scholarly journals Somatosensory responses to nothing: an MEG study of expectations during omission of tactile stimulations

2018 ◽  
Author(s):  
Lau M. Andersen ◽  
Daniel Lundqvist
Keyword(s):  
Index Finger ◽  
Beta Band ◽  
Secondary Somatosensory Cortex ◽  
Inferior Parietal Cortex ◽  
Future Events ◽  
Somatosensory Responses ◽  
The Right ◽  
Gamma Band Activity ◽  
The Brain ◽  
Band Activity

AbstractThe brain builds up expectations to future events based on the patterns of past events. This function has been studied extensively in the auditory and visual domains using various oddball paradigms, but only little exploration of this phenomenon has been done in the somatosensory domain. In this study, we explore how expectations of somatosensory stimulations are established and expressed in neural activity as measured with magnetoencephalography. Using tactile stimulations to the index finger, we compared conditions with actual stimulation to conditions with omitted stimulations, both of which were either expected or unexpected.Our results show that when a stimulation is expected but omitted, a time-locked response occurs ∼135 ms subsequent to the expected stimulation. This somatosensory response to “nothing” was source localized to the secondary somatosensory cortex and to the insula. This provides novel evidence of the capability of the brain of millisecond time-keeping of somatosensory patterns across intervals of 3000 ms.Our results also show that when stimuli are repeated and expectations are established, there is associated activity in the theta and beta bands. These theta and beta band expressions of expectation were localized to the primary somatosensory area, inferior parietal cortex and cerebellum. Furthermore, there was gamma band activity in the right insula for the first stimulation after an omission, which indicates the detection of a new stimulation event after an expected pattern has been broken.Finally, our results show that cerebellum play a crucial role in predicting upcoming stimulation and in predicting when stimulation may begin again.

scholarly journals Reducing future fears by suppressing the brain mechanisms underlying episodic simulation

2016 ◽  
Vol 113 (52) ◽  
pp. E8492-E8501 ◽  
Author(s):  
Roland G. Benoit ◽  
Daniel J. Davies ◽  
Michael C. Anderson
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Ventromedial Prefrontal Cortex ◽  
Episodic Simulation ◽  
Dorsolateral Prefrontal ◽  
Future Events ◽  
The Right ◽  
Development Of Anxiety ◽  
The Brain

Imagining future events conveys adaptive benefits, yet recurrent simulations of feared situations may help to maintain anxiety. In two studies, we tested the hypothesis that people can attenuate future fears by suppressing anticipatory simulations of dreaded events. Participants repeatedly imagined upsetting episodes that they feared might happen to them and suppressed imaginings of other such events. Suppressing imagination engaged the right dorsolateral prefrontal cortex, which modulated activation in the hippocampus and in the ventromedial prefrontal cortex (vmPFC). Consistent with the role of the vmPFC in providing access to details that are typical for an event, stronger inhibition of this region was associated with greater forgetting of such details. Suppression further hindered participants’ ability to later freely envision suppressed episodes. Critically, it also reduced feelings of apprehensiveness about the feared scenario, and individuals who were particularly successful at down-regulating fears were also less trait-anxious. Attenuating apprehensiveness by suppressing simulations of feared events may thus be an effective coping strategy, suggesting that a deficiency in this mechanism could contribute to the development of anxiety.

Music Affects Learning of a Braille-Like Task by Sighted Subjects

1989 ◽  
Vol 69 (3-1) ◽  
pp. 923-929
Author(s):  
Robert F. Kennison ◽  
Richard A. Mcfarland
Keyword(s):  
College Students ◽  
Sensory Input ◽  
Index Finger ◽  
Practical Importance ◽  
Left Index Finger ◽  
Interhemispheric Competition ◽  
Male College ◽  
The Right ◽  
The Brain ◽  
Male College Students

24 consistently right-handed male college students felt sets of four Braille symbols with either the right or the left index finger and identified by touch alone which two of the four symbols in each set were identical. During the task music was played to either the right ear, the left ear, both ears, or neither ear. Significantly fewer errors were made when the music was in the ear contralateral to whichever hand performed the task. The ipsilateral, binaural, and no-music groups did not differ significantly from each other. It is suggested that monaural music to the ear contralateral to the engaged hand led to reduced interhemispheric competition acting on the hemisphere controlling the hand. Such a facilitating effect may be of practical importance in tasks during which one hemisphere receives the bulk of the task-related sensory input and/or processes the final order from the brain to the task-related muscles.

scholarly journals Right inferior frontal gyrus implements motor inhibitory control via beta-band oscillations in humans

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Michael Schaum ◽  
Edoardo Pinzuti ◽  
Alexandra Sebastian ◽  
Klaus Lieb ◽  
Pascal Fries ◽  
...  
Keyword(s):  
Inhibitory Control ◽  
Response Inhibition ◽  
Supplementary Motor Area ◽  
Inferior Frontal Gyrus ◽  
Neural Mechanisms ◽  
Beta Band ◽  
Changing Environments ◽  
Band Power ◽  
The Right ◽  
Band Activity

Motor inhibitory control implemented as response inhibition is an essential cognitive function required to dynamically adapt to rapidly changing environments. Despite over a decade of research on the neural mechanisms of response inhibition, it remains unclear, how exactly response inhibition is initiated and implemented. Using a multimodal MEG/fMRI approach in 59 subjects, our results reliably reveal that response inhibition is initiated by the right inferior frontal gyrus (rIFG) as a form of attention-independent top-down control that involves the modulation of beta-band activity. Furthermore, stopping performance was predicted by beta-band power, and beta-band connectivity was directed from rIFG to pre-supplementary motor area (pre-SMA), indicating rIFG’s dominance over pre-SMA. Thus, these results strongly support the hypothesis that rIFG initiates stopping, implemented by beta-band oscillations with potential to open up new ways of spatially localized oscillation-based interventions.

scholarly journals The Role of Insula-Associated Brain Network in Touch

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Pengxu Wei ◽  
Ruixue Bao
Keyword(s):  
Parietal Cortex ◽  
Superior Temporal Gyrus ◽  
Normal Subjects ◽  
Brain Network ◽  
Seed Region ◽  
Secondary Somatosensory Cortex ◽  
Inferior Parietal Cortex ◽  
Posterior Insula ◽  
The Right ◽  
Post Hoc

The insula is believed to be associated with touch-evoked effects. In this work, functional MRI was applied to investigate the network model of insula function when 20 normal subjects received tactile stimulation over segregated areas. Data analysis was performed with SPM8 and Conn toolbox. Activations in the contralateral posterior insula were consistently revealed for all stimulation areas, with the overlap located in area Ig2. The area Ig2 was then used as the seed to estimate the insula-associated network. The right insula, left superior parietal lobule, left superior temporal gyrus, and left inferior parietal cortex showed significant functional connectivity with the seed region for all stimulation conditions. Connectivity maps of most stimulation conditions were mainly distributed in the bilateral insula, inferior parietal cortex, and secondary somatosensory cortex. Post hoc ROI-to-ROI analysis and graph theoretical analysis showed that there were higher correlations between the left insula and the right insula, left inferior parietal cortex and right OP1 for all networks and that the global efficiency was more sensitive than the local efficiency to detect differences between notes in a network. These results suggest that the posterior insula serves as a hub to functionally connect other regions in the detected network and may integrate information from these regions.

scholarly journals Alpha-to-beta- and gamma-band activity reflect predictive coding in affective visual processing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreas Strube ◽  
Michael Rose ◽  
Sepideh Fazeli ◽  
Christian Büchel
Keyword(s):  
Visual Processing ◽  
Predictive Coding ◽  
Stimulus Presentation ◽  
Gamma Band ◽  
Prediction Errors ◽  
Beta Band ◽  
Picture Processing ◽  
Gamma Band Activity ◽  
Spectral Patterns ◽  
Band Activity

AbstractProcessing of negative affective pictures typically leads to desynchronization of alpha-to-beta frequencies (ERD) and synchronization of gamma frequencies (ERS). Given that in predictive coding higher frequencies have been associated with prediction errors, while lower frequencies have been linked to expectations, we tested the hypothesis that alpha-to-beta ERD and gamma ERS induced by aversive pictures are associated with expectations and prediction errors, respectively. We recorded EEG while volunteers were involved in a probabilistically cued affective picture task using three different negative valences to produce expectations and prediction errors. Our data show that alpha-to-beta band activity after stimulus presentation was related to the expected valence of the stimulus as predicted by a cue. The absolute mismatch of the expected and actual valence, which denotes an absolute prediction error was related to increases in alpha, beta and gamma band activity. This demonstrates that top-down predictions and bottom-up prediction errors are represented in typical spectral patterns associated with affective picture processing. This study provides direct experimental evidence that negative affective picture processing can be described by neuronal predictive coding computations.

scholarly journals Induced Gamma-Band Activity during Actual and Imaginary Movements: EEG Analysis

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1545
Author(s):  
Carlos Amo Usanos ◽  
Luciano Boquete ◽  
Luis de Santiago ◽  
Rafael Barea Navarro ◽  
Carlo Cavaliere
Keyword(s):  
Brain Activity ◽  
Motor Task ◽  
Gamma Band ◽  
Mean Power ◽  
Significant Difference ◽  
Actual Movement ◽  
The Mean ◽  
The Right ◽  
Gamma Band Activity ◽  
Band Activity

The purpose of this paper is to record and analyze induced gamma-band activity (GBA) (30–60 Hz) in cerebral motor areas during imaginary movement and to compare it quantitatively with activity recorded in the same areas during actual movement using a simplified electroencephalogram (EEG). Brain activity (basal activity, imaginary motor task and actual motor task) is obtained from 12 healthy volunteer subjects using an EEG (Cz channel). GBA is analyzed using the mean power spectral density (PSD) value. Event-related synchronization (ERS) is calculated from the PSD values of the basal GBA (GBAb), the GBA of the imaginary movement (GBAim) and the GBA of the actual movement (GBAac). The mean GBAim and GBAac values for the right and left hands are significantly higher than the GBAb value (p = 0.007). No significant difference is detected between mean GBA values during the imaginary and actual movement (p = 0.242). The mean ERS values for the imaginary movement (ERSimM (%) = 23.52) and for the actual movement (ERSacM = 27.47) do not present any significant difference (p = 0.117). We demonstrated that ERS could provide a useful way of indirectly checking the function of neuronal motor circuits activated by voluntary movement, both imaginary and actual. These results, as a proof of concept, could be applied to physiology studies, brain–computer interfaces, and diagnosis of cognitive or motor pathologies.

FEATURE EXTRACTION OF ELECTROENCEPHALOGRAM SIGNAL GENERATED FROM WRITING IN DYSLEXIC CHILDREN USING DAUBECHIES WAVELET TRANSFORM

2016 ◽  
Vol 78 (6-8) ◽  
Author(s):  
Zulkifli Mahmoodin ◽  
Wahidah Mansor ◽  
Lee Yoot Khuan ◽  
Noor Bariah Mohamad ◽  
Sariah Amirin
Keyword(s):  
Feature Extraction ◽  
Wavelet Transform ◽  
Right Hemisphere ◽  
Electrode Placement ◽  
Daubechies Wavelet ◽  
Eeg Signal ◽  
Beta Band ◽  
Reading And Writing ◽  
The Right ◽  
The Brain

Dyslexia which causes learning deficiencies in reading and writing is due to a neurological disorder where the brain processes information differently. This paper describes the feature extraction of (EEG) signal using Daubechies wavelet transform. The EEG signals were recorded from capable and poor dyslexic children during writing activities of non-words. Brain learning pathway theories for reading and writing were used to localize electrode placement to 8 positions, namely C3, C4, P3, P4, T7, T8, FC5 and FC6. Daubechies provide the wavelet function shape that represent the type of features in an EEG signal well, detecting variations in frequencies that corresponds to activation of areas in relation to activities. Results showed that capable dyslexic subjects exhibit higher beta band power feature of the frontal (FC6) and parietal (P4) right hemisphere if compared to poor dyslexics, where the normal left hemisphere processing center was utilized. This indicates that the brain of dyslexic is compensating its deficiencies of the left brain with activation of areas to the right.  

scholarly journals Parietal and Motor Cortical Dynamics Differentially Shape the Computation of Choice History Bias

2021 ◽  
Author(s):  
Anne E Urai ◽  
Tobias H Donner
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Random Sequence ◽  
Beta Band ◽  
Sensory Stimuli ◽  
Starting Point ◽  
Action Preparation ◽  
Motor History ◽  
Gamma Band Activity ◽  
Band Activity

Humans and other animals tend to systematically repeat (or alternate) their previous choices, even when judging sensory stimuli presented in a random sequence. Choice history biases may arise from action preparation in motor circuits, or from perceptual or decision processing in upstream areas. Here, we combined source-level magnetoencephalographic (MEG) analyses of cortical population dynamics with behavioral modeling of a visual decision process. We disentangled two neural history signals in human motor and posterior parietal cortex. Gamma-band activity in parietal cortex tracked previous choices throughout the trial and biased evidence accumulation toward choice repetition. Action-specific beta-band activity in motor cortex also carried over to the next trial and biased the accumulation starting point toward alternation. The parietal, but not motor, history signal predicted the next trial's choice as well as individual differences in choice repetition. Our results are consistent with a key role of parietal cortical signals in shaping choice sequences.

scholarly journals Anticipatory reinstatement of expected perceptual events during visual sequence learning

2020 ◽  
Author(s):  
Mehdi Senoussi ◽  
Rufin VanRullen ◽  
Leila Reddy
Keyword(s):  
Sequence Learning ◽  
Learning Task ◽  
Stimulus Onset ◽  
Beta Band ◽  
Time Frequency ◽  
Future Events ◽  
Alpha Beta ◽  
Multivariate Pattern ◽  
Successful Behavior ◽  
The Brain

AbstractBeing able to predict future events in learned sequences is a fundamental cognitive ability. Successful behavior requires the brain to not only anticipate an upcoming event, but to also continue to keep track of the sequence in case of eventual disruptions, (e.g., when a predicted event does not occur). However, the precise neural mechanisms supporting such processes remain unknown. Here, using multivariate pattern classification based on electroencephalography (EEG) activity and time-frequency amplitude, we show that the visual system represents upcoming expected stimuli during a sequence-learning task. Stimulus-evoked neural representations were reinstated prior to expected stimulus onset, and when an anticipated stimulus was unexpectedly withheld, suggesting proactive reinstatement of sensory templates. Importantly, stimulus representation of the absent stimulus co-occurred with an emerging representation of the following stimulus in the sequence, showing that the brain actively maintained sequence order even when the sequence was perturbed. Finally, selective activity was evident in the alpha-beta band (9-20 Hz) amplitude topographies, confirming the role of alpha-beta oscillations in carrying information about the nature of sensory expectations. These results show that the brain dynamically implements anticipatory mechanisms that reinstate sensory representations, and that allow us to make predictions about events further in the future.

scholarly journals Painful cutaneous laser stimuli induce event-related gamma-band activity in the lateral thalamus of humans

2015 ◽  
Vol 113 (5) ◽  
pp. 1564-1573 ◽  
Author(s):  
J. H. Kim ◽  
J. H. Chien ◽  
C. C. Liu ◽  
F. A. Lenz
Keyword(s):  
Experimental Pain ◽  
Gamma Band ◽  
Beta Band ◽  
Gamma Activation ◽  
High Gamma ◽  
Gamma Band Activity ◽  
Cross Frequency Coupling ◽  
Induce Event ◽  
Band Activity ◽  
Deep Brain

Although the thalamus is an important module in “pain networks,” there are few studies of the effect of experimental pain upon thalamic oscillations. We have now examined the hypothesis that, during a series of painful cutaneous laser stimuli, thalamic signals will show stimulus-related gamma-band spectral activity, which is modulated by attention to vs. distraction from the painful stimulus. When the series of laser stimuli was presented, attention was focused by counting the laser stimuli (count laser task), while distraction was produced by counting backward (count back plus laser task). We have studied the effect of a cutaneous laser on thalamic local field potentials and EEG activity during awake procedures (deep brain stimulation implants) for the treatment of essential tremor. At different delays after the stimulus, three low gamma- (30–50 Hz) and two high gamma-band (70–90 Hz) activations were observed during the two tasks. Greater high-gamma activation was found during the count laser task for the earlier window, while greater high-gamma activation was found during the count back plus laser task for the later window. Thalamic signals were coherent with EEG signals in the beta band, which indicated significant synchrony. Thalamic cross-frequency coupling analysis indicated that the phase of the lower frequency activity (theta to beta) modulated the amplitude of the higher frequency activity (low and high gamma) more strongly during the count laser task than during the count back plus laser task. This modulation might result in multiplexed signals each encoding a different aspect of pain.

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