Categorical vs. Gradient: What ... - The University of Texas at Austin

Categorical vs. Gradient: What asl fingerspelling teaches us about the phonetics-phonology interface
There are many phonological phenomena that have phonetic motivations in spoken languages (e.g., word-final devoicing in
German, flapping in English), but only a few such phenomena have been described for signed languages (sls). One is the use of
phonological word constituent boundaries to account for the assimilation of selected fingers in compounds (Sandler and Lillo-
Martin, 2006). In this paper statistical methods typically used with larger corpora shed light on questions of the phoneticsphonology
interface in sls, focusing on asl fingerspelling. Because fingerspelling involves rapid sequences of handshapes it is
an ideal place to investigate the phonetics and phonology of handshape (e.g., coarticulation, assimilation, as well as temporal
overlap of articulatory gestures). Additionally, these results contribute to general debates about the definition of phonetics and
phonology (Keating, 1996; Cohn, 1998). This paper focuses on two types of co-articulatory phenomena — ulnar digit extension
(ude; 1 & figure 1) (Cheek, 2001; Hoopes, 1998; Jerde et al., 2003; Tyrone et al., 2010), and ulnar digit flexion (udf; 2 & figure
2) — to demonstrate that by looking at the variability and distribution of such behaviors in detail we can better understand
the differences between phonetics and phonology of sls. ude and udf provide us with two informative case studies in this
regard. A new phonological operation is also described in the paper and attributed to Underspecification Theory.
Method We recorded nearly 3 hours of 2 native asl signers fingerspelling a total of 2,400 words, which included names,
nouns, and foreign words between 5 and 15 letters. Every target letter was tagged, labeled, and annotated for ude and udf
— approximately 8,000 handshapes were coded in all and used for both analyses below. The steps of transcription included
human coding, algorithmic averaging, forced alignment, and verification.
Analysis Using multilevel logistic regressions both ude and udf show significant main effects for signer (1, 2), word type
(noun, name, foreign), and environment (previous, following). Moreover, segment fusion may occur in ude when the selected
fingers of adjacent handshapes are completely distinct, such as -t- (thumb and index finger selected) and -i- (pinky finger
selected), as in a-c-t-i-v-[it]-y. These phonetic effects will elaborated upon in the talk.
In addition to these phonetic effects, we found that not all handshapes are equally likely to trigger ude, and not all targets are
equally likely to undergo udf. Our analysis for why -e- and -o- are the two handshapes most susceptible to udf involves Underspecification
Theory. In the Prosodic Model Brentari (1998) these two handshapes have unspecified values for the selected
fingers and we argue that it is this fact that facilitates the assimilation of neighboring values.
Conclusions The phenomena explored in this paper seem to be on either side of the boundary between phonetics and
phonology of handshape: ude is temporally gradient, and does not need to refer to abstract phonological features. Whereas
udf does not appear to be temporally gradient, and is most easily described by positing assimilation of an abstract phonological
feature (i.e., selected finger quantity).
1. Ulnar Digit Extension (ude) A target handshape was coded "+ude" if the tip of the pinky finger was above the plane
perpendicular to the palmar plane, at the base of the pinky finger (the metacarpal mcp joint) and the proximal interphalangeal
joint (pip) was more than half extended (less than 45 degrees). Otherwise, the handshape was coded " -ude".
(a) -r- [−ude] (b) -r- [+ude](c) -c- [−ude] (d) -c- [+ude] (e) -e- [−ude] (f) -e- [+ude]
Figure 1: Apogees from (a) d-i-n-o-s-a-u-r, (b) c-h-r-i-s, (c) z-a-c-k, (d) e-x-p-e-c-t-a-t-i-o-n, (e) e-v-e-r-g-l-a-d-e-s,
and (f) z-d-r-o-q-i-e
2. Ulnar Digit Flexion (udf) A target handshape was coded "+udf" if either the pip or the mcp joint was more flexed in
ulnar digits than radial digits. Otherwise, the handshape was coded "-udf".
(a) -d- [−udf] (b) -d- [+udf](c) -c- [−udf] (d) -c- [+udf] (e) -e- [−udf] (f) -e- [+udf] (g) -o- [−udf] (h) -o- [+udf]
Figure 2: Apogees from (a) d-i-n-o-s-a-u-r, (b) d-o-n, (c) c-a-d-i-l-l-a-c, (d) c-h-w-i-l-k-e, (e) f-e-l-e-s-e-g,
(f) k-a-h-d-e-k-s-a-n, (g) m-o-s-c-o-w, and (h) b-l-a-h-o-p-r-e-j-i

References
Brentari, D. (1998). A prosodic model of sign language phonology. The MIT Press.
Cheek, D. A. (2001). The Phonetics and Phonology of Handshape in American Sign Language. PhD thesis, University of Texas
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Cohn, A. C. (1998). The phonetics-phonology interface revisited: Where’s phonetics? In Texas Linguistic Forum, volume 41,
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function. Pinky extension and eye gaze: Language use in Deaf communities, pages 3–17.
Jerde, T. E., Soechting, J. F., and Flanders, M. (2003). Coarticulation in fluent fingerspelling. Journal of Neuroscience,
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