Pattern recognition involves identification of faces, objects, words, melodies, etc. The visual system does more than just interpret forms, contours and colors. Pattern recognition refers to the process of recognizing a set of stimuli

Stimulus (psychology)

In psychology, stimuli are energy patterns which are registered by the senses. In behaviorism and related stimulus–response theories, stimuli constitute the basis for behavior, whereas in perceptual psychology they constitute the basis for perception.In the second half of the 19th century, the...

 arranged in a certain pattern that is characteristic of that set of stimuli. Pattern recognition does not occur instantly, although it does happen automatically and spontaneously. Pattern recognition is an innate ability of animals.

Theories of pattern recognition

• Template matching
• Prototype matching
• Feature analysis
• Recognition by components
  Recognition by Components Theory
  The Recognition-by-components theory, or RBC theory, is a bottom-up process proposed by Irving Biederman to explain object recognition. According to RBC theory, we are able to recognize objects by separating them into geons...
  
  
• Fourier analysis
• Bottom-up and top-down processing
  Top-down and bottom-up design
  Top–down and bottom–up are strategies of information processing and knowledge ordering, mostly involving software, but also other humanistic and scientific theories . In practice, they can be seen as a style of thinking and teaching...
  
  

Template matching

The incoming sensory information is compared directly to copies (templates) stored in the long term memory. These copies are stored in the process of our past experiences and learning.

E.g. A A A are all recognized as the letter A but not B.

Note: This does not allow for variation in letters unless there are templates for each variation.

Prototype matching

Prototype means a concept of average characteristics of a particular subject. It can be found throughout the world. For instance a concept of small animal with feathers, beak, two wings that can fly is a prototype concept of a crow, sparrow, hen, eagle, etc. Prototype matching, unlike template matching, does not emphasize a perfect match between the incoming stimuli and the stored concept in the brain.

Feature analysis

According to this theory, the sensory system

Sensory system

A sensory system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing, somatic...

 breaks down the incoming stimuli into its features and processes the information. Some features may be more important for recognition than others. All stimuli have a set of distinctive features.
Feature analysis proceeds through 4 stages.

1. Detection
2. Pattern dissection
3. Feature comparison in memory
4. Recognition

Recognition of components

Irving Biederman

Irving Biederman

Irving Biederman is an American vision scientist specializing in the study of brain processes underlying humans' ability to quickly recognize and interpret what they see. He has a Ph.D...

 theorizes that every object is made up of geons

Geon (psychology)

Geons are the simple 2D or 3D forms such as cylinders, bricks, wedges, cones, circles and rectangles corresponding to the simple parts of an object in Biederman's theory of object recognition. The theory proposes that the visual input is matched against structural representations of objects in the...

—the building blocks of all objects (cylinders, cones, are combined in many ways: on top of, to the side, etc.).

Top down and bottom up processing

1. Top down processing can be seen as processing what one is perceiving using past information.It occurs when someone infers from a generalization,law etc. to conclude something about a particular example, instance, case etc.
2. Bottom up processing can be seen as starting with no knowledge on a subject.It is said to occur when one draws generalizations from particular examples, instances, cases etc. to capture commonalities between them.

Hierarchy of detectors:

1. Feature detectors — lowest and highest; respond to curves, edges, etc.
2. Geon detectors — activated by feature detectors
3. Higher level detectors — recognize combinations of features and geons

According to Biederman an individual on average is familiar with about 30,000 objects and recognizing them requires no more than 36 geons.

Multiple discrimination scaling

Template and feature analysis approaches to recognition of objects (and situations) have been merged / reconciled / overtaken by multiple discrimination theory. This states that the amounts in a test stimulus of each salient feature of a template are recognized in any perceptual judgment as being at a distance in the universal unit of 50% discrimination (the objective performance 'JND': Torgerson, 1958) from the amount of that feature in the template (Booth & Freeman, 1993, Acta Psychologica).

False pattern recognition

The human tendency to see patterns that do not actually exist is called apophenia

Apophenia

Apophenia is the experience of seeing meaningful patterns or connections in random or meaningless data.The term was coined in 1958 by Klaus Conrad, who defined it as the "unmotivated seeing of connections" accompanied by a "specific experience of an abnormal meaningfulness", but it has come to...

. Examples of apophenia include the Man in the Moon, faces or figures in shadows, clouds and in patterns with no deliberate design, such as the swirls on a baked confection, and the perception of causal relationships between events

Synchronicity

Synchronicity is the experience of two or more events that are apparently causally unrelated or unlikely to occur together by chance and that are observed to occur together in a meaningful manner...

 which are, in fact, unrelated. Apophenia figures prominently in conspiracy theories, gambling

Gambling

Gambling is the wagering of money or something of material value on an event with an uncertain outcome with the primary intent of winning additional money and/or material goods...

, misinterpretation of statistics

Statistics

Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....

 and scientific data, and some kinds of religious

Religion

Religion is a collection of cultural systems, belief systems, and worldviews that establishes symbols that relate humanity to spirituality and, sometimes, to moral values. Many religions have narratives, symbols, traditions and sacred histories that are intended to give meaning to life or to...

 and paranormal

Paranormal

Paranormal is a general term that designates experiences that lie outside "the range of normal experience or scientific explanation" or that indicates phenomena understood to be outside of science's current ability to explain or measure...

 experiences. Misperception of patterns in random data is called pareidolia

Pareidolia

Pareidolia is a psychological phenomenon involving a vague and random stimulus being perceived as significant. Common examples include seeing images of animals or faces in clouds, the man in the moon or the Moon rabbit, and hearing hidden messages on records played in reverse...

.

See also

• Gestalt psychology
  Gestalt psychology
  Gestalt psychology or gestaltism is a theory of mind and brain of the Berlin School; the operational principle of gestalt psychology is that the brain is holistic, parallel, and analog, with self-organizing tendencies...
  
  
• Apophenia
  Apophenia
  Apophenia is the experience of seeing meaningful patterns or connections in random or meaningless data.The term was coined in 1958 by Klaus Conrad, who defined it as the "unmotivated seeing of connections" accompanied by a "specific experience of an abnormal meaningfulness", but it has come to...
  
  
• Pareidolia
  Pareidolia
  Pareidolia is a psychological phenomenon involving a vague and random stimulus being perceived as significant. Common examples include seeing images of animals or faces in clouds, the man in the moon or the Moon rabbit, and hearing hidden messages on records played in reverse...
  
  
• The Gambler's Fallacy
  Gambler's fallacy
  The Gambler's fallacy, also known as the Monte Carlo fallacy , and also referred to as the fallacy of the maturity of chances, is the belief that if deviations from expected behaviour are observed in repeated independent trials of some random process, future deviations in the opposite direction are...