Chapter 3- Symbols and Rate Enhancement Flashcards
Symbol
Something that stands for or represents something else, the referent
Referent
That which a symbols represents
Symbols can be described in terms of characteristics, including
1/ realism 2/ iconicity 3/ ambiguiyt 4/ complexity 5/ figure-ground differential 6/ perceptual distinctness 7/ acceptability 8/ efficiency 9/ colour 10/ size
Iconicity
Any association that an individual forms between a symbol and its referent
Continuum from transparent to opaque
Transparent
Symbols in which the shape, motion, or function of the referent is depicted to such an extent that meaning of the symbol can be readily guessed in the absence of the referent
Opaque
Symbols in which no symbol-referent relationship is perceived even when the meaning of the symbol is known
Translucent
Symbols in which the meaning of the referent may or may not be obvious, but a relationship can be perceived between the symbol and the referent once the meaning is provided (e.g. flat hand gesture for “stop”)
Aided symbols
Require some type of external assistance such as a device for production. e.g. real objects, black-and-white line drawings
Unaided symbols
Require no external device for production. e.g. facial expressions, manual signs, natural speech and vocalizations
Combined symbol sets
Incorporation of both aided and unaided elements.
Symbol understanding - development
Meaning of symbol mediated by various factors intrinsic to viewer
- motivation
- neurological status
- developmental age
- sensory abilities
- cognitive skills
- communication/language abilities
- world experience
culture, time, experience
_______ plays a critical role in symbol learning process
Spoken language comprehension
How developmental age affects symbol understanding
Degree of iconicity does not facilitate meaning in 18-month olds, but does in 26-month-olds
“Pictorial competence” – the ability to perceive, interpret, understand, and use pictures communicatively, develops gradually over the first few years of life
Until end of second year, TD children respond to pictures as they would objects, by trying to grasp them
It is not until around age 3 that children begin to understand
1/ pictures are two-dimensional objects in their own right (dual representation)
2/ pictures can stand for objects or concepts (they are symbols)
3/ referents can be depicted symbolically in multiple ways (colour photograph, b/w line drawing)
The ability to comprehend and use a variety of symbol types continues to develop until..
at around age 5, children are able to consider attributes of the symbol producer as well (e.g. matching crudely drawn and sophisticated symbols with pictures of children and adults, respectively)
Pictorial competence does not emerge…
uniformly for all symbols.
happy before sad, angry, scared/afraid
nouns before verbs, descriptors, wh- questions
Children’s drawings of concepts tend to …
- be different from commercially available symbo lsets
- include familiar people
- embed concepts in contexts
Developmentally Appropriate Symbols
The _______ value of a referent is also likely to affect its learnability
reinforcement
abstract symbol for highly desired item may be learned more readily than highly guessable symbol for a less desirable item
Children’s ability to identify and generalize symbols that depict abstract linguistic concepts can be affected by factors such as
- Concreteness
- Familiarity
- Context
- Wholeness
- Colour
- Focus
Concreteness
Clearly depicted people and/or observable activities
Familiarity
Symbols depicting familiar activities in context
Wholeness
Symbols depicting complete people or object rather than elements or parts that are separated/disjoined
Colour
Symbols that use bright colours to highlight contrasts and details are more easily discriminated and more interesting
Focus
Symbols that emphasize relevant characteristics via size and position of characters or objects, vs. use of arrows or other markers to draw attention to relevant details
Visual Scene Displays
Use pictures to depict situations, places, or experiences. Clear images are contextually rich and depict people or objects in relation to one another. Language concepts placed under “hot spots” on the picture that speak the related message out loud when activated.
Unaided symbols
Nonverbal behaviour, such as gestures, vocalizations, and other paralinguistic elements; physical characteristics (physique, body, and breath odour); proxemics (seating arrangements, personal space requirements,); artefacts (clothes, perfume, makeup); and environmental factors that may influence impressions and interactions (neatness/disorder of a room)
Gestures
Fine and gross motor body movements, facial expressions, eye behaviours, and postures
Illustrators
Nonverbal behaviours that accompany speech and illustrate what is being said
1/ emphasize a word or phrase
2/ depict a referent or a spatial relationship
3/ depict the pacing of an event
4/ illustrate a verbal statement through repetition or substitution of a word or a phrase
- used less consciously, less deliberately than emblems
- most frequently when excited, when receiver not paying attention or not understanding, or when interaction is difficult
Emblems
gestural behaviours that can be translated or defined by a few words or a phrase and that can be used without speech to convey messages; high level of agreement within a culture; context-dependent
- comprehension may depend on cognitive and language abilities
Affect displays
Facial expressions or body movements that display emotional states
- more subtle, less stylized than emblems
- less intentional
- user may be unaware, although obvious to receiver
Regulators
Nonverbal behaviours that maintain and regulate conversational speaking and listening between two or more people
- initiate or terminate interactions
- tell speaker to continue, repeat, elaborate, hurry up, change topic, give listener chance to speak
- tend to be culturally-bound
- e..g head nods, eye behaviours
- emitted almost involuntarily
Adaptors
- Used more often when alone, not intentionally used in communication
- may be triggered by interactions that produce emotional responses
self-adaptors: manipulations of one’s own body (holding, rubbing ,scratching, pinching)
object-adaptors: manipulation of objects, learned later in life , have less social stigma
alter adaptors: learned early in life, in conjunction with interpersonal experiences, such as giving and taking or protecting oneself against impending harm
Vocalizations
People who have difficulty with speech often produce vocalizations that are communicative in nature, ranging from involuntary sounds (sneezing, coughing) to voluntary vocalizations, such as yawning, laughing, crying, moaning, yelling, belching, uh-huh, uh-uh,
- May be idiosyncratic and require interpretation by people familiar wit the individual’s repertoire of voice signals
Partner vocalizations / speech
May be used in auditory scanning
20 questions
Manual Sign Systems
Prior to 1990, manual signing was the form of augmentative communication used most often with people diagnosed as having autism or ID.
Six reasons why manual sign approaches might be appropriate alternatives to speech-only:
- language input is simplified and rate slowed when signs combined with speech
- expressive responding facilitated by reduction in physical demands and psychological pressure for speech and by enhancement of interventionist’s ability to shape gradual approximations and provide physical guidance
- vocabulary that is limited yet functional can be taught while maintaining the individual’s attention
- allow simplified language input while minimizing auditory short-term memory and processing requirements
- stimulus processing is facilitated with use of visual mode, which has temporal and referential advantages over the speech mode
- advantage over speech/symbolic representations because some signs are closer visually to their referents than are spoken words.
Manual Signs - Considerations for use
Intelligibility - most signs cannot be guesses by unfamiliar individuals
Iconicity - signs with high iconicity are easier to learn and to recognize
Motoric Complexity - first signs 1/ require contact between hands, 2/ produced in neutral space in front of body, against chin, mouth, forehead, or trunk, 3/ require single simple manual alphabet handshape, 4/ require bidirectional movements
Other considerations
Manual Signs - Combining with Speech or other AAC techniques
- Combined sign + speech intervention is often more effective in establishing production and/or comprehension skills than either mode taught singly
- “Simultaneous Communication” / “Total Communication”
- signs + line-drawing symbols on SGD > sign-alone in teaching use of two-word utterances
Manual Sign System refers to ..
three main types of systems
1/ Alternatives to spoken language of a particular country
2/ those that parallel spoken languages
3/ those that interact with or supplement another means of transmitting a spoken language
National Sign Language
Deaf communities in most countries have developed national sign languages
ASL, LSQ
- related neither to English/French or sign languages of other countries; does not follow or approximate English word order, so not used concurrently with speech
Manually Coded English Sign Systems
- Code English word order, syntax, and grammar
- Developed for educational use with individuals with hearing and other communicative impairments
- “Contact Sign” ASL-like English, English-like ASL
- Conceptually Accurate Signed English: English grammatical order + ASL signs, invented signs, fingerspelling
- keyword signing: spoken English + signs for critical words
- Signed English
- Signing Exact English
Tactile Signing
Commonly used by individuals with deaf-blindness who acquire their knowledge of sign language before becoming blind
- deaf-blind person places one or both hands on the dominant hand of the signer and passively traces the motion of the signing hand
- Formational properties of signs received tactually by deaf-blind person
- Deaf-blind person communicates expressively using conventional sign language
- Can receive ~ 1.5 signs/second (typical signing 2.5/second)
Aided Symbols - tangible symbols
Two- or three- dimensional aided symbols that are permanent, manipulable with a simple motor behaviour, tactually discriminable, and highly iconic.
- Symbols that can be discriminated based on tangible properties (shape, texture, consistency)
- Typically used with individuals with visual or dua lsensory impairments and severe cognitive disabilities
Tangible symbols - Real objects
May be identical to, similar to, or associate with referents.
- Many people with ID are able to match identical and non-identical object symbols with similar accuracy
Tangible symbols - miniature objects
- May be more practical than real objects
- May be more difficult for people with cognitive disabilities to recognize than some types of two-dimensional symbols.
- Have been used successfully with people with CP, dual sensory impairments, wide variety of intellectual, sensory, motor impairments
- ## Tactile similarity is critical for people with visual impairments
Tangible symbols - partial objects
e. .g top of spray bottle of window cleaner “washing the windows”
- symbols with one or two shared features, e.g. plastic symbols that are the same size and shape as referent
Tangible symbols - artificially associated and textured symbols
- Symbols constructed by selecting shapes and textures that can be artificially associated with a referent.
- May be logically or arbitrarily associated with referents
Aided symbols - Pictorial Symbols
Two-dimensional pictorial symbols, including photographs, line drawings abstract symbols
Aided symbols - Pictorial - Photographs
People with ID matched colour photographs to referents somewhat more accurately than B/W photos, B/W photos more accurately than line drawings
- May be better if objects are cut out
- Context may affect ability to recognize it
Aided symbols - Pictorial - Line-Drawing Symbols
Many sets have been developed to support communication and/or literacy development of individuals with CCN. Primary sets are:
- Picture Communication Symbols (PCS)
- Widgit Symbols
- Pictograms
- Blissymbols
Aided symbols - Pictorial - Line-Drawing Symbols - Picture Communication Symbols
- Most widely used line-drawing system for communication around the world
- more than 18,000 pictorial graphics representing words, phrases, concepts on a range of topics
- animated PCS for many verbs are available
- 44 languages
- clustering same-colour PCS symbols may facilitate accurate selections
- PCS for concrete nouns learned more readily than abstract nouns
- more transparent and easily learned than Blissymbols
- Iconicity of symbols depends on cultur e
Aided symbols - Pictorial - Line-Drawing Symbols - Widgit Symbols
- Developed in USA
- 11,000+ symbols cover vocabulary of 40,000+ words
- designed to conform to scheme, or set of standards and conventions
- used to support communication and literacy
Aided symbols - Pictorial - Line-Drawing Symbols - Pictograms
- Developed in Canada
- 1,500+ white-on-black picto-images designed to reduce figure-ground discrimination difficulties
- Less translucent than PCS but more translucent than Blissymbols
- children with ID learned to recognized animated Pictograms of action words more readily than static equivalents
- Available in 15 languages, widely used in Scandinavia and other countries in Northern Europe, as well as Japan
Aided symbols - Pictorial - Line-Drawing Symbols - Blissymbols
- Developed to function as auxiliary language for international written communication
- ~ 100 basic symbols can be used singly or in combination to encore virtually any message
- 4,500 symbols, with new Blissymbols added periodically by international panel
- Used in more than 33 countries, translated into 15 languages
- Less transparent and more difficult to learn and retain than other line-drawing symbols
Aided symbols - Pictorial - Others - Pictographic Communication Resources:
- Developed to assist health professional and other conversation partners communicate with adults who have aphasia and other acquired communication impairments
Aided symbols - Pictorial - Others - Gus Communication Symbols
- A set that consists of 5,500+ colour line-drawing symbols representing standard vocabulary words and those related to entertainment, sports, current events, politics, and other common topics of conversation.
- Designed to appeal to adolescents and adults, as well as children
Aided symbols - Pictorial - Others - Pics for PECS
- Set of 2,000 colour images that include vocabulary words for adolescents and adults, as well as children
Aided symbols - Pictorial - Others - Symbolstix
- 12,000+ colour line-drawing symbols depicting activities and people as lively stick figures “with an attitude”
- Used in Proloquo2Go
Aided symbols - Pictorial - Others - Imagine Symbols
- 3,600 realistic, colourful illustrations in 15 categories that include emotions, phrases, verbs, and computer devices
- Designed to be appealing to adults
Aided symbols - Orthography
Written characters used to transcribe particular linguistic systems
- Used in AAC in the form of single letters, words, syllables, sequences of commonly combined letters, phrases, and sentences
Aided symbols - Orthographic symbols -
Aided techniques that represent traditional orthography, such as braille and fingerspelling.
Aided symbols - Orthographic codes
Use letters as message abbreviations
Aided symbols - Orthographic symbols - Braille
- A tactile symbol system for reading and writing used by people with visual or dual sensory impairments.
- Formed by combinations of six embossed dots arranged within a cell of 2 vertical columns of 3 dots each
1 4
2 5
3 6 - Characters represent letters, parts of words, or entire words
- Alphabetic/uncontracted braille: one-to-one correspondence between each letter and braille cell
- Contracted braille: uses special symbols (contractions) that stand for entire words or combinations of letters
Aided symbols - Orthographic symbols - Fingerspelling
Fingerspelling used to represent single letters of the alphabet that can be combined to spell words for which there are not conventional signs
- many fingerspelled letters appear to be visually similar to graphic counterparts, and learning of letter-sound relationships might be enhanced by pairing the two during initial instruction
Combined symbol systems
Formal symbol systems that incorporate the use of at least manual signs with graphic symbols
Combined symbol systems - Makaton Vocabulary
- A language program offering a structured, multimodal approach for the teaching of communication, language, and literacy skills.
- Used extensively in the UK, adapted in many countries
- Combines speech, manual signs, graphic symbols
- Core vocabulary consists of ~450 concepts organized in series of 8 stages
- ~7,000 concepts for which there are manual signs and ysmbols
Conversational speaking rate of speakers who do not have disabilities
150-250 words per minute
Communication rates associated with AAC range from _________ times slower than spoken speech rates.
15 to 25
Such drastic reductions in communication rate are likely to interfere significantly with communication interactions, especially in educational and employment contexts with natural speakers who are accustomed to exchanging information at a much more rapid pace.
Communication __________ and ___________ limitations interfere with communication interactions of many individuals who rely on AAC to communicate
inefficiencies,
message-timing
A strategy that is often used to increase communication rates is to ________
store complete words, phrases, or sentences in AAC systems and to assign a code of some type to the stored message.
Encoding
Any technique in which one gives multiple signals that together specify a desired message
How codes are represented is an individual decision that should be matched to a person’s capabilities
Memory-based codes
require the person have excellent long-term memory skills
Display-base dcodes
codes presented on a visual display or menu, or recited aloud so the person can choose, require either good visual skills or good auditory discrimination skills
- may be used with eye pointing
Word Codes
Several types of codes can be use to represent single words, including letter, numeric, alphanumeric techniques
Alpha (letter) word codes
Two types
1/ Truncation codes - abbreviate words according to the first few letters only (HAMB = hamburger), typically have fewer letters and are easier to construct
2/ Contraction codes - abbreviate words according to the most salient letters (HMBGR = hamburger), may have advantage of being more flexible
Either may be memory or display based
Alphanumeric Word Codes
Use both letters and numbers for words
COMM1 = communicate
COMM2 = communication
COMM3 = community
the same letters can be used repeatedly across words that are differentiated by number
Letter-Category Word Codes
Initial letter usually superordinate category
Second letter usually first letter of specific word
F = fruit FA = apple, FB = banana DC = coffee, DM = milk
May use memory or display based systems depending on ability of the person using the system
Numeric encoding
Numeric codes alone are used to represent words or messages
- May be used when communication display must be small to accommodate limited motor capabilities
- Relationship between code and corresponding word is completely arbitrary
- Most systems display the codes and associated words or messages on a chart or a menu as part of the selection display so that neither person with CCN or partner must rely on memory for recall or translation
- Extensive training and instruction is necessary to memorize the codes otherwise
13 = YESTERDAY
24 = HELLO
Morse Code
International system that uses a series of dots and dashes to represent letters, punctuation, numbers
- in AAC systems, transmitted via microswitches through a device algorithm that translates them into orthographic letters and numbers
One study: case study, man with spinal cord injury, 25-30 words/minute
Encoding strategies - Learnability
1/ Arbitrary numeric code 2/ Alphabetically organized numeric codes in which consecutive numbers are assigned to words based on their alphabetic order 3/ Memory-based alphanumeric codes 4/ Chart-based alphanumeric codes 5/ Letter-category codes
- Most accurate and quick with encoding approaches that grouped words according to logical pattern – alphanumeric, alphabetically organized numeric, and letter-category codes
truncation > contraction > arbitrary
Message Codes - Alpha (Letter) Encoding
Letters used to encode messages
Usually memory based
Message Codes - Alpha Encoding - Salient Letter Encoding
Initial letters of salient content words in the message are used to construct the code.
PLEASE OPEN THE DOOR FOR ME –> OD
Familiarity with traditional orthography and ability to spell at least the first letter of words are necessary; Ability to recall messages in correct syntactic forms
Message Codes - Alpha - Letter-Category Message Encoding
Initial letter of code determined by an organizational scheme that categorizes messages
HELLO HOW ARE YOU?
GH -
G –> greetings
Second letter specifier within the category
Message Codes - Alphanumeric Encoding
Both letters and numbers
Alphabetic –> category of messages
Number –> arbitrarily specify individual messages within category
Desirable to combine memory and display based strategies
Message Codes - Numeric Encoding
Some type of system is often applied to organize the codes into categories.
Repertoire may be organized into categories using first number (e.g. 3 = wants/needs)
Display based system potentially mixed with memory based
Message Codes - Iconic Encodoing
Semantic compaction, Minspeak (Unity)
Icons = pictorial symbols combined to store words
e.g. apple icon = FOOD, FRUIT, SNACK, RED< ROUND
APPLE + SUN = Let’s have a barbecue.
Icons stored in an SGD
Colour Encoding
Usually in conjunction with specifiers such as numbers or symbols.
Eye-pointing communication systems
Colour + alpha codes (catalogued in code book)
or, with other types of access techniques – communication books, electronic displays, categories might be colour- (NB: b/w line drawings on colour-coded backgrounds recognized less rapidly than internally coloured symbols on white backgrounds in 2-5 year olds)
Message Encoding - Learnability
1) both alpha and salieint letter codes recalled most accurately
2/ iconic codes associated with least accurate performance, regardless of training
3/ concrete messages easier to learn than abstract, regardless of technique
4/ no apparent learning advantage of personalized codes
5/ long iconic codes more difficult to learn than short iconic codes
iconic - 4 year old: 1,000 instructional sessions for 1,000 word vocab
5 year old 400-500 sessions
requires learning time, considerable cognitive demand, especially in early stages of acquisition
Letter, Word, Message Prediction
Dynamic retrieval process in which the options oferred to an individual with CCN change according to the portion of a word or message that has already bene formulated. Can be used to enhance communication rates. Prediction algorithms occur at one or more of three levels:
- single letter
- word
- phrase/sentence
Single-Letter Prediction
Some letters occur more frequently than others (e,t,a,o,i,n,s,r,h) (z,q,u,x,k,j)
Probability of occurrence of a letter in a word is influenced by previous letter
- Some use probability of individual letters and letter combination relationships; menu of letters likely to follow
- Ambiguous keyboards (t9) and disambiguation algorithms to predict intended key
Optimized layouts can result in switch savings of 37-53% over simple alphabetic matrix
Word-Level Prediction
Three basic types: word prediction, word-pattern prediction, linguistic prediction
Word-Level Prediction: Word Prediction
Computer program provides set of likely words (weighted for frequency of use) in response to one’s keystrokes
e.g. person types L, system shows six most frequently used words that begin with L; not word choice not included in listing, person types next letter .. when desired word presented, person types associated number code
words may be preselected, programmed, or monitored and tailored to communication performance of person using the system
Word-Level Prediction: Patterns of Word Combinations
e. g. article follow a preposition in prepositional phrase
- menu of words likely to follow each word that is selected
Word-Level Prediction: Linguistic Prediction
- Algorithms that contain extensive information about the syntactic organization of the language, based on grammatical rules of language
- If first-person singular noun selected as subject, only verbs that agree in subject and number will be options
Phrase- or Sentence-Level Prediction
TALK Boards
700 phrase-based communication displays
42-64 words per minute, 3-6 times faster than phrase construction (ALS)
- structured situations, highly sequential and predictable
- keystroke savings
- Contact – incorporates word- and phrase-level prediction for social and structured conversation
Factors that should be considered when evaluating the effectiveness of various rate-enhancement strategies
- the nature and goal of the communication task itself
- the extent to which the vocabulary and/or codes available in the AAC system are contextually relevant and easily accessed
- The cognitive processing time needed to decide which selections or motor acts are necessary
- The search time (i.e. the amount of time it takes to locate a letter, word, or phrase from a prediction menu)
- The key press time (i.e. the amount of time it takes to activate a key or switch)
- The motor act index (i.e. the number of keystrokes necessary to produce a message)
- The time or duration of message production (i.e. how long it takes to produce a message)
