A precedence effect model to simulate localization dominance using an adaptive, stimulus parameter-based inhibition process

2013 ◽  
Vol 134 (1) ◽  
pp. 420-435 ◽  
Author(s):  
Jonas Braasch
Keyword(s):  
Precedence Effect ◽  
Stimulus Parameter ◽  
Localization Dominance ◽  
Effect Model ◽  
Inhibition Process

scholarly journals Behavior and modeling of two-dimensional precedence effect in head-unrestrained cats

2015 ◽  
Vol 114 (2) ◽  
pp. 1272-1285
Author(s):  
Yan Gai ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin
Keyword(s):  
Potassium Current ◽  
Horizontal Plane ◽  
Sagittal Plane ◽  
Precedence Effect ◽  
The Novel ◽  
Medial Superior Olive ◽  
Localization Dominance ◽  
Low Threshold ◽  
Spatial Locations ◽  
Auditory Illusion

The precedence effect (PE) is an auditory illusion that occurs when listeners localize nearly coincident and similar sounds from different spatial locations, such as a direct sound and its echo. It has mostly been studied in humans and animals with immobile heads in the horizontal plane; speaker pairs were often symmetrically located in the frontal hemifield. The present study examined the PE in head-unrestrained cats for a variety of paired-sound conditions along the horizontal, vertical, and diagonal axes. Cats were trained with operant conditioning to direct their gaze to the perceived sound location. Stereotypical PE-like behaviors were observed for speaker pairs placed in azimuth or diagonally in the frontal hemifield as the interstimulus delay was varied. For speaker pairs in the median sagittal plane, no clear PE-like behavior occurred. Interestingly, when speakers were placed diagonally in front of the cat, certain PE-like behavior emerged along the vertical dimension. However, PE-like behavior was not observed when both speakers were located in the left hemifield. A Hodgkin-Huxley model was used to simulate responses of neurons in the medial superior olive (MSO) to sound pairs in azimuth. The novel simulation incorporated a low-threshold potassium current and frequency mismatches to generate internal delays. The model exhibited distinct PE-like behavior, such as summing localization and localization dominance. The simulation indicated that certain encoding of the PE could have occurred before information reaches the inferior colliculus, and MSO neurons with binaural inputs having mismatched characteristic frequencies may play an important role.

Neural Correlates of the Precedence Effect in the Inferior Colliculus of Behaving Cats

2004 ◽  
Vol 92 (6) ◽  
pp. 3286-3297 ◽  
Author(s):  
Daniel J. Tollin ◽  
Luis C. Populin ◽  
Tom C. T. Yin
Keyword(s):  
Inferior Colliculus ◽  
Sound Localization ◽  
Species Differences ◽  
Behavioral Responses ◽  
Neural Correlates ◽  
Precedence Effect ◽  
Single Neurons ◽  
Localization Dominance ◽  
Echo Threshold ◽  
Spatial Locations

Several auditory spatial illusions, collectively called the precedence effect (PE), occur when transient sounds are presented from two different spatial locations but separated in time by an interstimulus delay (ISD). For ISDs in the range of localization dominance (<10 ms), a single fused sound is typically located near the leading source location only, as if the location of the lagging source were suppressed. For longer ISDs, both the leading and lagging sources can be heard and localized, and the shortest ISD where this occurs is called the echo threshold. Previous physiological studies of the extracellular responses of single neurons in the inferior colliculus (IC) of anesthetized cats and unanesthetized rabbits with sounds known to elicit the PE have shown correlates of these phenomena though there were differences in the physiologically measured echo thresholds. Here we recorded in the IC of awake, behaving cats using stimuli that we have shown to evoke behavioral responses that are consistent with the precedence effect. For small ISDs, responses to the lag were reduced or eliminated consistent with psychophysical data showing that sound localization is based on the leading source. At longer ISDs, the responses to the lagging source recovered at ISDs comparable to psychophysically measured echo thresholds. Thus it appears that anesthesia, and not species differences, accounts for the discrepancies in the earlier studies.

Spatial Localization of Concurrent Multiple Sound Sources Using Phase Candidate Histogram

2011 ◽  
Vol 15 (9) ◽  
pp. 1277-1286
Author(s):  
Huakang Li ◽  
◽  
Jie Huang ◽  
Minyi Guo ◽  
Qunfei Zhao
Keyword(s):  
Sound Source ◽  
Real Life ◽  
Source Distribution ◽  
Precedence Effect ◽  
Spherical Robot ◽  
Spatial Cues ◽  
Sound Sources ◽  
Effect Model ◽  
Reverberant Environments ◽  
Spatial Locations

Mobile robots communicating with people would benefit from being able to detect sound sources to help localize interesting events in real-life settings. We propose using a spherical robot with four microphones to determine the spatial locations of multiple sound sources in ordinary rooms. The arrival temporal disparities from phase difference histograms are used to calculate the time differences. A precedence effect model suppresses the influence of echoes in reverberant environments. To integrate spatial cues of different microphones, we map the correlation between different microphone pairs on a 3D map corresponding to the azimuth and elevation of sound source direction. Results of experiments indicate that our proposed system provides sound source distribution very clearly and precisely, even concurrently in reverberant environments with the Echo Avoidance (EA) model.

Responses of Auditory Cortical Neurons to Pairs of Sounds: Correlates of Fusion and Localization

2001 ◽  
Vol 86 (3) ◽  
pp. 1333-1350 ◽  
Author(s):  
Brian J. Mickey ◽  
John C. Middlebrooks
Keyword(s):  
Cortical Neurons ◽  
Stimulus Level ◽  
Precedence Effect ◽  
Localization Dominance ◽  
Fused Image ◽  
Single Burst ◽  
Left And Right ◽  
The Difference ◽  
Spike Patterns ◽  
Intense Source

When two brief sounds arrive at a listener's ears nearly simultaneously from different directions, localization of the sounds is described by “the precedence effect.” At inter-stimulus delays (ISDs) <5 ms, listeners typically report hearing not two sounds but a single fused sound. The reported location of the fused image depends on the ISD. At ISDs of 1–4 ms, listeners point near the leading source (localization dominance). As the ISD is decreased from 0.8 to 0 ms, the fused image shifts toward a location midway between the two sources (summing localization). When an inter-stimulus level difference (ISLD) is imposed, judgements shift toward the more intense source. Spatial hearing, including the precedence effect, is thought to depend on the auditory cortex. Therefore we tested the hypothesis that the activity of cortical neurons signals the perceived location of fused pairs of sounds. We recorded the unit responses of cortical neurons in areas A1 and A2 of anesthetized cats. Single broadband clicks were presented from various frontal locations. Paired clicks were presented with various ISDs and ISLDs from two loudspeakers located 50° to the left and right of midline. Units typically responded to single clicks or paired clicks with a single burst of spikes. Artificial neural networks were trained to recognize the spike patterns elicited by single clicks from various locations. The trained networks were then used to identify the locations signaled by unit responses to paired clicks. At ISDs of 1–4 ms, unit responses typically signaled locations near that of the leading source in agreement with localization dominance. Nonetheless the responses generally exhibited a substantial undershoot; this finding, too, accorded with psychophysical measurements. As the ISD was decreased from ∼0.4 to 0 ms, network estimates typically shifted from the leading location toward the midline in agreement with summing localization. Furthermore a superposed ISLD shifted network estimates toward the more intense source, reaching an asymptote at an ISLD of 15–20 dB. To allow quantitative comparison of our physiological findings to psychophysical results, we performed human psychophysical experiments and made acoustical measurements from the ears of cats and humans. After accounting for the difference in head size between cats and humans, the responses of cortical units usually agreed with the responses of human listeners, although a sizable minority of units defied psychophysical expectations.

scholarly journals Short-Latency, Goal-Directed Movements of the Pinnae to Sounds That Produce Auditory Spatial Illusions

2010 ◽  
Vol 103 (1) ◽  
pp. 446-457 ◽  
Author(s):  
Daniel J. Tollin ◽  
Elizabeth M. McClaine ◽  
Tom C. T. Yin
Keyword(s):  
Operant Conditioning ◽  
Sound Source ◽  
Neural Mechanisms ◽  
Precedence Effect ◽  
Eye Position ◽  
Sound Sources ◽  
The Gaze ◽  
Localization Dominance ◽  
Echo Threshold ◽  
Behavioral Constraint

The precedence effect (PE) is an auditory spatial illusion whereby two identical sounds presented from two separate locations with a delay between them are perceived as a fused single sound source whose position depends on the value of the delay. By training cats using operant conditioning to look at sound sources, we have previously shown that cats experience the PE similarly to humans. For delays less than ±400 μs, cats exhibit summing localization, the perception of a “phantom” sound located between the sources. Consistent with localization dominance, for delays from 400 μs to ∼10 ms, cats orient toward the leading source location only, with little influence of the lagging source. Finally, echo threshold was reached for delays >10 ms, where cats first began to orient to the lagging source. It has been hypothesized by some that the neural mechanisms that produce facets of the PE, such as localization dominance and echo threshold, must likely occur at cortical levels. To test this hypothesis, we measured both pinnae position, which were not under any behavioral constraint, and eye position in cats and found that the pinnae orientations to stimuli that produce each of the three phases of the PE illusion was similar to the gaze responses. Although both eye and pinnae movements behaved in a manner that reflected the PE, because the pinnae moved with strikingly short latencies (∼30 ms), these data suggest a subcortical basis for the PE and that the cortex is not likely to be directly involved.

scholarly journals Influence of Sound Source Location on the Behavior and Physiology of the Precedence Effect in Cats

2009 ◽  
Vol 102 (2) ◽  
pp. 724-734 ◽  
Author(s):  
Micheal L. Dent ◽  
Daniel J. Tollin ◽  
Tom C. T. Yin
Keyword(s):  
Auditory Nerve ◽  
Single Unit ◽  
Neural Correlates ◽  
Precedence Effect ◽  
Neural Responses ◽  
Localization Dominance ◽  
Single Unit Recordings ◽  
Echo Threshold ◽  
Unanesthetized Animals ◽  
Psychophysical Task

Psychophysical experiments on the precedence effect (PE) in cats have shown that they localize pairs of auditory stimuli presented from different locations in space based on the spatial position of the stimuli and the interstimulus delay (ISD) between the stimuli in a manner similar to humans. Cats exhibit localization dominance for pairs of transient stimuli with |ISDs| from ∼0.4 to 10 ms, summing localization for |ISDs| < 0.4 ms and breakdown of fusion for |ISDs| > 10 ms, which is the approximate echo threshold. The neural correlates to the PE have been described in both anesthetized and unanesthetized animals at many levels from auditory nerve to cortex. Single-unit recordings from the inferior colliculus (IC) and auditory cortex of cats demonstrate that neurons respond to both lead and lag sounds at ISDs above behavioral echo thresholds, but the response to the lag is reduced at shorter ISDs, consistent with localization dominance. Here the influence of the relative locations of the leading and lagging sources on the PE was measured behaviorally in a psychophysical task and physiologically in the IC of awake behaving cats. At all configurations of lead-lag stimulus locations, the cats behaviorally exhibited summing localization, localization dominance, and breakdown of fusion. Recordings from the IC of awake behaving cats show neural responses paralleling behavioral measurements. Both behavioral and physiological results suggest systematically shorter echo thresholds when stimuli are further apart in space.

Psychophysical Investigation of an Auditory Spatial Illusion in Cats: The Precedence Effect

2003 ◽  
Vol 90 (4) ◽  
pp. 2149-2162 ◽  
Author(s):  
Daniel J. Tollin ◽  
Tom C.T. Yin
Keyword(s):  
Horizontal Plane ◽  
Sagittal Plane ◽  
Source Location ◽  
Precedence Effect ◽  
Search Coil ◽  
Localization Dominance ◽  
Reverberant Environments ◽  
Echo Threshold ◽  
Search Coil Technique

The precedence effect (PE) describes several spatial perceptual phenomena that occur when similar sounds are presented from two different locations and separated by a delay. The mechanisms that produce the effect are thought to be responsible for the ability to localize sounds in reverberant environments. Although the physiological bases for the PE have been studied, little is known about how these sounds are localized by species other than humans. Here we used the search coil technique to measure the eye positions of cats trained to saccade to the apparent locations of sounds. To study the PE, brief broadband stimuli were presented from two locations, with a delay between their onsets; the delayed sound meant to simulate a single reflection. Although the cats accurately localized single sources, the apparent locations of the paired sources depended on the delay. First, the cats exhibited summing localization, the perception of a “phantom” sound located between the sources, for delays < ±400 μs for sources positioned in azimuth along the horizontal plane, but not for sources positioned in elevation along the sagittal plane. Second, consistent with localization dominance, for delays from 400 μs to about 10 ms, the cats oriented toward the leading source location only, with little influence of the lagging source, both for horizontally and vertically placed sources. Finally, the echo threshold was reached for delays >10 ms, where the cats first began to orient to the lagging source on some trials. These data reveal that cats experience the PE phenomena similarly to humans.

ANALISIS PENGARUH RASIO LIKUIDITAS, RASIO PROFITABILITAS, RASIO SOLVABILITAS DAN RASIO PASAR TERHADAP HARGA SAHAM PADA PERUSAHAAN YANG BERADA PADA INDEKS LQ45 DI BURSA EFEK INDONESIA

2016 ◽  
Vol 11 (02) ◽  
pp. 1-16
Author(s):  
Dilawatil Hikmah
Keyword(s):  
Fixed Effect Model ◽  
Fixed Effect ◽  
Cross Sectional ◽  
Effect Model

Penelitian ini dilakukan dengan tujuan untuk menguji pengaruh rasio likuiditas (CR), rasio profitabilitas (NPM, ROA, ROE, EPS), rasio solvabilitas (DER) dan rasio pasar (PER) terhadap harga saham (Y) pada perusahaan yang berada pada indeks LQ45 di Bursa Efek Indonesia. Metode pengumpulan data dilakukan dengan menggunakan laporan keuangan anggota emiten LQ45 periode Januari 2014 yang selama 5 tahun eksis dari Februari 2009 sampai Januari 2014. Metode sampel yang digunakan adalah purpose sampling (sampling bersyarat). Adapun jumlah sampel yang terpilih memenuhi syarat sebanyak 21 emiten dari 45 emiten. Teknis analisis data menggunakan Eviews 7.1 yaitu dengan metode cross sectional weight dengan pendekatan fixed effect model. Hasil penelitian menunjukkan bahwa secara bersama-sama maupun secara parsial variabel CR, NPM, ROA, ROE, EPS, DER, dan PER memiliki pengaruh terhadap harga saham. Namun variabel yang berpengaruh signifikan terhadap harga saham adalah NPM dan PER. Maka para investor dapat menilai kinerja perusahaan dengan melihat dari rasio keuangan dan melakukan penilaian terhadap harga saham sehingga dengan mudah dapat menentukan saham yang baik sebelum berinvestasi di BEI.

Sign in / Sign up

Export Citation Format

Share Document