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

Linear filtering precedes nonlinear processing in early vision

K Langley1, D J Fleet, P B Hibbard

  • 1Department of Psychology, University College London, UK. kl@psychol.ucl.ac.uk

Current Biology : CB
|July 1, 1996
PubMed
Summary

Early visual processing involves nonlinearities crucial for perceiving contrast. This study finds that contrast beat detection is frequency-specific, indicating a linear filtering stage precedes nonlinear processing.

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

Secretory vesicle and cell surface markers for human endocrine pancreatic and pituitary tumors.

Endocrine pathology·2020
Same author

A risk calculator to predict adult attention-deficit/hyperactivity disorder: generation and external validation in three birth cohorts and one clinical sample - ERRATUM.

Epidemiology and psychiatric sciences·2019
Same author

A risk calculator to predict adult attention-deficit/hyperactivity disorder: generation and external validation in three birth cohorts and one clinical sample.

Epidemiology and psychiatric sciences·2019
Same author

Multiple centre evaluation study of ADAMTS13 activity and inhibitor assays.

International journal of laboratory hematology·2017
Same author

Investigating the genetic underpinnings of early-life irritability.

Translational psychiatry·2017
Same author

Observation-Based Estimates of Global Glacier Mass Change and Its Contribution to Sea-Level Change.

Surveys in geophysics·2017

Area of Science:

  • Visual neuroscience
  • Perceptual psychology
  • Computational vision

Background:

  • Nonlinearities are fundamental in early visual processing.
  • They influence perception of contrast, transparencies, and textures.
  • This study investigates the processing stage where nonlinearities become significant.

Purpose of the Study:

  • To determine the stage of visual processing where nonlinearities become significant.
  • To investigate the frequency selectivity of contrast processing.
  • To model the initial stages of contrast beat perception.

Main Methods:

  • Psychophysical adaptation paradigm.
  • Sinusoidal grating adaptation followed by plaid pattern presentation.
  • Measurement of contrast modulation (beat) detection thresholds.

Related Experiment Videos

Main Results:

  • Threshold elevation for contrast modulation was maximal when adapting grating matched the test pattern's carrier frequency.
  • Adaptation to gratings near the modulation frequency had minimal effect.
  • Contrast processing demonstrated frequency selectivity with a peak tuning near 0.4 cycles per degree.

Conclusions:

  • Contrast beat processing occurs in a frequency-specific manner.
  • This processing follows an initial stage of linear filtering that is both frequency- and orientation-specific.