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A model of top-down gain control in the auditory system.

Schneider BA, Parker S, Murphy D - Atten Percept Psychophys (2011)

Bottom Line: There were three 20-session conditions: (1) four soft tones (25, 30, 35, and 40 dB SPL) in the set; (2) those four soft tones plus a 50-dB SPL tone; and (3) the four soft tones plus an 80-dB SPL tone.The results were well described by a top-down, nonlinear gain-control system in which the amplifier's gain depended on the highest intensity in the stimulus set.Individual participants' identification judgments were generally compatible with an equal-variance signal-detection model in which the mean locations of the distribution of effects along the decision axis were determined by the operation of this nonlinear amplification system.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd., Mississauga, ON, L5L 1C6, Canada. bruce.schneider@utoronto.ca

ABSTRACT
To evaluate a model of top-down gain control in the auditory system, 6 participants were asked to identify 1-kHz pure tones differing only in intensity. There were three 20-session conditions: (1) four soft tones (25, 30, 35, and 40 dB SPL) in the set; (2) those four soft tones plus a 50-dB SPL tone; and (3) the four soft tones plus an 80-dB SPL tone. The results were well described by a top-down, nonlinear gain-control system in which the amplifier's gain depended on the highest intensity in the stimulus set. Individual participants' identification judgments were generally compatible with an equal-variance signal-detection model in which the mean locations of the distribution of effects along the decision axis were determined by the operation of this nonlinear amplification system.

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Related in: MedlinePlus

The distance along the decision axis between the stimuli 1 and 4 (25 and 40 dB SPL) scaled in Laplace d-prime units, as a function of session block for the baseline (B), B + 50, and B + 80 conditions. Each point is based on the Laplace equal-variance model that best fits the matrix of stimulus–response probabilities averaged over individuals for the session block in question
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Fig5: The distance along the decision axis between the stimuli 1 and 4 (25 and 40 dB SPL) scaled in Laplace d-prime units, as a function of session block for the baseline (B), B + 50, and B + 80 conditions. Each point is based on the Laplace equal-variance model that best fits the matrix of stimulus–response probabilities averaged over individuals for the session block in question

Mentions: The obtained probability of response k, (1 ≤ k ≤ 4), given stimulus j, (1 ≤ j ≤ 4), for the 16 combinations of k and j, as a function of the predicted values of these probabilities obtained from the best-fitting Gaussian equal-variance model and from the best-fitting Laplace equal-variance model for the baseline, B + 50, and B + 80 conditions. The models in each condition were fit to the matrices of stimulus–response probabilities averaged over participants and sessions. The straight lines represent where the points would fall in these coordinates if the predictions of the model were perfect


A model of top-down gain control in the auditory system.

Schneider BA, Parker S, Murphy D - Atten Percept Psychophys (2011)

The distance along the decision axis between the stimuli 1 and 4 (25 and 40 dB SPL) scaled in Laplace d-prime units, as a function of session block for the baseline (B), B + 50, and B + 80 conditions. Each point is based on the Laplace equal-variance model that best fits the matrix of stimulus–response probabilities averaged over individuals for the session block in question
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3118000&req=5

Fig5: The distance along the decision axis between the stimuli 1 and 4 (25 and 40 dB SPL) scaled in Laplace d-prime units, as a function of session block for the baseline (B), B + 50, and B + 80 conditions. Each point is based on the Laplace equal-variance model that best fits the matrix of stimulus–response probabilities averaged over individuals for the session block in question
Mentions: The obtained probability of response k, (1 ≤ k ≤ 4), given stimulus j, (1 ≤ j ≤ 4), for the 16 combinations of k and j, as a function of the predicted values of these probabilities obtained from the best-fitting Gaussian equal-variance model and from the best-fitting Laplace equal-variance model for the baseline, B + 50, and B + 80 conditions. The models in each condition were fit to the matrices of stimulus–response probabilities averaged over participants and sessions. The straight lines represent where the points would fall in these coordinates if the predictions of the model were perfect

Bottom Line: There were three 20-session conditions: (1) four soft tones (25, 30, 35, and 40 dB SPL) in the set; (2) those four soft tones plus a 50-dB SPL tone; and (3) the four soft tones plus an 80-dB SPL tone.The results were well described by a top-down, nonlinear gain-control system in which the amplifier's gain depended on the highest intensity in the stimulus set.Individual participants' identification judgments were generally compatible with an equal-variance signal-detection model in which the mean locations of the distribution of effects along the decision axis were determined by the operation of this nonlinear amplification system.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd., Mississauga, ON, L5L 1C6, Canada. bruce.schneider@utoronto.ca

ABSTRACT
To evaluate a model of top-down gain control in the auditory system, 6 participants were asked to identify 1-kHz pure tones differing only in intensity. There were three 20-session conditions: (1) four soft tones (25, 30, 35, and 40 dB SPL) in the set; (2) those four soft tones plus a 50-dB SPL tone; and (3) the four soft tones plus an 80-dB SPL tone. The results were well described by a top-down, nonlinear gain-control system in which the amplifier's gain depended on the highest intensity in the stimulus set. Individual participants' identification judgments were generally compatible with an equal-variance signal-detection model in which the mean locations of the distribution of effects along the decision axis were determined by the operation of this nonlinear amplification system.

Show MeSH
Related in: MedlinePlus