Editing Perception (section)

=== Constancy ===
{{main|Subjective constancy|}}''Perceptual constancy'' is the ability of perceptual systems to recognize the same object from widely varying sensory inputs.<ref name="Bernstein20102"/>{{rp|118–120}}<ref name="AtkinsonAtkinson1990">{{cite book|url=https://books.google.com/books?id=Nw54PwAACAAJ|title=Introduction to psychology|last1=Atkinson|first1=Rita L.|last2=Atkinson|first2=Richard C.|last3=Smith|first3=Edward E.|date=March 1990|publisher=Harcourt Brace Jovanovich|isbn=978-0-15-543689-3|pages=177–183|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109162907/http://books.google.com/books?id=Nw54PwAACAAJ|archive-date=9 November 2011|url-status=live}}</ref> For example, individual people can be recognized from views, such as frontal and profile, which form very different shapes on the retina. A coin looked at face-on makes a circular image on the retina, but when held at angle it makes an elliptical image.<ref name="eop_constancy">{{cite book|chapter-url=https://books.google.com/books?id=Y4TOEN4f5ZMC&pg=PA136|title=Encyclopedia of Perception|last=Moore|first=Brian C. J.|date=15 October 2009|publisher=Sage|isbn=978-1-4129-4081-8|editor-last=Goldstein|editor-first=E. Bruce|pages=136–137|chapter=Audition|access-date=26 March 2011|archive-url=https://web.archive.org/web/20111109162606/http://books.google.com/books?id=Y4TOEN4f5ZMC&pg=PA136|archive-date=9 November 2011|url-status=live}}</ref> In normal perception these are recognized as a single three-dimensional object. Without this correction process, an animal approaching from the distance would appear to gain in size.<ref name="Sonderegger1998">{{cite book|url=https://books.google.com/books?id=UUrCHiSb_QsC&pg=PA45|title=Psychology|last=Sonderegger|first=Theo|date=16 October 1998|publisher=John Wiley and Sons|isbn=978-0-8220-5327-9|pages=43–46|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109162741/http://books.google.com/books?id=UUrCHiSb_QsC&pg=PA45|archive-date=9 November 2011|url-status=live}}</ref><ref name="enc_constancy">{{cite book|chapter-url=https://books.google.com/books?id=Y4TOEN4f5ZMC&pg=PA309|title=Encyclopedia of Perception|last=Goldstein|first=E. Bruce|date=15 October 2009|publisher=Sage|isbn=978-1-4129-4081-8|editor-last=Goldstein|editor-first=E. Bruce|pages=309–313|chapter=Constancy|access-date=26 March 2011|archive-url=https://web.archive.org/web/20111109162834/http://books.google.com/books?id=Y4TOEN4f5ZMC&pg=PA309|archive-date=9 November 2011|url-status=live}}</ref> One kind of perceptual constancy is ''[[color constancy]]'': for example, a white piece of paper can be recognized as such under different colors and intensities of light.<ref name="enc_constancy" /> Another example is ''roughness constancy'': when a hand is drawn quickly across a surface, the touch nerves are stimulated more intensely. The brain compensates for this, so the speed of contact does not affect the perceived roughness.<ref name="enc_constancy" /> Other constancies include melody, odor, brightness and words.<ref name="Roeckelein2006">{{cite book|url=https://books.google.com/books?id=1Yn6NZgxvssC&pg=PA126|title=Elsevier's dictionary of psychological theories|last=Roeckelein|first=Jon E.|publisher=Elsevier|year=2006|isbn=978-0-444-51750-0|page=126|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109162549/http://books.google.com/books?id=1Yn6NZgxvssC&pg=PA126|archive-date=9 November 2011|url-status=live}}</ref> These constancies are not always total, but the variation in the percept is much less than the variation in the physical stimulus.<ref name="enc_constancy" /> The perceptual systems of the brain achieve perceptual constancy in a variety of ways, each specialized for the kind of information being processed,<ref name="Yantis2001">{{cite book|url=https://books.google.com/books?id=GpGvYSTk9gYC&pg=PA7|title=Visual perception: essential readings|last=Yantis|first=Steven|publisher=Psychology Press|year=2001|isbn=978-0-86377-598-7|page=7|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109162254/http://books.google.com/books?id=GpGvYSTk9gYC&pg=PA7|archive-date=9 November 2011|url-status=live}}</ref> with [[Phonemic restoration effect|phonemic restoration]] as a notable example from hearing.