scholarly journals Auditory cortical generators of the Frequency Following Response are modulated by intermodal attention

2019 ◽  
Author(s):  
Thomas Hartmann ◽  
Nathan Weisz
Keyword(s):  
Primary Auditory Cortex ◽  
Top Down ◽  
Attention Task ◽  
Surface Level ◽  
Frequency Following Response ◽  
Speech Stimuli ◽  
Brainstem Response ◽  
Subcortical Regions ◽  
Cortical Regions ◽  
The Right

AbstractThe vast efferent connectivity of the auditory system suggests that subcortical (thalamic and brainstem) auditory regions should also be sensitive to top-down processes such as selective attention. In electrophysiology, the Frequency Following Response (FFR) to simple speech stimuli has been used extensively to study these subcortical areas. Despite being seemingly straight-forward in addressing the issue of attentional modulations of subcortical regions by means of the FFR, the existing results are highly inconsistent. Moreover, the notion that the FFR exclusively represents subcortical generators has been recently challenged. By applying these techniques to data recorded from 102 magnetoencephalography (MEG) magnetometers in 34 participants during a cross-modal attention task, we aimed to gain a more differentiated perspective on how the generators of the FFR are modulated by either attending to the visual or auditory input. In a first step our results confirm the strong contribution of also cortical regions to the FFR. Interestingly, of all regions exhibiting a measurable FFR response, only the right primary auditory cortex was significantly affected by intermodal attention. By showing a clear cortical contribution to the attentional FFR effect, our work significantly extends previous reports that focus on surface level recordings only. It underlines the importance of making a greater effort to disentangle the different contributing sources of the FFR and serves as a clear precaution of simplistically interpreting the FFR as brainstem response.

scholarly journals Auditory attention alterations in migraine: a behavioral and MEG/EEG study

2019 ◽  
Author(s):  
Rémy Masson ◽  
Yohana Lévêque ◽  
Geneviève Demarquay ◽  
Hesham ElShafei ◽  
Lesly Fornoni ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Orienting Response ◽  
List Type ◽  
Top Down ◽  
Attention Task ◽  
Bottom Up ◽  
Attentional Processes ◽  
Related Potentials ◽  
The Right ◽  
Task Irrelevant

AbstractObjectivesTo evaluate alterations of top-down and/or bottom-up attention in migraine and their cortical underpinnings.Methods19 migraineurs between attacks and 19 matched control participants performed a task evaluating jointly top-down and bottom-up attention, using visually-cued target sounds and unexpected task-irrelevant distracting sounds. Behavioral responses and MEG/EEG were recorded. Event-related potentials and fields (ERPs/ERFs) were processed and source reconstruction was applied to ERFs.ResultsAt the behavioral level, neither top-down nor bottom-up attentional processes appeared to be altered in migraine. However, migraineurs presented heightened evoked responses following distracting sounds (orienting component of the N1 and Re-Orienting Negativity, RON) and following target sounds (orienting component of the N1), concomitant to an increased recruitment of the right temporo-parietal junction. They also displayed an increased effect of the cue informational value on target processing resulting in the elicitation of a negative difference (Nd).ConclusionsMigraineurs appear to display increased bottom-up orienting response to all incoming sounds, and an enhanced recruitment of top-down attention.SignificanceThe interictal state in migraine is characterized by an exacerbation of the orienting response to attended and unattended sounds. These attentional alterations might participate to the peculiar vulnerability of the migraine brain to all incoming stimuli.HighlightsMigraineurs performed as well as healthy participants in an attention task.However, EEG markers of both bottom-up and top-down attention are increased.Migraine is also associated with a facilitated recruitment of the right temporo-parietal junction.

scholarly journals Auditory brainstem response asymmetries in older adults: An exploratory study using click and speech stimuli

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251287
Author(s):  
Alejandro Ianiszewski ◽  
Adrian Fuente ◽  
Jean-Pierre Gagné
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Auditory Processing ◽  
Auditory Brainstem Response ◽  
Auditory Brainstem ◽  
Normal Hearing ◽  
Spectral Amplitude ◽  
Speech Stimuli ◽  
Brainstem Response ◽  
The Right

Background Some evidence suggests that young adults exhibit a selective laterality of auditory brainstem response (ABR) elicited with speech stimuli. Little is known about such an auditory laterality in older adults. Objective The aim of this study was to investigate possible asymmetric auditory brainstem processing between right and left ear presentation in older adults. Methods Sixty-two older adults presenting with normal hearing thresholds according to their age and who were native speakers of Quebec French participated in this study. ABR was recorded using click and a 40-ms /da/ syllable. ABR was elicited through monaural right and monaural left stimulation. Latency and amplitude for click-and speech-ABR components were compared between right and left ear presentations. In addition, for the /da/ syllable, a fast Fourier transform analysis of the sustained frequency-following response (FFR) of the vowel was performed along with stimulus-to-response and right-left ear correlation analyses. Results No significant differences between right and left ear presentation were found for amplitudes and latencies of the click-ABR components. Significantly shorter latencies for right ear presentation as compared to left ear presentation were observed for onset and offset transient components (V, A and O), sustained components (D and E), and voiced transition components (C) of the speech-ABR. In addition, the spectral amplitude of the fundamental frequency (F0) was significantly larger for the left ear presentation than the right ear presentation. Conclusions Results of this study show that older adults with normal hearing exhibit symmetric encoding for click stimuli at the brainstem level between the right and left ear presentation. However, they present with brainstem asymmetries for the encoding of selective stimulus components of the speech-ABR between the right and left ear presentation. The right ear presentation of a /da/ syllable elicited reduced neural timing for both transient and sustained components compared to the left ear. Conversely, a stronger left ear F0 encoding was observed. These findings suggest that at a preattentive, sensory stage of auditory processing, older adults lateralize speech stimuli similarly to young adults.

scholarly journals Structural and functional brain asymmetries in the early phases of life: a scoping review

2021 ◽  
Author(s):  
Patrizia Bisiacchi ◽  
Elisa Cainelli
Keyword(s):  
Scoping Review ◽  
Right Hemisphere ◽  
Final Analysis ◽  
Brain Structures ◽  
Large Variability ◽  
Speech Stimuli ◽  
Morphological Asymmetry ◽  
Cerebral Asymmetries ◽  
The Right ◽  
And Function

AbstractAsymmetry characterizes the brain in both structure and function. Anatomical asymmetries explain only a fraction of functional variability in lateralization, with structural and functional asymmetries developing at different periods of life and in different ways. In this work, we perform a scoping review of the cerebral asymmetries in the first brain development phases. We included all English-written studies providing direct evidence of hemispheric asymmetries in full-term neonates, foetuses, and premature infants, both at term post-conception and before. The final analysis included 57 studies. The reviewed literature shows large variability in the used techniques and methodological procedures. Most structural studies investigated the temporal lobe, showing a temporal planum more pronounced on the left than on the right (although not all data agree), a morphological asymmetry already present from the 29th week of gestation. Other brain structures have been poorly investigated, and the results are even more discordant. Unlike data on structural asymmetries, functional data agree with each other, identifying a leftward dominance for speech stimuli and an overall dominance of the right hemisphere in all other functional conditions. This generalized dominance of the right hemisphere for all conditions (except linguistic stimuli) is in line with theories stating that the right hemisphere develops earlier and that its development is less subject to external influences because it sustains functions necessary to survive.

scholarly journals Frequency-Following Response (FFR) in Military Pilots

2020 ◽  
Author(s):  
Graziela Maria Martins-Moreira ◽  
Alessandra Spada Durante
Keyword(s):  
Pure Tone Audiometry ◽  
Control Group ◽  
Study Group ◽  
Aircraft Accidents ◽  
Frequency Following Response ◽  
Significant Difference ◽  
Qualitative Variables ◽  
Chi Squared ◽  
The Right ◽  
Military Pilots

Abstract Introduction Good hearing in pilots, including central auditory skills, is critical for flight safety and the prevention of aircraft accidents. Pure tone audiometry alone may not be enough to assess hearing in the members of this population who, in addition to high noise levels, routinely face speech recognition tasks in non-ideal conditions. Objective To characterize the frequency-following response (FFR) of a group of military pilots compared with a control group. Methods Twenty military pilots in the Study Group and 20 non-pilot military personnel, not exposed to noise in their work, in the Control Group, all with normal hearing, aged between 30 and 40 years old, completed a questionnaire to assess their hearing habits, and their FFRs were measured with a /da/ syllable (duration 40 milliseconds, speed 10.9/s), at 80 dB NA in the right ear. All procedures were approved by the ethical committee of the institution. Statistical analysis was performed using the t-Student or Mann-Whitney tests for quantitative variables, and the Fisher or chi-squared tests for qualitative variables, and a value of p < 0.05 was considered to be statistically significant. Results There was no significant difference between the groups regarding auditory habits. In the FFR, wave amplitudes A (p = 0.01) and C (p = 0.04) were significantly lower in the Study Group. Conclusion Working as a military pilot can be a crucial factor in determining an individual's typical FFR pattern, demonstrated in the present study by statistically significant reductions in the amplitudes of the A and C waves.

scholarly journals The Role of Primate Prefrontal Cortex in Bias and Shift Between Visual Dimensions

2019 ◽  
Vol 30 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Farshad A Mansouri ◽  
Mark J Buckley ◽  
Daniel J Fehring ◽  
Keiji Tanaka
Keyword(s):  
Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Top Down ◽  
Attentional Processes ◽  
Prefrontal Cortical ◽  
Frontopolar Cortex ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions ◽  
Visual Cortical ◽  
Bilateral Lesions

Abstract Imaging and neural activity recording studies have shown activation in the primate prefrontal cortex when shifting attention between visual dimensions is necessary to achieve goals. A fundamental unanswered question is whether representations of these dimensions emerge from top-down attentional processes mediated by prefrontal regions or from bottom-up processes within visual cortical regions. We hypothesized a causative link between prefrontal cortical regions and dimension-based behavior. In large cohorts of humans and macaque monkeys, performing the same attention shifting task, we found that both species successfully shifted between visual dimensions, but both species also showed a significant behavioral advantage/bias to a particular dimension; however, these biases were in opposite directions in humans (bias to color) versus monkeys (bias to shape). Monkeys’ bias remained after selective bilateral lesions within the anterior cingulate cortex (ACC), frontopolar cortex, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), or superior, lateral prefrontal cortex. However, lesions within certain regions (ACC, DLPFC, or OFC) impaired monkeys’ ability to shift between these dimensions. We conclude that goal-directed processing of a particular dimension for the executive control of behavior depends on the integrity of prefrontal cortex; however, representation of competing dimensions and bias toward them does not depend on top-down prefrontal-mediated processes.

scholarly journals The Right Hemisphere Is Responsible for the Greatest Differences in Human Brain Response to High-Arousing Emotional versus Neutral Stimuli: A MEG Study

2021 ◽  
Vol 11 (8) ◽  
pp. 960
Author(s):  
Mina Kheirkhah ◽  
Philipp Baumbach ◽  
Lutz Leistritz ◽  
Otto W. Witte ◽  
Martin Walter ◽  
...  
Keyword(s):  
Human Brain ◽  
Right Hemisphere ◽  
Emotional Stimuli ◽  
Brain Response ◽  
Whole Brain ◽  
Brain Responses ◽  
Cortical Regions ◽  
The Right ◽  
Healthy Participants

Studies investigating human brain response to emotional stimuli—particularly high-arousing versus neutral stimuli—have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270–320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.

Stent Graft Placement in the Top-Down Direction for Treating Traumatic Intra-Abdominal Suprahepatic Inferior Vena Cava Rupture: A Case Report

2021 ◽  
pp. 152660282110250
Author(s):  
Yun Chul Park ◽  
Hyoung Ook Kim ◽  
Nam Yeol Yim ◽  
Byung Chan Lee ◽  
Chan Park ◽  
...  
Keyword(s):  
Case Report ◽  
Inferior Vena Cava ◽  
Stent Graft ◽  
Inferior Vena ◽  
Vena Cava ◽  
Endovascular Management ◽  
Top Down ◽  
Life Threatening ◽  
The Right ◽  
Suprahepatic Inferior Vena Cava

Purpose The treatment of suprahepatic inferior vena cava (IVC) ruptures results in high mortality rates due to difficulty in performing the surgical procedure. Here, we present a case of successful endovascular management of a life-threatening suprahepatic IVC rupture with top-down placement of a stent graft. Case Report A 33-year-old woman was involved in a traffic accident and presented to our emergency department due to unstable hemodynamics after blunt abdominal wall trauma. Computed tomography (CT) revealed massive extravasation of contrast agent from the suprahepatic IVC, which suggested traumatic suprahepatic IVC rupture. To seal the IVC, to salvage major hepatic veins, and to prevent migration of the stent graft into the right side of the heart after placement, an aortic cuff with a proximal hook was introduced in a top-down direction via the right internal jugular vein. After closure of the injured IVC, the patient’s hemodynamics improved, and additional laparotomy was performed. After 3 months of trauma care, the patient recovered and was discharged. Follow-up CT after 58 months showed a patent stent graft within the IVC. Conclusion Endovascular management with top-down placement of a stent graft is a viable option for emergent damage control in patients with life-threatening hemorrhage from IVC rupture.

scholarly journals Causal modulation of right hemisphere fronto-parietal phase synchrony with Transcranial Magnetic Stimulation during a conscious visual detection task

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chloé Stengel ◽  
Marine Vernet ◽  
Julià L. Amengual ◽  
Antoni Valero-Cabré
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Visual Perception ◽  
Frequency Band ◽  
Magnetic Stimulation ◽  
Visual Detection ◽  
Detection Task ◽  
Oscillatory Activity ◽  
Top Down ◽  
The Right ◽  
High Beta

AbstractCorrelational evidence in non-human primates has reported increases of fronto-parietal high-beta (22–30 Hz) synchrony during the top-down allocation of visuo-spatial attention. But may inter-regional synchronization at this specific frequency band provide a causal mechanism by which top-down attentional processes facilitate conscious visual perception? To address this question, we analyzed electroencephalographic (EEG) signals from a group of healthy participants who performed a conscious visual detection task while we delivered brief (4 pulses) rhythmic (30 Hz) or random bursts of Transcranial Magnetic Stimulation (TMS) to the right Frontal Eye Field (FEF) prior to the onset of a lateralized target. We report increases of inter-regional synchronization in the high-beta band (25–35 Hz) between the electrode closest to the stimulated region (the right FEF) and right parietal EEG leads, and increases of local inter-trial coherence within the same frequency band over bilateral parietal EEG contacts, both driven by rhythmic but not random TMS patterns. Such increases were accompained by improvements of conscious visual sensitivity for left visual targets in the rhythmic but not the random TMS condition. These outcomes suggest that high-beta inter-regional synchrony can be modulated non-invasively and that high-beta oscillatory activity across the right dorsal fronto-parietal network may contribute to the facilitation of conscious visual perception. Our work supports future applications of non-invasive brain stimulation to restore impaired visually-guided behaviors by operating on top-down attentional modulatory mechanisms.

Auditory Imagery Modulates Frequency-specific Areas in the Human Auditory Cortex

2013 ◽  
Vol 25 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Jihoon Oh ◽  
Jae Hyung Kwon ◽  
Po Song Yang ◽  
Jaeseung Jeong
Keyword(s):  
Auditory Cortex ◽  
High Frequency ◽  
Low Frequency ◽  
Primary Auditory Cortex ◽  
Auditory Imagery ◽  
Neural Responses ◽  
Top Down ◽  
Visual Areas ◽  
Control Functional ◽  
Response Area

Neural responses in early sensory areas are influenced by top–down processing. In the visual system, early visual areas have been shown to actively participate in top–down processing based on their topographical properties. Although it has been suggested that the auditory cortex is involved in top–down control, functional evidence of topographic modulation is still lacking. Here, we show that mental auditory imagery for familiar melodies induces significant activation in the frequency-responsive areas of the primary auditory cortex (PAC). This activation is related to the characteristics of the imagery: when subjects were asked to imagine high-frequency melodies, we observed increased activation in the high- versus low-frequency response area; when the subjects were asked to imagine low-frequency melodies, the opposite was observed. Furthermore, we found that A1 is more closely related to the observed frequency-related modulation than R in tonotopic subfields of the PAC. Our findings suggest that top–down processing in the auditory cortex relies on a mechanism similar to that used in the perception of external auditory stimuli, which is comparable to early visual systems.

Abstract W MP14: Detection of Early Ischemia Varies Extensively with Topography: Concurrent CT versus DWI ASPECTS

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
David S Liebeskind ◽  
Sunil A Sheth ◽  
Farhad Mehrkhani ◽  
Shahmir Kamalian ◽  
Fabien Scalzo ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Symptom Onset ◽  
Regional Variation ◽  
Internal Capsule ◽  
Kappa Statistic ◽  
Subcortical Structures ◽  
Subcortical Regions ◽  
Cortical Regions ◽  
Ct And Mri ◽  
Good Agreement

Background: Numerous studies have compared CT with DWI ASPECTS, yet differences in timing between study acquisition may impart error or confound. We analyzed a large cohort of concurrently acquired CT and MRI to discern differences in regional variation in the ability to detect early ischemia. Methods: CT and DWI were acquired within 1 hour of each other during the first 8 hours after symptom onset and pooled from two large academic stroke centers for these analyses. Two raters independently scored CT ASPECTS and DWI ASPECTS at separate reading sessions. Modified DWI-ASPECTS (including only >20% per region) was also scored. Consensus readings were then utilized to compare regional ASPECTS across the 3 ASPECTS scales using the kappa statistic. Results: 136 patients underwent both CT and DWI within 1 hour of each other in the setting of acute ischemic stroke. Regional involvement on DWI included caudate in 57%, lentiform in 73%, insula in 69%, internal capsule in 24%, M1 in 34%, M2 in 49%, M3 in 36%, M4 in 21%, M5 in 57% and M6 in 41%. The agreement between CT and DWI varied by region, from caudate kappa 0.616 (0.484-0.748), to lentiform 0.602 (0.457-0.748), insula 0.690 (0.558-0.822), internal capsule 0.374 (0.189-0.559), M1 0.583 (0.435-0.731), M2 0.515 (0.389-0.641), M3 0.421 (0.275-0.568), M4 0.453 (0.262-0.644), M5 0.388 (0.268-0.507) and M6 0.500 (0.366-0.634). Modified DWI-ASPECTS (>20% per region) and CT demonstrated overall better agreement, yet still markedly varied by region. In general, CT and DWI ASPECTS reveal good agreement in subcortical structures, whereas very limited agreement is noted in several cortical ischemic regions. Modified-DWI ASPECTS improves cortical agreement, yet remains poor in the internal capsule. Conclusions: Detection of early ischemia varies considerably depending on the location or topography depicted with either CT or MRI. Deep subcortical regions are best detected with either modality, whereas cortical regions exhibit marked distinctions. Modified DWI ASPECTS improves agreement with CT ASPECTS in cortical regions.

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