Editing Perception (section)

== Features ==

=== 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.

=== Grouping (Gestalt) ===
{{main|Principles of grouping}}
[[File:Gestalt closure.svg|right|thumb|Law of Closure. The human brain tends to perceive complete shapes even if those forms are incomplete.]]
The ''principles of grouping'' (or ''Gestalt laws of grouping'') are a set of principles in [[psychology]], first proposed by [[Gestalt psychology|Gestalt psychologists]], to explain how humans naturally perceive objects with patterns and objects. Gestalt psychologists argued that these principles exist because the mind has an innate disposition to [[perceive]] patterns in the stimulus based on certain rules. These principles are [[Principles of grouping|organized into six categories]]:

# '''Proximity''': the principle of ''[[Proximity principle|proximity]]'' states that, [[Ceteris paribus|all else being equal]], perception tends to group stimuli that are close together as part of the same object, and [[Stimulus (psychology)|stimuli]] that are far apart as two separate objects.
# '''Similarity''': the principle of ''[[Similarity (psychology)|similarity]]'' states that, all else being equal, perception lends itself to seeing stimuli that physically resemble each other as part of the same object and that are different as part of a separate object. This allows for people to distinguish between adjacent and overlapping objects based on their [[Texture (visual arts)#Visual texture|visual texture]] and [[Nominalism|resemblance]].
# '''Closure''': the principle of ''[[Closure (psychology)|closure]]'' refers to the mind's tendency to see complete figures or forms even if a picture is incomplete, partially hidden by other objects, or if part of the information needed to make a complete picture in our minds is missing. For example, if part of a shape's border is missing people still tend to see the shape as completely enclosed by the border and ignore the gaps.
# '''Good Continuation:''' the principle of ''[[Principles of grouping#Good continuation|good continuation]]'' makes sense of stimuli that overlap: when there is an intersection between two or more objects, people tend to perceive each as a single uninterrupted object.
# '''Common Fate''': the principle of ''[[Principles of grouping#Common fate|common fate]]'' groups stimuli together on the basis of their movement. When visual elements are seen moving in the same direction at the same rate, perception associates the movement as part of the same stimulus. This allows people to make out moving objects even when other details, such as color or outline, are obscured.
# The principle of ''[[Principles of grouping#Good form|good form]]'' refers to the tendency to group together forms of similar shape, pattern, [[color]], etc.<ref>Gray, Peter O. (2006): ''Psychology'', 5th ed., New York: Worth, p. 281. {{ISBN|978-0-7167-0617-5}}</ref><ref>{{cite book|title=Sensation and Perception|last1=Wolfe|first1=Jeremy M.|last2=Kluender|first2=Keith R.|last3=Levi|first3=Dennis M.|last4=Bartoshuk|first4=Linda M.|last5=Herz|first5=Rachel S.|last6=Klatzky|first6=Roberta L.|last7=Lederman|first7=Susan J.|publisher=Sinauer Associates|year=2008|isbn=978-0-87893-938-1|edition=2nd|pages=78, 80|chapter=Gestalt Grouping Principles|chapter-url=http://www.sinauer.com./wolfe/chap4/gestaltF.htm|archive-url=https://web.archive.org/web/20110723150836/http://www.sinauer.com/wolfe/chap4/gestaltF.htm|archive-date=23 July 2011|url-status=dead}}</ref><ref>Goldstein (2009). pp. 105–107</ref><ref>{{cite encyclopaedia|encyclopedia=Encyclopaedic Dictionary of Psychological Terms|first=J. C.|last=Banerjee|publisher=M.D. Publications Pvt. Ltd|year=1994|isbn=978-81-85880-28-0|article=Gestalt Theory of Perception|pages=107–108}}</ref>

Later research has identified additional grouping principles.<ref>{{cite book|title=Psychology: themes and variations|last=Weiten|first=Wayne|publisher=Brooks/Cole Pub. Co.|year=1998|isbn=978-0-534-34014-8|edition=4th|page=144}}</ref>

=== Contrast effects ===
{{main|Contrast effect}}A common finding across many different kinds of perception is that the perceived qualities of an object can be affected by the qualities of context. If one object is extreme on some dimension, then neighboring objects are perceived as further away from that extreme.

"[[Contrast effect#Types|Simultaneous contrast effect]]" is the term used when stimuli are presented at the same time, whereas ''[[successive contrast]]'' applies when stimuli are presented one after another.<ref name="Corsini2002">{{cite book|url=https://books.google.com/books?id=0uxnglHzYaoC&pg=PA219|title=The dictionary of psychology|last=Corsini|first=Raymond J.|publisher=Psychology Press|year=2002|isbn=978-1-58391-328-4|page=219|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109162655/http://books.google.com/books?id=0uxnglHzYaoC&pg=PA219|archive-date=9 November 2011|url-status=live}}</ref>

The contrast effect was noted by the 17th Century philosopher [[John Locke]], who observed that lukewarm water can feel hot or cold depending on whether the hand touching it was previously in hot or cold water.<ref name="Kushner2008">{{cite book|url=https://books.google.com/books?id=TYn5VHp9jioC&pg=PA1|title=Contrast in judgments of mental health|last=Kushner|first=Laura H.|year=2008|isbn=978-0-549-91314-6|page=1|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109163219/http://books.google.com/books?id=TYn5VHp9jioC&pg=PA1|archive-date=9 November 2011|url-status=live}}</ref> In the early 20th Century, [[Wilhelm Wundt]] identified contrast as a fundamental principle of perception, and since then the effect has been confirmed in many different areas.<ref name="Kushner2008" /> These effects shape not only visual qualities like color and brightness, but other kinds of perception, including how heavy an object feels.<ref name="Plous1993">{{cite book|url=https://books.google.com/books?id=xvWOQgAACAAJ|title=The psychology of judgment and decision making|last=Plous|first=Scott|publisher=McGraw-Hill|year=1993|isbn=978-0-07-050477-6|pages=38–41|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109162735/http://books.google.com/books?id=xvWOQgAACAAJ|archive-date=9 November 2011|url-status=live}}</ref> One experiment found that thinking of the name "Hitler" led to subjects rating a person as more hostile.<ref name="Moskowitz2005">{{cite book|url=https://books.google.com/books?id=_-NLW8Ynvp8C&pg=PA421|title=Social cognition: understanding self and others|last=Moskowitz|first=Gordon B.|publisher=Guilford Press|year=2005|isbn=978-1-59385-085-2|page=421|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109163155/http://books.google.com/books?id=_-NLW8Ynvp8C&pg=PA421|archive-date=9 November 2011|url-status=live}}</ref> Whether a piece of music is perceived as good or bad can depend on whether the music heard before it was pleasant or unpleasant.<ref name="Popper2010">{{cite book|url=https://books.google.com/books?id=ZYXd3CF1_vkC&pg=PA150|title=Music Perception|last=Popper|first=Arthur N.|date=30 November 2010|publisher=Springer|isbn=978-1-4419-6113-6|page=150|access-date=24 March 2011|archive-url=https://web.archive.org/web/20111109163046/http://books.google.com/books?id=ZYXd3CF1_vkC&pg=PA150|archive-date=9 November 2011|url-status=live}}</ref> For the effect to work, the objects being compared need to be similar to each other: a television reporter can seem smaller when interviewing a tall basketball player, but not when standing next to a tall building.<ref name="Plous1993" /> In the brain, brightness contrast exerts effects on both neuronal [[Firing rate (cells)|firing rates]] and [[Neuronal synchronization|neuronal synchrony]].<ref>{{cite journal|last1=Biederlack|first1=J.|last2=Castelo-Branco|first2=M.|last3=Neuenschwander|first3=S.|last4=Wheeler|first4=D.W.|last5=Singer|first5=W.|last6=Nikolić|first6=D.|year=2006|title=Brightness induction: Rate enhancement and neuronal synchronization as complementary codes|journal=Neuron|volume=52|issue=6|pages=1073–1083|doi=10.1016/j.neuron.2006.11.012|pmid=17178409|s2cid=16732916|doi-access=free}}</ref>