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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.

Show MeSH
Projection values along the decision axis obtained from the Laplace equal-variance model as a function of the projection values predicted by the gain-control model for the data of the 6 participants in the three conditions of the present experiment and the data of the groups of participants in the low- and high-intensity baseline conditions in Parker et al. (2002)
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Fig9: Projection values along the decision axis obtained from the Laplace equal-variance model as a function of the projection values predicted by the gain-control model for the data of the 6 participants in the three conditions of the present experiment and the data of the groups of participants in the low- and high-intensity baseline conditions in Parker et al. (2002)

Mentions: Values of n and σ3 for the group of participants from Parker et al. (2002), and for the 6 participants from the present experiment for the gain-control model. The value of n did not vary across stimulus sets. The values of σ3 in this table specify the standard deviation of the Laplace distributions when the stimulus set contained only four elements (three criteria). For stimulus sets containing five elements (four criteria), the value of the standard deviation of the Laplace distributions, σ4, was found to be 1.19 σ3. The value of dBc in this model was 20.05, the value of s was 25.22, and the value of dBT was 24.3


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

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

Projection values along the decision axis obtained from the Laplace equal-variance model as a function of the projection values predicted by the gain-control model for the data of the 6 participants in the three conditions of the present experiment and the data of the groups of participants in the low- and high-intensity baseline conditions in Parker et al. (2002)
© Copyright Policy
Related In: Results  -  Collection

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

Fig9: Projection values along the decision axis obtained from the Laplace equal-variance model as a function of the projection values predicted by the gain-control model for the data of the 6 participants in the three conditions of the present experiment and the data of the groups of participants in the low- and high-intensity baseline conditions in Parker et al. (2002)
Mentions: Values of n and σ3 for the group of participants from Parker et al. (2002), and for the 6 participants from the present experiment for the gain-control model. The value of n did not vary across stimulus sets. The values of σ3 in this table specify the standard deviation of the Laplace distributions when the stimulus set contained only four elements (three criteria). For stimulus sets containing five elements (four criteria), the value of the standard deviation of the Laplace distributions, σ4, was found to be 1.19 σ3. The value of dBc in this model was 20.05, the value of s was 25.22, and the value of dBT was 24.3

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