Visual motion aftereffects arise from a cascade of two isomorphic adaptation mechanisms

Alan A. Stocker, Eero P. Simoncelli

Research output: Contribution to journalArticlepeer-review


Prolonged exposure to a moving stimulus can substantially alter the perceived velocity (both speed and direction) of subsequently presented stimuli. Here, we show that these changes can be parsimoniously explained with a model that combines the effects of two isomorphic adaptation mechanisms, one nondirectional and one directional. Each produces a pattern of velocity biases that serves as an observable "signature" of the corresponding mechanism. The net effect on perceived velocity is a superposition of these two signatures. By examining human velocity judgments in the context of different adaptor velocities, we are able to separate these two signatures. The model .ts the data well, successfully predicts subjects' behavior in an additional experiment using a nondirectional adaptor, and is in agreement with a variety of previous experimental results. As such, the model provides a unifying explanation for the diversity of motion aftereffects.

Original languageEnglish (US)
Article number9
JournalJournal of vision
Issue number9
StatePublished - Aug 24 2009


  • Aperture problem
  • Bias
  • Directional
  • Discrimination
  • Isomorphic mechanism
  • Motion adaptation
  • Nondirectional
  • Signature
  • Velocity

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems


Dive into the research topics of 'Visual motion aftereffects arise from a cascade of two isomorphic adaptation mechanisms'. Together they form a unique fingerprint.

Cite this