Editing Gestalt psychology (section)

=== ''Perceptual grouping – the law of {{Lang|de|Prägnanz}}'' ===
{{Main|Principles of grouping}}

Perceptual grouping (sometimes called perceptual segregation)<ref name="Eysenck2008">{{Cite book |last=Eysenck |first=Michael W. |title=Fundamentals of Cognition |date=2006 |publisher=Psychology Press |isbn=978-1-84169-374-3 |location=Hove, UK |pages=62–64}}</ref> is a form of perceptual organization.<ref name="Wagemans2012I" /> Perceptual grouping is the process that determines how organisms perceive some parts of their perceptual fields as being more related than others,<ref name="Wagemans2012I" /> using such information for [[object detection]].<ref name="Eysenck2008" /> 

The Gestaltists were the first psychologists to systematically study perceptual grouping.<ref name="Eysenck2008" /> According to Gestalt psychologists, the fundamental principle of perceptual grouping is the law of '''{{Lang|de|Prägnanz}}''',<ref name="Eysenck2008" /> also known as the law of good Gestalt. {{Lang|de|Prägnanz}} is a German word that directly translates to {{Gloss|pithiness}} and implies salience, conciseness, and orderliness.<ref name="todorvic" /> The law of {{Lang|de|Prägnanz}} says that people tend to experience things as regular, orderly, symmetrical, and simple.<ref name="Koffka1935">{{Cite book| publisher = Harcourt, Brace| last = Koffka| first = K.| title = Principles Of Gestalt Psychology| location = New York| access-date = 13 October 2019| date = 1935| url = https://archive.org/details/in.ernet.dli.2015.7888}}</ref> In other words, human perception is biased towards simplicity.

Gestalt [[psychologist]]s attempted to discover refinements of the law of ''{{Lang|de|Prägnanz}}'', which involved writing down [[law (principle)|laws]] that predict the interpretation of sensation.<ref name="gestaltpsych">{{cite book | last=Sternberg | first=Robert | title=Cognitive psychology | publisher=Thomson/Wadsworth | publication-place=Belmont, CA | year=2003 | edition=3rd | isbn=978-0-15-508535-0 | oclc=883578008 | language=en | page=}}</ref> Wertheimer defined a few principles that explain the ways humans perceive objects based on similarity, proximity, and continuity.<ref>{{Cite book|url=https://books.google.com/books?id=F7vd7JQ4zlcC&q=gestalt|title=The Concise Corsini Encyclopedia of Psychology and Behavioral Science|last1=Craighead|first1=W. Edward|last2=Nemeroff|first2=Charles B.|date=19 April 2004|publisher=John Wiley & Sons|isbn=9780471220367|pages=401–404|language=en|chapter=Gestalt psychology|access-date=2 October 2020|archive-date=15 April 2021|archive-url=https://web.archive.org/web/20210415221411/https://books.google.com/books?id=F7vd7JQ4zlcC&q=gestalt|url-status=live}}</ref> 

====Law of proximity====
[[Image:Gestalt proximity.svg|right|thumb|Law of proximity]]
The law of proximity states that when an individual perceives an assortment of objects, they perceive objects that are close to each other as forming a group. For example, in the figure illustrating the law of proximity, there are 72 circles, but we perceive the collection of circles in groups. Specifically, we perceive that there is a group of 36 circles on the left side of the image and three groups of 12 circles on the right side of the image. This law is often used in advertising logos to emphasize which aspects of events are associated.<ref name="stevenson">{{cite web|last=Stevenson|first=Herb|title=Emergence: The Gestalt Approach to Change|url=https://www.clevelandconsultinggroup.com/articles/emergence-gestalt-approach-to-change.php|publisher=Unleashing Executive and Orzanizational Potential|access-date=7 April 2012|archive-date=21 June 2012|archive-url=https://web.archive.org/web/20120621053349/https://www.clevelandconsultinggroup.com/articles/emergence-gestalt-approach-to-change.php|url-status=live}}</ref><ref name="Soegaard">{{cite book|last=Soegaard|first=Mads|title=Gestalt Principles of form Perception|url=https://www.interaction-design.org/encyclopedia/gestalt_principles_of_form_perception.html|publisher=Interaction Design|access-date=8 April 2012|archive-date=10 April 2012|archive-url=https://web.archive.org/web/20120410055022/https://www.interaction-design.org/encyclopedia/gestalt_principles_of_form_perception.html|url-status=live}}</ref>

====Law of similarity====
[[Image:Gestalt similarity.svg|right|thumb|upright|Law of similarity]]
The law of similarity states that elements within an assortment of objects are perceptually grouped together if they are similar to each other in shape, colour, size etc. For example, the figure illustrating the law of similarity portrays 36 circles all equal distance apart from one another forming a square. In this depiction, 18 of the circles are shaded dark, and 18 of the circles are shaded light. We perceive the dark circles as grouped together and the light circles as grouped together, forming six horizontal lines within the square of circles. This perception of lines is due to the law of similarity.<ref name="Soegaard" />
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====Law of closure====
[[Image:Gestalt closure.svg|right|thumb|Law of closure]]
[[File:IBM logo.svg|thumb|IBM logo and the law of closure]]
Gestalt psychologists believed that humans tend to perceive objects as complete rather than focusing on the gaps that the object might contain.<ref>{{Cite book|title=The Psychology of Perception|last=Hamlyn|first=D. W.|date=27 March 2017|isbn=9781315473291|doi=10.4324/9781315473291}}</ref> For example, a circle has good Gestalt in terms of completeness. However, we will also perceive an incomplete circle as a complete circle.<ref name="Brennan">{{Cite book |last1=Brennan |first1=James F. |title=History and Systems of Psychology |last2=Houde |first2=Keith A. |date=26 October 2017 |publisher=Cambridge University Press |isbn=9781107178670 |doi=10.1017/9781316827178 |s2cid=142935847}}</ref> That tendency to complete shapes and figures is called closure.<ref name="Brennan" /> The law of closure states that individuals perceive objects such as shapes, letters, pictures, etc., as being whole when they are not complete. Specifically, when parts of a whole picture are missing, our perception fills in the visual gap. Research shows that the reason the mind completes a regular figure that is not perceived through sensation is to increase the regularity of surrounding stimuli. For example, the figure that depicts the law of closure portrays what we perceive as a circle on the left side of the image and a rectangle on the right side of the image. However, gaps are present in the shapes. If the law of closure did not exist, the image would depict an assortment of different lines with different lengths, rotations, and curvatures—but with the law of closure, we perceptually combine the lines into whole shapes.<ref name="stevenson" /><ref name="Soegaard" /><ref>{{Cite web|url=https://www.gizmodo.co.uk/2013/05/why-your-brain-thinks-these-dots-are-a-dog/|title=Why Your Brain Thinks These Dots Are a Dog|website=Gizmodo UK|date=17 May 2013 |language=en|access-date=23 March 2018|archive-date=24 September 2015|archive-url=https://web.archive.org/web/20150924022412/https://www.gizmodo.co.uk/2013/05/why-your-brain-thinks-these-dots-are-a-dog/|url-status=live}}</ref> This law can be used effectively in logo design to create interest. For example, the IBM logo, consisting of horizontal blue lines is immediately perceived as a single object.

====Law of symmetry====
[[Image:Law of Symmetry.jpg|right|thumb|Law of symmetry]]
The law of symmetry states that the mind perceives objects as being symmetrical and forming around a center point. It is perceptually pleasing to divide objects into an even number of symmetrical parts. Therefore, when two symmetrical elements are unconnected the mind perceptually connects them to form a coherent shape. Similarities between symmetrical objects increase the likelihood that objects are grouped to form a combined symmetrical object. For example, the figure depicting the law of symmetry shows a configuration of square and curled brackets. When the image is perceived, we tend to observe three pairs of symmetrical brackets rather than six individual brackets.<ref name="stevenson" /><ref name="Soegaard" />

====Law of common fate====
The law of common fate states that objects are perceived as lines that move along the smoothest path. Experiments using the visual sensory modality found that the movement of elements of an object produces paths that individuals perceive that the objects are on. We perceive elements of objects to have trends of motion, which indicate the path that the object is on. The law of continuity implies the grouping together of objects that have the same trend of motion and are therefore on the same path. For example, if there is an array of dots and half the dots are moving upward while the other half are moving downward, we would perceive the upward moving dots and the downward moving dots as two distinct units.<ref name="todorvic">{{cite journal|last=Todorovic|first=Dejan|title=Gestalt Principles|volume=3|issue=12|pages=5345|journal=[[Scholarpedia]]|doi=10.4249/scholarpedia.5345|year=2008|bibcode=2008SchpJ...3.5345T|doi-access=free}}</ref>

====Law of continuity====
[[File:CrossKeys.png|thumb|upright|Law of continuity]]
The law of continuity (also known as the law of good continuation) states that elements of objects tend to be grouped together, and therefore integrated into perceptual wholes if they are aligned within an object. In cases where there is an intersection between objects, individuals tend to perceive the two objects as two single uninterrupted entities. Stimuli remain distinct even with overlap. We are less likely to group elements with sharp abrupt directional changes as being one object. For example, the figure depicting the law of continuity shows a configuration of two crossed keys. When the image is perceived, we tend to perceive the key in the background as a single uninterrupted key instead of two separate halves of a key.<ref name="stevenson" />

====Law of past experience====
The law of past experience implies that under some circumstances visual stimuli are categorized according to past experience. If objects tend to be observed within close proximity, or small temporal intervals, the objects are more likely to be perceived together. For example, the English language contains 26 letters that are grouped to form words using a set of rules. If an individual reads an English word they have never seen, they use the law of past experience to interpret the letters "L" and "I" as two letters beside each other, rather than using the law of closure to combine the letters and interpret the object as an uppercase U.<ref name="todorvic" />

====Music====
An example of the Gestalt movement in effect, as it is both a process and result, is a music sequence. People are able to recognise a sequence of perhaps six or seven notes, despite them being transposed into a different tuning or key.<ref>{{cite book|title=A source book of Gestalt psychology|last1=Ellis|first1=Willis D.|date=1999|publisher=Psychology Press|volume=2}}</ref> An early theory of gestalt grouping principles in music was composer-theorist [[James Tenney]]'s ''Meta+Hodos'' (1961).<ref>Tenney, James. (1961) 2015. “Meta+Hodos.” ''In [https://www.press.uillinois.edu/books/?id=p084379 From Scratch: Writings in Music Theory]''. Edited by Larry Polansky, Lauren Pratt, Robert Wannamaker, and Michael Winter. Urbana: University of Illinois Press. 13–96.</ref> [[Auditory scene analysis]] as developed by [[Albert Bregman]] further extends a gestalt approach to the analysis of sound perception.