Editing Cognition (section)

== Psychology ==
[[File:Generalization process using trees.svg|thumb|alt=Diagram|When the mind makes a generalization such as the [[concept]] of ''tree'', it extracts similarities from numerous examples; the simplification enables higher-level thinking (abstract thinking).]]{{See also|Cognitivism (psychology)}}
In [[psychology]], the term "cognition" is usually used within an [[Information processing (psychology)|information processing]] view of an individual's psychological [[functionalism (philosophy of mind)|functions]],<ref name="Sternberg2009">{{cite book | vauthors = Sternberg RJ, Sternberg K | date = 2009 | title = Cognitive Psychology | edition = 6th | location = Belmont, CA | publisher = [[Cengage|Wadsworth Cengage]] Learning }}{{ISBN?}}</ref> and such is the same in [[cognitive engineering]].<ref name="Blomberg">{{cite journal| vauthors = Blomberg O |year = 2011|title = Concepts of cognition for cognitive engineering|journal = [[International Journal of Aviation Psychology]]|volume = 21|issue = 1|pages = 85–104|doi = 10.1080/10508414.2011.537561|s2cid = 144876967}}</ref> In the study of [[social cognition]], a branch of [[social psychology]], the term is used to explain [[Attitude (psychology)|attitudes]], [[Attribution (psychology)|attribution]], and [[group dynamics]].<ref name="Sternberg2009" /> However, psychological research within the field of cognitive science has also suggested an embodied approach to understanding cognition. Contrary to the traditional computationalist approach, [[embodied cognition]] emphasizes the body's significant role in the acquisition and development of cognitive capabilities.<ref name="calvo_gomila_2008">{{Cite book |title=Handbook of cognitive science: an embodied approach |publisher=Elsevier Science |editor=Paco Calvo |editor2=Antoni Gomila |date=2008 |isbn=978-0-08-091487-9 |location=Amsterdam |oclc=318353781}}</ref><ref>{{Cite journal |last=Lakoff |first=George |date=2012 |title=Explaining Embodied Cognition Results |journal=Topics in Cognitive Science |volume=4 |issue=4 |pages=773–785 |doi=10.1111/j.1756-8765.2012.01222.x |pmid=22961950 |s2cid=18978114 |issn=1756-8757|doi-access=free }}</ref>

Human cognition is conscious and [[Unconscious cognition|unconscious]], [[Tangibility|concrete]] or [[Abstraction|abstract]], as well as [[Intuition|intuitive]] (like knowledge of a language) and [[Conceptualism|conceptual]] (like a model of a language). It encompasses processes such as [[memory]], [[Association of Ideas|association]], [[concept formation]], [[pattern recognition]], [[language]], [[attention]], [[perception]], [[action (philosophy)|action]], [[problem solving]], and [[mental image]]ry.<ref>[[Stanley Coren|Coren, Stanley]], [[Lawrence M. Ward]], and James T. Enns. 1999. ''Sensation and Perception'' (5th ed.)''.'' [[Harcourt (publisher)|Harcourt Brace]]. {{ISBN|978-0-470-00226-1}}. p. 9.</ref><ref>{{cite book | vauthors = Best JB | date = 1999 | title = Cognitive Psychology | edition = 5th | pages = 15–17 }}{{ISBN?}}</ref> Traditionally, [[emotion]] was not thought of as a cognitive process, but now much research is being undertaken to examine the [[cognitive psychology]] of emotion; research is also focused on one's awareness of one's own strategies and methods of cognition, which is called [[metacognition]]. The concept of cognition has gone through several revisions through the development of disciplines within psychology.{{citation needed|date=August 2024}}

Psychologists initially understood cognition governing human action as information processing. This was a movement known as cognitivism in the 1950s, emerging after the Behaviorist movement viewed cognition as a form of behavior.<ref>{{cite book |last1=Pyszczynski |first1=Tom |last2=Greenberg |first2=Jeff |last3=Koole |first3=Sander |last4=Solomon |first4=Sheldon |article=Experimental Existential Psychology: Coping With the Facts of Life |year=2010|title=Handbook of Social Psychology |pages=socpsy001020 |editor-last=Fiske |editor-first=Susan T. |editor2-last=Gilbert |editor2-first=Daniel T. |editor3-last=Lindzey |editor3-first=Gardner |location=Hoboken, NJ |publisher=John Wiley & Sons |language=en |doi=10.1002/9780470561119.socpsy001020 |isbn=978-0-470-56111-9}}</ref> Cognitivism approached cognition as a form of computation, viewing the mind as a machine and consciousness as an executive function.<ref name="calvo_gomila_2008" /> However; post cognitivism began to emerge in the 1990s as the development of cognitive science presented theories that highlighted the necessity of cognitive action as embodied, extended, and producing dynamic processes in the mind.<ref>{{Cite book |date=2007 |editor-last=Zelazo |editor-first=Philip David |editor2-last=Moscovitch |editor2-first=Morris |editor3-last=Thompson |editor3-first=Evan |title=The Cambridge Handbook of Consciousness |doi=10.1017/cbo9780511816789|isbn=9780511816789 }}</ref> The development of Cognitive psychology arose as psychology from different theories, and so began exploring these dynamics concerning mind and environment, starting a movement from these prior dualist paradigms that prioritized cognition as systematic computation or exclusively behavior.<ref  name="calvo_gomila_2008" />

=== Piaget's theory of cognitive development ===
{{Main|Piaget's theory of cognitive development}}
For years, [[List of sociologists|sociologists]] and [[psychologist]]s have conducted studies on [[cognitive development]], i.e. the construction of human thought or mental processes.{{citation needed|date=August 2024}}

[[Jean Piaget]] was one of the most important and influential people in the field of [[developmental psychology]]. He believed that humans are unique in comparison to animals because we have the capacity to do "abstract symbolic reasoning". His work can be compared to [[Lev Vygotsky]], [[Sigmund Freud]], and [[Erik Erikson]] who were also great contributors in the field of developmental psychology. Piaget is known for studying the cognitive development in children, having studied his own three children and their intellectual development, from which he would come to a [[Piaget's theory of cognitive development|theory of cognitive development]] that describes the developmental stages of childhood.<ref>{{cite web|last=Cherry|first=Kendra|name-list-style=vanc|title=Jean Piaget Biography|url=http://psychology.about.com/od/profilesofmajorthinkers/p/piaget.htm|publisher=The New York Times Company|access-date=18 September 2012|archive-date=19 April 2016|archive-url=https://web.archive.org/web/20160419045331/http://psychology.about.com/od/profilesofmajorthinkers/p/piaget.htm|url-status=dead}}</ref>

{| class="wikitable"
|-
! Stage !! Age or Period !! Description<ref>{{cite book | vauthors = Parke RD, Gauvain M | date = 2009 | title = Child Psychology: A Contemporary Viewpoint | edition = 7th | location = Boston | publisher = [[McGraw-Hill Education|McGraw-Hill]] }}{{ISBN?}}</ref>
|-
| Sensorimotor stage ||[[Infant|Infancy]] (0–2 years) || Intelligence is present; motor activity but no symbols; knowledge is developing yet limited; knowledge is based on experiences/ interactions; mobility allows the child to learn new things; some language skills are developed at the end of this stage. The goal is to develop [[object permanence]], achieving a basic understanding of [[causality]], time, and space.
|-
| Preoperational stage ||[[Toddler]] and [[Early childhood|Early Childhood]] (2–7 years) || Symbols or language skills are present; memory and imagination are developed; non-reversible and non-logical thinking; shows intuitive [[problem solving]]; begins to perceive relationships; grasps the concept of conservation of numbers; predominantly [[Egocentrism|egocentric]] thinking.
|-
| Concrete operational stage || Elementary and Early [[Adolescence]] (7–12 years) || Logical and systematic form of intelligence; manipulation of symbols related to [[Physical object|concrete objects]]; thinking is now characterized by reversibility and the ability to take the role of another; grasps concepts of the [[conservation of mass]], length, weight, and volume; predominantly operational thinking; nonreversible and egocentric thinking
|-
| Formal operational stage || Adolescence and [[Adult]]hood (12 years and on) || Logical use of symbols related to abstract concepts; Acquires flexibility in thinking as well as the capacities for abstract thinking and mental hypothesis testing; can consider possible alternatives in complex reasoning and problem-solving.
|}

=== Beginning of cognition ===
Studies on cognitive development have also been conducted in children beginning from the embryonal period to understand when cognition appears and what environmental attributes stimulate the construction of human thought or mental processes. Research shows the intentional engagement of fetuses with the environment, demonstrating cognitive achievements.<ref name="ValDanilov_SI_Modulation 2023">{{Cite journal |last=Val Danilov |first=Igor |date= 2023|title=Shared Intentionality Modulation at the Cell Level: Low-Frequency Oscillations for Temporal Coordination in Bioengineering Systems |url=https://www.lidsen.com/journals/neurobiology/neurobiology-07-04-185 |journal=OBM Neurobiology |language=en |volume=7 |issue=4 |pages=1–17 |doi=10.21926/obm.neurobiol.2304185|s2cid=263722179 |doi-access=free }}</ref> However, organisms with simple reflexes cannot cognize the environment alone because the environment is the cacophony of stimuli (electromagnetic waves, chemical interactions, and pressure fluctuations).<ref>{{cite book | chapter-url=https://link.springer.com/chapter/10.1007/978-3-031-10467-1_19 | doi=10.1007/978-3-031-10467-1_19 | chapter=Smartphone in Detecting Developmental Disability in Infancy: A Theoretical Approach to Shared Intentionality for Assessment Tool of Cognitive Decline and e-Learning | title=Intelligent Computing | series=Lecture Notes in Networks and Systems | date=2022 | last1=Val Danilov | first1=Igor | volume=508 | pages=305–315 | isbn=978-3-031-10466-4 }}</ref> Their sensation is too limited by the noise to solve the cue problem–the relevant stimulus cannot overcome the noise magnitude if it passes through the senses (see the [[binding problem]]). Fetuses need external help to stimulate their nervous system in choosing the relevant sensory stimulus for grasping the perception of objects.<ref name="ValDanilov_Perspective 2022">{{Cite journal |last1=Val Danilov |first1=Igor |last2=Mihailova |first2=Sandra |date= 2022|title=A New Perspective on Assessing Cognition in Children through Estimating Shared Intentionality |journal=Journal of Intelligence |language=en |volume=10 |issue=2 |page=21 |doi=10.3390/jintelligence10020021 |issn=2079-3200 |pmc=9036231 |pmid=35466234 |doi-access=free }}</ref> The [[Shared intentionality]] approach proposes a plausible explanation of perception development in this earlier stage. Initially, Michael Tomasello introduced the [[psychological construct]] of [[Shared intentionality]], highlighting its contribution to cognitive development from birth.<ref>{{cite book|last=Tomasello|first=Michael|title=Becoming Human: A Theory of Ontogeny|location=Cambridge, Massachusetts|publisher=[[Harvard University Press]]|year=2019|isbn=9780674988651}}{{page needed|date=August 2024}}</ref> This primary interaction provides unaware collaboration in mother-child dyads for environmental learning. Later, Igor Val Danilov developed this notion, expanding it to the intrauterine period and clarifying the [[Neurophysiology|neurophysiological]] processes underlying [[Shared intentionality]].<ref name="ValDanilov_Theoretical 2023">Val Danilov I. (2023). "Theoretical Grounds of Shared Intentionality for Neuroscience in Developing Bioengineering Systems". ''OBM Neurobiology'' 2023; 7(1): 156; {{doi|10.21926/obm.neurobiol.2301156}}</ref> According to the [[Shared intentionality]] approach, the mother shares the essential sensory stimulus of the actual cognitive problem with the child.<ref>Val Danilov Igor, Mihailova Sandra. (2021). "Neuronal Coherence Agent for Shared Intentionality: A Hypothesis of Neurobiological Processes Occurring during Social Interaction". ''OBM Neurobiology'' 2021;5(4):26; {{doi|10.21926/obm.neurobiol.2104113}}.</ref> By sharing this stimulus, the mother provides a template for developing the young organism's nervous system.<ref name="ValDanilov_LF 2023">{{Cite journal |last=Val Danilov |first=Igor |date= 2023|title=Low-Frequency Oscillations for Nonlocal Neuronal Coupling in Shared Intentionality Before and After Birth: Toward the Origin of Perception |url=https://www.lidsen.com/journals/neurobiology/neurobiology-07-04-192 |journal=OBM Neurobiology |language=en |volume=7 |issue=4 |pages=1–17 |doi=10.21926/obm.neurobiol.2304192|s2cid=265002516 |doi-access=free }}</ref>

Recent findings in research on child cognitive development <ref name="ValDanilov_Perspective 2022" /><ref name="ValDanilov_Theoretical 2023" /><ref>Castiello, U.; Becchio, C.; Zoia, S.; Nelini, C.; Sartori, L.; Blason, L.; D'Ottavio, G.; Bulgheroni, M.; Gallese, V. (2010). "Wired to be social: the ontogeny of human interaction." ''PloS one,'' 5(10), p .e13199.</ref><ref>Kisilevsky, B.C. (2016). "Fetal Auditory Processing: Implications for Language Development? Fetal Development." ''Research on Brain and Behavior, Environmental In uences, and Emerging Technologies,'': 133–152.</ref><ref>Lee, G.Y.C.; Kisilevsky, B.S. (2014). "Fetuses respond to father's voice but prefer mother's voice after birth." ''Developmental Psychobiology,'' 56: 1–11.</ref><ref>Hepper, P.G.; Scott, D.; Shahidullah, S. (1993). "Newborn and fetal response to maternal voice." ''Journal of Reproductive and Infant Psychology,'' 11: 147–153.</ref><ref>Lecanuet, J.P.; Granier‐Deferre, C.; Jacquet, A.Y.; Capponi, I.; Ledru, L. (1993). "Prenatal discrimination of a male and a female voice uttering the same sentence." ''Early development and parenting,'' 2(4): 217–228.</ref><ref>Hepper P. (2015). "Behavior during the prenatal period: Adaptive for development and survival." ''Child Development Perspectives,'' 9(1): 38–43. {{doi|10.1111/cdep.12104}}.</ref><ref>Jardri, R.; Houfflin-Debarge, V.; Delion, P.; Pruvo, J-P.; Thomas, P.; Pins, D. (2012). "Assessing fetal response to maternal speech using a noninvasive functional brain imaging technique." ''International Journal of Developmental Neuroscience,'' 2012, 30: 159–161. {{doi|10.1016/j.ijdevneu.2011.11.002}}.</ref>{{excessive citations inline|date=March 2025}} and advances in inter-brain neuroscience experiments<ref name="pmid37563301">{{cite journal | vauthors = Liu J, Zhang R, Xie E, Lin Y, Chen D, Liu Y, Li K, Chen M, Li Y, Wang G, Li X | display-authors = 6 | title = Shared intentionality modulates interpersonal neural synchronization at the establishment of communication system | journal = Communications Biology | volume = 6 | issue = 1 | page = 832 | date = August 2023 | pmid = 37563301 | pmc = 10415255 | doi = 10.1038/s42003-023-05197-z }}</ref><ref name="pmid34188170">{{cite journal | vauthors = Painter DR, Kim JJ, Renton AI, Mattingley JB | title = Joint control of visually guided actions involves concordant increases in behavioural and neural coupling | journal = Communications Biology | volume = 4 | issue = 1 | page = 816 | date = June 2021 | pmid = 34188170 | pmc = 8242020 | doi = 10.1038/s42003-021-02319-3 }}</ref><ref name="pmid29292232">{{cite journal | vauthors = Hu Y, Pan Y, Shi X, Cai Q, Li X, Cheng X | title = Inter-brain synchrony and cooperation context in interactive decision making | journal = Biological Psychology | volume = 133 | issue =  | pages = 54–62 | date = March 2018 | pmid = 29292232 | doi = 10.1016/j.biopsycho.2017.12.005 | s2cid = 46859640 }}</ref><ref name="pmid30060130">{{cite journal | vauthors = Fishburn FA, Murty VP, Hlutkowsky CO, MacGillivray CE, Bemis LM, Murphy ME, Huppert TJ, Perlman SB | display-authors = 6 | title = Putting our heads together: interpersonal neural synchronization as a biological mechanism for shared intentionality | journal = Social Cognitive and Affective Neuroscience | volume = 13 | issue = 8 | pages = 841–849 | date = September 2018 | pmid = 30060130 | pmc = 6123517 | doi = 10.1093/scan/nsy060 }}</ref><ref name="pmid28284802">{{cite journal | vauthors = Szymanski C, Pesquita A, Brennan AA, Perdikis D, Enns JT, Brick TR, Müller V, Lindenberger U | display-authors = 6 | title = Teams on the same wavelength perform better: Inter-brain phase synchronization constitutes a neural substrate for social facilitation | journal = NeuroImage | volume = 152 | issue =  | pages = 425–436 | date = May 2017 | pmid = 28284802 | doi = 10.1016/j.neuroimage.2017.03.013 | hdl = 11858/00-001M-0000-002D-059A-1 | s2cid = 3807834 | hdl-access = free }}</ref> have made the above proposition plausible. Based on them, the [[shared intentionality|shared intentionality hypothesis]] introduced the notion of pre-perceptual communication in the mother-fetus communication model due to nonlocal neuronal coupling.<ref name="ValDanilov_SI_Modulation 2023" /><ref name="ValDanilov_Theoretical 2023" /><ref name="ValDanilov_LF 2023" /> This nonlocal coupling model refers to communication between two organisms through the copying of the adequate ecological dynamics by biological systems indwelling one environmental context, where a naive actor (Fetus) replicates information from an experienced actor (Mother) due to intrinsic processes of these [[Dynamical systems theory|dynamic systems]] ([[Embodied cognition|embodied information]]) but without interacting through sensory signals.<ref name="ValDanilov_SI_Modulation 2023" /><ref name="ValDanilov_Theoretical 2023" /><ref name="ValDanilov_LF 2023" /> The Mother's heartbeats (a low-frequency oscillator) modulate relevant local neuronal networks in specific subsystems of both her and the nervous system of the fetus due to the effect of the [[Wave interference|interference]] of the low-frequency oscillator (Mother heartbeats) and already exhibited gamma activity in these neuronal networks (interference in physics is the combination of two or more electromagnetic waveforms to form a resultant wave).<ref name="ValDanilov_SI_Modulation 2023" /><ref name="ValDanilov_Theoretical 2023" /><ref name="ValDanilov_LF 2023" /> Therefore, the subliminal perception in a fetus emerges due to [[Shared intentionality]] with the mother that stimulates cognition in this organism even before birth.<ref name="ValDanilov_SI_Modulation 2023" /><ref name="ValDanilov_Theoretical 2023" /><ref name="ValDanilov_LF 2023" />

Further, cognition and emotions develop with the association of affective cues with stimuli responsible for triggering the neuronal pathways of simple reflexes.<ref name="Reflexes Cognition">{{cite journal |last1=Danilov |first1=Igor Val |last2=Mihailova |first2=Sandra |title=Reflexes and Shared Intentionality in the Origins of Emotions Development: A Scoping Review of Studies on Blinking in Infants |journal=OBM Neurobiology |date=January 2025 |volume=9 |issue=1 |pages=1–21 |doi=10.21926/obm.neurobiol.2501263 |url=https://www.lidsen.com/journals/neurobiology/neurobiology-09-01-263 |language=en |issn=2573-4407|doi-access=free }}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}</ref> This pre-perceptual multimodal integration can succeed owing to neuronal coherence in mother-child dyads beginning from pregnancy.<ref name="Reflexes Cognition" /> According to the pre-perceptual multimodal integration hypothesis based on empirical evidence, these cognitive-reflex and emotion-reflex stimuli conjunctions further form simple innate neuronal assemblies, shaping the cognitive and emotional neuronal patterns in statistical learning that are continuously connected with the neuronal pathways of reflexes.<ref name="Reflexes Cognition" />

Another crucial question in understanding the beginning of cognition is memory storage about the relevant ecological dynamics by the naive nervous system (i.e., memorizing the ecological condition of relevant sensory stimulus) at the molecular level – an [[Engram (neuropsychology)|engram]]. Evidence derived using [[optical imaging]], [[Molecular genetics|molecular-genetic]] and [[Optogenetics|optogenetic]] techniques in conjunction with appropriate behavioural analyses continues to offer support for the idea that changing the strength of connections between neurons is one of the major mechanisms by which engrams are stored in the brain.<ref>Takeuchi, T; Duszkiewicz, A.J.; Morris, R.G. (2013). "The synaptic plasticity and memory hypothesis: encoding, storage and persistence." ''Philos Trans R Soc Lond B Biol Sci.'' 2013 Dec 2;369(1633):20130288. {{doi|10.1098/rstb.2013.0288}}. {{PMID|24298167}}; {{PMCID|PMC3843897}}.</ref>

Two (or more) possible mechanisms of cognition can involve both quantum effects<ref>Kerskens, C. M.; Pérez, D. L. (2022). "Experimental indications of non-classical brain functions." ''Journal of Physics Communications,'' 6(10), 105001. {{doi|10.1088/2399-6528/ac94be}}</ref> and synchronization of brain structures due to electromagnetic interference.<ref>Hanslmayr, S.; Axmacher, N.; Inman, C. S. (2019). "Modulating human memory via entrainment of brain oscillations." ''Trends in neurosciences,'' 42(7), 485–499. {{doi|10.1016/j.tins.2019.04.004}}</ref><ref name="ValDanilov_SI_Modulation 2023" /><ref name="ValDanilov_Theoretical 2023" /><ref name="ValDanilov_LF 2023" />

=== Common types of tests on human cognition ===
====Serial position====
The ''[[Serial-position effect]]'' is meant to test a theory of memory that states that when information is given in a serial manner, we tend to remember information at the beginning of the sequence, called the ''primacy effect'', and information at the end of the sequence, called the ''recency effect''. Consequently, information given in the middle of the sequence is typically forgotten, or not recalled as easily. This study predicts that the recency effect is stronger than the primacy effect, because the information that is most recently learned is still in working memory when asked to be recalled. Information that is learned first still has to go through a retrieval process. This experiment focuses on human memory processes.<ref>{{cite journal | vauthors = Surprenant AM | title = Distinctiveness and serial position effects in tonal sequences | journal = Perception & Psychophysics | volume = 63 | issue = 4 | pages = 737–745 | date = May 2001 | pmid = 11436742 | doi = 10.3758/BF03194434 | doi-access = free }}</ref>

====Word superiority====
The ''[[word superiority effect]] experiment'' presents a subject with a word, or a letter by itself, for a brief period of time, i.e. 40&nbsp;ms, and they are then asked to recall the letter that was in a particular location in the word. In theory, the subject should be better able to correctly recall the letter when it was presented in a word than when it was presented in isolation. This experiment focuses on human speech and language.<ref>{{cite journal | vauthors = Krueger LE | title = The word-superiority effect and phonological recoding | journal = Memory & Cognition | volume = 20 | issue = 6 | pages = 685–694 | date = November 1992 | pmid = 1435271 | doi = 10.3758/BF03202718 | doi-access = free }}</ref>

====Brown–Peterson====
In the ''[[Brown–Peterson cohomology]] experiment'', participants are briefly presented with a [[trigram]] and in one particular version of the experiment, they are then given a distractor task, asking them to identify whether a sequence of words is in fact words, or non-words (due to being misspelled, etc.). After the distractor task, they are asked to recall the trigram from before the distractor task. In theory, the longer the distractor task, the harder it will be for participants to correctly recall the trigram. This experiment focuses on human [[short-term memory]].<ref>{{cite journal |vauthors=Nairne J, Whiteman H, Kelley M |title=Short-term forgetting of order under conditions of reduced interference |journal=Quarterly Journal of Experimental Psychology A |year=1999 |volume=52 |pages=241–251 |doi=10.1080/713755806 |s2cid=15713857 |url=http://www1.psych.purdue.edu/~nairne/pdfs/32.pdf |access-date=2018-01-09 |archive-date=2022-07-30 |archive-url=https://web.archive.org/web/20220730173204/http://www1.psych.purdue.edu/~nairne/pdfs/32.pdf |url-status=dead }}</ref>

====Memory span====
During the ''[[memory span]] experiment'', each subject is presented with a sequence of [[Stimulus (physiology)|stimuli]] of the same kind; words depicting objects, numbers, letters that sound similar, and letters that sound dissimilar. After being presented with the stimuli, the subject is asked to recall the sequence of stimuli that they were given in the exact order in which it was given. In one particular version of the experiment, if the subject recalled a list correctly, the list length was increased by one for that type of material, and vice versa if it was recalled incorrectly. The theory is that people have a memory span of about seven items for numbers, the same for letters that sound dissimilar and short words. The memory span is projected to be shorter with letters that sound similar and with longer words.<ref>{{cite journal | vauthors = May CP, Hasher L, Kane MJ | title = The role of interference in memory span | journal = Memory & Cognition | volume = 27 | issue = 5 | pages = 759–767 | date = September 1999 | pmid = 10540805 | doi = 10.3758/BF03198529 | doi-access = free }}</ref>

====Visual search====
In one version of the ''[[visual search]] experiment'', a participant is presented with a window that displays circles and squares scattered across it. The participant is to identify whether there is a green circle on the window. In the ''featured'' search, the subject is presented with several trial windows that have blue squares or circles and one green circle or no green circle in it at all. In the ''[[Conjunctive tasks|conjunctive]]'' search, the subject is presented with trial windows that have blue circles or green squares and a present or absent green circle whose presence the participant is asked to identify. What is expected is that in the feature searches, reaction time, that is the time it takes for a participant to identify whether a green circle is present or not, should not change as the number of distractors increases. Conjunctive searches where the target is absent should have a longer reaction time than the conjunctive searches where the target is present. The theory is that in feature searches, it is easy to spot the target, or if it is absent, because of the difference in color between the target and the distractors. In conjunctive searches where the target is absent, reaction time increases because the subject has to look at each shape to determine whether it is the target or not because some of the distractors if not all of them, are the same color as the target stimuli. Conjunctive searches where the target is present take less time because if the target is found, the search between each shape stops.<ref>{{cite journal| vauthors = Wolfe J, Cave K, Franzel S |title=Guided search: An alternative to the feature integration model for visual search|journal=Journal of Experimental Psychology: Human Perception and Performance|year=1989|volume=15|pages=419–433|doi=10.1037/0096-1523.15.3.419 |issue=3 |pmid=2527952|citeseerx=10.1.1.551.1667 }}</ref>

====Knowledge representation====
The [[semantic network]] of [[Knowledge representation and reasoning|knowledge representation]] systems have been studied in various paradigms. One of the oldest paradigms is the [[leveling and sharpening]] of stories as they are repeated from memory studied by [[Frederic Bartlett|Bartlett]]. The [[semantic differential]] used [[factor analysis]] to determine the main meanings of words, finding that the [[ethical value]] of words is the first factor. More controlled experiments examine the categorical relationships of words in [[free recall]]. The hierarchical structure of words has been explicitly mapped in [[George Armitage Miller|George Miller]]'s [[WordNet]]. More dynamic models of semantic networks have been created and tested with computational systems such as [[neural network (machine learning)|neural networks]], [[latent semantic analysis]] (LSA), [[Bayesian analysis]], and multidimensional factor analysis. The meanings of words are studied by all the disciplines of [[cognitive science]].<ref>{{cite journal | vauthors = Pinker S, Bloom P | title = Natural language and natural selection. |date=December 1990 |journal=Behavioral and Brain Sciences |volume=13 |issue=4 |pages=707–727 |doi=10.1017/S0140525X00081061 | s2cid = 6167614 }}</ref>