Communication Disorders Therapy (CDT)


Intensely Special Education (ISE)


Most speech-language pathologists (SLPs) never realize that they have been trained to design speech-language therapy according to formalist theories of grammar. Fewer are taught that functionalist alternatives even exist, much less that such an approach is sometimes necessary for therapy to be effective (or to avoid harm).

Frankly, for the vast majority of SLPs and students, this distinction is never really an issue. Most school-based SLPs spend their entire careers working with students whose experience of our shared world is largely conventional. Even without therapy, then, such students will still tend to develop an understanding of reality that is broadly the same as that of their communication partners; for example, even though a student might be relatively delayed in their consistent use of past tense morphemes, they would still understand the concept of [PAST TIME] in the same way as their peers. Formalist therapy (no matter what it was called) would be adequate to harmlessly help that student pattern their language more in line with the rules that were familiar to their partners.

However, in those cases where the functionalist distinction does matter, it matters a lot, and cannot safely be ignored. Some SLPs work in life skills classrooms, where moderate-to-profound cognitive, mobility, and sensory differences affect a student’s experience of our shared world in such a remarkably individualized manner that even when they do develop language, it might only seem to pattern after a familiar system of rules. Such a student might not understand the concept of [PAST TIME] in the same way as their peers, or they might not understand that an item retains its identity when it is rotated in their visual space. The design of their therapy should not attempt to jam their communication skills into a formalist cubby. In these sorts of intensely special education programs (ISE), the functionalist distinction always matters, and the SLP provides communication disorders therapy (CDT) that is substantially transdisciplinary in nature.

This tutorial, then, is intended for those people who have to design that functionalist therapy, which requires a serious tour under the hood.

In short (and chock-full o’ acronyms): Informed design of CDT in ISE requires training that takes SLPs (including CFY students) well beyond the typical limits of professional education in communication disorders and sciences (CDS); in conjunction, this tutorial provides a solid introduction to functionalist linguistics, as that approach is more appropriate for the development of CDT in ISE (and frankly elsewhere) than the formalist perspective that is commonly taught in CDS graduate programs.


Formalist Linguistics (Formalist theories of grammar)

• Grammar is treated as an autonomously isolated system within cognition.

• Every language is defined by a set of utterances whose elements can be sorted into a set of strictly isolated categories (i.e., phonemes, morphemes, words, sentences, and so on).

• A strict system of rules can account for all and only those units that a conventional user of that language will judge to be valid or well formed.

• Context (such as intent or function) is held to be irrelevant in such judgment, and any utterance that does not obey the rules is summarily discarded as bad data (thus salvaging the theorized rule system).

Functionalist Linguistics (Functional theories of grammar)

• Grammar is not strictly bounded within cognition (i.e., it represents an interaction).

• Categories are not strictly bounded within grammar (e.g., some entities are not strictly morphemes or words, and so on).

• Well-formedness judgments are not strictly bounded (i.e., some utterances are identified as being perfectly fine in some circumstances, but not nearly as fine in others).

• Context and meaning are relevant, and utterances with unusual forms will simply tend to convey unusual meanings (thus adjusting the theory to honor the data).


(Skip to Content)

Note Well


Order of Events

Semeiognomy Basics

Form: a Word Shape

Concept: a Thought Feeling

Semantics: a Conception's Evoked Contents

Foundation: A Diagrammatic Semantic Structure

Meaning: the Construal of a Conception

Ymage: a Construed Conception Shape

Symbol: a Form-Ymage Pairing

Iconicity: When Form is Ymage

Synaesthesia and Ideasthesia

Grammar: Symbolic Assembly

Summary: Communication versus Language

Generation to Communication



Generation and Reception





Mirror Neurons

Myth: Swiss Cheese Metaphor

Power, Precision, and Prominence



Communication Context

Communication from Generation

Communication into Language

Subjective Reality

Ground (G)

Time (t)

Awareness (A) and Irreality (I)

Entirety (E)

Nonphysical Context: Awareness

Idealized Cognitive Model (ICM)

The Archive (X)

Objective Reality (O)

The World (W)

Everything (E)

Physical Context

Universal Somatosensory Experiences (USE)

The Vault (V)


Current Discourse Space (CDS)

Objective Scene (OS)

Communication and Sensory Lifestyles


Sources and Suggested Reading

Note Well

This training is not critical of any CDS program or CDT practitioner. It does address some challenges associated with contemporary CDS graduate programs, as well as conventional SLP experience, specifically in regards to experience with intensely special education.

Such a disclaimer is prudent given the distinct history of personal escalation in such fields as linguistics (e.g., the linguistics wars) and special education (e.g., facilitated communication, vaccine hesitancy, presumption of competence, and so on).

In this training, any perception of offense is most likely due to a misunderstanding, and we are well open to clarifying passages that present too high a risk of such misinterpretation. Should you happen to read anything that triggers emotional escalation, contact information is given below.


University coursework and subsequent professional development focus heavily on conventional communication disorders. This makes some sense, as most school SLPs will be designing therapy for the likes of articulation, (specific) language impairment, fluency, social pragmatics, and so on.

But when it comes to intensely special education (ISE), particularly as associated with low-incidence disabilities, there is much more to communication, language, and their associated disorders than can reasonably be addressed solely by master’s coursework in CDS (or in any other field), or by an SLP’s experience in any typical P-21 education setting. This means that there is much more to learn (and unlearn) before it is possible to design contemporary therapy for a student whose cognitive, physical, and sensory abilities are moderately-to-profoundly different from those of a student who (for example) faces familiar articulatory challenges without those concomitant disabilities.

This tutorial, then, represents continuing professional education and exposure, including a scaffolded display of constructs that can help you to design informed therapy for low-incidence venues.

As an SLP, you already have access to several cognitive constructs that hold you in good stead; for example, as you entered your graduate studies you started at the surface with such content knowledge as the names of various body parts, then deepened your understanding by studying and observing how and why those parts are supposed to interact as systems. With increasing real-world experience, you constructed cognitive models allowing you to perform a bedside examination without having to literally dissect your client (i.e., you relied on the “mental images” that you had developed). You are now well able to imagine functioning systems for the likes of articulation (and phonological processes), phonation, respiration, and feeding/swallowing. This higher level of mastery (i.e., improved constructs) is an emergent property of your (subjective) experience of the (objective) reality in which we all live.

In contrast, very few people (SLPs or otherwise) are exposed to the full range of knowledge (surface and deep) necessary to emerge into cognitive constructs that interweave sensory processing, communication, language, and their associated disorders (including theories of mind and reality, and so on). That rarity only increases when therapy must take concomitant low-incidence disabilities into account, or an appeal to assistive technology (AT). An SLP’s training, both during and after grad school, is a process of peeling back layers of myth in these areas to expose increasingly functional models of reality.

For example, for the vast majority of people in the world, it is harmless to believe that your lungs work like a pair of bellows; in contrast, SLPs must be trained to design therapy according to a more realistic and functional model of respiration. Grad school for CDS does a good job in that arena, and few SLPs are left believing that bellows represent an accurate model of the lungs.

Similarly, and for an equally vast majority of people, it is harmless to believe popular myths about language function. Even for those few people who do study linguistics, it doesn’t really matter if their exposure is more “formalist” than “functionalist”; that is to say, it doesn’t matter if formalism treats meaning as if it were irrelevant to analyzing structure, because formalism is not concerned with the actual function of communication. It doesn’t matter if formalism adjusts real-world data to conform to a particular theory, because evidence-based practice is not an applicable standard for those particular academic pursuits. It doesn’t matter that a formalist model relies on a theoretical component such as “deep structure,” if an SLP has learned that such a process is not intended to portray a psychologically real part of language use. To be clear: all of these formalist principles are harmless as long as linguists and other interested theorists are only engaging with one another, and are not designing therapy that will put someone’s well-being at risk.

In distinct contrast, then, it matters a great deal when SLPs are taught about language in that same formalist sandbox, as part of their grad program. Once again, SLPs must base their designs on a more realistic and functional language model, because their therapy is supposed to affect a client’s health. This tutorial exists, then, because grad school for CDS does not teach that necessary functional model, so most SLPs are left harboring formalist notions regarding language and its associated cognition. And while it might be harmless to write software that generates a defined set of “well formed” sentences, it is harmful to design therapy with the expectation that a client will run such a program in their head.

Just as one example (among many), I came across a CDS master’s project in which an elementary school student was expected to demonstrate increasing awareness of “wh- traces.” This is significantly disturbing because formalist theories are not intended to model human communication in the first place, much less real-world language performance, and clients should not be used to debug formalist software (in essence). The client should not be punished due to their inability to memorize a formalist model.

Crucially, this assessment is not a matter of finding fault. For all of their expertise, instructors who hold advanced degrees in CDS do not tend to have pursued graduate studies in such fields as linguistics and cognitive science. Even had they done so, that linguistics education would often still tend to be formalist in nature. (There will of course be exceptions to this trend, but such versed individuals are not members of our focal audience here.) Designers of a CDS graduate program, therefore, will not tend to be informed evaluators of the linguistics education available in their university. CDS programs, then, end up relying on formalist approaches that were never intended to account for communication, dysfunction, or therapy, much less their interaction. Too many SLPs are left wrestling with the misimpression that a formalist model represents actual cognition, which it does not do, as that was never its purpose.

Therefore, we will present a functionalist contrast here, as a natural component of our discussion of ISE. It is not that functionalism is better than formalism, but rather that it serves a different purpose, one which is better suited to the development of CDT. This tutorial will not, however, go so far back as to provide proof (or specific explanation) for the following functionalist assertions:

1) mechanism can tolerate mentalism (i.e., neurochemistry need not suffer a case of the vapours when we talk about “meaning”);

2) competence can appreciate performance (i.e., when the data runs counter to one’s predictions, one should reconcile the theory, and not question the validity of the data);

3) cognition and scientific disciplines can both thrive when distributed in a balanced fashion (e.g., Dcog and Transdisciplinarity); and

4) primitive behavior is shared behavior, both among species and among forms of communication.

Much of the original work forming the basis of this tutorial was completed in fewer than ten years after these four windows finally came to open simultaneously around the early 1980s (Harris, The Linguistics Wars; Harris, pc), which was thoroughly refined during a couple of decades’ worth of application in natural language processing and CDT by Mansfield and associated colleagues.

If you would prefer not to take the validity of those four fundamental statements for granted, then we suggest starting with Beyond Nature-Nurture (Tomasello; 2005).

While individual organizations at the state-equivalent level hold conferences on low-incidence special education, there exists no “International Low-Incidence Special Education Association” (ILISEA); however, the notion of founding that very entity is intriguing enough to merit some serious pondering.

Order of Events

First, we will introduce you to semeiognomy (pr. Seh-my-AH-nuh-me) as a study of communication (in specific) in terms of symbol systems and cognition (Gk. semeio- + -gnomy). We will start with semeiognomy basics, specifically the structure and function of the symbols (i.e., the form-meaning packages) that communication participants transductively exchange.

Where semeiognomy examines communication as a systematic symbolic process, cognitive linguistics analyzes language as one type of that communication. We will characterize language from two perspectives derived from cognitive linguistics foundations (which have analogs elsewhere), the first of which is that of an isolated individual reacting to its environment, and the second of which is that of a group of individuals interacting with one another in a shared environment which changes over time. That first set of stages brings us from generation to communication, and the second moves us on from communication and into language.

Once having explained why we provide intensely special students with experiential and productive access to a rich variety of forms, we can meaningfully describe how we go about doing that, as we address sensory lifestyles, sensitivity, and desensitization.

The primary goal of this tutorial is to improve your understanding of that specific topic, and if you stop right there you will already be much better prepared to provide informed service in ISE.

For those of you who remain interested beyond that point, we can recommend materials on cognitive grammar, as that approach (and related areas such as mental spaces) comes closest to plausibly reflecting the models that people use when communicating.

This water's deep, and we want to get to the bottom, so let’s dive in from the top of the cliff.

Semeiognomy Basics

This discussion of basic semeiognomic principles supports the importance of a person’s exposure to a variety of sensory experiences in their development of communication and language. As those are both symbolic systems, we will begin by refining your existing definition of the term “symbol,” and establish additional vocabulary that will facilitate the subsequent discussions.

The most fundamental ideas in this section of the tutorial are not those of the primary author (see Sources, especially Langacker); although Mansfield (1997) is the source for research on prominence and direct iconic proportion, and in later work the clarifying use of “ymage,” and the term “semeiognomy” itself (because there was not an existing label that adequately identified this field).       

Generation to Communication

The tutorial on semeiognomy basics (above) thoroughly discusses the nature of the symbolic packages that are exchanged during communication. This section of the tutorial details the actual process of that transfer.    

Communication into Language

This part of the tutorial moves you away from formalist models that treat language like a simplified game, and toward a functional analysis that describes what a real user is doing when they navigate language in real life.

Why is that shift important?

Because when you create real therapy programs, you are (in essence) developing a flying simulator with which to train real-life pilots. For that sort of real instructional purpose (i.e., not a video game), you would not base your model on the formalist type of broomstick flying portrayed in the Harry Potter novels. You would not measure your student’s progress based on their playground Quidditch score.

You would instead base your program on your deep understanding of functional flying as defined by real models of physics, and actual airplane control panels. 

So we still need to go into far more detail about (a) language beyond its origins, including discussions of reality (e.g., objective reality, subjective reality, and areas beyond the spatial realm), and (b) the nature of form-meaning associations.

Communication and Sensory Lifestyles

The tutorials up to this point have built up to the following notion:

If a person grows up in an environment with an impoverished inventory of sensory experiences (i.e., they experience an unusually limited portion of “everything” in objective reality), then they do not end up with a typical range of forms to draw upon as they develop language (i.e., they contain an unusually limited “entirety” as their subjective reality); therefore, that early lack of equitable access to sensational engagement significantly challenges the development of their communication.

At base, then, sensory lifestyles (once known as “sensory diets”) improve the opportunity to develop communication by adding variety to the range of sensory engagement typically available to a neurodiverse individual.

Furthermore, consider how different a person’s forms and meanings might be, much less their symbolic pairings, if their sensory experience of our objective reality is intensely diverse.

You have to exercise some care, then, in the choice of representations that you are using with a student (i.e., pictures, audio cues, tactile object sets); for example, if you are using pictures, will they be:

• Realistic Abstract (e.g., photos, cartoons, line drawings, sight words)

• Color, monochrome, greyscale, black and white

• How many in a field (from which to choose)?

• Contextual (i.e., a figure with a background)

• Multimodal (pictures with audio feedback, pictures with raised textures, and so on)

For pictures, there is a test that the AAC Specialist can administer that can help to figure this out (Test of Aided Communication Symbol Performance; TASP). Note that this tool requires some modification as it is based in Boardmaker® products.

Lane ESD describes an approach to sensory lifestyles, sensitivity, and desensitization in their special education programs. That material considers: a) the design (with a specialist) and implementation of a sensory lifestyle; b) engagement in simple sensory interactions with students (including adjusting their environment); and c) just trying to figure out what’s going on in a student.


When it comes to understanding communication, it is inadequate to follow formalist paradigms that study form in the absence of meaning, sentences in the absence of conception, syntax in the absence of semantics, or (generally speaking) x in the absence y; in contrast, we have illuminated several functionalist principles that directly inform the development of appropriate CDT, where:

• conception is ultimately grounded in sensorimotor experience,

• grammar is a part of cognition (being deeply conceptual and imaginative in nature),

• syntax is not autonomous (nor are other categories), and

• proposed elements in our system are grounded in events that are directly perceived to occur (i.e., they are real), without our suggesting any props, filters, or other kludges.

In our functionalist approach, grammatical morphemes do have meaning, and in fact those meanings have their historical origins in lexical items. Idiomatic expressions fall somewhere between the grammatical (with an idiom’s predictable structure) and the lexical (with their open-classed variety). So, rather than using exclusive categories (typical of linguistics formalisms), a spectrum describes the fluid boundaries of phonology, lexicon, morphology, syntax, semantics, and pragmatics.

Formalisms do have a respectable place in the study of language. In a non-trivial sense, they are sports whose rules generate only a specific subset of sentence structures while ignoring their meaning; in that context, there is no harm in propping up such a system with auxiliary elements that have no perceived form or meaning of their own (e.g., “wh- traces”), or in crafting tidy screens (e.g., case filters) that selectively erase any messy overage that the rules create. Such grooming elements, however, have no linguistic identity (i.e., no reality) outside of the proposed rule system, which is only harmful when CDT is then designed to teach that specific game to a client, rather than actual communication and language. No client should be expected to show an awareness of “traces,” or a mastery of filters, and yet this sort of therapy exists. So this is not the fault of the formalisms, but rather of their misapplication. They were never intended for this purpose.

In addition to those concerns, formalist grammars simply do not lend themselves modally to an adequate representation of conceptualization in all its encyclopedic glory, continuous prototype categorization, and symbolic compositionality. And to be clear: while diagrammatic systems are useful for teaching (as we have shown here), and might eventually find some usefulness in the development of some formalist details, not enough is known yet about communication and language for that project to be viable.

In the meantime, we have some hope that this tutorial will help to remedy the situation.  

Sources and Suggested Reading

Clyr Ink Press © 2021

Policies and Terms

Email the webmaster.

Built with Sparkle.