scholarly journals Predictive entrainment of natural speech through two fronto-motor top-down channels

2018 ◽  
Author(s):  
Hyojin Park ◽  
Gregor Thut ◽  
Joachim Gross
Keyword(s):  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Precentral Gyrus ◽  
Top Down ◽  
Low Frequencies ◽  
Left Inferior Frontal Gyrus ◽  
Delta Phase ◽  
Beta Power ◽  
Intelligible Speech ◽  
Spatio Temporal

AbstractNatural communication between interlocutors is enabled by the ability to predict upcoming speech in a given context. Previously we showed that these predictions rely on a fronto-motor top-down control of low-frequency oscillations in auditory-temporal brain areas that track intelligible speech. However, a comprehensive spatio-temporal characterisation of this effect is still missing. Here, we applied transfer entropy to source-localised MEG data during continuous speech perception. First, at low frequencies (1-4 Hz, brain delta phase to speech delta phase), predictive effects start in left fronto-motor regions and progress to right temporal regions. Second, at higher frequencies (14-18 Hz, brain beta power to speech delta phase), predictive patterns show a transition from left inferior frontal gyrus via left precentral gyrus to left primary auditory areas. Our results suggest a progression of prediction processes from higher-order to early sensory areas in at least two different frequency channels.

scholarly journals Signature patterns for top-down and bottom-up information processing via cross-frequency coupling in macaque auditory cortex

2018 ◽  
Author(s):  
Christian D. Márton ◽  
Makoto Fukushima ◽  
Corrie R. Camalier ◽  
Simon R. Schultz ◽  
Bruno B. Averbeck
Keyword(s):  
Information Processing ◽  
Auditory Cortex ◽  
Predictive Coding ◽  
Low Frequency ◽  
Information Need ◽  
Top Down ◽  
Bottom Up ◽  
Low Frequencies ◽  
Frequency Coupling ◽  
Cross Frequency Coupling

AbstractPredictive coding is a theoretical framework that provides a functional interpretation of top-down and bottom up interactions in sensory processing. The theory has suggested that specific frequency bands relay bottom-up and top-down information (e.g. “γ up, β down”). But it remains unclear whether this notion generalizes to cross-frequency interactions. Furthermore, most of the evidence so far comes from visual pathways. Here we examined cross-frequency coupling across four sectors of the auditory hierarchy in the macaque. We computed two measures of cross-frequency coupling, phase-amplitude coupling (PAC) and amplitude-amplitude coupling (AAC). Our findings revealed distinct patterns for bottom-up and top-down information processing among cross-frequency interactions. Both top-down and bottom-up made prominent use of low frequencies: low-to-low frequency (θ, α, β) and low frequency-to-high γ couplings were predominant top-down, while low frequency-to-low γ couplings were predominant bottom-up. These patterns were largely preserved across coupling types (PAC and AAC) and across stimulus types (natural and synthetic auditory stimuli), suggesting they are a general feature of information processing in auditory cortex. Moreover, our findings showed that low-frequency PAC alternated between predominantly top-down or bottom-up over time. Altogether, this suggests sensory information need not be propagated along separate frequencies upwards and downwards. Rather, information can be unmixed by having low frequencies couple to distinct frequency ranges in the target region, and by alternating top-down and bottom-up processing over time.1SignificanceThe brain consists of highly interconnected cortical areas, yet the patterns in directional cortical communication are not fully understood, in particular with regards to interactions between different signal components across frequencies. We employed a a unified, computationally advantageous Granger-causal framework to examine bi-directional cross-frequency interactions across four sectors of the auditory cortical hierarchy in macaques. Our findings extend the view of cross-frequency interactions in auditory cortex, suggesting they also play a prominent role in top-down processing. Our findings also suggest information need not be propagated along separate channels up and down the cortical hierarchy, with important implications for theories of information processing in the brain such as predictive coding.

scholarly journals Changes in resting-state measures of prostate cancer patients exposed to androgen deprivation therapy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julio Plata-Bello ◽  
Ana Plata-Bello ◽  
Yaiza Pérez-Martín ◽  
David López-Curtis ◽  
Silvia Acosta-López ◽  
...  
Keyword(s):  
Androgen Deprivation Therapy ◽  
Resting State ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Region Of Interest ◽  
Androgen Deprivation ◽  
Receptor Expression ◽  
Control Group ◽  
Precentral Gyrus ◽  
The Right

AbstractThe aim of the present work is to describe the differences in rs-fMRI measures (Amplitude of low frequency fluctuations [ALFF], Regional Homogeneity [ReHo] and Functional Connectivity [FC]) between patients exposed to Androgen deprivation therapy (ADT) and a control group. Forty-nine ADT patients and fifteen PC-non-ADT patients (Controls) were included in the study. A neuropsychological evaluation and a resting-state fMRI was performed to evaluate differences in ALFF and ReHo. Region of interest (ROI) analysis was also performed. ROIs were selected among those whose androgen receptor expression (at RNA-level) was the highest. FC analysis was performed using the same ROIs. Higher ALFF in frontal regions and temporal regions was identified in Controls than in ADT patients. In the ROI analysis, higher activity for Controls than ADT patients was shown in the left inferior frontal gyrus and in the left precentral gyrus. Lower ALFF in the right hippocampus and the lateral geniculate nucleus of the right thalamus was identified for Controls than ADT patients. Higher ReHo was observed in Controls in the left parietal-occipital area. Finally, ADT patients presented an increase of FC in more regions than Controls. These differences may reflect an impairment in brain functioning in ADT users.

scholarly journals Effect of Repetitive Transcranial Magnetic Stimulation on the Right Superior Temporal Gyrus for Severe Aphasia Caused by Damage to the Left Inferior Frontal Gyrus

2019 ◽  
Vol 11 (2) ◽  
pp. 189-198 ◽  
Author(s):  
Mimpei Kawamura ◽  
Nobuhiro Takahashi ◽  
Yasutaka Kobayashi
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Superior Temporal Gyrus ◽  
Verbal Expression ◽  
Left Inferior Frontal Gyrus ◽  
The Right ◽  
Low Frequency Rtms

Several reports on repetitive transcranial magnetic stimulation (rTMS) for the treatment of aphasia caused by damage to the left inferior frontal gyrus state that low-frequency rTMS therapy for the right inferior frontal gyrus, which is contralateral to the focus area, is effective for improving verbal expression. However, most of these reports have studied the effects of rTMS therapy for comparatively mild aphasia. This study attempted to perform low-frequency rTMS on the right posterior superior temporal gyrus (BA22), which is the center for language reception for aphasia patients with a drastic decline in verbal expression due to damage to the left inferior frontal gyrus and a considerable decline in language perception. The participants performed a language task that was displayed on a computer monitor during rTMS. In addition, intensive speech-language and hearing therapy was performed by the therapist after rTMS. This study reports that a resultant improvement in language perception was observed in the activated brain regions based on neuropsychological tests and functional magnetic resonance imaging. This study is considered to be significant as it highlights a new method of rTMS treatment for severe aphasia.

scholarly journals Amplitude of low-frequency fluctuations on Alzheimer’s disease with depression: evidence from resting-state fMRI

2020 ◽  
Vol 33 (4) ◽  
pp. e100147
Author(s):  
Yuzhu Mu ◽  
Yumei Li ◽  
Qi Zhang ◽  
Zhongxiang Ding ◽  
Mei Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Resting State ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Middle Frontal Gyrus ◽  
Left Inferior Frontal Gyrus ◽  
Superior Frontal Gyrus ◽  
Frequency Fluctuations ◽  
Left Middle

BackgroundThe prevalence of Alzheimer’s disease (AD) comorbid with depression is common. However, the mechanisms of AD with depression remain unclear.AimsTo investigate the regional alterations of brain activity of AD with depression in resting-state functional magnetic resonance imaging (rs-fMRI).Methods154 patients with AD who met the inclusion criteria were recruited from the Zhejiang Provincial People’s Hospital from October 2014 to October 2016. According to whether the core symptoms of depression were present, patients were divided into two groups, 22 patients with AD with depression (AD-D) and 52 patients with AD without depression (AD-nD). The amplitude of low frequency fluctuations (ALFF) was compared between two groups by performing independent-samples t-test.ResultsCompared with the AD-D group, increased ALFF values in the bilateral superior frontal gyrus, left middle frontal gyrus and left inferior frontal gyrus were observed in the AD-nD group. The brain activity in the AD-nD group in the bilateral superior frontal gyrus, left middle frontal gyrus and the left inferior frontal gyrus was higher than the AD-D group.ConclusionsResting-state brain functional alterations may be closely bound up with the pathophysiologic features of patients with AD with depressive symptoms.

scholarly journals Altered patterns of fractional amplitude of low-frequency fluctuation and regional homogeneity in abstinent methamphetamine-dependent users

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
An Xie ◽  
Qiuxia Wu ◽  
Winson Fu Zun Yang ◽  
Chang Qi ◽  
Yanhui Liao ◽  
...  
Keyword(s):  
Resting State ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Regional Homogeneity ◽  
Anterior Cingulate ◽  
Frequency Fluctuation ◽  
Early Recovery ◽  
Left Inferior Frontal Gyrus ◽  
The Right

AbstractMethamphetamine (MA) could induce functional and structural brain alterations in dependent subjects. However, few studies have investigated resting-state activity in methamphetamine-dependent subjects (MADs). We aimed to investigate alterations of brain activity during resting-state in MADs using fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo). We analyzed fALFF and ReHo between MADs (n = 70) and healthy controls (HCs) (n = 84) and performed regression analysis using MA use variables. Compared to HCs, abstinent MADs showed increased fALFF and ReHo values in the bilateral striatum, decreased fALFF in the left inferior frontal gyrus, and decreased ReHo in the bilateral anterior cingulate cortex, sensorimotor cortex, and left precuneus. We also observed the fALFF values of bilateral striatum were positively correlated with the age of first MA use, and negatively correlated with the duration of MA use. The fALFF value of right striatum was also positively correlated with the duration of abstinence. The alterations of spontaneous cerebral activity in abstinent MADs may help us probe into the neurological pathophysiology underlying MA-related dysfunction and recovery. Since MADs with higher fALFF in the right striatum had shorter MA use and longer abstinence, the increased fALFF in the right striatum might implicate early recovery during abstinence.

scholarly journals Intracranial Recordings and Computational Modeling of Music Reveal the Time Course of Prediction Error Signaling in Frontal and Temporal Cortices

2019 ◽  
Vol 31 (6) ◽  
pp. 855-873 ◽  
Author(s):  
Diana Omigie ◽  
Marcus Pearce ◽  
Katia Lehongre ◽  
Dominique Hasboun ◽  
Vincent Navarro ◽  
...  
Keyword(s):  
Prediction Error ◽  
Time Course ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Anterior Cingulate ◽  
Predictive Processing ◽  
Gamma Activity ◽  
Oscillatory Activity ◽  
Middle Temporal Gyrus ◽  
Beta Power

Prediction is held to be a fundamental process underpinning perception, action, and cognition. To examine the time course of prediction error signaling, we recorded intracranial EEG activity from nine presurgical epileptic patients while they listened to melodies whose information theoretical predictability had been characterized using a computational model. We examined oscillatory activity in the superior temporal gyrus (STG), the middle temporal gyrus (MTG), and the pars orbitalis of the inferior frontal gyrus, lateral cortical areas previously implicated in auditory predictive processing. We also examined activity in anterior cingulate gyrus (ACG), insula, and amygdala to determine whether signatures of prediction error signaling may also be observable in these subcortical areas. Our results demonstrate that the information content (a measure of unexpectedness) of musical notes modulates the amplitude of low-frequency oscillatory activity (theta to beta power) in bilateral STG and right MTG from within 100 and 200 msec of note onset, respectively. Our results also show this cortical activity to be accompanied by low-frequency oscillatory modulation in ACG and insula—areas previously associated with mediating physiological arousal. Finally, we showed that modulation of low-frequency activity is followed by that of high-frequency (gamma) power from approximately 200 msec in the STG, between 300 and 400 msec in the left insula, and between 400 and 500 msec in the ACG. We discuss these results with respect to models of neural processing that emphasize gamma activity as an index of prediction error signaling and highlight the usefulness of musical stimuli in revealing the wide-reaching neural consequences of predictive processing.

scholarly journals TOPICALITY OF MONITORING OF INDUSTRIAL FREQUENCY MAGNETIC FIELDS OF 50 HZ IN RESIDENTIAL AND PUBLIC BUILDINGS

2019 ◽  
Vol 98 (6) ◽  
pp. 597-600
Author(s):  
Taisiya V. Kalyada ◽  
V. P. Plekhanov
Keyword(s):  
Magnetic Fields ◽  
Low Frequency ◽  
Epidemiological Studies ◽  
Electric Transport ◽  
Residential Areas ◽  
Public Buildings ◽  
Low Frequencies ◽  
Relevant Today ◽  
Spatio Temporal

The problem of ensuring safety of electric and magnetic fields (EMF) of extremely low frequencies (ELF) is resulted from the development of the first low-frequency generators producing penetrating effect and causing negative biological outcomes. World power resources are doubling every 10 years, and ELF EMF are generated around by such sources. The number of sources on the scale of application, power and design diversity significantly exceeds those generating EMF in other frequency ranges. The population is exposed to 50 Hz ELF at work, in electric transport, in residential and public buildings, in residential areas. ELF EMF was found both to “pollute” the environment, be an environmental health risk factor, and affect negatively the health with potential long-term outcomes. Development of various methods and means of protection against the effect of ELF EMF remains relevant today. Limitation (regulation) of the effect of the factor both in terms of intensity and exposure is the most effective protection. Epidemiological studies to identify the relationship between exposure to ELF magnetic fields (MF) and carcinogenesis are on-going. A task panel group of research experts, established by WHO in 2005, conducted a routine procedure to assess health risks resulting from exposure to ELF MFs and, in particular, cancer and considered them to lack evidence. However, the significance of the data obtained was noted to be reduced due to procedural problems, potential systematic error of assessment. The problem remains unsolved. Research using various types of monitoring: social and hygienic, sanitary and epidemiological, is going on. Spatio-temporal monitoring of 50 Hz ELF MF in enclosed spaces of residential and public buildings, where a variety of equipment, devices, power supply systems, generating different MF levels, is an important area. The population is exposed to these conditions most of the day. Monitoring will allow assessing electromagnetic load at short-term and long-term exposures.

scholarly journals Altered Spontaneous Neural Activity and Functional Connectivity in Parkinson’s Disease With Subthalamic Microlesion

2021 ◽  
Vol 15 ◽  
Author(s):  
Bei Luo ◽  
Yue Lu ◽  
Chang Qiu ◽  
Wenwen Dong ◽  
Chen Xue ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Functional Connectivity ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Precentral Gyrus

BackgroundTransient improvement in motor symptoms are immediately observed in patients with Parkinson’s disease (PD) after an electrode has been implanted into the subthalamic nucleus (STN) for deep brain stimulation (DBS). This phenomenon is known as the microlesion effect (MLE). However, the underlying mechanisms of MLE is poorly understood.PurposeWe utilized resting state functional MRI (rs-fMRI) to evaluate changes in spontaneous brain activity and networks in PD patients during the microlesion period after DBS.MethodOverall, 37 PD patients and 13 gender- and age-matched healthy controls (HCs) were recruited for this study. Rs-MRI information was collected from PD patients three days before DBS and one day after DBS, whereas the HCs group was scanned once. We utilized the amplitude of low-frequency fluctuation (ALFF) method in order to analyze differences in spontaneous whole-brain activity among all subjects. Furthermore, functional connectivity (FC) was applied to investigate connections between other brain regions and brain areas with significantly different ALFF before and after surgery in PD patients.ResultRelative to the PD-Pre-DBS group, the PD-Post-DBS group had higher ALFF in the right putamen, right inferior frontal gyrus, right precentral gyrus and lower ALFF in right angular gyrus, right precuneus, right posterior cingulate gyrus (PCC), left insula, left middle temporal gyrus (MTG), bilateral middle frontal gyrus and bilateral superior frontal gyrus (dorsolateral). Functional connectivity analysis revealed that these brain regions with significantly different ALFF scores demonstrated abnormal FC, largely in the temporal, prefrontal cortices and default mode network (DMN).ConclusionThe subthalamic microlesion caused by DBS in PD was found to not only improve the activity of the basal ganglia-thalamocortical circuit, but also reduce the activity of the DMN and executive control network (ECN) related brain regions. Results from this study provide new insights into the mechanism of MLE.

Abstract 4666: Anatomic Substrate as Determinant of Dominant Frequency Dynamics During Human Ventricular Fibrillation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Karthikeyan Umapathy ◽  
Stephane Masse ◽  
Elias Sevaptsidis ◽  
John Asta ◽  
Talha Farid ◽  
...  
Keyword(s):  
Low Frequency ◽  
Electrode Array ◽  
Peak Frequency ◽  
Dominant Frequency ◽  
Physiological Factors ◽  
Low Frequencies ◽  
Bipolar Electrodes ◽  
Df Analysis ◽  
Spatio Temporal ◽  
Spatial Locations

Background: Dominant frequency (DF) analysis is a common way of quantitatively studying the spatio-temporal variation of frequency during VF. Areas of high frequencies (e.g. rotors) and low frequencies (e.g. blocks) have been associated with the occurrence and maintenance of VF. However, the relation of these high or low frequency areas to anatomical or physiological substrate remains unclear. Objective: We tested the hypothesis that the Max-Min DF locations in the epicardium during VF are due to anatomical substrate. Methods and Results: We analyzed 33, 4 seconds VF episodes acquired from 6 isolated human hearts using a Langendorff setup. The hearts were received from the heart-transplanted patients with informed consent. Electrode array consisting 112 bipolar electrodes was used to acquire the surface unipolar and bipolar electrograms from the epicardium. DF was computed as the peak frequency of the VF segment from each of electrodes using Welch’s modified periodogram method. From the DF distribution, the regions of max and min frequencies were identified for LV and RV regions. Scar maps were computed for each of the 6 hearts using a previously published method by mapping the amplitude of bipolar electrograms (<0.5mv = scar) during the pacing protocol. The areas of max-min DF frequencies in each of the VF episode were compared to the corresponding spatial locations in the scar map. Table 1 shows the match between the max-min DF frequency locations and the scar locations. 50% of max-min DF frequencies locations match the scar locations and in 97% of the matched locations the max-min DF occur at the vicinity of the scar. Conclusion: During human VF, DF dynamics are only partially explained by the anatomical substrate. This suggests that ion channel heterogeneity and dynamic physiological factors may play an important role in determining fibrillation dynamics. Match Between Max-Min DF locations and Scar Locations

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