Encyclopedia of Clinical Neuropsychology

2018 Edition
| Editors: Jeffrey S. Kreutzer, John DeLuca, Bruce Caplan

Mach Bands

  • Nicole R. NissimEmail author
  • Adam J. Woods
Reference work entry
DOI: https://doi.org/10.1007/978-3-319-57111-9_9118

Named after the physicist Ernst Mach, Mach bands are a type of optical illusion where the contrast between edges of minimally differing shades of gray become exaggerated once the edges are in contact with one another (Ratcliff 1965). Optical illusions are not due to optics of the eye, but in the properties of visual areas of the human brain (Rees 2009). Perceiving this type of illusion is the result of lateral inhibition: a neural process where excited neurons reduce the activity of neighboring neurons causing the deactivation of neurons in the lateral direction (Ratcliff 1965). The resulting phenomenon is a sharp exaggeration of the contrast of edges.


  1. Ratcliff, F. (1965). Mach bands. San Francisco: Holder-Day.Google Scholar
  2. Rees, G. (2009). Awareness: Functional imaging. In Encyclopedia of neuroscience (pp. 1055–1062).CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Clinical and Health Psychology College of Public Health and Health Professions, Center for Cognitive Aging and Memory, McKnight Brain Institute (Primary)University of FloridaGainesvilleUSA
  2. 2.Department of NeuroscienceUniversity of FloridaGainesvilleUSA
  3. 3.Department of Clinical and Health Psychology, College of Public Health and Health ProfessionsUniversity of FloridaGainesvilleUSA
  4. 4.Center for Cognitive Aging and Memory, McKnight Brain InstituteUniversity of FloridaGainesvilleUSA