Cochlear Nucleus

Author(s):  
Eric D. Young ◽  
Donata Oertel

Neuronal circuits in the brainstem convert the output of the ear, which carries the acoustic properties of ongoing sound, to a representation of the acoustic environment that can be used by the thalamocortical system. Most important, brainstem circuits reflect the way the brain uses acoustic cues to determine where sounds arise and what they mean. The circuits merge the separate representations of sound in the two ears and stabilize them in the face of disturbances such as loudness fluctuation or background noise. Embedded in these systems are some specialized analyses that are driven by the need to resolve tiny differences in the time and intensity of sounds at the two ears and to resolve rapid temporal fluctuations in sounds like the sequence of notes in music or the sequence of syllables in speech.

2021 ◽  
Vol 12 (1) ◽  
pp. 348
Author(s):  
Vincent Martin ◽  
Isabelle Viaud-Delmon ◽  
Olivier Warusfel

Audio-only augmented reality consists of enhancing a real environment with virtual sound events. A seamless integration of the virtual events within the environment requires processing them with artificial spatialization and reverberation effects that simulate the acoustic properties of the room. However, in augmented reality, the visual and acoustic environment of the listener may not be fully mastered. This study aims to gain some insight into the acoustic cues (intensity and reverberation) that are used by the listener to form an auditory distance judgment, and to observe if these strategies can be influenced by the listener’s environment. To do so, we present a perceptual evaluation of two distance-rendering models informed by a measured Spatial Room Impulse Response. The choice of the rendering methods was made to design stimuli categories in which the availability and reproduction quality of acoustic cues are different. The proposed models have been evaluated in an online experiment gathering 108 participants who were asked to provide judgments of auditory distance about a stationary source. To evaluate the importance of environmental cues, participants had to describe the environment in which they were running the experiment, and more specifically the volume of the room and the distance to the wall they were facing. It could be shown that these context cues had a limited, but significant, influence on the perceived auditory distance.


1984 ◽  
Vol 29 (7) ◽  
pp. 567-568
Author(s):  
Gilles Kirouac
Keyword(s):  
The Face ◽  

Author(s):  
Robert V. Shannon

The auditory brainstem implant (ABI) is a surgically implanted device to electrically stimulate auditory neurons in the cochlear nucleus complex of the brainstem in humans to restore hearing sensations. The ABI is similar in function to a cochlear implant, but overall outcomes are poorer. However, recent applications of the ABI to new patient populations and improvements in surgical technique have led to significant improvements in outcomes. While the ABI provides hearing benefits to patients, the outcomes challenge our understanding of how the brain processes neural patterns of auditory information. The neural pattern of activation produced by an ABI is highly unnatural, yet some patients achieve high levels of speech understanding. Based on a meta-analysis of ABI surgeries and outcomes, a theory is proposed of a specialized sub-system of the cochlear nucleus that is critical for speech understanding.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Giulio Tononi ◽  
Chiara Cirelli

Sleep must serve an essential, universal function, one that offsets the risk of being disconnected from the environment. The synaptic homeostasis hypothesis (SHY) is an attempt to identify this essential function. Its core claim is that sleep is needed to reestablish synaptic homeostasis, which is challenged by the remarkable plasticity of the brain. In other words, sleep is “the price we pay for plasticity.” In this issue, M. G. Frank reviewed several aspects of the hypothesis and raised several issues. The comments below provide a brief summary of the motivations underlying SHY and clarify that SHY is a hypothesis not about specific mechanisms, but about a universal, essential function of sleep. This function is the preservation of synaptic homeostasis in the face of a systematic bias toward a net increase in synaptic strength—a challenge that is posed by learning during adult wake, and by massive synaptogenesis during development.


Author(s):  
Clairton Marcolongo Pereira ◽  
Tayná B. Silva ◽  
Laiz Zaché Roque ◽  
Bárbara Barros ◽  
Luiz Alexandre Moscon ◽  
...  
Keyword(s):  
The Face ◽  

2012 ◽  
Vol 23 (12) ◽  
pp. 1455-1460 ◽  
Author(s):  
Lisa Legault ◽  
Timour Al-Khindi ◽  
Michael Inzlicht

Self-affirmation produces large effects: Even a simple reminder of one’s core values reduces defensiveness against threatening information. But how, exactly, does self-affirmation work? We explored this question by examining the impact of self-affirmation on neurophysiological responses to threatening events. We hypothesized that because self-affirmation increases openness to threat and enhances approachability of unfavorable feedback, it should augment attention and emotional receptivity to performance errors. We further hypothesized that this augmentation could be assessed directly, at the level of the brain. We measured self-affirmed and nonaffirmed participants’ electrophysiological responses to making errors on a task. As we anticipated, self-affirmation elicited greater error responsiveness than did nonaffirmation, as indexed by the error-related negativity, a neural signal of error monitoring. Self-affirmed participants also performed better on the task than did nonaffirmed participants. We offer novel brain evidence that self-affirmation increases openness to threat and discuss the role of error detection in the link between self-affirmation and performance.


2003 ◽  
Vol 89 (6) ◽  
pp. 3070-3082 ◽  
Author(s):  
Jason S. Rothman ◽  
Paul B. Manis

In the ventral cochlear nucleus (VCN), neurons transform information from auditory nerve fibers into a set of parallel ascending pathways, each emphasizing different aspects of the acoustic environment. Previous studies have shown that VCN neurons differ in their intrinsic electrical properties, including the K+ currents they express. In this study, we examine these K+ currents in more detail using whole cell voltage-clamp techniques on isolated VCN cells from adult guinea pigs at 22°C. Our results show a differential expression of three distinct K+ currents. Whereas some VCN cells express only a high-threshold delayed-rectifier-like current ( IHT), others express IHT in combination with a fast inactivating current ( IA) and/or a slow-inactivating low-threshold current ( ILT). IHT, ILT, and IA, were partially blocked by 1 mM 4-aminopyridine. In contrast, only ILT was blocked by 10–100 nM dendrotoxin-I. A surprising finding was the wide range of levels of ILT, suggesting ILT is expressed as a continuum across cell types rather than modally in a particular cell type. IA, on the other hand, appears to be expressed only in cells that show little or no ILT, the Type I cells. Boltzmann analysis shows IHT activates with 164 ± 12 (SE) nS peak conductance, -14.3 ± 0.7 mV half-activation, and 7.0 ± 0.5 mV slope factor. Similar analysis shows ILT activates with 171 ± 22 nS peak conductance, -47.4 ± 1.0 mV half-activation, and 5.8 ± 0.3 mV slope factor.


Author(s):  
Veryudha Eka Prameswari ◽  
ASIROTUL MA’RIFAH ◽  
NANING PUJI SURYANTINI ◽  
INDAH KUSMINDART

Dysmenorrhea is a menstrual problem that usually occurs in young women. When dysmenorrhea, interferes with activity, non-pharmacological treatment will be an alternative to reduce dysmenorrhea. One way to deal with pain in a non-pharmacological way is by intellectual distraction, with the theory of reticular activation, which can inhibit pain stimulation when a person receives adequate or excessive sensory input, which results in the inhibition of pain impulses to the brain. Intellectual distraction techniques include filling in crosswords, playing cards, doing hobbies (in bed) such as collecting stamps, writing stories. This study aims to identify the effectiveness of intellectual disorders in reducing dysmenorrhea in young women. This study uses a design that is Quasi-Experiment with a pretest and posttest design without a control group. Population In this study were 122 female students from Mojoanyar Middle School. The sample in this study were all students of Mojoanyar Middle School who experienced dysmenorrhoea who had fulfilled the inclusion criteria of 23 respondents. The tool used to determine changes in the level of pain of respondents is the Face pain rating. The intervention provided was that respondents were asked to fill in the TTS. The collected data was analyzed using SPSS data normality test using the Wilcoxon test with SPSS 23 for Windows. And it was found that before less than half (43.5%) of Intellectual Distraction or 10 respondents experienced mild pain, whereas after being given Intellectual Distraction less than half (34.8%) or 8 respondents experienced mild and moderate pain and no more respondents experienced very severe pain. Therefore young women need to reduce the intensity of menstrual pain by providing Intellectual Distractions techniques with crosswords and accessing them can be through cellphones


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