Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 15603145

Constructing a cochlear transducer function from the summating potential using a low-frequency bias tone.

Chul-Hee Choi·Mark E Chertoff·Lin Bian·David Lerner
View original source ↗Export metadata ↓

Abstract

A new method is developed to construct a cochlear transducer function using modulation of the summating potential (SP), a dc component of the electrical response of the cochlea to a sinusoid. It is mathematically shown that the magnitude of the SP is determined by the even-order terms of the power series representing a nonlinear function. The relationship between the SP magnitudes and the second derivative of the transducer function was determined by using a low-frequency bias tone to position a high-frequency probe tone at different places along the cochlear transducer function. Two probe tones (6 kHz and 12 kHz) ranging from 70 to 90 dB SPL and a 25-Hz bias tone at 130 dB SPL were simultaneously presented. Electric responses from the cochlea were recorded by an electrode placed at the round window to obtain the SP magnitudes. The experimental results from eight animals demonstrated that the SP magnitudes as a function of bias levels are essentially proportional to the second derivative of a sigmoidal Boltzmann function. This suggests that the low-frequency modulated SP amplitude can be used to construct a cochlear transducer function.

Explore related subjects

Acoustic StimulationAction PotentialsAnimalsCochleaCochlear Microphonic PotentialsComputer SimulationFourier AnalysisGerbillinaeHair Cells, AuditoryModels, BiologicalSignal TransductionJournal ArticleResearch Support, N.I.H., ExtramuralResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Chul-Hee Choi, Mark E Chertoff, Lin Bian, David Lerner. 2004. Constructing a cochlear transducer function from the summating potential using a low-frequency bias tone.. https://doi.org/10.1121/1.1791722

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2008

Sensory filtering phenomenology in PTSD.

Disrupted sensory filtering, or problems with suppressing irrelevant environmental sensory stimuli, has been reported in individuals with posttraumatic stress disorder (PTSD). However, the relationship of sensory filtering deficits to specific PTSD symptoms versus an association with general trauma exposure is unclear. These relationships were examined by administering self-report measures of trauma exposure, PTSD, and sensory gating phenomenology to undergraduate participants with PTSD (n=32), with trauma history but without PTSD (n=144), and with minimal trauma history (n=153). Subjects with PTSD reported greater filtering disruption than individuals in the trauma only and low trauma groups, who did not differ. Individuals endorsing reexperiencing and numbing symptoms, and females endorsing hypervigilance, reported disrupted sensory filtering phenomenology. These results suggest that impaired filtering differentiates between individuals with PTSD symptoms and asymptomatic individuals exposed to multiple traumas and low-trauma controls.

Acoustic Stimulation↗
PubMed2007

Hypoglycemia reduces the blood-oxygenation level dependent signal in primary auditory and visual cortex: a functional magnetic resonance imaging study.

Studies of the effects of hypoglycemia on the brain using neurocognitive testing have suggested that mainly complex functions subserved by secondary and tertiary cortex are affected by mild to moderate hypoglycemia and that intensively treated patients with Type I diabetes mellitus (T1DM) may have altered sensitivity to the central nervous system effects of hypoglycemia. Functional magnetic resonance imaging provides a sensitive, regionally-specific probe of possible neurophysiologic changes related to hypoglycemia in the brain. Eleven intensively-treated T1DM patients and 11 matched non-diabetic controls took part in a 2-day protocol in which functional magnetic resonance imaging (MRI) was used to measure changes in the patterns of brain activation produced by simple auditory and visual stimuli in different conditions. On one day, participants were euglycemic the entire time. On the other day, an initial 50-min euglycemic period was followed by a 50-min hypoglycemic period. Results indicated that hypoglycemia reduced the amplitude of the blood-oxygenation level dependent response in primary auditory and visual cortex to simple auditory and visual stimuli. The latency and duration of the transient hemodynamic response function were not affected. Responses to hypoglycemia were similar in diabetic and non-diabetic participants. These results suggest that mild to moderate hypoglycemia may alter the balance of blood flow and oxygen extraction when glucose levels are lowered. Intensively-treated T1DM, with its attendant frequent hypoglycemic episodes, did not seem to alter hypoglycemic responses in primary visual and auditory cortex.

Acoustic Stimulation↗
PubMed2007

Song discrimination learning in zebra finches induces highly divergent responses to novel songs.

Perceptual biases can shape the evolution of signal form. Understanding the origin and direction of such biases is therefore crucial for understanding signal evolution. Many animals learn about species-specific signals. Discrimination learning using simple stimuli varying in one dimension (e.g. amplitude, wavelength) can result in perceptual biases with preferences for specific novel stimuli, depending on the stimulus dimensions. We examine how this translates to discrimination learning involving complex communication signals; birdsongs. Zebra finches (Taeniopygia guttata) were trained to discriminate between two artificial songs, using a Go/No-Go procedure. The training songs in experiment 1 differed in the number of repeats of a particular element. The songs in experiment 2 differed in the position of an odd element in a series of repeated elements. We examined generalization patterns by presenting novel songs with more or fewer repeated elements (experiment 1), or with the odd element earlier or later in the repeated element sequence (experiment 2). Control birds were trained with only one song. The generalization curves obtained from (i) control birds, (ii) experimental birds in experiment 1, and (iii) experimental birds in experiment 2 showed large and systematic differences from each other. Birds in experiment 1, but not 2, responded more strongly to specific novel songs than to training songs, showing 'peak shift'. The outcome indicates that learning about communication signals may give rise to perceptual biases that may drive signal evolution.

Acoustic Stimulation↗