scholarly journals Evolving perspectives on the sources of the frequency-following response

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Emily B. J. Coffey ◽  
Trent Nicol ◽  
Travis White-Schwoch ◽  
Bharath Chandrasekaran ◽  
Jennifer Krizman ◽  
...  
Keyword(s):  
Neural Encoding ◽  
Complex Sounds ◽  
Frequency Following Response ◽  
Auditory Neuroscience ◽  
Non Invasive ◽  
Auditory Processes ◽  
The Brain

Abstract The auditory frequency-following response (FFR) is a non-invasive index of the fidelity of sound encoding in the brain, and is used to study the integrity, plasticity, and behavioral relevance of the neural encoding of sound. In this Perspective, we review recent evidence suggesting that, in humans, the FFR arises from multiple cortical and subcortical sources, not just subcortically as previously believed, and we illustrate how the FFR to complex sounds can enhance the wider field of auditory neuroscience. Far from being of use only to study basic auditory processes, the FFR is an uncommonly multifaceted response yielding a wealth of information, with much yet to be tapped.

Aging Degrades the Neural Encoding of Simple and Complex Sounds in the Human Brainstem

2013 ◽  
Vol 24 (07) ◽  
pp. 590-599 ◽  
Author(s):  
Christopher G. Clinard ◽  
Kelly L. Tremblay
Keyword(s):  
Phase Coherence ◽  
Neural Representation ◽  
Neural Encoding ◽  
Aging Effects ◽  
Complex Sounds ◽  
Frequency Following Response ◽  
Hearing Sensitivity ◽  
Normal Limits ◽  
Age Related ◽  
Impaired Speech

Background: Older adults, with or without normal peripheral hearing sensitivity, have difficulty understanding speech. This impaired speech perception may, in part, be due to desynchronization affecting the neural representation of acoustic features. Here we determine if phase-locked neural activity generating the brainstem frequency-following response (FFR) exhibits age-related desynchronization and how this degradation affects the neural representation of simple and complex sounds. Purpose: The objectives of this study were to (1) characterize the effects of age on the neural representation of simple tones and complex consonant-vowel stimuli, (2) determine if sustained and transient components of the FFR are differentially affected by age, and (3) determine if the inability to encode a simple signal predicts degradation in representation for complex speech signals. Research Design: Correlational Study Sample: Thirty four adults (aged 22–77 yr) with hearing thresholds falling within normal limits. Data Collection and Analysis: Stimuli used to evoke FFRs were 1000 Hz tone bursts as well as a consonant-vowel /da/ sound. Results: The neural representation of simple (tone) and complex (/da/) stimuli declines with advancing age. Tone-FFR phase coherence decreased as chronological age increased. For the consonant-vowel FFRs, transient onset and offset response amplitudes were smaller, and offset responses were delayed with age. Sustained responses at the onset of vowel periodicity were prolonged in latency and smaller in amplitude as age increased. FFT amplitude of the consonant-vowel FFR fundamental frequency did not significantly decline with increasing age. The ability to encode a simple signal was related to degradation in the neural representation of a complex, speechlike sound. Tone-FFR phase coherence was significantly related to the later vowel response components but not the earlier vowel components. Conclusions: FFR components representing the tone and consonant-vowel /da/ stimulus were negatively affected by age, showing age-related reductions in response synchrony and amplitude, as well as prolonged latencies. These aging effects were evident in middle age, even in the absence of significant hearing loss.

NON-INVASIVE BCI METHOD: EEG - ELECTROENCEPHALOGRAPHY

2019 ◽  
pp. 139-145
Author(s):  
Selma Büyükgöze
Keyword(s):  
Brain Computer Interface ◽  
Computer Interface ◽  
Electrode Placement ◽  
Eeg Signals ◽  
Non Invasive ◽  
Brain Signals ◽  
Brain States ◽  
The Brain

Brain Computer Interface consists of hardware and software that convert brain signals into action. It changes the nerves, muscles, and movements they produce with electro-physiological signs. The BCI cannot read the brain and decipher the thought in general. The BCI can only identify and classify specific patterns of activity in ongoing brain signals associated with specific tasks or events. EEG is the most commonly used non-invasive BCI method as it can be obtained easily compared to other methods. In this study; It will be given how EEG signals are obtained from the scalp, with which waves these frequencies are named and in which brain states these waves occur. 10-20 electrode placement plan for EEG to be placed on the scalp will be shown.

In vivo exploration of brain phosphorus 31 metabolism in patients with senile dementia of Alzheimer type

1994 ◽  
Vol 9 (2) ◽  
pp. 105-109
Author(s):  
G Mecheri ◽  
Y Bissuel ◽  
J Dalery ◽  
JL Terra ◽  
G Balvay ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Senile Dementia ◽  
Phospholipid Metabolism ◽  
Alzheimer Type ◽  
Dementia Of Alzheimer Type ◽  
Non Invasive ◽  
Significant Difference ◽  
The Brain

SummaryIn vivo NMR 31p spectroscopy is a non invasive, non ionizing method of exploration of energy and phospholipid metabolism in the brain. This study consisted of comparing 31p spectra in five patients with Senile Dementia of Alzheimer Type (SDAT) with those of four controls of similar ages. Abnormal phosphonionocsters (PME) concentrations, either high or low, were found in the patients, but statistical analysis did not elicit any significant difference relative to controls.

scholarly journals The brain timewise: how timing shapes and supports brain function

2015 ◽  
Vol 370 (1668) ◽  
pp. 20140170 ◽  
Author(s):  
Riitta Hari ◽  
Lauri Parkkonen
Keyword(s):  
Human Brain ◽  
Brain Imaging ◽  
Brain Function ◽  
Temporal Dynamics ◽  
Generative Models ◽  
Network Activity ◽  
Brain Diseases ◽  
Specific Information ◽  
Non Invasive ◽  
The Brain

We discuss the importance of timing in brain function: how temporal dynamics of the world has left its traces in the brain during evolution and how we can monitor the dynamics of the human brain with non-invasive measurements. Accurate timing is important for the interplay of neurons, neuronal circuitries, brain areas and human individuals. In the human brain, multiple temporal integration windows are hierarchically organized, with temporal scales ranging from microseconds to tens and hundreds of milliseconds for perceptual, motor and cognitive functions, and up to minutes, hours and even months for hormonal and mood changes. Accurate timing is impaired in several brain diseases. From the current repertoire of non-invasive brain imaging methods, only magnetoencephalography (MEG) and scalp electroencephalography (EEG) provide millisecond time-resolution; our focus in this paper is on MEG. Since the introduction of high-density whole-scalp MEG/EEG coverage in the 1990s, the instrumentation has not changed drastically; yet, novel data analyses are advancing the field rapidly by shifting the focus from the mere pinpointing of activity hotspots to seeking stimulus- or task-specific information and to characterizing functional networks. During the next decades, we can expect increased spatial resolution and accuracy of the time-resolved brain imaging and better understanding of brain function, especially its temporal constraints, with the development of novel instrumentation and finer-grained, physiologically inspired generative models of local and network activity. Merging both spatial and temporal information with increasing accuracy and carrying out recordings in naturalistic conditions, including social interaction, will bring much new information about human brain function.

scholarly journals Brain–Computer Interfacing Using Functional Near-Infrared Spectroscopy (fNIRS)

Biosensors ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 389
Author(s):  
Kogulan Paulmurugan ◽  
Vimalan Vijayaragavan ◽  
Sayantan Ghosh ◽  
Parasuraman Padmanabhan ◽  
Balázs Gulyás
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Brain Function ◽  
Near Infrared ◽  
Functional Near Infrared Spectroscopy ◽  
Non Invasive ◽  
Neuron Function ◽  
Brain Computer Interfacing ◽  
The Brain ◽  
Computer Interfacing

Functional Near-Infrared Spectroscopy (fNIRS) is a wearable optical spectroscopy system originally developed for continuous and non-invasive monitoring of brain function by measuring blood oxygen concentration. Recent advancements in brain–computer interfacing allow us to control the neuron function of the brain by combining it with fNIRS to regulate cognitive function. In this review manuscript, we provide information regarding current advancement in fNIRS and how it provides advantages in developing brain–computer interfacing to enable neuron function. We also briefly discuss about how we can use this technology for further applications.

scholarly journals Increased Expression of Plasma miRNA-320a and let-7b-5p in Heroin-Dependent Patients and Its Clinical Significance

2021 ◽  
Vol 12 ◽  
Author(s):  
Haixiong Liu ◽  
Wenjin Xu ◽  
Jiying Feng ◽  
Hong Ma ◽  
Jianbin Zhang ◽  
...  
Keyword(s):  
Roc Curves ◽  
Brain Diseases ◽  
Circulating Mirnas ◽  
Heroin Use ◽  
Non Invasive ◽  
Heroin Use Disorder ◽  
Subjective Reports ◽  
The Brain ◽  
Potential Use ◽  
Plasma Mirnas

Heroin use disorder is a chronic and relapsing disease that induces persistent changes in the brain. The diagnoses of heroin use disorders are mainly based on subjective reports and no valid biomarkers available. Recent researches have revealed that circulating miRNAs are useful non-invasive biomarkers for diagnosing brain diseases such as Alzheimer's disease, multiple sclerosis, schizophrenia, and bipolar disorder. However, studies on circulating miRNAs for the diagnosis of heroin use disorders are rarely reported. In this study, we investigated the differential expression of plasma miRNAs in 57 heroin-dependent patients. Based on literature research and microarray analysis, two candidate miRNAs, miR-320a and let-7b-5p, were selected and analyzed by quantitative real-time RT-PCR. The results showed miR-320a and let-7b were significantly upregulated in plasma of the heroin-dependent patients compared to that in healthy controls. The area under curves (AUCs) of receiver operating characteristic (ROC) curves of miR-320a and let-7b-5p were 0.748 and 0.758, respectively. The sensitivities of miR-320a and let-7b-5p were 71.9 and 70.2%, while the specificities of miR-320a and let-7b-5p were 76.1 and 78.3%, respectively. The combination of these two miRNAs predicted heron dependence with an AUC of 0.782 (95% CI 0.687–0.876), with 73.7% sensitivity and 82.6% specificity. Our findings suggest a potential use for circulating miRNAs as biomarkers for the diagnosis of heroin abuse.

Abstract WMP102: Pilot Study of a Non-invasive Radiofrequency Method to Monitor Intracranial Hemorrhage: A First-in-Human Study

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Matthew L Flaherty ◽  
Joseph Korfhagen ◽  
George J Shaw ◽  
Opeolu Adeoye ◽  
William Knight
Keyword(s):  
Human Study ◽  
Clinical Work ◽  
Head Ct ◽  
Non Invasive ◽  
Complete Measurement ◽  
Invasive Method ◽  
Bedside Monitor ◽  
Transmitting Antenna ◽  
The Brain ◽  
Ct Studies

Introduction: Intracerebral hemorrhage (ICH) is a devastating form of stroke. Hemorrhage expansion after ICH occurs in ~40% of patients and leads to worse outcomes. Currently, ICH patients are monitored for hemorrhage expansion by neurologic exam and head CT. CT studies are a source of radiation exposure and can require transporting the patient out of the ICU. There is a clinical need for a non-invasive bedside monitor of ICH. Methods: A radiofrequency based monitor (RFM) was developed as a non-invasive method to monitor ICH at the bedside. The RFM consists of a 9-antenna array mounted around the head, cables, and driving electronics. A 913 MHz signal is transmitted from a given antenna, crosses the brain, and is received by the remaining 8 antennae. A complete measurement consists of one cycle with all antenna serving as the transmitting antenna. As the signal traverses the brain, it is partially scattered and absorbed by the ICH, thus changing the signal at the receiving antennae. The altered signal can be compared to signals at earlier times to detect changes induced by ICH expansion. Based upon pre-clinical work it was hypothesized that ICH expansion of ≥3 ml would be detected by the RFM. The RFM device was approved for human study under an IDE from the FDA. The device was tested on 10 ICH subjects admitted within 24 hours of stroke onset. All subjects received a baseline head CT and a repeat head CT at 12 (+/- 6) hours. ICH volumes were determined by a blinded neuroradiologist. Subjects were scanned with the device every 10 minutes. Results: Data from one subject was lost due to user error. Among the remaining nine, two experienced hemorrhage expansion of ≥ 3ml (3 and 8.2 ml respectively). The RFM readings were 100% concordant with CT scans in identifying presence and absence of hemorrhage expansion. The figure shows monitor readings from a subject with expansion. Conclusion: The RFM may be useful in detection of real-time hemorrhage expansion in ICH patients. A pivotal clinical study is planned.

Odor Perception

2012 ◽  
pp. 44-59 ◽  
Author(s):  
Mitsuo Tonoike
Keyword(s):  
Signal Transduction ◽  
Central Nervous System ◽  
Nervous System ◽  
Information Processing ◽  
Non Invasive ◽  
Olfactory Acuity ◽  
Central Regions ◽  
Olfactory Systems ◽  
The Central Nervous System ◽  
The Brain

Though olfaction is one of the necessary senses and indispensable for the maintenance of the life of the animal, the mechanism of olfaction had not yet been understood well compared with other sensory systems such as vision and audition. However, recently, the most basic principle of “signal transduction on the reception and transmission for the odor” has been clarified. Therefore, the important next problem is how the information of odors about is processed in the Central Nervous System (CNS) and how odor is perceived in the human brain. In this chapter, the basic olfactory systems in animal and human are described and examples such as “olfactory acuity, threshold, adaptation, and olfactory disorders” are discussed. The mechanism of olfactory information processing is described under the results obtained by using a few new non-invasive measuring methods. In addition, from a few recent studies, it is shown that olfactory neurophysiological information is passing through some deep central regions of the brain before finally being processed in the orbito-frontal areas.

scholarly journals Non-Invasive Delivery of Therapeutics into the Brain: The Potential of Aptamers for Targeted Delivery

Biomedicines ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 120 ◽  
Author(s):  
Bakhtiar Bukari ◽  
Rasika M. Samarasinghe ◽  
Jinjutha Noibanchong ◽  
Sarah L. Shigdar
Keyword(s):  
Brain Tissue ◽  
Targeted Delivery ◽  
Focused Ultrasound ◽  
Circulatory System ◽  
Non Invasive ◽  
Therapeutic Delivery ◽  
Macromolecular Drugs ◽  
Efficient Delivery ◽  
Alternative Delivery ◽  
The Brain

The blood-brain barrier (BBB) is a highly specialised network of blood vessels that effectively separates the brain environment from the circulatory system. While there are benefits, in terms of keeping pathogens from entering the brain, the BBB also complicates treatments of brain pathologies by preventing efficient delivery of macromolecular drugs to diseased brain tissue. Although current non-invasive strategies of therapeutics delivery into the brain, such as focused ultrasound and nanoparticle-mediated delivery have shown various levels of successes, they still come with risks and limitations. This review discusses the current approaches of therapeutic delivery into the brain, with a specific focus on non-invasive methods. It also discusses the potential for aptamers as alternative delivery systems and several reported aptamers with promising preliminary results.

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