽  
Spatial Dynamics ◽  
Continuous Wavelet ◽  
Brain Electrical Activity ◽  
Spatio Temporal

In the framework of this work a new method based on continuous wavelet transform was proposed for analyzing the spatio-temporal dynamics of brain activity patterns. We described the example of this method application for the analysis of brain electrical activity signals. It is shown that this method has the ability to visually detect the occurrence and spatial dynamics of frequency patterns.

scholarly journals Common neural and transcriptional correlates of inhibitory control underlie emotion regulation and memory control

2020 ◽  
Vol 15 (5) ◽  
pp. 523-536 ◽  
Author(s):  
Wei Liu ◽  
Nancy Peeters ◽  
Guillén Fernández ◽  
Nils Kohn
Keyword(s):  
Emotion Regulation ◽  
Inhibitory Control ◽  
Brain Activity ◽  
Activity Patterns ◽  
Enrichment Analysis ◽  
Brain Atlas ◽  
Activation Patterns ◽  
Memory Control ◽  
The Right ◽  
Meta Analyses

Abstract Inhibitory control is crucial for regulating emotions and may also enable memory control. However, evidence for their shared neurobiological correlates is limited. Here, we report meta-analyses of neuroimaging studies on emotion regulation, or memory control and link neural commonalities to transcriptional commonalities using the Allen Human Brain Atlas (AHBA). Based on 95 functional magnetic resonance imaging studies, we reveal a role of the right inferior parietal lobule embedded in a frontal–parietal–insular network during emotion regulation and memory control, which is similarly recruited during response inhibition. These co-activation patterns also overlap with the networks associated with ‘inhibition’, ‘cognitive control’ and ‘working memory’ when consulting the Neurosynth. Using the AHBA, we demonstrate that emotion regulation- and memory control-related brain activity patterns are associated with transcriptional profiles of a specific set of ‘inhibition-related’ genes. Gene ontology enrichment analysis of these ‘inhibition-related’ genes reveal associations with the neuronal transmission and risk for major psychiatric disorders as well as seizures and alcoholic dependence. In summary, this study identified a neural network and a set of genes associated with inhibitory control across emotion regulation and memory control. These findings facilitate our understanding of the neurobiological correlates of inhibitory control and may contribute to the development of brain stimulation and pharmacological interventions.

Differential Effects of Encoding Instructions on Brain Activity Patterns of Item and Associative Memory

2017 ◽  
Vol 29 (3) ◽  
pp. 545-559 ◽  
Author(s):  
Nina Becker ◽  
Grégoria Kalpouzos ◽  
Jonas Persson ◽  
Erika J. Laukka ◽  
Yvonne Brehmer
Keyword(s):  
Specific Binding ◽  
Brain Activity ◽  
Memory Performance ◽  
Inferior Frontal Gyrus ◽  
Activity Patterns ◽  
Critical Role ◽  
Recognition Task ◽  
Brain Correlates ◽  
Incidental Encoding ◽  
The Right

Evidence from neuroimaging studies suggests a critical role of hippocampus and inferior frontal gyrus (IFG) in associative relative to item encoding. Here, we investigated similarities and differences in functional brain correlates for associative and item memory as a function of encoding instruction. Participants received either incidental (animacy judgments) or intentional encoding instructions while fMRI was employed during the encoding of associations and items. In a subsequent recognition task, memory performance of participants receiving intentional encoding instructions was higher compared with those receiving incidental encoding instructions. Furthermore, participants remembered more items than associations, regardless of encoding instruction. Greater brain activation in the left anterior hippocampus was observed for intentionally compared with incidentally encoded associations, although activity in this region was not modulated by the type of instruction for encoded items. Furthermore, greater activity in the left anterior hippocampus and left IFG was observed during intentional associative compared with item encoding. The same regions were related to subsequent memory of intentionally encoded associations and were thus task relevant. Similarly, connectivity of the anterior hippocampus to the right superior temporal lobe and IFG was uniquely linked to subsequent memory of intentionally encoded associations. Our study demonstrates the differential involvement of anterior hippocampus in intentional relative to incidental associative encoding. This finding likely reflects that the intent to remember triggers a specific binding process accomplished by this region.

scholarly journals Exploring alterations in sensory pathways in migraine

2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Noemi Meylakh ◽  
Luke A. Henderson
Keyword(s):  
Visual Cortex ◽  
Sensory Processing ◽  
Brain Activity ◽  
Activity Patterns ◽  
Oscillatory Activity ◽  
Somatosensory Processing ◽  
Somatosensory Cortices ◽  
And Gender ◽  
The Right ◽  
Sensory Processes

Abstract Background Migraine is a neurological disorder characterized by intense, debilitating headaches, often coupled with nausea, vomiting and sensitivity to light and sound. Whilst changes in sensory processes during a migraine attack have been well-described, there is growing evidence that even between migraine attacks, sensory abilities are disrupted in migraine. Brain imaging studies have investigated altered coupling between areas of the descending pain modulatory pathway but coupling between somatosensory processing regions between migraine attacks has not been properly studied. The aim of this study was to determine if ongoing functional connectivity between visual, auditory, olfactory, gustatory and somatosensory cortices are altered during the interictal phase of migraine. Methods To explore the neural mechanisms underpinning interictal changes in sensory processing, we used functional magnetic resonance imaging to compare resting brain activity patterns and connectivity in migraineurs between migraine attacks (n = 32) and in healthy controls (n = 71). Significant differences between groups were determined using two-sample random effects procedures (p < 0.05, corrected for multiple comparisons, minimum cluster size 10 contiguous voxels, age and gender included as nuisance variables). Results In the migraine group, increases in infra-slow oscillatory activity were detected in the right primary visual cortex (V1), secondary visual cortex (V2) and third visual complex (V3), and left V3. In addition, resting connectivity analysis revealed that migraineurs displayed significantly enhanced connectivity between V1 and V2 with other sensory cortices including the auditory, gustatory, motor and somatosensory cortices. Conclusions These data provide evidence for a dysfunctional sensory network in pain-free migraine patients which may be underlying altered sensory processing between migraine attacks.

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