Memorized vs. Computed

 

I have previously written about why I believe that distinctions in the literature between words (or sentences) that are “stored” as units vs. words (or sentences) that are “computed” are not well articulated.  I claimed, instead, that, in a sense that is crucial for understanding language processing, all words (and all sentences) are both stored AND computed, even those words and sentences a speaker has never encountered before.  A speaker stores or memorizes all the infinite number of words (and sentences) in his/her language by learning a grammar for the language.  Attempts in the literature to distinguish the stored words from the computed ones fail to be clear about what it means to store or compute a word – particularly on what it means to memorize a word.  I claimed that, as we become clear on how grammars can be used to recognize and produce words (and sentences), any strict separation between the stored and the computed disappears.

 

Despite my earlier efforts, however, I find that I have not convinced my audience.  So here I’ll follow a line of argument suggested to me by Dave Embick and try again.

 

Let’s start with Jabberwocky, by Lewis Carroll of course (1871, this text from Wikipedia):

 

Twas brillig, and the slithy toves
Did gyre and gimble in the wabe;
All mimsy were the borogoves,
And the mome raths outgrabe.

“Beware the Jabberwock, my son!
The jaws that bite, the claws that catch!
Beware the Jubjub bird, and shun
The frumious Bandersnatch!”

He took his vorpal sword in hand:
Long time the manxome foe he sought—
So rested he by the Tumtum tree,
And stood awhile in thought.

And as in uffish thought he stood,
The Jabberwock, with eyes of flame,
Came whiffling through the tulgey wood,
And burbled as it came!

One, two! One, two! And through and through
The vorpal blade went snicker-snack!
He left it dead, and with its head
He went galumphing back.

“And hast thou slain the Jabberwock?
Come to my arms, my beamish boy!
O frabjous day! Callooh! Callay!”
He chortled in his joy.

‘Twas brillig, and the slithy toves
Did gyre and gimble in the wabe;
All mimsy were the borogoves,
And the mome raths outgrabe.

 

The poem is full of words that the reader might not recognize and/or be able to define.  Quick quiz:  which words did Carroll make up?

 

Not so easy, at least for me.  Some words that Carroll was the first to use (as far as lexicographers know) have entered the language subsequently, e.g., vorpal (sword).  What about chortle?  Are you sure?  How about gyre?  Gimble?  Beamish?  Whiffling?

 

The fact is that when we encounter a word in context, we use our knowledge of grammar, including our knowledge of generalizations about sound/meaning connections, to assign a syntax and semantics to the word. (Chuang, Yu-Ying, et al. “The processing of pseudoword form and meaning in production and comprehension: A computational modeling approach using linear discriminative learning.” Behavior research methods (2020): 1-32.)  Suppose the word is one we have not previously encountered, but it is already in use in the language.  Can we tell it’s a “real” word as opposed to Jabberwocky?  That the word has found a place in the language probably means that it fits with generalizations in the language, including those about correlations between sound and meaning and between sound and syntactic category. Children must be in this first encounter position all the time when they’re listening  – and I doubt that many of them are constantly asking, is that really a word of English?  Suppose, now, that the-new-to-us word in question is actually not yet a word in use in English, as was the case for the first readers of Jabberwocky encountering chortle.  In the course of things, there’s no difference between encountering in context a word that’s in use and you haven’t heard yet, but fits the grammar of your language, and one that the speaker made up, but also fits the grammar of your language equally well.  Lewis Carroll made up great words, extremely consistent with English, and many of them stuck.

 

Speakers of English have internalized a phonological grammar (a phonology) that stores our knowledge of the well-formedness of potentially infinite strings of phonemes.  The phonotactics of a language include an inventory of sounds (say an inventory of phonemes) and the principles of phonotactics – the sounds’ legal combinations.  The phonology – the phonotactic grammar – stores (and generates) all the potential words of the language, but doesn’t distinguish possible from “actual” words by itself.  Are the “actual” words distinguished as phoneme-strings carrying the extra feature [+Lexical Insertion], as Morris Halle once claimed for morphologically complex words that are in use as opposed to potential but not “actual” words (Halle, M. (1973). Prolegomena to a theory of word formation. Linguistic inquiry, 4(1), 3-16)?  It’s not particularly pertinent to the question at hand whether people can say, given a string of letters or phonemes in isolation, this a word of my language.  Experimental subjects are asked to do this all the time in lexical decision experiments, and some are surprisingly accurate, as measured against unabridged dictionaries or large corpora.  Most subjects are not so accurate, however, as one can see from examining the English Lexicon Project’s database of lexical decisions – 85% correct is fairly good for both the words (correct response is yes) and pronounceable non-words (correct response is no) in that database.  Lexical Decision is a game probing recognition memory – can I recover enough of my experiences with a letter or phoneme string to say with some confidence that I encountered it before in a sentence?  A better probe of our knowledge of potential and actual words is placing the strings in sentential context – the Jabberwocky probe.  Do we think a Jabberwocky word is a word in our language.  Here we see that our judgments are graded, with no clear intuition corresponding to a binary word/non-word classification.

 

For phonology, it’s somewhat clear what we mean when we say that the generative grammar “stores” the forms of potential and existing words in the language.  The consequences of this for the Chomskyan linguist (committed to the principle that there are not separate competence and performance grammars) is that the phonological grammar is used in recognizing and producing the words.  For committed Chomskyans, like me, at a first pass, we expect that phonotactic well-formedness will always play a role in word recognition and production – “knowing” a word doesn’t exempt it from obligatory “decomposition” via the grammar in use into, e.g., phonemes, and analysis via the phonotactic grammar.  “Retrieving” the phonological form of a word from memory and “generating” it from the grammar become the same process.

 

What is, then, the difference between words like chatter and Jabberwocky like chortle?  Although our grammar will assign a meaning to any well-formed possible word, without sentential or other context, the meaning might be vague.  As we experience words in context, we can develop sharper accounts of their meaning, perhaps primarily via word co-occurrences.  The sharpness of a semantic representation isn’t a property of the phonological grammar, but it is a property of the grammar as a whole.  For linguists, a “whole” grammar includes, in addition to a syntax that organizes morphemes into hierarchical tree structures and a phonology that maps the syntactic structure into a structured sequence of prosodic units like phonological words, also what Chomsky calls a language’s “externalization” in the conceptual system, i.e., in this case the meaning of words.

 

In important ways, words are like human faces to human speakers.  We have internalized a grammar of faces that allow us to recognize actual and potential faces.  We store this grammar, at least partially, in what is called the Fusiform Face Area.  Recognizing faces (as faces) involves obligatory decomposition into the elements of a face (like the eyes, ears, and nose) whose grammatical combinations the face grammar describes.  For faces, we don’t call the faces of people that we haven’t seen “potential” or “pseudo” faces – they’re just faces, and the faces of people that we have encountered (and can recall as belonging to people we’ve seen or met) we call “familiar” faces.  For words, I propose we adopt the same nomenclature – words and potential words should just be “words,” while words to which we push the “yes” button to in Lexical Decision experiments should be called “familiar words.”

 

Note that, for written words, there’s an even greater parallel between words and faces.  Our orthographic grammar, describing the orthotactics of the language, generates thus stores all the orthographic forms of the words of the language.  From neuroscientific studies, we know that the orthographic grammar – and thus the orthographic forms of words – is (at least partially) stored in an area of the brain adjacent to the Fusiform Face Area (called the “Visual Word Form Area”), and the recognition of words follows a parallel processing stream and time frame as the recognition of faces.  One can speculate (as I will in a future post) that the phonological grammar and thus the phonological forms of words (really morphemes of course) live in secondary auditory cortices on the superior temporal lobe, where auditory word recognition is parallel to the recognition of faces and visual word forms, with the interesting complication that the recognition process plays out over time, as the word is pronounced.

 

[To be continued…..]