The polarity-sensitive intensifier mouth gestures in Japanese Sign Language

As we consider the unique linguistic properties of Japanese Sign Language (Nihon Shuwa, JSL), it is important to note that cultural gestures of hearing Japanese were adopted into JSL and "grammaticized"to become a part of the language. Polarity-sensitive mouth gestures are discussed as an interesting example of grammaticized gestures in JSL. Matsuoka et al. (2012) reported that "polarity-sensitive"mouth gestures appear in antonym pairs in emphatic contexts. The choice of mouth gestures is determined by the positive/negative polarity of the signed adjectives. We investigated those polarity-sensitive mouth gestures with absolute and relative adjectives (specifically Kennedy and McNally's 2005 "totally closed/totally open adjectives") and argue that those mouth gestures themselves are intensifiers and the choice of the mouth gesture reflects the semantic properties of the adjective it accompanies. In addition, the data of eyebrow raise/furrow are provided to demonstrate that lexical and attitudinal polarity is expressed by different non-manuals.