Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

The normal distribution in scaling subjective stimulus differences: less "normal" than we think?

A Hellström1

  • 1Department of Psychology, Stockholm University, Sweden.

Perception & Psychophysics
|July 1, 1993
PubMed
Summary

The t-distribution with 4 degrees of freedom (t(4)) effectively models subjective loudness differences, outperforming standard Gaussian models in psychophysical studies. This addresses limitations of the central limit theorem for mixed distributions.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Morphology and biological data in cord blood eryhtrocyte units resembles adult units after processing and storage - Meets current quality recommendations.

Transfusion and apheresis science : official journal of the World Apheresis Association : official journal of the European Society for Haemapheresis·2022
Same author

Adherence to oxygen saturation targets increased in preterm infants when a higher target range and tighter alarm limits were introduced.

Acta paediatrica (Oslo, Norway : 1992)·2019
Same author

Life weariness and suicidal thoughts in late life: a national study in Sweden.

Aging & mental health·2017
Same author

Cohort study of growth patterns by gestational age in preterm infants developing morbidity.

BMJ open·2016
Same author

Screening for retinopathy of prematurity can be started in postmenstrual week 31 in very premature babies!

Eye (London, England)·2016
Same author

Impact of Nutritional Status and Sleep Quality on Hospital Utilisation in the Oldest Old with Heart Failure.

The journal of nutrition, health & aging·2016

Area of Science:

  • Psychophysics
  • Statistics
  • Cognitive Science

Background:

  • The Gaussian (normal) distribution is widely used for subjective quantities, relying on the central limit theorem.
  • However, the central limit theorem does not apply to mixtures of Gaussian distributions with varying standard deviations.
  • Such mixtures result in heavier-tailed distributions than the Gaussian, potentially due to fluctuating attention in psychophysical experiments.

Purpose of the Study:

  • To identify suitable statistical models for distributions of subjective quantities that are heavier-tailed than the Gaussian.
  • To evaluate the performance of the logistic distribution and the t-distribution (with few degrees of freedom) for such data.

Main Methods:

  • Reanalysis of experimental data from three-category loudness comparison tasks.

Related Experiment Videos

  • Conducting a Monte Carlo simulation to test model performance.
  • Comparing the fit of the t-distribution with 4 degrees of freedom (t(4)) against other models.

    • Main Results:

    • The t-distribution with 4 degrees of freedom (t(4)) provided a satisfactory fit to the data.
    • This model effectively captured the mixed inter- and intraindividual distribution of subjective loudness differences.
    • The findings highlight the inadequacy of the standard Gaussian model for these types of psychophysical data.

    Conclusions:

    • The t(4) distribution is a robust candidate for modeling subjective loudness differences in psychophysical research.
    • This approach addresses the limitations of the central limit theorem when dealing with mixed-effects distributions.
    • The study suggests that t-distributions should be considered when analyzing psychophysical data exhibiting heavier tails.