Frequency and intensity discrimination measured in a maximum-likelihood procedure from young and aged normal-hearing subjects

1998 ◽  
Vol 103 (1) ◽  
pp. 553-565 ◽  
Author(s):  
Ning-ji He ◽  
Judy R. Dubno ◽  
John H. Mills
Keyword(s):  
Maximum Likelihood ◽  
Normal Hearing ◽  
Intensity Discrimination ◽  
Maximum Likelihood Procedure

scholarly journals Task-dependent effects of nicotine treatment on auditory performance in young-adult and elderly human nonsmokers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuping Sun ◽  
Michelle R. Kapolowicz ◽  
Matthew Richardson ◽  
Raju Metherate ◽  
Fan-Gang Zeng
Keyword(s):  
Frequency Modulation ◽  
Auditory Processing ◽  
Frequency Discrimination ◽  
Normal Hearing ◽  
Post Treatment ◽  
Intensity Discrimination ◽  
Modulation Identification ◽  
Baseline Performance ◽  
Auditory Performance ◽  
Pre Treatment

AbstractElectrophysiological studies show that nicotine enhances neural responses to characteristic frequency stimuli. Previous behavioral studies partially corroborate these findings in young adults, showing that nicotine selectively enhances auditory processing in difficult listening conditions. The present work extended previous work to include both young and older adults and assessed the nicotine effect on sound frequency and intensity discrimination. Hypotheses were that nicotine improves auditory performance and that the degree of improvement is inversely proportional to baseline performance. Young (19–23 years old) normal-hearing nonsmokers and elderly (61–80) nonsmokers with normal hearing between 500 and 2000 Hz received nicotine gum (6 mg) or placebo gum in a single-blind, randomized crossover design. Participants performed three experiments (frequency discrimination, frequency modulation identification, and intensity discrimination) before and after treatment. The perceptual differences were analyzed between pre- and post-treatment, as well as between post-treatment nicotine and placebo conditions as a function of pre-treatment baseline performance. Compared to pre-treatment performance, nicotine significantly improved frequency discrimination. Compared to placebo, nicotine significantly improved performance for intensity discrimination, and the improvement was more pronounced in the elderly with lower baseline performance. Nicotine had no effect on frequency modulation identification. Nicotine effects are task-dependent, reflecting possible interplays of subjects, tasks and neural mechanisms.

Intensity discrimination in normal‐hearing and hearing‐impaired listeners

1994 ◽  
Vol 96 (5) ◽  
pp. 2683-2693 ◽  
Author(s):  
Anna C. Schroder ◽  
Neal F. Viemeister ◽  
David A. Nelson
Keyword(s):  
Normal Hearing ◽  
Hearing Impaired ◽  
Intensity Discrimination

Use of residual maximum likelihood to evaluate accuracy of two NIRS calibration procedures, relative to Kjeldahl, for determining nitrogen concentration of soybeans

1991 ◽  
Vol 71 (2) ◽  
pp. 385-392 ◽  
Author(s):  
G. B. Schaalje ◽  
H. -H. Mündel
Keyword(s):  
Maximum Likelihood ◽  
Near Infrared ◽  
Nitrogen Concentration ◽  
Principal Component Regression ◽  
Principal Component ◽  
Field Trials ◽  
Near Infrared Reflectance ◽  
Residual Maximum Likelihood ◽  
Maximum Likelihood Procedure ◽  
Calibration Methods

The accuracy of estimates of plant properties based on near-infrared reflectance spectroscopy (NIRS) varies with many factors including the biological material in question and the method used to calibrate the NIRS instrument. This study investigated the accuracy, relative to Kjeldahl analysis, of NIRS analysis based on two calibration methods in estimating nitrogen concentration of four stages and/or parts of soybean (Glycine max (L.) Merr.) plants. Samples of whole top growth at anthesis, whole top growth at maturity, whole top growth at maturity excluding seeds, and seeds were obtained from two field trials and one phytotron experiment. Two Kjeldahl determinations of nitrogen concentration were obtained for each sample, as well as reflectance values at each of 19 infrared wavelengths, using a Technicon InfraAlyser 400R. Different subsets of the sample data were used for calibration and assessment of accuracy. The instrument was calibrated using stepwise multiple linear regression (SMLR) and principal component regression (PCR). The residual maximum likelihood procedure was useful in showing that NIRS estimates based on either SMLR or PCR were at least as accurate as Kjeldahl estimates for all stages and/or parts except whole top growth at maturity excluding seeds. Key words: Calibration, principal component regression, stepwise regression

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