Logogen model: Difference between revisions

Revision as of 00:19, 15 June 2009

Latest revision as of 10:21, 29 March 2023

(30 intermediate revisions by 22 users not shown)

Line 1:

{{orphanno footnotes|date=December 20072008}}

The '''logogen model''' of 1969 is a model of [[speech recognition]] that uses units called "logogens" to explain how humans comprehend spoken or written words. Logogens are a vast number of specialized recognition units, each able to recognize one specific word. This model provides for the effects of context on [[word recognition]].

== Overview ==

The word logogen can be traced back to the [[Greek language|Greek-language]] word ''[[logos]]'', which means "word", and ''[[genus]]'', which means "birth".

[[British people|British]] scientist [[John Morton (scientist)|John Morton]]'s logogen model was designed to explain word recognition using a new type of unit known as a logogen. A critical element of this theory is the involvement of [[lexicon]]s, or specialized aspects of memory that include [[semantic]] and [[phonemic]] information about each item that is contained in memory. A given lexicon consists of many smaller, abstract items known as logogens.

<!-- Deleted image removed: [[Image:Logogen.jpg|right|]] -->

[[John Morton (scientist)|Morton]]'s Logogen model was designed to explain [[word]] [[recognition]] using a new type of unit known as a "[[logogen]]." A critical element of this theory is the involvement of lexicons, or specialized aspects of memory that include semantic and phonemic information about each item that is contained in memory. A given [[lexicon]] consists of many smaller, abstract items known as logogens. The word logogen can be traced back to the Greek word ''logos'', which means "word", and ''genus'', which means "birth." Logogens contain a variety of properties about given word such as their appearance, sound, and meaning. It is important to note that logogensLogogens do not store words within themselves, but rather they store information that is specifically necessary for retrieval of whatever word is being searched for. A given logogen will become activated by [[Stimulus (psychology)|psychological stimuli]] or [[context (language use)|contextual]] information (words) that is consistent with the properties of that specific logogen and when the logogen's activation level rises to or above its threshold level, the [[pronunciation]] of the given word is sent to the output system. Certain stimuli can affect the activation levels of more than one word at a time, usually involving words that are similar to one another. When this occurs, whichever of the words' activation levels reaches the threshold level, it is that word that is then sent to the output system with the subject remaining unaware of any partially excited logogens. This assumption was made by Marslen-Wilson and Welch (1978), who added to the model some assumptions of their own in order to account for their experimental results. They also assumed that the analysis of phonetic input can only become available to other parts of the system by process of how the input affects the logogen system. Finally, Marslen-Wilson and Welch assume that the first [[syllable]] of a given word will increase the activation level of a given logogen more than those of the latter syllables, which supported the data found at the time.

Certain stimuli can affect the activation levels of more than one word at a time, usually involving words that are similar to one another. When this occurs, whichever of the words' activation levels reaches the threshold level, it is that word that is then sent to the output system with the subject remaining unaware of any partially excited logogens.

== Analysis ==

This assumption was made by [[Marslen-Wilson]] and Welch (1978), who added to the model some assumptions of their own in order to account for their experimental results. They also assumed that the analysis of phonetic input can only become available to other parts of the system by process of how the input affects the logogen system. Finally, Marslen-Wilson and Welch assume that the first [[syllable]] of a given word will increase the activation level of a given logogen more than those of the latter syllables, which supported the data found at the time.

The logogen model can be used to help linguists explain particular occurrences in the human language. The most helpful application of the model is to show how we access words and their meanings in our [[lexicon]]. The word-frequency effect is best explained by the logogen model in that words (or logogens) that have a higher frequency (or are more common) have a lower threshold. This means that they require less perceptual power in the brain to be recognized and decoded from the lexicon and are recognized faster than those words that are less common. Also, with high frequency words, the recovery from lowering the item's threshold is less fulfilled compared to low frequency words so less sensory information is needed for that particular items recognition. There are ways to lower thresholds, such as repetition and [[semantic]] [[priming]]. Also, each time a word is encountered through these methods, the threshold for that word is temporarily lowered partially because of its recovering ability. This model also conveys that specific concrete words are recalled better because they use images and logogens, whereas abstract words are not as easily recalled well because they only use logogens, hence showing the difference in thresholds between these two types of words.

Morton's logogen model at its time of inception was one of the most influential models in springing up other parallel word access models and served as the essential basis for

these models that followed after. Morton's model was also extremely influential on the other contemporary theories on lexical access.

However, despite the advantages that the logogen theory presents, it also displays some negative facets. First and foremost, the logogen model does not explain all occurrences in language, such as the introduction of new words or non-words into a persons lexicon. Also, because of the distinctive model application, it may vary in its effectiveness in different languages.

== CriticismsAnalysis ==

The logogen model can be used to help linguists explain particular occurrences in the human language. The most-helpful application of the model is to show how one accesses words and their meanings in the lexicon.

The logogen model can be used to help linguists explain particular occurrences in the human language. The most helpful application of the model is to show how we access words and their meanings in our [[lexicon]]. The word-frequency effect]] is best explained by the logogen model in that words (or logogens) that have a higher frequency (or are more common) have a lower threshold. This means that they require less perceptual power in the brain to be recognized and decoded from the lexicon and are recognized faster than those words that are less common. Also, with high -frequency words, the recovery from lowering the item's threshold is less fulfilled compared to low -frequency words so less sensory information is needed for that particular itemsitem's recognition. There are ways to lower thresholds, such as repetition and [[semantic]] [[priming]]. Also, each time a word is encountered through these methods, the threshold for that word is temporarily lowered partially because of its recovering ability. This model also conveys that specific concrete words are recalled better because they use images and logogens, whereas abstract words are not as easily recalled well because they only use logogens, hence showing the difference in thresholds between these two types of words.

While this model does a decent job in understanding the underlying semantics of many aspects in psycholinguistics, there are some flaws that have been pointed out in the logogen model. It has been argued that the prior stimulus patterns that have been seen in the logogen theory are not centrally localized in the logogen itself but are actually distributed throughout the different pathways over which the stimulus is being processed. What this directs at is that the notion and proliferation of logogens was due to modality. In essence the logogen is unnecessary in the idea of attaining the title of being a recognition unit because of the variety of pathways that it is open to, not just logogens. Another criticism has been that this model essentially ignores larger and more critical structures in language and phonetics such as the different syntactic rules or grammatical construction that innately exists in language. Since this model overtly limits itself to the scope of lexical access then this model is seen as biased and misunderstood. To many psychologists, the logogen model does not meet the functional or representational adequecy that a theory should include to sufficiently comprehend language. Also, another criticism is that the logogen theory was supposed to predict that stimulus degradation should effect priming and word frequency in humans. However, many psychologist have conducted studies and researched the model to show that only priming and not word frequency is interacted with stimulus degradation. Priming is supposed to deteriorate a stimulus because it postulates that the semantic characteristics of previously known words are fed back into the detector of a person which in turn raises the threshold of related items. In word frequency, stimulus degradation is supposed to occur because it postulates that familiar words have lower thresholds than their low frequency counterparts. However, in studies, priming is the only structure that does show observable and notable stimulus decadence. Even though the logogen theory has many unfilled holes, Morton was a revolutionary of his field whose speculation and research has opened up a remarkable era of psycholinguistics.

Morton'sAt logogenthe modeltime atof its timeconception, ofMorton's inceptionlogogen model was one of the most influential models in springing up other parallel word access models and served as the essential basis for these subsequent models. Morton's model also strongly influenced other contemporary theories on lexical access.

== Other Models to Consider ==

However, despite the advantages that the logogen theory presents, it also displays some negative facets. First and foremost, the logogen model does not explain all occurrences in language, such as the introduction of new words or non-words into a personsperson's lexicon. Also, because of the distinctive model application, it may vary in its effectiveness in different languages.

-'''[[Cohort model|Cohort Model]]''': This model was proposed by Marslen-Wilson and was designed specifically to account for auditory word recognition. The Cohort Model works by breaking the word down. This model states that when a word is heard all words that begin with the first sound of the target word are activated. This set of words is considered the Cohort. Once the first cohort has been activated, the other information, or sounds in the word narrow down the choices. The person recognizes the word when you are left with a single choice; this is considered the "recognition point."

== Criticisms ==

While this model does a reasonable job of understanding the underlying semantics of many aspects in [[psycholinguistics]], there are some flaws that have been pointed out in the logogen model.

It has been argued that the prior stimulus patterns that have been seen in the logogen theory are not centrally localized in the logogen itself but are actually distributed throughout the different pathways over which the stimulus is being processed. What this directs at is that the notion and proliferation of logogens was due to [[Modality (semiotics)|modality]]. In essence, the logogen is unnecessary in the idea of attaining the title of being a recognition unit because of the variety of pathways that it is open to, not just logogens.

-'''Checking Model''': This model was developed by Norris (1986). In this particular model the approach he took was that any word that partially matches the input is analyzed and checked to see if it fits with the context of the situation.

Another criticism has been that this model essentially ignores larger and more critical structures in language and phonetics such as the different syntactic rules or grammatical construction that innately exists in language. Since this model overtly limits itself to the scope of lexical access then this model is seen as biased and misunderstood. To many psychologists, the logogen model does not meet the functional or representational adequacy that a theory should include to sufficiently comprehend language.

-'''Interactive Activation Model''': This model is considered a connectionist model. It was proposed by McClelland and Rumelhurt in 1981-1982. This model is based around nodes. Nodes are visual features, and positions of letters within a given word. They also act as word detectors which have inhibitory and excitatory connections between them. This model starts with first letter and suggests that all the words with that first letter are activated at first and then going through the word one can determine what the word is they are looking at. The main principle is that mental phenomena can be described by interconnected networks of simple units.

Also, another criticism is that the logogen theory was supposed to predict that stimulus degradation should affect priming and word frequency in humans. However, many psychologists have conducted studies and researched the model to show that only priming and not word frequency is interacted with stimulus degradation. Priming is supposed to deteriorate a stimulus because it postulates that the semantic characteristics of previously known words are fed back into the detector of a person which in turn raises the threshold of related items. In word frequency, stimulus degradation is supposed to occur because it postulates that familiar words have lower thresholds than their low-frequency counterparts. However, in studies, priming is the only structure that does show observable and notable stimulus decadence.

-'''Verification Model''': The model was developed by Curtis Becker in 1970. The main idea is that a small number of candidates that are activated in parallel are subject to a serial verification process. This model starts the word recognition process with a basic representation of the stimulus. Then, sensory trace, consisting of line features is used to activate word detectors. When an acceptable number of detectors are activated these are used to generate a search set. These items are drawn from the lexicon on the basis of similarity to the sensory trace, which help with the identity of the stimulus. Then, in a serial process the candidates are compared to the representation of the sensory trace input.

Even though the logogen theory has many unfilled holes, Morton was a revolutionary of his field whose speculation and research has opened up a remarkable era of psycholinguistics.

== Related Concepts ==

== Other Modelsmodels to Considerconsider ==

'''Word Frequency ''': This is the belief that the speed and accuracy with which a word is recognized is related to how frequently the word occurs in our language. Each logogen has a threshold (for identification) and words with higher frequencies have lower thresholds. Words with higher frequencies also require less sensory evidence. (Morrison & Ellis, 1995)

-'''* [[Cohortcohort model|Cohort Model]]''':{{spaced ndash}}This model was proposed by Marslen-Wilson and was designed specifically to account for auditory word recognition. The Cohort ModelIt works by breaking the word down. This modeland states that when a word is heard all words that begin with the first sound of the target word are activated. This set of words is considered the Cohortcohort. Once the first cohort has been activated, the other information, or sounds in the word narrow down the choices. The person recognizes the word when you are left with a single choice; this is considered the "recognition point.".

-'''Checking* Model''':[[checking model]]{{spaced ndash}}This model was developed by Norris{{who|date=February 2012}} in (1986). In this particular model the approach, he took wasthe approach that any word that partially matches the input is analyzed and checked to see if it fits with the context of the situation.

-'''Interactive* Activation[[interactive Model''':activation model|interactive-activation model]]{{spaced ndash}}This model is considered a connectionist model. It was proposedProposed by McClelland and RumelhurtRumelhart in the 1981- to 1982. Thisperiod, modelit is based around nodes., Nodeswhich are visual features, and positions of letters within a given word. They also act as word detectors which have inhibitory and excitatory connections between them. This model starts with first letter and suggests that all the words with that first letter are activated at first and then going through the word one can determine what the word is they are looking at. The main principle is that mental phenomena can be described by interconnected networks of simple units.

-'''Verification* Model''':[[verification model]]{{spaced ndash}}The model was developed by [[Curtis Becker]] in 1970. The main idea is that a small number of candidates that are activated in parallel are subject to a serial -verification process. This model starts the word -recognition process with a basic representation of the stimulus. Then, sensory trace, consisting of line features is used to activate word detectors. When an acceptable number of detectors are activated these are used to generate a search set. These items are drawn from the lexicon on the basis of similarity to the sensory trace, which help with the identity of the stimulus. Then, in a serial process the candidates are compared to the representation of the sensory -trace input.

== Related Conceptsconcepts ==

'''Age of Acquisition ''': This term generally refers to the age at which a concept or skills is learned. The most studied however, is language acquision. Words that are learned earlier in life are more quickly recognized and used more frequently than those learned later. This is the reason many hypothesize that children are better at learning a second language than adults. (Morrison & Ellis, 2005). There are various hypotheses for why this is so. One is the "phonological completeness hypothesis" proposed by Brown and Watson in 1989. This states that the reason earlier words are learned quicker is because they are stored holistically. Later in life, new words are stored in fragments. They are recalled slowly because the fragments most be placed together.

'''Word* Frequency[[word ''':frequency]]{{spaced ndash}}This is the belief that the speed and accuracy with which a word is recognized is related to how frequently the word occurs in our language. Each logogen has a threshold (for identification) and words with higher frequencies have lower thresholds. Words with higher frequencies also require less sensory evidence. (Morrison & Ellis, 1995)

'''Age* of[[age Acquisitionof ''':acquisition]]{{spaced ndash}}This term generally refers to the age at which a concept or skills is learned. The most studied however, is language acquisionacquisition. Words that are learned earlier in life are more quickly recognized and used more frequently than those learned later. This is the reason many hypothesize that children are better at learning a second language than adults. (Morrison & Ellis, 2005). There are various hypotheses for why this is so. One is the "phonological completeness hypothesis" proposed by Brown and Watson{{who|date=February 2012}} in 1989. This states that the reason earlier words are learned quicker is because they are stored [[holism|holistically]]. Later in life, new words are stored in fragments. They are recalled slowly because the fragments most be placed together.

'''Repetition* Priming''':[[repetition Nonpriming]]{{spaced ndash}}Non-conscious form of memory in which [[neural]] activity is reduced once exposure has occurred repeatedly. A more recognizable word will result in a quicker -response time.

==See also==

'''Repetition Priming''': Non conscious form of memory in which neural activity is reduced once exposure has occurred repeatedly. A more recognizable word will result in a quicker response time.

{{portal|Linguistics}}

{{clear}}

== References ==

{{div col|colwidth=30em}}

{{nofootnotes|date=December 2008}}

* [[Peter D. Eimas|Eimas, Peter]]; Miller, and Joanne Miller(1983). ''Perspectives on the Study of Speech''. [[Lawrence Erlbaum Associates,]]. 1981p. &nbsp;274.

* Feldman (undated). [https://web.archive.org/web/20110527160215/http://www.ling.ohio-state.edu/~afeldman/371/internal_lexicon2_4up.pdf Cohort Model. In The Internal Lexicon, Part II] ([[Portable Document Format|PDF format]]; [[Adobe Acrobat]] required). Retrieved December 5, 2007.

*Payne, David, and Michael Wenger. Cognitive Psychology. Boston, MA: Houghton Mifflin Company, 1998. 339-340.

* Hernandez, A. (2007) Psychological Bulletin. Vol.133 (4) pp. 638–650. Retrieved December 1, 2007, from [http://search.ebscohost.com/login.aspx?direct=true&db=psyh&AN=2007-09203-004&loginpage=Login.asp&site=ehost-live]. ''[[Psychological Bulletin]]''. Vol.133 (4) pp.&nbsp;638&ndash;650. Retrieved December 1, 2007.

* [http://www.bbc.co.uk/dna/h2g2/A650620 Dyslexia and the Mental Lexicon]

* [[Daniel Jurafsky|Jurafsky, Daniel]] (1991). [http://www.eecs.berkeley.edu/Pubs/TechRpts/1992/CSD-92-676.pdf An Online Computational Model of Human Sentence Interpretation: A Theory of the Representation and Use of Linguistic Knowledge] ([[Portable Document Format|PDF format]]; [[Adobe Acrobat]] required). Retrieved December 2, 2007 from http://www.eecs.berkeley.edu/Pubs/TechRpts/1992/CSD-92-676.pdf

*[http://www.epistemics.co.uk/staff/nmilton/papers/word-recognition.htm Word Recognition]

* [[Stephan Lewandowsky|Lewandowsky, Stephan]] (1993) [https://web.archive.org/web/20070906150240/http://www.psy.uwa.edu.au/Users%20web%20pages/cogscience/documents/Lewandowsky%20%281993%29%20-%20Rewards%20%26%20Hazards%20of%20Simulation.pdf "The Rewards and Hazards of Computer Simulations"] ([[Portable Document Format|PDF format]]; [[Adobe Acrobat]] required). [[American Psychological Society]]. Vol. 4 (4). pp.&nbsp;236&ndash;243. Retrieved December 2, 2007.

*Feldman. (n.d.). Cohort Model. In The Internal Lexicon, Part II. Retrieved December 5, 2007, from http://www.ling.ohio-state.edu/~afeldman/371/internal_lexicon2_4up.pdf

* Milton, N. (undated). [https://web.archive.org/web/20081120224840/http://www.epistemics.co.uk/staff/nmilton/papers/word-recognition.htm Word Recognition]. Retrieved December 5, 2007.

*Language, Thinking, and Memory. (n.d.). Retrieved December 5, 2007, fromhttp://www.lifesci.sussex.ac.uk/home/Alan_Garnham/Teaching/LTM/visword.ppt#256,1,LANGUAGE,THINKING AND MEMORY

* Morrison, C.; Ellis, A. [http://search.ebscohost.com/login.aspx?direct=true&db=pdh&AN=xlm-21-1-116&loginpage=Login.asp&site=ehost-live "Roles of Word Frequency"]. ''[[Journal of Experimental Psychology: Learning, Memory, and Cognition]]''. Vol.21 (1). pp.&nbsp;116&ndash;133. Retrieved December 3, 2007.

*The Logogen Model. (n.d.). Search the Lexicon. Retrieved December 5, 2007, from http://www2.let.uu.nl/UiLOTS/Lexicon/zoek.pl?lemma=Logogen+model&lemmaode=1235

* [[David Payne (psychologist)|Payne, David, and]]; [[Michael Wenger (psychologist)|Wenger, Michael]] (1998). ''Cognitive Psychology''. Boston, MAMassachusetts: [[Houghton Mifflin Company,]]. 1998pp. &nbsp;339-&ndash;340.

*Morrison, C. & Ellis, A. Roles of Word Frequency Journal of Experimental Psychology: Learning, Memory, and Cognition. Vol.21 (1) pp. 116–133. Retrieved December 3, 2007, from http://search.ebscohost.com/login.aspx?direct=true&db=pdh&AN=xlm-21-1-116&loginpage=Login.asp&site=ehost-live

* Polk, T.; Seifert, C. (undated). [https://books.google.com/books?id=FJblV_iOPjIC&dq=norris's+checking+model&pg=PA19 Cognitive Modeling]. (via [[Google Books]]). Retrieved December 5, 2007.

*Milton, N. (n.d.). Word Recognition. Retrieved December 5, 2007, from http://www.epistemics.co.uk/staff/nmilton/papers/word-recognition.htm

* [[David Rumelhart|Rumelhart, David E.]]; [[James McClelland (psychologist)|McClelland, James L.]] (1985). [http://www-psych.stanford.edu/~jlm/papers/PublicationFiles/80-89_Add_To_ONLINE_Pubs/RumelhartMcClelland85LevelsIndeed!.pdfLevels Indeed! A Response to Broadbent]{{dead link|date=January 2017 |bot=InternetArchiveBot |fix-attempted=yes }}. Vol. 114 (2). pp.&nbsp;193–197. Retrieved December 2, 2007.

*Hernandez, A. (2007) Psychological Bulletin. Vol.133 (4) pp. 638–650. Retrieved December 1, 2007, from http://search.ebscohost.com/login.aspx?direct=true&db=psyh&AN=2007-09203-004&loginpage=Login.asp&site=ehost-live

* Underwood, G.; Batt, V. (undated). [https://books.google.com/books?id=uW8wRIzwXsC&dq=becker's+verification+model&pg=PA37 "Chapter 2: Cognitive Processes in Word Recognition"] (via [[Google Books]]). In ''Reading and Understanding: An Introduction to the Psychology of Reading''. pp.&nbsp;37&ndash;70. Retrieved December 5, 2007.

*Jurafsky, Daniel (1991) An Online Computational Model of Human Sentence Interpretation: A Theory of the Representation and Use of Linguistic Knowledge. Retrieved December 2, 2007 from http://www.eecs.berkeley.edu/Pubs/TechRpts/1992/CSD-92-676.pdf

* [https://web.archive.org/web/20070218192958/http://www.bbc.co.uk/dna/h2g2/A650620 Dyslexia and the Mental Lexicon].

*Lewandowsky, Stephan (1993) The Rewards and Hazards of Computer Simulations. American Psychological Society. Vol. 4 (4) pp. 236–243. Retrieved December 2, 2007 from http://www.psy.uwa.edu.au/Users%20web%20pages/cogscience/documents/Lewandowsky%20(1993)%20-%20Rewards%20&%20Hazards%20of%20Simulation.pdf

* (undated). [http://www.lifesci.sussex.ac.uk/home/Alan_Garnham/Teaching/LTM/visword.ppt#256,1,LANGUAGE,THINKINGANDMEMORY Language, Thinking, and Memory]{{dead link|date=January 2017 |bot=InternetArchiveBot |fix-attempted=yes }}. Retrieved December 5, 2007.

*Polk, T., & Seifert, C. (n.d.). Cognitive Modeling. Retrieved December 5, 2007, from http://books.google.com/ books?id=FJblV_iOPjIC&pg=PA21&lpg=PA21&dq=norris's+checking+model&source=web&ots=zWLp8gJWZP&sig=qewzXQ0iq4NFzhj5P9-ArmpaaAY#PPA19,M1

* (undated). [http://www2.let.uu.nl/UiLOTS/Lexicon/zoek.pl?lemma=Logogen+model&lemmaode=1235 The Logogen Model. Search the Lexicon]{{dead link|date=January 2017 |bot=InternetArchiveBot |fix-attempted=yes }}. Retrieved December 5, 2007.

*Rumelhart, David E & McClelland, James L. (1985) Levels Indeed! A Response to Broadbent. Vol. 114 (2) pp.193–197. Retrieved December 2, 2007 from http://www-psych.stanford.edu/~jlm/papers/PublicationFiles/80-89_Add_To_ONLINE_Pubs/RumelhartMcClelland85LevelsIndeed!.pdf

* [https://web.archive.org/web/20081120224840/http://www.epistemics.co.uk/staff/nmilton/papers/word-recognition.htm Word Recognition].

*Underwood, G., & Batt, V. (n.d.). Chapter 2: Cognitive Processes in Word Recognition. In Reading and Understanding: An Introduction to the Psychology of Reading (pp. 37–70). Retrieved December 5,2007, from http://books.google.com/books?id=uW8wRIzwXsC&pg=PA69&lpg=PA69&dq=becker's+verification+model&source=web&ots=5iXZ4kbbfB&sig=cmseVV3S3d0qPbsRKQadniVkv98#PPA37,M1

{{div col end}}

[[Category:Speech recognition]]