Increasing probability of sign language learning by severely mentally retarded individuals: a discussion of learner, sign production, and linguistic variables

Applied Research in Mental Retardation, Vol. 3, pp. 8 1 - 9 7 , 1982 Printed in the USA. All rights reserved.

0270-3092182/010081 - 17503.00/0 Copyright ,g 1982 Pergamon Press Lid

Increasing Probability of Sign Language Learning by Severely Mentally Retarded Individuals: A Discussion of Learner, Sign Production, and Linguistic Variables Richard L. Luftig Miami University, Ohio A pervasive problem for educators of the severely mentally retarded is language training. In spite of extensive oral language training, many severely mentally retarded individuals never acquire functional oral language. Many of these clients, however, are able to acquire sign language communication skills. The present article discusses sign language learning in terms of learner attributes, production variables in sign, and the referential concepts which the signs represent. More specifically, it is hypothesized that by taking into account variables such as sign translucency, referential concreteness, learner readiness, and by externally organizing the signs to be learned along visual continuums, the probability of sign learning by severely mentally retarded individuals can be increased.

One of the most pervasive problems among mentally retarded individuals is communication deficiencies (Fristoe & Lloyd, 1980). It has been estimated that at least 15% of all mentally retarded individuals possess hearing impairments, that over 70% have a speech problem, that a majority of severely/profoundly mentally retarded people possess little or no functional speech, and that virtually all mentally retarded individuals possess a language deficiency to some degree (Bensberg & Sigelman, 1976; Fristoe & Lloyd, 1979; Lloyd, 1970; Spradlin, 1963). Traditionally, professionals interested in remediating language deficits with mentally retarded clients have utilized techniques designed to improve oral lanRequests for reprints may be addressed to Richard L. Luftig, Educational Psychology/SpecialEducation, 201 McGuffeyHall, Miami University,Oxford,Ohio 45056. 81

82

Richard L. Luftig

guage. The use of these techniques has often been predicated on the assumption that oral language is the most natural form of communications for humans, and this is the easiest for humans to learn. In addition, many professionals have held that by teaching non-oral means of communication the probability is increased that the client would become unmotivated to use oral communication (Frey, Note 1). These beliefs have sometimes led to negative positions on the usage of nonoral communication; for example, cases where deaf students were forbidden to use sign language while enrolled in communication intervention programs under threat of expulsion from the educational program (Lloyd, Note 2). Despite beliefs and assumptions regarding advantages of oral language training over non-oral intervention, oral communication techniques have generally proven to be unsuccessful with severely mentally retarded populations (Graham, 1976; Kopchick & Lloyd, 1976). Although some studies have demonstrated ability of nonverbal mentally retarded individuals in developing very limited speech, no program of speech training with these individuals has been reported which indicated that the mentally retarded pupils increased their vocabularies, generalized to new language situations, or improved in syntactic structure (Kahn, 1981~ Sailor, Guess, & Baer, 1973). According to Fristoe and Lloyd (1979), however, rather than question the assumptions of the oral communication model for these clients, educators have often concluded that language intervention for many severely/profoundly mentally retarded persons was a useless endeavor. Thus, two classes of mentally retarded individuals have begun to emerge; one which may benefit from oral language intervention and a residual, more handicapped group which cannot (Graham, 1976; Guess, Sailor, & Baer, 1977). A body of clinical and empirical evidence exists, however, which indicates that the use of nonspeech systems can facilitate language development in heretofore nonlanguage clients (Berger, 1972; Bricker, 1972; Carr, Binkoff, & Kologinsky, 1978; Casey, 1978; Kahn, 1981; Konstantareas, Oxman, & Webster, 1977). For example, Kahn (1981) compared speech training and sign language training methods on the language learning of severely/profoundly mentally retarded children and found that while all of the students in the signing condition learned some signs, only half of the students in the speech condition learned any words. Additionally, some of the pupils in the sign condition learned to spontaneously combine signs into phrases and generalize sign language to new situations. Likewise, the use of sign language has proven to be effective with autistic children (Carr et al., 1978; Casey, 1978; Konstantareas et al., 1977). Additionally, sign language training with these clients has indicated that autistic children not only learn signing skills, but generalize the use of these skills from the training environment to the natural environment (Casey, 1978). Finally, it has been demonstrated that as these individuals acquire language, a significant reduction in heretofore deviant and unmodifiable social behaviors have also occurred (Casey, 1978; Fristoe & Lloyd, 1979; Graham, 1976; Lloyd, 1976,

Increasing Probability of Sign Learning

83

Fristoe, Note 3). Presumably, these reductions in deviant behavior occurred because the client possessed a more efficient and acceptable way of making her/ his wants and needs known (Lloyd, 1976). Finally, contrary to earlier beliefs, the acquisition of nonspeech language competency by severely mentally retarded individuals apparently did not adversely affect spoken language development. It was reported that not only did the clients develop non-oral communication expertise but that many also began to speak for the first time. Apparently nonspeech communication competency acted as an impetus for spoken communication in many of these individuals (Fristoe, 1975; Lloyd, 1976; Frey, Note 1). Under what types of situations may nonspeech language intervention programs prove to be facilitative? According to Fristoe and Lloyd (1979), the need for a nonspeech communication intervention program occurs when spoken communication intervention has been repeatedly attempted with little or no success. Such a failure would only be admitted after a variety of teaching methods, materials, instructional procedures, and learning modalities had been attempted with the degree of resultant language learning reflected by the client's language usage (either receptive or expressive) still at or near baseline levels. According to Fristoe and Lloyd, failures in spoken communication intervention techniques may occur for a variety of reasons. These include nonfacilitative environmental conditions (e.g., an environment which is too noisy or distant for optimal speech communication), as well as personal factors related to the individual. Such personal factors would include physical constraints which inhibit the adequate production of speech sounds (e.g., cerebral palsy), cognitive/developmental constraints which inhibit comprehension in oral language learning (e.g., mental retardation or aphasia), or linguistic constraints between speaker and receiver (e.g., lack of sharing of a common language). When such environmental and/or personal factors exist so as to inhibit the effectiveness of adequate speech communication or oral language intervention, nonspeech language instruction and non-oral language usage is appropriate. At the time that nonspeech language intervention is deemed to be appropriate for a client, one of three language goals may be selected (Fristoe & Lloyd, 1979), One goal may be the use of nonspeech communication as a temporary means of communication for the client. Adoption of this philosophical goal by the professional implies that nonspeech communication is utilized only until such time that the client begins to use rudimentary oral speech. At the point of such a development, nonspeech communication is phased out and oral speech is actively encouraged. Such a goal explicitly demands that the professional provide an environment conducive to non-oral communication in the present and oral communication for the future. Adoption of such a goal implies that oral sounds be rewarded rather than ignored and that long-term planning provisions include the eventual fading of non-oral communication responses from the client's communication repertoire.

84

Richard L. Lufiig

A second goal which may be chosen for the client is the choice of nonspeech communication as the lifelong medium of communication. Adoption of this goal precludes the active encouragement of oral communication at a later date and does not provide for eventual fading and/or extinction of non-oral communication responses from the client's language repertoire. Such an extreme position would probably be appropriate only after years of unsuccessful oral language intervention and would be predicated on the assumption that the current learning in the non-oral communication mode and eventual switching to oral communication intervention procedures represents too great a cognitive demand on the severely mentally retarded learner. Such a decision would also be affected by the prognosis for the learner as to her/his eventual release from the caretaking institution to a less restrictive environment. Such a goal would only be adopted if eventual return of the client to a lifestyle outside the institution was neither imminent nor feasible and the client's lifelong communication interaction needs were predicted to be only with institutional staff. Adoption of such a goal would represent a closed communication system and would clearly delineate and circumscribe the receivers of communication messages by the severely mentally retarded individual. Finally, a third goal which may be adopted for clients is simultaneous training in nonspeech and oral communication. Known as the "total communication" hypothesis of language instruction, this method prescribes the simultaneous teaching of language in the oral and non-oral modes with the goal that the client communicate in whichever mode she/he finds preferable. Inherent in the total communication approach is the belief that the presentation of oral language not be postponed to a later time but be paired from the first with nonspeech language. Although some critics of this third goal have argued that the simultaneous presentation of oral and non-oral language intervention techniques is confusing to the client (Cart et al., 1978), there is evidence to suggest that the simultaneous pairing of oral and non-oral language can be facilitative to language learning (Luftig, Gauthier, Freeman, & Lloyd, 1980). However, prior to adoption of a total language training technique, the professional must ascertain that simultaneous modality language stimulation does not overload either the cognitive ability or the modality information processing capacity of the learner (Broadbent, 1958; Bruininks & Clark, 1972; Luftig et al., 1980). There are a variety of nonspeech systems from which professionals may choose. Generally, these have been divided into aided and unaided systems (Fristoe & Lloyd, 1980). While aided systems include symbol boards and/or electronic aids (e.g., Bliss symbol board, Blisscom, chin switches, optical pointers), unaided systems refer to nonspeech communication which the client may utilize without resorting to external aids or devices (Fristoe & Lloyd, 1979; McNaughton & Kates, Note 4; Cleeter, Note 5). Unaided systems usually refer to visual productions which take the form of either gestures or signs and sign systems. According to Fristoe and Lloyd (1979), signs are formalized gestures.

Increasing Probabili~ of Sign Learning

85

Thus, signs that conform to rules have psycholinguistic constraints on their formation and usage. Additionally, signs are further constrained into linguistic systems which contain syntax, grammatical structure and are able to represent tense. Gestures have no such constraints. Furthermore, while signs may be abstract, gestures are concrete and guessable (Hoemann, 1975; Luftig & Lloyd, 1981). Among professionals utilizing nonspeech communication intervention techniques with the severely mentally retarded, the use of unaided systems and the use of sign language over gestural systems seem to be the systems of choice. Sign languages frequently utilized in the nonspeech communication training of severely mentally retarded clients are American Sign Language (ASL) and Signed English, a language with signs similar to ASL but with grammatical syntax closer to English (Bornstein, 1978; Fulwiler & Fouts, 1976; Sutherland & Beckett, 1969). The use of manual sign language has led to higher levels of communication in a wide variety of handicapped learning populations including the severely mentally retarded (Kahn, 1977; Shaffer & Goehl, 1974; Topper, 1975), the deaf retarded (Hall & Talkington, 1973; Hoffmeister & Farmer, 1972), the autistic (Bonvillian & Nelson, 1976; Fulwiler & Fouts, 1976), and the cerebral palsied (Fenn, 1976; Fenn & Rowe, 1975). Thus, the recent attention paid to sign systems in the exceptional learner literature as well as increased popularity in usage with severely handicapped learner populations appear to be justified. However, a problem with the increased reliance on sign as an alternative communication mode with the mentally retarded is that choices of initial sign lexicons to be taught have often not been made on sound psycholinguistic and psychological grounds (Fristoe & Lloyd, 1980; Luftig & Lloyd, 1981). Rather, lexical choices for mentally retarded learners are often made on the intuitive belief of the teacher as to which signs ought to be in the learner's vocabulary (Frey, Note 1). This is not to say that choosing a functional lexicon of frequently occurring signs is not important but rather that it is only one variable (albeit a relevant one) which should be taken into account as the sign lexicon is chosen. To enhance sign learning efficiency, other psychological and psycholinguistic variables need to be taken into account and to ignore the relevancy of these variables is to insure inhibited learning by clients and frustration on the part of professional staff (Kopchick & Lloyd, 1976). The present paper discusses the teaching of sign (ASL) in terms of the educational and cognitive attributes of the mentally retarded learner, psycholinguistic components of signs and referents, and the relationship between learner and sign system. The purpose of this paper is not to list a first lexicon of signs to be taught since the choice of an initial lexicon is partially dependent on the unique living environment of the learner. Rather, the variables not usually taken into consideration by professionals in choosing an initial lexicon will be discussed. It is posited that by taking these factors into account, the teacher will increase the probability that the initial lexicon will be learned and increase the time efficiency of learning.

86

Richard L. Luftig

LEARNER ATTRIBUTES INFLUENCING THE ABILITY OF MENTALLY RETARDED INDIVIDUALS TO LEARN SIGN: ORGANIZATION AND METACOGNITION As indicated earlier, attempts at developing speech in severely/profoundly mentally retarded people have been relatively unsuccessful. Furthermore, even in cases where clients have acquired limited speech, they have generally been unable to generate new language or use vocabulary spontaneously. One hypothesis for this limited oral language success with severely mentally retarded individuals posits that these learners lack the metacognitive control abilities with which to sensibly organize incoming verbal language stimuli (Brown, 1974; Brown & Barclay, 1976; Luftig & Johnson, Note 6; Luftig, Note 7). Metacognition refers to what a person comes to know, or knows how to find out about, his/her cognitive abilities (Brown, 1975; Flavell & Wellman, 1977). Included in the taxonomy of metacognitive skills is the ability to cognitively organize and reorganize incoming stimuli in such a way so as to maximize understanding, optimize meaningful placement into memory, and facilitate spontaneous retrieval and usage in appropriate situations (Luftig & Johnson, Note 6; Luftig, Note 8). Spitz (1966) has argued that mentally retarded individuals oftentimes view the world as more chaotic and unorganized than normal learners and he has asserted that many verbal learning deficits in severely mentally retarded individuals are not caused by a physical inability to learn but rather by an inability to appropriately organize and categorize incoming verbal stimuli. Likewise, a retardate selective attention hypothesis has been advanced which holds that retardate learning deficits are caused by an inability to selectively attend to relevant stimulus attributes while nonattending to salient but unimportant stimuli (Fisher & Zeaman, 1973; Zeaman & House, 1963). There is an impressive body of evidence which supports metacognitive organizational and attentional explanations of learning deficits in the verbal learning of mentally retarded individuals (see Mercer & Snell, 1977 for reviews). The educational implications of these hypotheses suggest that learning deficits of mentally retarded individuals are due to deficits in control processes rather than to problems in structural features (Atkinson & Shiffrin, 1968). According to Atkinson and Shiffrin, structural features are invariant components of the learning system which are unmodifiable while control processes are optional strategies under the control of the learner. Structural features may be thought of as akin to the hardware of a computer while control processes may be thought of as the possible operations which the computer can perform and which are under the control of the computer operator. While structural features are unmodifiable, control processes are susceptible to training. Thus, it follows that

Increasing Probability of Sign Learning

87

if deficits in verbal learning are due to control process problems rather than problems of structural features, these deficits may be partially remediable by appropriate external organization of language stimuli imposed by the teacher. This would free the mentally retarded learner from internal language organization demands and would be hypothesized to facilitate retardate language learning (Flavell, 1970). This metacognitive organizational deficit and selective attention hypothesis operation of control process deficiencies have been supported by empirical evidence. In a wide variety of situations, when external teacher organization of to-be-learned stimuli has been imposed or when the salient, important conceptual attributes of to-be-learned stimuli have been stressed, retardate learning has been enhanced (see Brown, 1974 for a review). Why are severely retarded individuals who cannot orally communicate nevertheless able to learn and use sign? Borrowing from the Spitz (1966) organizational theory and the selective attention hypothesis outlined above (Fisher & Zeaman, 1973; Zeaman & House, 1963), it may be that the attributes of sign impose an external organization on the to-be-learned stimuli which is not present in spoken language. Hoffmeister and Farmer (1972), for example, have hypothesized that the concrete, pictorial nature of sign allows the mentally retarded learner to use visual imagery in learning. Hoffmeister and Farmer point out that since signs are ideographic in nature, action signs which are presented visually allow the mentally retarded learner to associate the verbal instruction with the ideographic sign. Such a system thus imposes an organizational structure on the signs to be learned and cuts down on the relatively high information processing demands made by most verbal materials (Luftig et al., 1980). Finally, it may be that by using sign, attention to relevant production and linguistic attributes are optimized since in initial action signs to be learned, relevant sign-production conceptlearning cues are highlighted and made salient for the learner. In such cases, the high selective attentional demands of oral systems would be reduced for the mentally retarded learner and language learning would be facilitated. Thus, even in cases where the client could not utter the oral sounds, she/he would still be able to produce the signs ideographically. What learner attributes might be taken into account in order to increase the probability that severely mentally retarded clients will learn the ideographic relationships necessary for sign language learning? Sutherland and Kates (Note 9) have isolated "factors which determine the suitability of symbols," and "factors which influence the nature of the program to be used." Factors which determine the suitability of sign include the learner's desire to communicate and the developmental level of the learner. According to the authors, the first factor to be considered in deciding if a sign program should be initiated would be a decision as to whether the learner understands that signs may be used to symbolically manipulate her/his environment and whether the client shows a desire to manipulate the environment through communication procedures. This knowledge

88

Richard L. Luftig

of the environmental manipulation potential of sign and a desire to use it is assessed prior to and is separate from the client's learning of sign. The developmental level of the client in terms of ability to learn sign would include recognition of concrete objects, recognition of representations (e.g., miniatures or pictures) of objects, and recognition of functions of objects. If the client did not recognize concrete objects or know their function, such training would have to be completed before sign language intervention techniques could be instituted. Taken together, decisions about client desire to communicate and language developmental levels constitute readiness to learn sign and contribute toward predicting whether sign language intervention is likely to be successful for the client. Sutherland and Kates (Note 9) have also identified a number of factors which would influence the nature of the program designed for the client. Among the most important factors for the ability to use sign are the level of alertness of the client, her/his visual acuity, figure ground perception, hearing acuity, factors of attention, frustration level, and hand function. Sutherland and Kates argue that each of these variables must be assessed independently prior to choosing a sign lexicon of appropriate concreteness and visuality and in planning the length and intensity of training sessions. Taken into account, these factors would help insure that learning would not be frustrating to the student and would aid in presenting stimuli at an appropriate cognitive level thus increasing probability of meaningful sign learning. In conclusion, it appears that when material is externally organized for the client, when important conceptual attributes are highlighted, and when the factors outlined by Sutherland and Kates (Note 9) are taken into account, it seems more likely that previously noncommunicative severely mentally retarded individuals will acquire sign language. Kiernan (1977) states: "It is safe to draw the conclusion that mentally handicapped people can learn to understand and use signs . . . . What is clear is that the area offers exciting possibilities for a breakthrough which can have far reaching effects. The available evidence is inadequate but exciting" (p. 27). EFFECTS OF SOME PSYCHOLINGUISTIC PROPERTIES OF SIGN LANGUAGE ON SIGN LANGUAGE LEARNING: ICONICITY AND TRANSLUCENCY The last decade has seen a growth in interest in the psycholinguistic attributes of sign which facilitate its learning by severely mentally retarded individuals. Fristoe and Lloyd (1979), for example, have hypothesized that one attribute of sign which facilitates learning is the role of visual representation. Fristoe and Lloyd have posited that visual representativeness frees the individual from having to depend on the use of abstract sounds to express referential concepts.

Increasing Probability of Sign Learning

89

The visual representativeness of sign language may be delineated by the attributes of iconicity, transparency, and translucency (Griffith & Robinson, 1980). Iconicity refers to the guessability of a sign. An iconic sign is one where the sign so physically resembles its meaning (its gloss) as to be readily guessable (Harrell, Bowers, & Bacal, 1973). Thus, for truly iconic signs, a person unfamiliar with sign language should be able to determine the meaning of a sign by looking at it or should be able to produce the sign when given its gloss. Sign iconicity is not a dichotomous variable but rather falls along the continuum of transparency. Transparency refers to the ease of "seeing through" the sign and inferring its meaning from sign production (Luftig, Page, & Lloyd, Note 10). Some signs are easy to see through (high iconicity) while other signs are of intermediate iconicity and have a relatively good probability of being guessed. Finally, some signs seem to have little or no transparency and are said to be opaque. The phenomenon of sign translucency is related to iconicity but is not identical to it. Translucency refers to a judgment of the degree of relatedness perceived by raters between a sign and its meaning. Typically, in a translucency task, the rater is given a sign, told its meaning, and is then asked to judge relatedness between sign and gloss. By comparison, in the typical iconicity task, the subject is given a sign and asked to guess the gloss. In the acquisition of manual signs by naive sign learners, the linking of the sign to its referent by perceiving the relationship between the two (translucency) may be likened to the P-A (paired-associate) experimental learning paradigm since the learner is taught the sign by seeing the sign production and being given the gloss. Afterward, the sign is assumed to be learned when the learner can make the sign on being given the referent, can orally tell the referent when shown the sign, or can use the sign spontaneously in language-appropriate contexts. In learning a given sign, acquisition of sign and referent should be relatively easy when the sign is translucent. Conversely, for signs low in translucency, learning of sign-referent pairs should be relatively difficult. Substantially more research has been conducted on effects of sign iconicity on learning than on sign translucency and learning (Bonvillian & Nelson, 1976; Luftig & Lloyd, 1981; Siple, Fischer, & Bellugi, 1977; Brown, Note 11). Overwhelming evidence has indicated that signs high in iconicity are relatively easy to learn. For example, Bonvillian and Nelson (1976) found that of the first 56 signs taught to an autistic, mentally retarded client, 38 were judged to be iconic. Likewise, Brown (Note 11) demonstrated that signs high in transparency were learned easier by normal preschool children than signs low in transparency. Thus, over a wide range of situations and learning populations, transparent signs were learned best. Thus, it appears that signs high in iconicity are relatively easy to learn. However, recent research also indicates that sign language is less iconic than

90

Richard L. Luftig

originally believed (Hoemann, 1975; Hoemann & Hoemann, 1973; Luftig, Note 7; Page, Note 12). For example, Hoemann (1975) reported that by using a conservative estimate, only 10 to 15% of ASL signs are transparent while by using a liberal criterion, 20 to 25% of signs are highly transparent. These figures have also been substantiated by Bellugi and Klima (1976). If this is the case, then why are initial signs nevertheless easier to learn than spoken words for severely/profoundly retarded clients? Two explanations have been posited (Luftig & Lloyd, 1981; Luftig, Note 7). First, while it is probably correct that only a minority of ASL signs are truly iconic, many of these iconic signs nevertheless appear in the mentally retarded learner's first sign lexicon. Thus, it may be that these initial lexicons are "overloaded" with iconic signs (Brown, Note 11). The second explanation hypothesizes, however, that it is not iconicity (guessability) which is the key factor in sign learning, but rather the crucial variable is translucency or the degree of perceived relationship between sign and gloss after both have been given to the learner (Luftig & Lloyd, 1981; Luftig, Note 7; Luftig et al., Note 10). According to Luftig and Lloyd (1981), while guessability can be likened to the game of charades where the person sees the gesture and then must guess the message, translucency may be viewed as being similar to S-R (stimulus-response) learning in a paired-associate (P-A) paradigm. In a typical P-A sign learning model, the learner is shown a sign and simultaneously told its meaning rather than being shown a sign and having to guess its meaning. Afterward, the sign is assumed to be learned when the learner can produce the sign on being told the referent, can orally say the referent when shown the sign, or can use the sign appropriately and spontaneously in language contexts. Luftig and Lloyd have thus argued that the attribute of translucency more nearly approximates real-life learning of sign than explanations of sign learning based on iconicity. It has been demonstrated that among naive signers, signs judged to be relatively high in translucency are easier to learn than signs which are judged to be relatively low in that trait (Bellugi & Klima, 1976; Luftig & Lloyd, 1981; Sipple et al., 1977). Luftig et al. (Note 10), for example, obtained sign translucency ratings for 800 ASL signs. College raters were shown a sign, given its meaning, and were then asked to rate the sign on a scale of "1" low translucency to "7" high translucency. In a subsequent study (Luftig & Lloyd, 1981), subjects were required to learn the meaning of signs either high or low in translucency in a P-A paradigm. The results indicated that signs high in translucency were learned significantly faster and were remembered better than low translucency signs. Similar findings have been reported for children as young as preschoolers and with mildly mentally retarded children (Page, Note 12). Based on such findings, a hypothesis has been advanced that sign language translucency may be a potent predictor of learnability for severely mentally retarded individuals (Luftig & Lloyd, 1981).

Increasing Probability of Sign Learning

91

T R A N S L U C E N C Y OF S I G N - CONCRETENESS OF REFERENT IN THE LEARNABILITY OF SIGN

Up to this point, only the attributes of the signs themselves have been discussed in sign language learning. But what about the other half of the P-A pair, the concepts (glosses) which the signs represent? According to Harrell et al. (1973), there is a relationship between every sign and the concept which the sign represents. What effect does the psycholinguistic attributes of the concepts have on sign learning? The linguistic properties of concepts may be analyzed in a variety of ways such as word class, word length, relatedness, frequency of usage, etc. One of the most powerful dimensions of concept learnability has been shown to be that of concreteness/abstractness (Begg & Robertson, 1973; Bull & Wittrock, 1973; Conlin & Paivio, 1975; Paivio, 1980). Concrete concepts refer to concepts which have corresponding sense data in the phenomenal world (Harrell et al., 1973); that is, a concrete concept is one which comes under the jurisdiction of a sense modality (usually sight or sound). As the relationship between the concept and corresponding sense data becomes more tenuous or distant, the concept is said to be relatively abstract. Thus, the concept "dog" would be thought of as being relatively concrete while "truth" would be judged to be relatively abstract. Concrete concepts have been shown to be easier to learn than abstract concepts with a variety of normal populations (Bower, 1972; Paivio & Csapo, 1969; Paivio, Yuille, & Rogers, 1969), and the mentally retarded (Blake, 1976a, 1976b; Lebrato & Ellis, 1974; Taylor, Joshberger, & Knowlton, 1972; Yarmey & Brown, 1972). In a variety of learning situations and with a variety of learning materials, stimuli judged to be relatively high in concreteness were learned most efficiently. Luftig and Lloyd (1981) have hypothesized an interactive effect of sign translucency and concept concreteness in the learning of sign. Based on the ASL translucency ratings obtained by Luftig et al. (Note 10), Luftig and Lloyd (1981) constructed lists consisting of four classes of sign referent pairs; high transluc e n c y - h i g h concreteness (e.g., baby), low translucency--low concreteness (e.g., fun), high translucency--low concreteness (e.g., time), low transluc e n c y - h i g h concreteness (e.g., teacher). Students then attempted to learn the lists in a P-A learning study paradigm. The authors reported that both sign translucency and referent concreteness influenced the learning of lists of signreferent pairs. Additionally, these factors had a cumulative effect, in that learning was significantly facilitated when both factors were high and inhibited when both factors were low. Thus, available evidence appears to suggest that high translucency of sign and high concreteness of referent facilitate learning of sign language in normal hearing adults (Luftig & Lloyd, 1981), in young children,

92

Richard L. Luftig

and in mentally retarded individuals (Page, Note 12). If translucency of sign and concreteness of referent facilitate sign learning, then it would follow that these variables should be considered in choosing the severely retarded individual's first sign lexicon. TEACHING SIGN LANGUAGE TO SEVERELY RETARDED INDIVIDUALS: CONCLUSIONS AND RECOMMENDATIONS Selecting signs high in translucency and referential concreteness presents special problems for professionals interested in choosing sign lexicons. One such problem is how might such judgments be determined? Paivio, Yuille, and Madigan (1968) as well as Lippman (1974) have established a reliable procedure for judging the concreteness of nouns and verbs while Luftig et al. (Note 10) have established a methodology for rating sign translucency. These procedures entail the rating of perceived concreteness and translucency on a scale from "1" to "7" and the subsequent rank orderings of the concepts or signs along the appropriate continuum. One shortcoming has emerged, however, in these procedures as they apply to mentally retarded learners in that although these ratings have proved to be reliable, they were obtained on nonretarded nonning populations. Brown (Note 11) has argued that linguistic continuums like concreteness and translucency are determined by the rater's age, experience, and culture. Thus, what is judged to be translucent in one culture or age group might not be translucent in another. The sign for "milk" is a case in point. The ASL sign for milk is the gesture of milking a cow. Such a sign was probably highly translucent 100 years ago when children lived on dairy farms and milked cows by hand. But how translucent would the same sign be to an urban child who buys milk in cardboard containers or the mentally retarded child who doesn't know that milk comes from the cow? For these signers, the sign for milk might be relatively opaque. More research needs to be conducted investigating the correlation between cognitive functioning levels, culture, and perceived translucency before decisions can be confidently made as to the ease or difficulty of learning signs by severely mentally retarded learners. Even with understanding of the effects of translucency/concreteness on learning incomplete, however, the finding that translucency and concreteness are important factors in sign learning holds implications for the selection and teaching of signs to severely mentally retarded individuals. Traditionally, signs have been taught on the basis of functionality and word frequency. These variables are important and will continue to be important in choosing initial lexicons for severely/profoundly mentally retarded clients. But once a group of signs to be taught have been identified in terms of functionality and frequency, in what order should those desired signs be taught? Take, for example, the high frequency concepts and often taught signs "baby," "arm," "doll," "fun," "shoe," and

Increasing Probabili~ of Sign Learning

93

"mother." The variables of functionality or frequency give no indication in which order these signs might be taught nor do the variables predict the learnability of each individual sign. However, when the variables of concreteness and translucency are taken into account, a clearer picture begins to emerge. Since the first three signs are high in both concreteness and translucency, they should be easier to learn. Likewise, since the latter two are judged to be concrete but relatively opaque, it should be more difficult to learn these signs. Finally, since the sign for "fun" is judged to be low in both concreteness and translucency, it is predicted that the sign for "fun" should be quite difficult to learn by mentally retarded individuals. Educators interested in teaching a number of initial signs to these clients might best be served by taking concreteness, translucency, and learner attributes into consideration. In conclusion, it appears that severely/profoundly mentally retarded individuals can learn to express themselves for the first time in their lives by the use of manual sign. Additionally, it appears that the acquisition of sign language may have a secondary but important effect of diminishing socially undesirable behaviors in these individuals, presumably because these clients are able to express themselves linguistically for the first time in their lives It has been demonstrated clearly, however, that these clients have little or no chance of learning sign language incidently. Rather, the learning environment and the tobe-learned stimulus material must be structured in precise ways so as to optimize probability of learning. In structuring the environment, the educator has the responsibility of organizing learning on as many relevant variables and dimensions as possible. Foremost among these variables are: sign functionality, frequency, transparency, translucency, and concreteness. By taking these variables into account, it is hoped that the sign language learning efficiency of all nonverbal students will be significantly increased.

Acknowledgements--The author wishes to thank the Deans of the Graduate School, Research Office, and School of Education and Allied Professions of Miami University and the Chair of the Department of Educational Psychology, Miami University, for their support. Additionally, this paper could not have been completed without the guidance and support of Lyle L. Lloyd, Professor of Special Education and Audiology, Purdue University. Finally, the author wishes to thank four anonymous reviewers and Dr. Rowland P. Barrett for their extremely helpful comments and criticisms.

REFERENCE NOTES 1. Frey, M. C. The suitabili~ of American Sign Language in language inter~,ention programs: Some linguistic, psycholinguistic, and sociolinguistic considerations. Unpublished manuscript, Purdue University, 1979. 2. Lloyd, L. L. Personal communication, 1978. 3. Fristoe, M. Centennial audit: National survey of language intervention for the retarded. Paper presented at the 100th Annual Meeting of the American Association on Mental Deficiency, Chicago, October 1976.

94

Richard L. Luftig

4. McNaughton, S., & Kates, B. The application of Blissymbolics. Paper presented at the Conference on Non-Speech Communication, Gulf Shores, AL, 1977. 5. Cleeter, S. New trends in Blissymbolics. Unpublished manuscript, Purdue University, 1979. 6. Luftig, R. L., & Johnson, R. E. Identification and recall of structurally important units by mentally retarded learners. Paper presented at the meeting of the International Council for Exceptional Children, New York, 1981. 7. Luftig, R. L. lconicity and translucency qf sign and concreteness/abstractness of referent in learning ~?fASL. Unpublished manuscript, Purdue University, 1979. 8. Luftig, R. L. Identification and recall of structurally important units in verbal discourse as a Junction ~f the metacognitive processing ~f mentally retarded children. Unpublished doctoral dissertation, Purdue University, 1980. 9. Sutherland, D., & Kates, B. Considerations in assessing a child's communication needs. Ontario Crippled Children's Center, Toronto, 1975. 10. Luftig, R. L., Page, J. L., & Lloyd, L. L. Translucency ratings for 800 signs. Unpublished manuscript, Purdue University, 1981. 1 I. Brown, R. Why are signed languages easier to learn than spoken languages? Keynote address. National Association of the Deaf Symposium on Sign Language Research and Teaching, Chicago, 1977. 12. Page, J. L. A comparison of translucency ratings for signs obtained from normal, pre-school children, school-age children, and adults. Unpublished doctoral dissertation, Purdue University, 1981.

REFERENCES Atkinson, R. C., & Shiffrin, R. M. Human memory: A proposed system and its control processes. In K. W. Spence & J. T. Spence (Eds.), The psychology of learning and motivation (Vol. 2). New York: Academic Press, 1968. Begg, I., & Robertson, R. Imagery and long-term retention. Journal of Verbal Learning and Verbal Behavior, 1973, 12,689-700. Bellugi, U., & Klima, E. Two faces of sign: Iconic and abstract. In S. Harmad, H. Steklis, & J. Lancaster (Eds.), The origins and evaluation of language and speech. New York: Annal of the New York Academy of Sciences, 1976. Bensberg, G. J., & Sigelman, C. K. Definitions and prevalence. In L. L. Lloyd (Ed./, Communication assessment and intervention strategies. Baltimore: University Park Press, 1976. Berger. S. L. A clinical program for developing multimodal language responses with atypical deaf children. In J. E. McClean, D. E. Yoder, & R. L. Schiefelbusch (Eds.), Language intervention with the retarded. Baltimore: University Park Press, 1972. Blake. K. Abstractness and concreteness in retarded and normal pupil's sentence comprehension. Journal of Research and Development in Education, 1976, 9, 90-91. (a) Blake. K. Concreteness and abstractness and retarded pupil's learning of synonyms. Journal of Research and Development in Education, 1976, 9, 59-60. (b) Bonvillian, F. D., & Nelson, K. E. Development of sign language in autistic children and other handicapped individuals. In P. Sipple (Ed.), Understanding language through sign language research. New York: Academic Press, 1976. Bornstein. H. A. Galluadet Signed English Series. Washington, D.C.: Galluadet College Press, 1978. Bower, G. H. Mental imagery and associative learning. In L. W. Gregg (Ed.), Cognition in learning and memory. New York: Wiley, 1972. Bricker, D. D. Imitative sign training as a facilitator of word object associations with low functioning children. American Journal of Mental Deficiency, 1972, 76, 509-516. Broadbent, D. E. Perception and communication. New York: Pergamon, 1958.

Increasing Probabili~ of Sign Learning

95

Brown, A. L. The role of strategic behavior in retardate memory. In N. R. Ellis (Ed.), International review of research in mental retardation (Vol. 7). New York: Academic Press. 1974. Brown, A. L. The development of memory: Knowing, knowing about knowing, and knowing how to know. In H. W. Reese (Ed.), Advances in child development and behavior (Vol. 10L New York: Academic Press, 1975. Brown, A. L., & Barclay, C. R. The effects of training specific mnemonics on the metacognitive efficiency of retarded children. Child Development, 1976, 47, 71-80. Bruininks, R. H., & Clark, C. R. Auditory and visual paired associate learning in first grade retarded and nonretarded children. American Journal of Mental Deficiency, 1972, 76, 561-567. Bull, B., & Wittrock, M. C. Imagery in the language of verbal definitions. British Journal (~f Experimental Psychology, 1973, 43, 289-293. Carr, E. G., Binkoff, J. A., Kologinsky, E., & Eddy, M. Acquisition of sign language by autistic children. I: Expressive labelling. Journal of Applied Behavior Analysis, 1978, 11,489-501. Casey, L. O. Development of communicative behavior in autistic children: A parent program using manual signs. Journal of Autism and Childhood Schizophrenia, 1978, 8, 45 59. Conlin, D., & Paivio, A. The associate learning of the deaf: The effects of word imagery, and signability. Memory and Cognition, 1975, 3, 335-340. Fenn, G. Development of language in profoundly deaf children. Sign Language Studies, 1976, 11. 109-120. Fenn, G., & Rowe, J. A. An experiment in manual communication. British Jourr,!al t?J'Disorders in Communication, 1975, 10, 3-16. Fisher, M. A., & Zeaman, D. An attention-retention theory of retardate discrimination learning. In N. R. Ellis (Ed.), International review of research in mental retardation (Vol. 6). New York: Academic Press, 1973. Flavell, J. H. Developmental studies of mediated memory. In H. W. Reese & L. P. Lipsitt (Eds I. Advances in child development and behavior (Vol. 5). New York: Academic Press, 1970. Flavell. J. H., & Wellman, H. M. Metamemory. In R. V. Kail, Jr. & J. W. Hagen (Eds.), Perspectives in the development of memory' and cognition. H illsdale, N.J.: Erlbaum, 1977. Fristoe, M. Language intervention systems for the retarded: A catalogue of original structured language programs in use in the U.S. Montgomery, AL: State of Alabama Department of Education, 1975. Fristoe. J., & Lloyd, L. L. Signs used in manual communication training with persons having severe communication impairment. AAESPH Review. 1980, 4, 1-4. Fristoe, M., & Lloyd, L. L. Non-speech communication. In N. R. Ellis (Ed.), Handbook of mental deficiency: Psychological theory and researeh (2nd ed.). Hillsdale, N.J.: Erlbaum, 1979. Fulwiler, R. L., & Fouts, R. S. Acquisition of American Sign Language by a non-communicating autistic child. Journal of Autism and Childhood Schizophrenia, 1976, 6 . 4 3 - 5 1 . Graham, L. W. Language programming and intervention. In L. L. Lloyd (Ed.), Communication assessment and intervention strategies. Baltimore: University Park Press, 1976 Griffith, P. L., & Robinson, J. H. Influence oficonicity and phonological similarity on sign learning by mentally retarded children. American Journal of Mental Deficiency, 1980, 85, 291-298. Guess. D., Sailor, W., & Baer, D. M. A behavioral remedial approach to language: training for the severely handicapped. In E. Sontag, J. Smith, & N. Certo (Eds.), Educational programming .fbr the severely and profoundly handicapped. Reston, VA: The Council for Exceptional Children, 1977. Hall, S. M., & Talkington, L. Evaluation of a coordinated programming effort for deaf retarded. Journal of Rehabilitation of the Deaf, 1973, 6, 41-45. Harrell, M., Bowers, J. W., & Bacal, J. P. Another stab at meaning: Concreteness, iconicity, and conventionality. Speech Monographs, 1973, 40, 199-207. Hoemann, H. W. The transparency of meaning of sign language gestures. Sign Language Studies, 1975, 7, 151-161.

96

Richard L, Luftig

Hoemann, H. W., & Hoemann, S. A. Sign language flash cards. Silver Springs, MD: National Association for the Deaf, 1973. Hoffmeister, R. J., & Farmer, A. The development of manual sign language in mentally retarded individuals. Journal of Rehabilitation of the Deaf, 1972, 6, 19-26. Kahn, J. V. A comparison of oral and language training with mute retarded children. Mental Retardation, 1977, 15, 21-23. Kahn, J. V. A comparison of sign and verbal language training with nonverbal retarded children. Journal of Speech and Hearing Research, 1981, 24, 113-119. Kiernan, C. Alternatives to speech: A review of research on manual and other forms of communication with the mentally handicapped and other noncommunication populations. British Journal of Mental Subnormality, 1977, 23, 6-28. Konstantareas, M. M., Oxman, J., & Webster, C. D. Simultaneous communication with autistic and other severely dysfunctional nonverbal children. Journal of Communication Disorders, 1977, 10, 267-282. Kopchick, G. A., & Lloyd, L. L. Total communication for the severely language impaired: A 24hour approach. In L. L. Lloyd (Ed.), Communication assessment and intervention strategies. Baltimore: University Park Press, 1976. Lebrato, M. T., & Ellis, N, R. Imagery mediation in paired-associate learning by retarded and nonretarded subjects. American Journal of Mental Deficiency, 1974, 78, 704-713. Lippman, M. Z. Enactive imagery in paired-associate learning. Memory. and Cognition, 1974, 2, 385-390. Lloyd, L. L. (Ed.). Communication assessment and intervention strategies. Baltimore: University Park Press, 1976, Lloyd, L. L. Audiologic aspects of mental retardation. In N. R. Ellis (Ed.), International review of research in mental retardation. New York: Academic Press, 1970. Luftig, R. L., Gauthier, R. A., Freeman, S. A., & Lloyd, L. L. Modality preference and facilitation of learning using mixed and pure sign, oral, and graphic inputs. Sign Language Studies, 1980, 28, 255-266. Luftig, R. L., & Lloyd, L. L. Manual sign translucency and referential concreteness in the learning of sign. Sign Language Studies, 1981, 30, 49-60. Mercer, C. D., & Snell, M. E. Learning theory research in mental retardation: Implications for teaching. Columbus, Ohio: Charles E. Merrill, 1977. Paivio, A. Imagery and verbal processes (2nd ed.). New York: Holt, Reinhart, and Winston, 1980. Paivio, A., & Csapo, K. Concrete images and verbal memory codes. Journal of Experimental Psychology, 1969, 80, 279-285. Paivio, A., Yuille, J. C., & Madigan, S. Concreteness, imagery, and meaningfulness values for 925 nouns. Journal of Experimental Psychology Monographs, 1968, 76, (1, pt. 2). Paivio, A., Yuille, J. C., & Rogers, T. B. Noun imagery and meaningfulness in free and serial recall. Journal of Experimental Psychology, 1969, 79, 590-614. Sailor, W., Guess, D., & Baer, D. M. Functional language for verbally deficient children. Mental Retardation, 1973, 11, 27-35. Shaffer, T. R., & Goehl, H. The alinguistic child. Mental Retardation, 1974, 12, 3-6. Siple, P., Fischer, S. D., & Bellugi, U. Memory for nonsemantic attributes of American Sign Language and English words. Journal of Verbal Learning and Verbal Behavior, 1977, 16, 561 - 574. Spitz, H. H. The role of imput organization in the learning and memory in mental retardates. In N. R. Ellis (Ed.), International review of research in mental retardation (Vol. 2). New York: Academic Press, 1966. Spradlin, J. E. Language and communication of mental defectives. In N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963.

Increasing Probability of Sign Learning

97

Sutherland, G. F., & Beckett, J. W. Teaching the mentally retarded sign language, Journal of Rehabilitation of the Deaf, 1969, 2, 55-60. Taylor, A. M., Joshberger, J., & Knowlton, J. Q. Mental elaboration and learning in EMR children. American Journal of Mental Deficiency, 1972, 77, 69-76. Topper, S. T. Gesture language for nonverbal severely retarded males. Mental Retardation, 1975, 13, 30-31. Yarmey, A. D., & Brown, N. V. The role of imagery in incidental learning of educable retarded and normal children. Journal of Experimental Child Psychology, 1972, 14, 303-312. Zeaman, D., & House, B. J. The role of attention in retardate discrimination learning. In N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963.