A preliminary description and analysis of the phonology of Portuguese Sign Language for computational modeling purposes

Since the 1960s, when Stokoe (1960) demonstrated that sign languages are linguistic systems with typical behavior of natural languages, sign languages began to be studied as complex structural linguistic systems, even if their visual modality differs from the auditive modality of spoken languages. After Stokoe (1960) proved that American Sign Language (ASL) has minimal sign pairs, research on sign language has shown that signs are composed of small meaningful units which, when combined in a certain way, create a lexicon. Several approaches have been proposed for the structure of signs: Supalla & Newport (1978) observed in ASL that there are pairs of verbs and nouns that can be distinguished by the movement associated with them. Lidell & Jonhson (1986, 1989) proposed the Move-Hold Model, which shows that the internal structure of signs is composed of movements and holds features based on a possible syllable structure of discrete sign languages. In recent years, developments in autosegmental theory led to research focusing on the simultaneous and sequential phonological elements of the internal structure of the sign. Following this approach, Sandler (1989) presented the Hand Tier Model, which proposes that handshape, location and movement are the three major categories taking part in sign languages, which can be combined in a sequential way in the sign structure. The Hand Tier Model is based on some of the categorizations of Stokoe (1960) and has introduced elements from the Move-Hold Model by Lidell & Jonhson (1986, 1989). Despite the large number of studies of sign languages in the last 50 years, Portuguese Sign Language (Língua Gestual Portuguesa, LGP) only began to be scientifically studied since 1980, with a small systematic analysis of its phonological, morphological and syntactic aspects by Prata & Martins (1980). Since then, Amaral et al. (1994) have published research grounded in an exploratory approach to grammatical features of LGP. Although some important studies were carried out and a number of limited sign vocabularies have been created, so far LGP has not been studied in a systematic and consistent manner in the major areas of linguistics and was only officially recognized by at State level in 1997. In this paper we present the first systematic study on the phonological structure of signs in LGP, based on the three sequentially combined major categories. The research involved a nearly exhaustive collection of possible segments, features, articulators and traces from the three major categories as well as …