One of the unique things about human language is its abundant, open-ended 'wordiness'. In childhood, we undergo a vocabulary explosion, and then effortlessly store and retrieve many thousands of words in a lifetime, with the ability learn multiple languages and specialized terminology well into adulthood. This species-specific capacity for large flexible vocabularies exists in sign languages as well as spoken languages, yet the nature of the mental lexicon in sign languages — that is, the storage and retrieval of words in the brain — is not well understood, due in part to properties of the language modality that make studying combinations of form and meaning a challenge.
One of the unique things about human language is its abundant, open-ended 'wordiness'. In childhood, we undergo a vocabulary explosion, and then effortlessly store and retrieve many thousands of words in a lifetime, with the ability learn multiple languages and specialized terminology well into adulthood. This species-specific capacity for large flexible vocabularies exists in sign languages as well as spoken languages, yet the nature of the mental lexicon in sign languages — that is, the storage and retrieval of words in the brain — is not well understood, due in part to properties of the language modality that make studying combinations of form and meaning a challenge.
Words in sign languages are made up of both discrete units (e.g., selected fingers) and gradient aspects (e.g., degrees of flexion in the joints of the arm) in articulation, just as in spoken languages. One difference in language modality, however, is the degree to which signers to use the body's resources — handshapes, movements, locations, relations in space, etc. — to depict objects and actions through visual symbols and metaphors. For instance, as shown below, there is a sign in Kenyan Sign Language meaning 'to contemplate, muse, ponder' (below, right) in which the sign for 'word' (below left; one of several variants) moves off the head repeatedly, as if pulling words out of the mind. Signs are also made up of highly simultaneous constructions, unlike sequences of consonant and vowel sounds in spoken words.
Words in sign languages are made up of both discrete units (e.g., selected fingers) and gradient aspects (e.g., degrees of flexion in the joints of the arm) in articulation, just as in spoken languages. One difference in language modality, however, is the degree to which signers to use the body's resources — handshapes, movements, locations, relations in space, etc. — to depict objects and actions through visual symbols and metaphors. For instance, as shown below, there is a sign in Kenyan Sign Language meaning 'to contemplate, muse, ponder' (below, right) in which the sign for 'word' (below left; one of several variants) moves off the head repeatedly, as if pulling words out of the mind. Signs are also made up of highly simultaneous constructions, unlike sequences of consonant and vowel sounds in spoken words.