Stimulus Level of Dichotically Presented Tones and Cat Superior Olive S‐Segment Cell Discharge

1969 ◽  
Vol 46 (4B) ◽  
pp. 979-988 ◽  
Author(s):  
Chiyeko Tsuchitani ◽  
James C. Boudreau
Keyword(s):  
Stimulus Level ◽  
Superior Olive ◽  
Cell Discharge ◽  
Segment Cell

scholarly journals Varying Overall Sound Intensity to the Two Ears Impacts Interaural Level Difference Discrimination Thresholds by Single Neurons in the Lateral Superior Olive

2010 ◽  
Vol 103 (2) ◽  
pp. 875-886 ◽  
Author(s):  
Jeffrey J. Tsai ◽  
Kanthaiah Koka ◽  
Daniel J. Tollin
Keyword(s):  
Computational Models ◽  
Auditory Pathway ◽  
Stimulus Level ◽  
Sound Level ◽  
Neuronal Firing ◽  
Interaural Level Difference ◽  
Experimental Conditions ◽  
Lateral Superior Olive ◽  
Superior Olive ◽  
Level Difference

The lateral superior olive (LSO) is one of the earliest sites in the auditory pathway involved in processing acoustical cues to sound location. LSO neurons encode the interaural level difference (ILD) cue to azimuthal location. Here we investigated the effect of variations in the overall stimulus levels of sounds at the two ears on the sensitivity of LSO neurons to small differences in ILDs of pure tones. The neuronal firing rate versus ILD functions were found to depend greatly on the overall stimulus level, typically shifting along the ILD axis toward the excitatory ear and attaining greater maximal firing rates as stimulus level increased. Seventy-five percent of neurons showed significant shifts with changes in overall sound level. The range of ILDs corresponding to best neural acuity for ILDs shifted accordingly. In a simulation using the empirical data, when the overall stimulus level was randomly changed from one trial to the next, the neural discrimination thresholds for ILD, or ILD acuities, were worsened by 50–60% across the population of neurons relative to fixed stimulus levels whether ILD acuity was measured at the azimuthal midline or the ILD pedestal producing the best acuity. The impairment in ILD discrimination was attributed to the increased neural response variance imparted by varying the stimulus level. These results contrast to those observed in psychophysical studies where ILD discrimination thresholds under similar experimental conditions are invariant to overall changes in stimulus level. A simple computational model that incorporated the antagonistic inputs of bilateral LSO nuclei as well as the dorsal nuclei of the lateral lemniscus to the inferior colliculus produced a more robust encoding of ILD even in the setting of roving stimulus level. Testable predictions of this model and comparison to other computational models addressing stimulus invariance were considered.

Temporal-Gap Detection by Cochlear Prosthesis Users

1989 ◽  
Vol 32 (4) ◽  
pp. 849-856 ◽  
Author(s):  
John P. Preece ◽  
Richard S. Tyler
Keyword(s):  
Magnitude Estimation ◽  
Stimulus Level ◽  
Electrode Placement ◽  
Frequency Effect ◽  
Gap Detection ◽  
Cochlear Prosthesis ◽  
Sensation Level

Minimum-detectable gaps for sinusoidal stimuli were measured for three users of a multi electrode cochlear prosthesis as functions of stimulus level, frequency, and electrode place within the cochlea. Stimulus level was scaled by sensation level and by growth-of-loudness functions generated for each condition by direct magnitude estimation. Minimum-detectable gaps decreased with increase in either sensation level or loudness, up to a plateau. When compared at equal sensation levels, the minimum-detectable gaps decreased with frequency increases. The frequency effect on minimum-detectable gaps is reduced if the data are considered at equal loudness. Comparison across place of stimulation within the cochlea showed minimum-detectable gaps to be shorter for more basal electrode placement at low stimulus levels. No differences in minimum-detectable gap as a function of place were found at higher stimulus levels.

scholarly journals GABA is a modulator, rather than a classical transmitter, in the medial nucleus of the trapezoid body–lateral superior olive sound localization circuit

2019 ◽  
Vol 597 (8) ◽  
pp. 2269-2295 ◽  
Author(s):  
Alexander U. Fischer ◽  
Nicolas I. C. Müller ◽  
Thomas Deller ◽  
Domenico Del Turco ◽  
Jonas O. Fisch ◽  
...  
Keyword(s):  
Sound Localization ◽  
Lateral Superior Olive ◽  
Superior Olive ◽  
Medial Nucleus ◽  
Trapezoid Body

scholarly journals Real-time finite element analysis allows homogenization of tissue scale strains and reduces variance in a mouse defect healing model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Graeme R. Paul ◽  
Esther Wehrle ◽  
Duncan C. Tourolle ◽  
Gisela A. Kuhn ◽  
Ralph Müller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fracture Healing ◽  
Real Time ◽  
Mechanical Stimulus ◽  
Stimulus Level ◽  
Micro Computed Tomography ◽  
Reference Distribution ◽  
Element Analysis ◽  
Computed Tomography Images

AbstractMechanical loading allows both investigation into the mechano-regulation of fracture healing as well as interventions to improve fracture-healing outcomes such as delayed healing or non-unions. However, loading is seldom individualised or even targeted to an effective mechanical stimulus level within the bone tissue. In this study, we use micro-finite element analysis to demonstrate the result of using a constant loading assumption for all mouse femurs in a given group. We then contrast this with the application of an adaptive loading approach, denoted real time Finite Element adaptation, in which micro-computed tomography images provide the basis for micro-FE based simulations and the resulting strains are manipulated and targeted to a reference distribution. Using this approach, we demonstrate that individualised femoral loading leads to a better-specified strain distribution and lower variance in tissue mechanical stimulus across all mice, both longitudinally and cross-sectionally, while making sure that no overloading is occurring leading to refracture of the femur bones.

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