Perception & Psychophysics 1983,33 (3),215-231 Perception of movement in American Sign Language: Effects oflinguistic structure and linguistic experience
HOWARD POIZNER TheSalkInstitute/or Biological Studies, La Jolla, California
In order to reveal the psychological representation of movement from American Sign Lan guage (ASL), deaf native signers and hearing subjects unfamiliar with sign were asked to make triadic comparisons of movements that had been isolated from lexical and from grammatically inflected signs, An analysis of the similarity judgments revealed a small Ilet of physically specifiable dimensions that accounted for most of the variance. The dimensions underlying the perception of lexical movement were in general different from tholle underlying inflectional movement, for both groups of subjects. Most strikingly, deaf and hearing subjects significantly differed in their patterns of dimensional salience for movements, both at the lexical and at the inflectional levels. Linguistically relevant dimensions were of increased salience to native signers. The difference in perception of linguistic movement by native signers and by naive ob servers demonstrates that modification of natural perceptual categories after language acquisi tion is not bound to a particular transmission modality, but rather can be a more general consequence of acquiring a formal linguistic system.
American Sign Language (ASL) is the visual and as a system with biological bases. In order to gestural language used by deaf communities in the bring these issues into focus, a brief description of United States. Since the language has developed com ASL will be presented first. pletely outside the auditory modality, its study can ASL is a language passed from one generation of provide clues both to the nature of language and to deaf people to the next as a native language. It is a those psychological processes upon which the com fully autonomous language with complex organiza prehension and production of language rest. The tional properties not derived from spoken languages. present article is concerned with how deafsigners and ASL is a highly inflective language much more like hearing subjects unfamiliar with sign perceive move Hebrew or Latin than like English (Bellugi, 1980; ments of the hands and arms that function in very Klima" Bellugi, 1979; Lane &: Grosjean, 1980; Siple, specific ways in the linguistic system of ASL. By 1978; Wilbur, 1979; Bellugi " Klima, Note 1). Like comparing perception of linguistic movement in sub all spoken languages, ASL shows duality of pattern jects who do and who do not know the language, we ing: basic lexical units are formed from a limited set can begin to uncover the ways in which linguistic ofcombining elements that are themselves essentially categorizations are based on the perceptual con without meaning, and meaningful units are com straints of the observer, and the ways in which such bined in the signed sentence by grammatical rules. categorizations are more arbitrarily determined. In However, the mechanisms by which this linguistic this way we can begin to address the correspondence structure is conveyed strongly bear the mark of the between language analyzed both as a formal system modality in which the language developed. With respect to the first level of patterning, signs from ASL are composed of three major formational This work was supported in part by National Institutes of parameters: configuration of the hands, movement Health Grant HD13249 and by National Science Foundation of the hands and arms, and location of the hands Grant BNS79-16423 to the SalkInstitute for Biolopcal Studies. I relative to the body (Stokoe, Casterline, &: Croneberg, thank Ursula Bellup for her valuable help throughout this project, 196'). Each parameter comprises an inventory of and Don Newkirk and Edward Klima for helpful discussions of the discrete representatives that combine concurrently paper. Malinda Williams, Crail Will, and Mike Herrera assisted with the experiment. I thank Emilio Bizzi, John Hollerbach, and rather than linearly. These representatives function Mike Atkenson for use of and assistance with the Selspot separately, however, to contrast minimally different mevement-monltoring system, which diptized the hand move signs, much as the phonemes of spoken language ments presented in Fiaure 3. Bell Labs kindly supplied the minimally contrast words. In the sign HOMEI, for SINDSCAL computer program, Portions of the experiment on lexical movement were reported in Sclencr, 1981, 212, 691-693. example, an O-shaped hand makes two contacts on Requests for reprints should be sent to Howard Poizner, The Salk the cheek. The sign HOME differs in form from the Institute, P.O. Box 85800, San Diego, California 92138. sign PEACH only in movement: in PEACH, the 0
215 Copyright 1983 Psychonomic Society, Inc. 216 POIZNER hand makes a circling movement on the cheek. Sim Bellugi, 1979, and Supalla & Newport, 1978, for a ilarly, other pairs of signs are minimally differen more complete description of these and other mor tiated by representatives of other formational param phological processes in ASL). Importantly, these eters. Furthermore, the formational parameters of modifications of signs are transmitted by superim signs not only describe linguistic structure but are posed changes in the movement of signs. also clearly important to the way signers process Fundamentally, the present study asks three ques signs(Bellugi, Klima, & Siple, 1975; Newkirk, Klima, tions about the perception of movement in ASL. Pedersen, & Bellugi, 1980; Poizner, Bellugi, & First, if the various movements at both the lexical Tweney, 1981). and the inflectional levels are perceived in terms of a The concurrent packaging of structural informa limited set of underlying dimensions, how might ob tion in ASL is also apparent at the morphological tained perceptual dimensions, for deaf and for hear level. With respect to the second level of pattern ing subjects, relate to the linguistic dimensions that ing in ASL, basic signs themselves undergo inflec have been proposed to account for relationships in tional processes that modify their meanings. These the linguistic system? processes impose regular changes in form across Second, do the dimensions that may underlie per syntactic classes of signs, and serveas a major vehicle ception of lexical movement differ from those that in ASL for expressingsemantic distinctions. Further may underlie perception of inflectional movement? more, inflections in ASL, as in speech, are not op If some perceived dimensions at the two linguistic tional but, rather, are required in sentential con levels differ, then data from language processing texts of the language (Klima & Bellugi, 1979). The would support the linguistic analysis that suggests distinctions between lexical units and inflectional that formational material at the two linguistic levels processes acting on them have also been shown to may in part be different. This situation would dif have psychological as well as linguistic validity fer from that of most spoken languages, in which the (Poizner, Newkirk, Bellugi & Klima, 1981). How same kinds of speech sounds are used to form both ever, unlike English, which typically inflects words basic words and their grammatical inflections, and by adding segments to the end of a word, such as the might point to ways in which the transmission past tensemarker [fJd] in needed, or the plural marker modality might shape the form that languages take. [s] in books, ASL inflects signs by modulating the Finally, and most importantly, does the psycho movement and spatial contouring of the sign. Bellugi logical representation of movement in ASL differ and Klima (Note 1)argued that the appropriate anal between native signers and naive observers? If so, ysis of morphological structure in ASL is in terms of then the linguistic experience of the deaf must have, multiple tiers: an underlying lexical root, and in in part, determined their perception of this forma flectional and derivational tiers overlaid concurrently tional parameter. Related experiments on the percep with the root. They pointed out that uninflected lexi tion of speech indicate that either natural nonlin cal stems are embedded in simultaneously overlaid earities of the auditory system or particular phono changes in movement and spatial contouring: a sign logical experience can determine a speaker's percep and its inflectional marker co-occur in time. Further tion of phonemes. As an example of the former, more, it appears that some of the building blocks and natural nonlinearities of the auditory system for dis combinations of building blocks used to construct criminating differences in the temporal order of lexical items and inflectional processes may differ. events have been linked to the perception of voic For example, a certain inflectional process embeds ing contrasts in speech (Aslin & Pisoni, 1980; sign stems in iterations along a circle of a horizon Jusczyk, Pisoni, Walley, & Murray, 1980; Pisoni, tal plane; another embeds sign stems in uneven re 1977). The following pattern of results serves as an duplicated elliptical movement. These (and other) example of the phonological determination of lan global movement contours do not occur as move guage perception. Human infants discriminate ments of basic uninflected signs(Bellugi, 1980; Klima acoustic differences that cue the distinction between & Bellugi, 1979). the phonemes Irl and III much as do English ASL inflections mark such grammatical categories speaking adults, in whose language the distinction is as person, number, distributional aspect, and tem phonologically contrastive (Bimas, 19"). Infants poral aspect. The semantic modifications entailed by and adult English speakers are much better able to these grammatical categories include pronominal discriminate the same physical difference for stimuli reference, indication of the number of arguments of across the English phoneme boundary than for the verb (one, two, many), distributed action to the stimuli within either phoneme category. The distinc arguments of the verb (e.g., "to each," "to certain tion between Irl and Ill, however, is not contrastive ones"), and the temporal recurrence of events (e.g., in Japanese phonology, and unlike infants and "for a long time," "regularly," "incessantly") (see English-speaking adults, Japanese-speaking adults Bellugi, 1980, Fischer & Gough, 1978, Klima & fail to discriminate these acoustic differences PERCEPTION OF MOVEMENT 217
(Miyawaki, Strange, Verbrugge, Liberman, Jenkins, first language and who currently used ASL as their primary mode & Fujimura, 1975). Linguistic experience has in this of communication. Their ages ranged from 20 to 24 years (mean = 22.0 years). The second group of subjects comprised five case modified innate auditory sensitivities. Is the normally hearing adults who had no knowledge of sign language modification of perception due to linguistic experi whatsoever. Their ages ranged from 17 to 47 years (mean=28.4 ence bound to the oral-auditory transmission years). modality? The differences between visual and audi tory perception seem, after all, more striking than the Stimuli similarities(Julesz & Hirsh, 1972). Since this study is concerned with perception of movement, a technique was used to isolate movement from sign forms in Two studies have compared perception of certain order to study movement directly. One of Johansson's (1973) formational parameters of lexical signs in ASL by methods for presenting biological motion as patterns of moving deaf signers and by naive hearing subjects; neither lights was adapted for this purpose. Small incandescent grain found differences between the two groups in the pat of-wheat lights were attached to the signer, and videotaping was performed in a darkened room. The brightness and con tern of perception of these parameters. Poizner and trast controls were adjusted during playback so that only the Lane (1978) required deaf and hearing subjects to patterns of moving spots of light were visible. One light was identify the location, relative to the body, at which a placed on the head of the signer, directly over the spine, and sign was being made. Stungis (1981) required sub other lights were placed one on each shoulder, elbow, wrist, jects to identify and discriminate the configuration of and index fingertip. Poizner, Bellugi, and Lutes-Driscoll (1981) showed that these dynamic point-light displays convey ASL the hand. Both studies found congruent patterns of movement at both the lexical and inflectional levels quite verid identification and discrimination for deaf and hear ically, and, indeed, do so when presented in two-dimensional ing subjects, indicating no modification of percep as well as in three-dimensional displays. The advantage of this tion due to linguistic experience for these sign at technique lies in its dramatic reduction of cues other than those of interest here, namely, movement and the spatial contour tributes. ing of the movement path in relation to the body of the signer. Location of the hand and configuration of the The configuration of the hand, the expression on the face, and hand are static attributes, however, and we may well the body of the signer are not displayed, thus allowing direct expect sign movement to be processed differently. focus on movement and spatial contouring. Indeed, studies on the perception of speech have Fifteen one-handed movements each at the lexical and at the inflectional levels were used. The lexical movements Included found that listeners process temporal variation in a 13 movement primes listed in Stokoe et aI. (1965) that did not very different manner from steady-state information. involve interacting movement of the two hands or finger move For example, precisely those speech sounds that are ment only (hand internal movement). Two one-handed circular cued by rapid temporal changes are the ones that are movements were added to this set. These two movements and the one circular movement listed in Stokoe et aI. (1965) occurred perceived categorically; steady-state speech sounds in three distinct planes. seem to be perceived in terms of continuous vari Signs with the following types of movements were used: su ation (Liberman, Cooper, Shankweiler, & Studdert pinating rotation (DIE, Figure la); pronating rotation (HAPPEN, Kennedy, 1967). Similarly, speech sounds with rapid Figure Ib); nodding or bending action (SHOULD, Figure Ic); temporal change are generally processed more ef upward movement (pOLE, Figure Id); downward movement (DOWN, Figure Ie); up-and-down movement (SAME-vertical ficiently by the left rather than the right cerebral plane, Figure If); rightward movement (FIRST, Figure Ig); hemisphere, whereas this is not the case for steady leftward movement (TO-LEFT, Figure Ih); side-to-side move state speech sounds (Liberman et al., 1967;Schwartz ment (SAME-horizontal plane, Figure Ii); movement toward & Tallal, 1980). Temporal variation, indeed, is im the signer (PICK, Figure lj); movement away from the signer (LOOK-AT, Figure lk); and to-and-fro movement (TWO-OF portant in determining cerebral asymmetries for ASL US, Figure 11). Three circular movements were used: one in a signs as well (Poizner, Battison, & Lane, 1979). plane parallel to the front of the signer's body (AREA, Fig Perception of ASL movement may likewise gener ure lm), one in a sagittal plane (pITY, Figure In), and one in ally differ in nature from perception of static ASL an oblique plane (ALWAYS, Figure 10). parameters. Perhaps for movement, deaf signers will Fifteen inflections, described in detail in Klima and Bellugi (1979), were used. All occurred here with the basic sign LooK be more sensitive to some kinds of differences be AT and all were made with one hand. Five of these inflections tween stimuli than to others, depending on the role of marked temporal aspect (habitual, incessant, durational, itera the stimuli in the linguistic system. If the psycho tive, continuative), seven indicated number and distributional logical representation of ASL movement does differ aspect (dual, multiple, exhaustive, seriated external, apportion ative external, seriated internaI, apportionative internal), and between native signers and naive observers, then the three indicated referential indexing (third-person object, third modification of natural perceptual categories after person 1 subject to third-person 2 object, and third-person sub language acquisition would not be bound to the ject to first-person object). auditory modality, but rather could be a more gen Figure 2 presents the 15 inflectional movements with the sign eral consequence of acquiring a formal linguistic LOOK-AT. The habitual inflection (Figure 2&), meaning "to (verb) regularly," is formed by rapidly and smoothly repeating system. short outward movements from the signer's body. The inces sant inflection (Figure 2b), meaning "incessantly," is made METHOD with even faster and shorter, but tensed, repetitions of outward Subjects movement. The durational inflection (Figure 2c), meaning Two groups of subjects were used. The first comprised five "continuously," has a pattern of smooth circular repetition. congenitally deaf signers, of deaf parents, who learned ASL as a The iterative inflection (Figure 2d), meaning "over and over 218 POlZNER .S·L ~ ~ ~ (l AI SUPINATING B) &PRONATING CI NOODI~ 0) UPWARD E) DOWNWARD ROTATION ROTATION ACTION MOVEMENT MOVEMENT
.S·L L .SL. ~ t1 tji 0 F) UP-AND-DOWN GI 13RIGHTWARD HI LEFTWARD II SIDE -TO-SIDE J)TOWARD MOVEMENT MOVEMENT MOVEMENT MOVEMENT SIGNER
.LS' lj ~I K) AWAY8FROM L) TO-AND-FRO M) CIRCULAR:fJ N) CIRCULAR: 0)tJCIRCULAR: SIGNER MOVEMENT FRONTAL PLANE SAGITTAL PLANE OBLIQUE PLANE
Flpre 1. Tbe 15 lexical movements ued. Description of rlgbtward or leftward move ment Isw1tb relIpect to tbe signer, not tbe obse"er.
A) HABITUAL B) INCESSANT C) DURATIONAL D) ITERATIVE E) CONTINUATIVE I reouiarly I 'incessantly' 'continuously I over and over again' 'for Q long time'
F) DUAL Gl IIULTIPLE H) EXHAUSTIVE Il SERIATED J) APPORTIONATIVE Ito both' 'to them' '10eoch of them' EXTERNAL EXTERNAL
across a clossI among members ofa group
.SL ~ Qj tr=U ~U~ K) SERIATED Ll APPORTIONATIVE II) r d PERSON N) 3'd PERSON 1 SUBJECT 0)tU 3'd PERSON SUBJECT INTERNAL INTERNAL OBJECT TO 3" PERSON 2 OBJECT TO 1" PERSON OBJ ECT 'with respect to 'all over 'to him I 'he 10him' 'he to me' internol features'
Fllure 1. Tbe 15 Inflectional movements used. Blackened portions of arrows Indicate slow, tense movement. Tbe 15 Inflections apply to verb sllns. Wben tbe babltuallnflectlon occun wltb the basic slln LooK·AT, for example, tbe Inflected slln means "to look at ~ularly"; wben It occ:un with tbe basic slln GIVE, tbe Inflected slln means "to Kive regularly," and so fortb. PERCEPTION OF MOVEMENT 219 again," and the continuative inflection (Figure 2e), meaning object inflection (Figure 2m), as in "to him," involves a single "for a long time," both involve long movements of uneven outward movement to the right of the signer; the third-person dynamics, having a pronounced deceleration of the hand near subject-to-third-person-object inflection (Figure 2n), as in "she the point of maximal extension from the body. The iterative to him," involves moving the hand contralaterally across the inflection is made with a straight outward movement, whereas body between two points in the space in front of the signer in the continuative inflection follows an elliptical path. The dual a plane horizontal with respect to the signer's body. Finally, inflection (Figure 2f), meaning "to both," makes the outward in the third-person-subject-to-first-person-object inflection movement of the basic sign twice, once diagonally outward to (Figure 20), as in "he to me," the orientation of the sign is turned the left of the signer, once to the right. The multiple inflection so that the hand moves inward towards the signer's body from (Figure 2g), meaning "to them," involves a lateral sweeping a point to the right of the body. movement to the right of the signer, and the exhaustive inflec The line illustrations in Figures I and 2 and in the figures that tion (Figure 2h) meaning "to each of them," is formed with follow only schematically represent the movements. Figure 3 outward movements of the hand embedded in a lateral arc to presents the actual point-light paths of the fingertips (panel B) the right of the signer. The seriated-external inflection (Fig of the two inflected signs illustrated in panel A of the figure. ure 2i), meaning "across a class," and the apportionative The movement of the hand was digitized and then reconstructed external inflection (Figure 2j), meaning "among members of in three dimensions on a computer-graphic system (see Poizner, a group," have iterated movements occurring in a plane hori Klima, Bellugi, & Livingston, in press, and Loomis, Poizner, zontal to the signer's body. The seriated-external inflection oc Bellugi, Blakemore, & Hollerbach, Note 2). Figure 3c presents the curs along a straight line close to the signer's body; the appor velocity and acceleration of the hand along the movement path, tionative-external inflection involves repetitions embedded in over time. Figure 3 shows that the durational inflection involves a circular path. The seriated-internal inflection (Figure 2k), a smooth repeated circular movement, whereas, the continua meaning "with respect to internal features," and the appor tive inflection has a repeated elliptical movement in which the tionative-internal inflection (Figure 21), meaning "allover," hand moves very rapidly during the outward and downward embed repetitions along a line and a circle, respectively, in a portion of a cycle, rapidly decelerates, turns around, returns plane parallel to the front of the signer's body. The third-person- to the starting position, and beginsa newcycle.
A B c
LOOK-AT [DURATIONAL]
(\ (\ ) I\ /'-~ l ', -, j
LOOK-AT [CONTINUATIVE]
Figure 3. Line drawings of two inflected signs (A) together with computer-graphic reconstructions of the actual movement path of the hand (B) and the associated temporal proffles (C). Velocity is given in meters/second, acceleration in meters/second? ,and time in milliseconds. 220 POIZNER
Design and Procedure The fit between the scaling solution and the obtained similarity The task involved triadic comparisons of either lexical or in scores is captured by the percentage of variance in the data ac flectional movement. An incomplete balanced design was used counted for by the scaling. Finally, unlike the nonmetric multi to reduce to a manageable size the number of triads that a sub dimensional scaling procedures, individual differences scaling pro ject would have to judge. Levelt, Van De Geer, and Plomp vides a mathematically preferred orientation of the axes of the (1966) have developed such a design for triadic comparisons solution, and, indeed, the axes or dimensions have generally been of 15 stimuli having the following properties: four blocks of found to correspond to psychologically significant processes 35 triads are presented. Within each block of triads, all possible (Carroll & Chang, 1970;Wish & Carroll, 1974). pairs of the 15 stimuli occur once. These 105 pairs are distrib A single scaling combining data from both deaf and hearing uted over 35 triads, with each stimulus present in seven differ subjects is used, because it provides a much stronger test of ent triads. Furthermore, each pair of stimuli occurs with a dif whether perception differs between deaf and hearing subjects than ferent third member in each of the four blocks of triads. Triads do separate scalings of judgments of the two groups. If deaf and for the 15 lexical and for the 15 inflectional movements of the hearing subjects indeed differ, then they will be separated in one present study were constructed following the lists published in and the same scaling solution based solely on their judgments of Levelt et al. (1966, p. 166). The method of triadic comparisons movement similarity. A single scaling combining data from both is particularly useful for the present study because it allows both groups allows for the possibility of differential degrees of overlap signers and nonsigners to easily make comparisons among the between groups on any dimension, rather than simply assigning a same stimuli using the same responses. The subjects made a dimension to a group or not. In separate scalings, dimensions that single judgment for each triad, simply deciding which two of were different for the groups as wholes could be obtained, but in the three stimuli were most similar. The subjects were supplied dividual subjects from the groups could overlap without one's ever response booklets containing, for each triad, the three numbers knowing. The use of a single pooled scaling makes explicit the 1, 2, and 3 arranged on the page in the form of an equilateral precise degree of overlap, or lack of overlap, between groups. triangle. These numbers corresponded to the first, second, and third stimulus of the triad, respectively. The subjects indicated RESULTS which two stimuli of the triad they considered most similar by circling the corresponding two numbers in the response booklet. In order to get a measure of the reliability of subjects' judg Similarity matrices were constructed for each repli ments, each subject was run on each of the four blocks of lex cation of the four blocks of lexical and of inflectional ical and inflectional movement twice. The order of presenta movement for each subject. The similarity of any tion of the four blocks was independently randomized for each subject within each replication of lexical and inflectional move pair of movements was determined by the frequency ment. Order of presentation of each replication of lexical and with which that pair was judged as most similar in the inflectional movement was counterbalanced across subjects. triads in which it occurred. These matrices served as A deaf, fluent ASL signer with point-lights attached was video input to the SINDSCAL program. taped making all stimuli (Sony AV3650 videotape recorder). Stimulus durations varied slightly depending upon the normal duration of the movement; however, in order to make stimulus Lexical Movement durations roughly equal, repeated movements of long dura In order to evaluate initially whether deaf subjects tion were repeated only as many times as would be necessary perceived relationships among lexical movements of in sentential context rather than the many times that would oc ASL differently from the way hearing subjects did, a cur in citation form. The signer, paced by a flashing metronome (Seth Thomas E962-OOO), made stimuli approximately 1 sec in discrete method of grouping subjects was performed. duration, with 1.5 sec between members of a triad and 6 sec First of all, the similarity matrix for each replication separating triads. of each subject (deaf and hearing) was correlated The deaf subjects were instructed in ASL, on videotape, and against every other similarity matrix. The resulting the hearing subjects were given spoken-English instructions. correlation matrix specifying relationships among Eight practice trials preceded each test tape to make sure that the subjects understood the task. Stimuli were presented on subjects was thenhierarchically clustered by Johnson's videotape (Sony AV3650 videotape recorder), with subjects (1967) HICLUS procedure (complete-link option) seated approximately 2.5 ft from the TV monitor (Sony CVM 131). (also see Hartigan, 1975). Figure 4 presents this Each subject was run in four separate 45-rninsessions. clustering. The terminal nodes of the tree represent Data Reduction Multidimensional scaling provides a geometric model of the LEXICAL psychological representation of a stimulus array by representing MOVEMENT the stimuli as points in a multidimensionalspace (Carroll &:Arabie, 1980; Kruskal, 1964a, 1964b; Shepard, 1962a, 1962b, 1980). The distance separating any two stimuli in the spatial solution cor responds to the judged similarity of that pair, and, hence, the closer together two stimuli are in the spatial solution, the more similar they appear to be to the observer. Carroll and Chang's (1970)individual differences scaling model, implemented with the SINDSCAL computer program (Pruzansky, Note 3) was used in the present study. Weights that reflect the importance or salience of a given dimension for a given subject are recovered. Thus, 0000000000 HHHHHHHHHH although the model produces a group or average space for all the 2211433455 3344112255 subjects, the weights provide a measure of what aspects of that 8 ...... 88 ... 8 ...... 8 ... 8 ... 8"'8 ... 8 ... 8 space apply to a given subject. A weight of zero, for example, would indicate that a particular dimension simply had no relevance Flaure ... Hierarchical c1usterlnl of IntenubJect correlations of for a givensubject. slmllarlty matrices for lexical movement. PERCEPTION OF MOVEMENT 221 each replication (A or B) of each deaf (Dl through DS) and each hearing (HI through HS) subject. Strik I' A I ingly, the clustering separated the subjects into two I distinct groups, based entirely on whether the sub ~ jects were deaf or hearing. Clearly, deaf and hearing [ subjects perceive lexical movement in different ways. ~ ------~"L---""--i------SINDSCAL scalings on all 20 matrices were per formed in one through six dimensions. The four ~ ~~ I dimensional solution was selected because it ac ~r- ~ i - counted for 70.0010 of the variance in the data, a mag nitude only slightly less than the 76.9010 of variance ~ ----4l------l-----~------accounted for by the six-dimensional solution. Within the four-dimensional solution, Dimension 1 accounted for 43.8010 of the variance, Dimension 2, 10.7010, Dimension 3,8.8010, and Dimension 4, 6.7010. iPI Figures Sa and Sb present the four-dimensional I SINDSCAL group solution. The location of each I stimulus in the spatial configuration is at the center DIM.I: REPETITION of each of the schematized figures representing the 1S movements. Where figures overlap, asterisks indicate I the location of figures marked by arrows. Figure Sa B presents Dimension 2 against Dimension 1. The 8 dashed lines in the figure were positioned by the author, rather than by the scaling program, in order z to help make clear the interpretation of the con o figuration. Stimuli on the left-hand side of Dimen i3 sion 1 all have repeated movements, whereas each '"~ stimuli to the right of the dashed vertical line has a ",r- fiI!Jl - single, unrepeated movement. Dimension 1 was thus labeled "repetition," capturing the fact that the lexi ~ ------~------~------_tJ----- cal movements were first separated on the basis of Sll whether or not they were repeated. Projections along Dimension 2 fall into three broad categories. The Sl D l~ tJ four stimuli in the upper portion of the figure all tJ I I occur in a plane parallel to the front of the signer's I body, whereas the seven stimuli in the lowermost II portion of the figure all occur primarily in a hori DIM. 3: ARCNESS zontal plane, perpendicular to the front of the Flpre 5. Conflluradon of Idmull In tbe SINDSCALloludon signer's body. Finally, the four stimuli projecting to for lexical movement. (A) Dime_Ion 1 venul DimeDllon 1. the center of Dimension 2 occur either in a sagittal (8) Dime_Ion" venul Dime_Ion 3. plane (movement in PITY and in YOU-AND-I) or in a plane oblique with respect to the signer's body ning and ending points. The mean values of arcness (movement in ALWAYS and in SHOULD). Dimen for each of the IS movements were then correlated sion 2 was thus labeled''plane." against the coordinates of each of the movements Figure Sb presents the configuration in Dimen along Dimension 3 of the scaling solution. The cor sion 4 versus Dimension 3. Stimuli to the left of the relation was a very substantial r= .91, p < .01, indi vertical dashed line in the figure are predominantly cating that Dimension 3 reflected variation in the straight in path. As we move further to the right degree of arcness of the movement forms. Dimen along Dimension 3, stimuli become increasingly sion 3 was thus labeled "arcness." arced, until movements become circular for stimuli at With respect to Dimension 4, stimuli below the the far right of the figure. In order to measure the horizontal dashed line in Figure Sb all have move degree of "arcness" in the actual stimulus items, the ments directed toward the left of the TV screen, sevenoccurrences of each stimulus from one block of whereas stimuli above the horizontal dashed line all trials were first traced directly from the video moni have movement components toward the right of the tor, videofield by videofield. The degree of arcness of TV screen. In order to measure the degree of direc the movement of the hand in each of these tracings tional movement in the stimulus items, a ruled grid was then taken by measuring the maximal deviation was placed over the field by field-tracing each stim of the movement from the line connecting the begin- ulus item from one block of trials. The grid was 222 POIZNER aligned with the signer's shoulders and head and the ing subjects (two replications per subject) across the degree of leftward or rightward displacement of the four dimensions. The analysis yielded, first of all, a hand from its initial point was measured. The mean significant effect of dimension [F(3,3) =16.4, values of the degree of rightward or leftward dis p <.025], indicating that, overall, some dimensions placement of each of the 15 movements were then were more highly weighted than were others. Second, correlated against the coordinates of each of the deaf and hearing subjects did not differ significantly movements along Dimension 4 of the scaling solu in the overall magnitude of weights applied [F(1,8) = tion. The correlation was a substantial r =.86, p < .80, n.s.]. Finally, and most interestingly, there was a .01, indicating that Dimension 4 reflected variation highly significant interaction between the weights of in the degree of rightward or leftward displacement deaf and hearing subjects across the four dimensions of the movement forms. Dimension 4 was thus [F(3,24)= 8.9, p < .001], reflecting the differential labeled "direction." relevance or salience of dimensions to subjects in Figure 5a and Figure 5b presented the group each group." SINDSCAL stimulus configuration incorporating Individual subject variation and the reliability of both deaf and hearing subject matrices. We now turn the pattern of dimension weights are presented in to the weightings of different subjects on each dimen Figure 7. Each replication (denoted by an A or a Bin sion and see in Figure 6 a very different pattern of the figure) of each hearing (H) and deaf (D) subject weights for deaf and for hearing subjects. The figure is represented. The combined weight for a given sub shows the mean weights of deaf (open circles, dashed ject on two dimensions is equal to the square root of line) and hearing subjects (filled circles, solid line) for the sum of his squared weights on those dimensions each dimension of the solution. Standard errors of (Wish & Carroll, 1974). Figure 7 plots the combined the means are presented above and below each point. weight of each subject on Dimensions 2 and 4 against Figure 6 indicates that the deaf subjects heavily the combined weight ofeach subject on Dimensions 1 weighted Dimension 1 (repetition) of the solution, and 3. First of all, we notice that with only one ex moderately weighted Dimension 3 (arcness), and ception (H2A), the deaf subjects simply do not over negligibly weighted Dimensions 2 and 4 (plane and lap with the hearing subjects in their pattern of direction). The hearing subjects, on the other hand, weights on these dimensions. The deaf subjects provided moderate weights ofall four dimensions. weight Dimensions 1 and 3 very highly, whereas A mixed-design analysis of variance was per virtually all hearing subjects weight Dimensions 2 formed on the weights obtained for deaf and hear- and 4 more highly than does any deaf subject. In the second place, the figure shows that the pattern of .9...---.,....----r----r---.....,.-..., weights for a given subject is highly reliable, as evi denced by the closeness of the points for the two LEXICAL replications of each subject. Furthermore, the one .8 MOVEMENT exception (H2A) to the nonoverlapping distributions ~ of the deaf and hearing subjects in Figure 7 occurred ~ .7 (!) \ precisely for that subject (H2) who had the least re \ I&l liable pattern of dimension weights. ~ \ \ z .6 \ Q \ Inflectional Movement Ul \ ~ .5 \ SINDSCAL runs were performed in one through 2 \ \ six dimensions on the 20 similarity matrices derived is from both the replications of judgments of inflec z .4 \ c \ I&l tional movement by each of the 10 subjects (deaf 2 \ \ and hearing). The four-dimensional solution was ILl .3 \ again selected, as it accounted for 71.3010 of the u \ Z \ variance in the data, a magnitude only slightly less ILl \ /. ::J .2 \ / r} than the 76.6% of the variance accounted for by
v o .70 r-----r-~--r--"'T""--"'T"""--_r_--r_-.....,--__r--_r--.,. Z H48 « H4A (\J lJ) ~ .60 H58 in H5A z HI8 w ~ .50 o HIA H28 z H38 o H3A ~ 40 ::I: (!) W D2A H2A ~ .30 u, o D48 W D28 II:: :5 .20 o D~'58 lJ) LEXICAL I MOVEMENT ~ .10 lJ) D3A I ot- o II:: 0 .10 .20 .30 AO .50 .60 .70 .80 .90 1.0 ROOT- SUM- SQUARE OF WEIGHTS ON DIMENSIONS I AND 3
FIllure 7. Root lum lICIulm of lubJect welllbtl on Dlmeulou 2 Ind .. venUI root Ium lICIUarel of of lubJect welllbtl on Dlmeulonl 1 and 3.
The single stimulus in the second division from the curs along a line that moves downward in front of left of the figure (dual) has exactly two repetitions. the signer rather than outward along a sagittal axis. The five stimuli projecting along the middle of Dimension 2 was labeled "displacement," reflect Dimension 1 have a movement cycle that is repeated ing the division of movements into those primar at least once. These five stimuli are inflections for ily along a sagittal axis from those displaced from temporal aspect. Finally, the five rightmost move that axis. Interestingly, also, those five movements ments along Dimension 1 are all single-cycle move along the sagittal axis are all inflections for tem ments that have numerous repetitions of a movement poral aspect, whereas the other 11 movements con within various spatial displacements. The entire cycle veyperson, number, and distributional aspect. is not repeated; and these movements are inflections Figure 8b presents the configuration in Dimen for distributional aspect. Thus, the IS movements sion 4 versus Dimension 3. Movements fall into fall along Dimension 1 into those with single move two categories along Dimension 3. Those to the ments, with exactly two movements, with move left of the vertical dashed line have movement com ments reduplicated across cycles, and with move ponents directed toward the left of the TV screen. ments iterated within a cycle. Dimension 1 was The stimuli projecting to the right of the vertical thus labeled "cyclicity." Cyclicity differs from the dashed line in Figure 8b, however, generally move lexical dimension repetition in that it comprises to the right of the TV screen. The rightward or four distinctly different types of articulation, leftward movement of the seven occurrences of whereas repetition has only two values, single and each inflection from one block of stimuli was mea repeated. sured in a manner similar to that described for mea The stimuli below the horizontal line in Figure 8 suring the direction of lexical movement. The mean are made in a sagittal plane, whereas the other stim displacement of each inflection to the signer's right uli are not. The only possible exception to this cate or left was then correlated against the coordinates gorization is seriated internal, which has iterated of the inflections on Dimension 3 of the scaling movements downward along a line in a plane par solution. The correlation was a substantial r =.82, allel to the front of the signer's body. However, p < .01, indicating that Dimension 3 reflected vari since a line does not uniquely determine a plane, ation in the degree of rightward or leftward dis this movement could be described as occurring in placement of movement forms. Dimension 3 was a sagittal plane also. Nonetheless, the main com therefore labeled "direction." ponent of the movement in seriated internal oc- Stimuli along Dimension 4 seem to fall into two 224 POIZNER
I I they weight the four dimensions. The dimension A I I most important to the deaf, cyclicity, is least im ;: ! I I) portant to the hearing subjects, whereas the dimen I. i LJa sion most important to the hearing subjects, direc "I I () VI ~;;~'I' I I,Ll tion, is least important to the deaf. Dimensions 2 ~! § \)=('1 II : I - and 4 of the solution, displacement and iteration ~.~ I: Ji length, seem equally weighted by deaf and hearing ~ ~ )~ subjects and occur as the second and third, respec i f?t-I - (f) LJ I "M'" I tively, most weighted dimensions by each group. s II A mixed-design analysis of variance was per '"~ I I ------r---f------r------formed on the weights obtained for deaf and hear o I I {I I II 01 I ing subjects across the four dimensions. There was I I S' I no significant effect of dimension [F(3,24) = 2.6, I: n \~1ln.1 I I\ '.i. \ J1 ~ I I I I I n.s.] or of subject group [F(l,8) = 1.0, n.s.]. The II lack of reliable effects here reflects the facts that, II I: pooled over the deaf and hearing subjects, the weights I along the four dimensions did not reliably differ DIM. I CYCLICITY and that, pooled over dimensions, the mean weights of the deaf and hearing subjects did not reliably B differ. Most importantly, however, the analysis yielded a highly significant interaction between sub ject group and dimension [F(3,24)=6.6, p < .005]. :I: This interaction indicates that the deaf and hearing o I subjects reliably differed in their pattern of weights ~ n I ...J 't"1 I applied to the four dimensions." ~ I If] Figure 9 indicated that Dimensions I, 2, and 4 g~ ~ i - of the group solution were perceptually important I------n------I---H------to the deaf subjects, whereas Dimension 3 seemed ... ~~'I Sl I l1H ~ "'1.~l··,,=,U I· (;4i of little perceptual relevance to these subjects. Fig o I.. I Ii!)( ure 10 presents the' configuration in the three di i u"!- mensions important to deaf subjects and thus rep I I' I, I It) resents perceived relationships among the inflec I I I tional movements by native ASL signers. Vertically, I I II DIM. 3· DIRECTION .6 ~ 1NFLECTIONAL Fllare I. Conftpntlon of ItimaU In tbe SINDSCAL lolatlon :I: MOVEMENT for Inflectionalmovement. (A) Dlmeulon 1 venal Dlmeulon 1. (!) ~ (8) Dlmeulon .. YenDl Dlmeulon3. .5 z o in .4 z , classes. Those movements above the horizontal w ,, :=E , dashed line in Figure 8b have a very short path o .3 , z \ movement, whereas movements below the hori <[ w \[ ,/ zontal line in Figure 8b have longer path move ~ .2 ments. Dimension 4 was thus labeled "iteration w u -: length," reflecting the separation of movements ~ .1 into two groups on the basis of length of stem move :J ment. «en Just as deaf and hearing subjects differentially O'---":;---"':<--~--r~ weighted the dimensions of the group solution for lexical movement, so did they differentially weight the dimensions of the group solution for inflec tional movement. Figure 9 presents the mean weights for deaf and for hearing subjects for each dimen Fllare 9. Perceptual laUence of eacb dlmeulon of tbe seaUnl sion of the solution. The figure shows that the deaf lolatlon of Inftectlonal movement for deaf labJects (dubed Une) and hearing subjects differ dramatically in the way and for bearlnllabJects (Iolld line). PERCEPTION OF MOVEMENT 225
------
...... ~~~ flo.C~'" \s~\, 2·Q\ Q\"'" INFLECTIONAL MOVEMENT DEAF SUBJECTS
FllUre 10. CODnlaradoD of ItimaU ID the three dlmeulou ImportaDt to deaf labJecti for IDnecdoDai movemeDt. The dubed crOlHeCdou ID the nlUre are pOildoDedto IDdlcatethe foar IroaplDp of IdmaU aloal the vertical dlmeuloa, cycUclty. the movements are grouped on the basis of their the groups as a whole, differed in the pattern of pattern of cyclicity (single movements, two move weights applied to the four dimensions. Figure 11 ments, reduplicated across cycles, and iterated presents the distribution of combined weights on within cycles). The five forms that are not displaced Dimensions 3 and 4 versus the combined weights from the sagittal axis are separated from the other on Dimensions 1 and 2 for the 20 input matrices. movements along Dimension 2, displacement. The Strikingly, this distribution falls into groups based final dimension, iteration length, then separates on whether the subjects were hearing or deaf. The movements on the basis of the length of an iter nine points below the horizontal dashed line in the ated movement. The figure reveals several major figure show relatively high combined weights on clusters of movements. The five uppermost forms Dimensions 1 and 2, and all represent deaf sub (apportionative internal, seriated internal, appor jects. Furthermore, the 11 points above the dashed tionative external, seriated external, and exhaustive) line show relatively high combined weights on Di are seen not only to share a pattern of cyclicity mensions 3 and 4, and 10 of these points represent that involves iterations within a cycle, but also hearing subjects. The one exception to this com to share displacement off the sagittal axis and plete bifurcation of the distribution into deaf and iterated movements of short length. Similarly, the hearing subjects (D2B) comes from the one sub five movements directly below these along the ver ject, of all those run, with the least reliable pattern tical dimension (incessant, habitual, durational, of weights (as seen in the very large separation of continuative, and iterative) share not only a pat Subject D2's replications, A and B). Otherwise, tern of movement that involves reduplicated move the pattern of weights for a given subject seems ment cycles, but also movement along the sagittal quite reliable: the two replications for a given sub axis. The next vertical section contains the dual in ject tend to be close together. Several deaf subjects flection, which has exactly two iterations. The fig do show, however, somewhat greater reliability of ure shows this movement to be quite distinct from their combined weights on Dimensions 1 and 2 than the others. Finally, the four movements closest to on Dimensions 3 and 4. the base of the cube in Figure 10 also form a tight class; all are single, nonrepeated movements, all DISCUSSION are displaced from the sagittal axis, and the spatial paths of all the movements are relativelylong. The scaling solutions clearly indicated that deaf Individual deaf and hearing subjects, as well as and hearing subjects perceived both lexical and in- 226 POIZNER
of language experience on perception occur for JUSCZYK, P. W., PISONI, D. B., WALLEY, A., & MURRAY, J. spoken language, the phenomenon does not de Discrimination of relative onset time of two component tones pend on the particular transmission modality, be by infants. Journal ofthe Acoustical Society ofAmerica, 1980, 67,262-270. it spoken or signed, but rather can be a more gen KLIMA, E. S., & BELLUGI, U. The signs oflanguage. Cambridge, eral consequence of acquiring a formal linguistic Mass: Harvard University Press, 1979. system. KRUSKAL, J. B. Multidimensional scaling by optimizing good ness of fit to a nonmetric hypothesis. Psychometrika, 1964, 29, 1-27. (a) KRUSKAL, J. B. Nonmetric multidimensional scaling: A numerical REFERENCE NOTES method. Psychometrika, 1964,29, 115-129. (b) LANE, H., & GR08.JEAN, F. (Eds.) Recent perspectives on Ameri 1. Bellugi, U., & Klima, E. S. The acquisition ofthree morpho can Sign Language. Hillsdale, N.J: Erlbaum, 1980. logical systems in American Sign Language. (Papers and Reports LEVELT, W. J. M., VAN DE GEER, J. P., & PLOMP, R. Triadic on Child Language Development, Vol. 21, KI-35). Stanford comparisons of musical intervals. British Journal ofMathemati University, 1982. cal andStatistical Psychology, 1966,19,163-179. 2. Loomis, J., Poizner, H., Bellugi, U., Blakemore, A., & LIBERMAN, A. M., COOPER, F. S., SHANKWEILER, D. S., & Hollerbach, J. Computer graphic modelling of American Sign STUDDERT-KENNEDY, M. Perception of the speech code. Language. Unpublished manuscript, The Salk Institute, 1982. Psychological Review, 1967,74,431-461. 3. Pruzansky, S. How to use SINDSCAL. A computerprogram MIYAWAKI, K., STRANGE, W., VERBRUGGE, R. R., LIBERMAN, for individual differences in multidimensional scaling. Murray Hill, A. M., JENKINS, J. J., & FUJIMURA, O. An effect of linguistic N.J: Bell Telephone Laboratories, 1975. experience: The discrimination of Irl and III by native speakers 4. Kruskal, J. B., Young, F. W., & Seery, J. B. How to use of Japanese and English. Perception &: Psychophysics, 1975, KYST·2A, a very flexible program to do multidimensional scaling 11,331-340. and unfolding. Murray Hill, N.J: Bell Telephone Laboratories, NEWKIRK, D., KLIMA, E. S., PEDERSEN, C. C., & BELLUGI, U. 1978. Linguistic evidence from slips of the hand. In V. Fromkin (Bd.), Errors in linguistic performance. New York: Academic Press, 1980. REFERENCES NEWPORT, E. S. Task specificity in language learning? Evidence from speech perception and American Sign Language. In L. R. ASLIN, R. N., & PISONI, D. B. Effects of early linguistic ex Gleitman & E. Wanner (Eds.), Language acquisition: The state perience on speech discrimination by infants: A critique of Eilers, ofthe art. New York: Cambridge University Press, 1982. Gavin, lind Wilson (1979). Child Development, 1980, SI, PISONI, D. B. Identification and discrimination of the relative 107-112. onset time of two component tones: Implications for voicing BELLMAN, K., POIZNER, H., & BELLUGI, U. Invariant character perception in stops. Journal of the Acoustical Society of isticsof some American Sign Language morphological processes. America, 1977,61,1352-1361. Discourse Processes, in press. POIZNER, H., BATTISON, R., & LANE, H. Cerebral asymmetry BELLUGI, U. The structuring of language: Clues from the sim for American Sign Language: The effects of moving stimuli. ilarities between signed and spoken language. In U. Bellugi & Brain andLanguage, 1979,7,351-362. M. Studdert-Kennedy (Bds.), Signed and spoken language: POIZNER, H., BELLUGI, U., & LUTES-DRISCOLL, V. Perception Biological constraints on linguisticform (Dahlem Konferenzen), of American Sign Language in dynamic point-light displays. WeinheimlDeerfield Beach, FIa: Verlag Chemie, 1980. Journal of Experimental Psychology: Human Perception and BELLUGI, U., KLIMA, E. S., & SIPLE, P. Remembering in signs. Performance, 1981,7,430-440. Cognition: International Journal of Cognitive Psychology, POIZNER, H., BELLUGI, U., & TwENEY, R. D. Processing of 1975,3,93-125. formational, semantic, and iconic information of signs from CARROLL, J. D., & ARABIE, P. Multidimensional scaling. Annual American Sign Language. Journal ofExperimental Psychology: Review ofPsychology, 1980, 31, «J7-649. Human Perception and Performance, 1981,7,1146-1159. CARROLL, J. D., & CHANG, J. J. Analysis of individual dif POIZNER, H., KLIMA, E. S., BELLUGI, U., & LIVINGSTON, R. ferences in multidimensional scaling via an N-WAY generaliza Motion analysis of grammatical processes in American Sign tion of "Eckart-Young" decomposition. Psychometrika, 1970, Language. SIGGRAPHISIGART workshop on motion: Repre 3S,283-319. sentation and Perception, in press. EIMAS, P. D. Auditory and phonetic coding of the cues for POIZNER, H., & LANE, H. Discrimination of location in American speech: Discrimination of the [roll distinction by young in Sign Language. In P. Siple (Ed.), Understanding language fants. Perception &: Psychophysics, 1975, 1" 341-347. through sign language research. New York: Academic Press, FISCHER, S., & GOUGH, B. Verbs in American Sign Language. 1978. Sign Language Studies, 1978,18,17-48. POIZNER, H., NEWKIRK, D., BELLUGI, U., & KLIMA, E. S. HARTIGAN, J. A. Clustering algorithms. New York: Wiley, 1975. Representation of inflected signs from American Sign Language HELM, C. E. A multidimensional ratio scaling analysis of per in short-term memory. Memory &: Cognition, 1981,9, 121-131. ceived color relations. Journal ofthe Optical Society ofAmerica, ScHWARTZ, J., & TALLAL, P. Rate of acoustic change may under 1964,54,256-262. lie hemispheric specialization for speech perception. Science, JOHANSSON, G. Visual perception of biological motion and a 1980,107, 1380-1381. model for its analysis. Perception &: Psychophysics, 1973, 14, SHEPARD, R. N. The analysis of proximities: Multidimensional 201-211. scaling with an unknown distance function, I. Psychometrika, JOHNSON, S. C. Hierarchical clustering schemes. Psychometrika, 1962,27, 12S-140. (a) 1967,31,241-254. SHEPARD, R. N. The analysis of proximities: Multidimensional JULESZ, B., & HIRSH, I. J. Visual and auditory perception scaling with an unknown distance function, 11. Psychometrika, An essay of comparison. In E. E. David & P. B. Denes (Eds.), 1962,27,219-246. (b) Human communication: A unified view. New York: McGraw SHEPARD, R. N. Multidimensional scaling, tree-fitting, and HiII,I972. clustering. Science, 1980,210,390-398. 230 POIZNER
SIPLE, P. (Ed.). Understanding language through sign language Third, pooling deaf and hearing subjects together In the SIND research. New York: Academic Press, 1978. SCAL analysis did not affect the nature of the dimensions re STOKOE, W. C., CASTERLINE, D. C., & CRONEBERG, C. G. A covered for each group individually. Separate KYST scalings for dictionary 0/ American Sign Language. Washington, D.C: each group reflected the same dimensions important to each group Gallaudet College Press, 1965. in the SINDSCAL analysis, and, hence, reflected the same dif STRANGE, W., & JENKINS, J. J. The role of linguistic experi ferences between the groups. A single SINDSCAL analysis pro ence in perception. In H. L. Pick, Jr., &; R. D. Wald (Bds.), Per vides, of course, a much more powerful way for quantifying dif ception and experience. New York: Plenum, 1979. ferences between groups as well as allows more dimensions to be STUNOIS, J. Identification and discrimination of handshape in recovered (see discussion In text). American Sign Language. Perception cI Psychophysics, 1981, 3. As for lexical movements, separate KYST scallngs of deaf 19,261-276. and hearing subjects for Inflectional movement revealed different SUPALLA, T. Morphology of verbs of motion and location in dimensions for the two groups, dimensions that also appeared in American Sign Language. In F. Caccamise &; D. Hicks (Bds.), the SINDSCAL analysis. Both groups showed two-dimensional Proceedings 0/ the Second National Symposium on Sign solutions. Dimensions for the deaf subjects were cyclicity (with the LangUflgeRU«lrch and Teaching. Silver Sprinl, Md: National same four divisions as In that dimension from SINDSCAL) and Association ofthe Deaf, 1980. displacement. These two dimensions were exactly the same two SUPALLA, T., &; NEWPORT, E. How many seats in a chair? The dimensions most heavily weighted by the deaf subjects in the derivation of nouns and verbs in American Sign Languale. SINDSCAL solution. The solution of the hearing subjects dif In P. Siple (Ed.), Understanding IflngUflge through sign language fered from that of the deaf subjects. The dimensions for the hear res«lrch. New York: Academic Press, 1978. ing subjects were displacement and iteration length, two of the WILBUR, R. American Sign Language and sign systems: Ruearch three dimensions that were most highly weighted by hearing sub and applications. Baltimore, Md: University Park Press, 1979. jects in the SINDSCAL solution. Thus, pooling deaf and hearing WISH, M., & CARROLL, J. D. Application of individual differ subjects together in the SINDSCAL analysis did not produce the ences scaling to studies of human perception and judgment. differences between groups or affect the nature of the recovered In E. C. Carterette &; M. P. Friedman (Eds.), Handbook 0/ dimensions for each group; likewise, SINDSCAL's metric as perception (Vol. 2). New York: Academic Press, 1974. sumption could not have artlfactually produced the results. 4. The lexical and Inflectional movements used in the experi ment are naturally a subset of all lexical and inflectional move ments in ASL. The movements were selected, however, to be NOTES representative of movements at each level. The inflections spanned cate&ories of temporal aspect, grammatical number, person, and I. Lexical silns are denoted by English glosses in full capitals, distributional aspect. Furthermore, they spanned multiple values of for example, HOME. Multiword glosses for single-sign forms are all II spatial and temporal dimensions, except doubling of the hyphenated, as in OIVE-A-OIFT. Superscript labels, as in GIVE hands, proposed on linguistic grounds to underlie the structure of A.OIFTlmuItipleJ, refer to specific inflectional processes that signs inflectional movement (Klima &; Bellugl, 1979). All have path have undergone. movement (movement of the hand and arm through space). Like 2. The difference in the psychological representation of the lexi wise, the lexical movements represent all the lexical movement cal movements for deaf as opposed to hearing observers is also primes listed In Stokoe et al. (1965) that have path movement clearly evident when judgments of deaf and hearing subjects are except those that Involve two hands (this excludes movements such separately scaled. Nonparametric multidimensional scalinls using as movements only of the fingers or twisting movements of the the KYST computer program (Kruskal, Young, &; Seery, Note 4) hand). were performed separately on the grouped heannl and grouped 5. The dependence of the perception of speech sounds on the deaf data. The use of a nonparametric scaling, furthermore, pro linguistic experience of the listener has, of course, nothing what vides a check on the metric assumptions of SINDSCAL. ever to do with the meanings of the sounds, for which there are SINDSCAL assumes a particular relationship between the dis none, but rather on the usage of the sounds In the respective tances separatinl stimuli in the scaling solution and the obtained phonological systems. Similarly, the differences in perception of similarity scores, namely, a linear relationship. KYST assumes no ASL movement by deaf signers and by naive hearing subjects have particular function relating the two, other than that the function nothing to do with meaning. At the lexical level, movement is only be monotonically decreasing. KYST thus affords the opportunity one of several co-occurring parameters that form meaningful to check the SINDSCAL assumption of linearity and, in the pro signs. At the inflectional level, movements do represent grammati cess, to provide a strong test of the effect of single versus sepa cal morphemes, but the data Indicate that the subjects made judl rate scallnp of the data. KYST scalings of the judlments of the ments on the basis of movement form. To take just one example, deaf subjects yielded a two-dimensional solution, whose dimen we note the grouping of stimuli along Dimension I, cyclicity. The sions were repetition and arcness. These dimensions were the same cyclic nature of the movements is not completely divorced from two dimensions that the INDSCAL solution showed to be im meaninl and thus makes possible a strong test of whether judg portant to the deaf subjects, when judaments of deaf and hear ments were based on form or on meaning. Inflections that in Ing subjects were scaled together, KYST scallngs of judaments of dicate recurrence of events over time have more than one articula the hearinl subjects differed from those of the deaf subjects. The tion, as do most of the Inflections that Indicate action to a plural, heannl subjects had a two-dimensional solution with dimensions as opposed to a singular, object of the verb. However, one In of repetition and direction. These two dimensions were two of the flection that Indicates a plural object of the verb, the multiple, Is three most hiahly weighted dimensions of the heannl subjects made with only one articulation. This Inflection was positioned from the SINDSCAL solution. As in that solution, direction ap along Dimension I of the scalinl solution with Inflections having a plied only to the hearinl subjects, not to the deaf. The results of single articulation, rather than with Inflections Indicating a plural these separate scalinp of deaf and hearing subjects thus demon object of the verb (which all had repeated articulations). strate three points. In the first place, SINDSCAL's metric as· A second consideration In Interpreting the present experiment Is sumptlon could not have artifactually produced the results, since that multidimensional scaling of triadic comparisons Is a differ very similar solutions were obtained with nonmetric scalings. ent procedure from that used to assess perception of the Ir/-/II Second, the difference In the psychological representation of lexi contrast by Japanese and American listeners. Multidimensional cal movement for deaf and hearinl subjects is not due to group scaling, however, has been amply demonstrated to be relevant to Ing deaf and hearing data together in a SINDSCAL analysis. perception. For example, Wish and Carroll (1974) performed an PERCEPTION OF MOVEMENT 231
INDSCAL scaling on some triadic comparisons of color similarity sions of this solution and those of other applications correspond so collected by Helm (1964). They performed a single scaling on judg well to known perceptual dimensions when we have a priori ments from both normal and color-deficient subjects. The scaling knowledge of the dimensions, there can be little doubt that these captured, in an elegant way, already known psychophysical rela analyses reveal how subjects perceive stimuli. tions among colors, both for the normal and color-deficient sub jects. The dimension weightings for the color-deficient subjects (Manuscript received May 3, 1982; corresponded to their known color weaknesses. Since the dimen- revision accepted for publication December 14, 1982.)