Publications

Abstract

A central question in the study of the mental lexicon is how morphologically complex words are processed. We consider this question from the viewpoint of statistical models of morphology. As an indicator of the mental processing cost in the brain, we use reaction times to words in a visual lexical decision task on Finnish nouns. Statistical correlation between a model and reaction times is employed as a goodness measure of the model. In particular, we study Morfessor, an unsupervised method for learning concatenative morphology. The results for a set of inflected and monomorphemic Finnish nouns reveal that the probabilities given by Morfessor, especially the Categories-MAP version, show considerably higher correlations to the reaction times than simple word statistics such as frequency, morphological family size, or length. These correlations are also higher than when any individual test subject is viewed as a model.

Abstract

This paper describes how reciprocity is expressed in the Papuan (i.e. non-Austronesian­) language Savosavo, spoken in the Solomon Islands. The main strategy is to use the reciprocal nominal mapamapa, which can occur in different NP positions and always triggers default third person singular masculine agreement, regardless of the number and gender of the referents. After a description of this as well as another strategy that is occasionally used (the ‘joint activity construction’), the paper will provide a detailed analysis of data elicited with set of video stimuli and show that the main strategy is used to describe even clearly asymmetric situations, as long as more than one person acts on more than one person in a joint activity.

Abstract

Common ground is an essential prerequisite for coordination in social interaction, including language use. When referring back to a referent in discourse, this referent is ‘given information’ and therefore in the interactants’ common ground. When a referent is being referred to for the first time, a speaker introduces ‘new information’. The analyses reported here are on gestures that accompany such references when they include definite and indefinite grammatical determiners. The main finding from these analyses is that referents referred to by definite and indefinite articles were equally often accompanied by gesture, but speakers tended to accompany definite references with gestures focusing on action information and indefinite references with gestures focusing on entity information. The findings suggest that speakers use speech and gesture together to design utterances appropriate for speakers with whom they share common ground.

Abstract

Indo-Pakistani Sign Language (IPSL) is the sign language used by deaf communities in a large region across India and Pakistan. This visual-gestural language has a dedicated construction for specifically expressing reciprocal relationships, which can be applied to agreement verbs and to auxiliaries. The reciprocal construction relies on a change in the movement pattern of the signs it applies to. In addition, IPSL has a number of other strategies which can have a reciprocal interpretation, and the IPSL lexicon includes a good number of inherently reciprocal signs. All reciprocal expressions can be modified in complex ways that rely on the grammatical use of the sign space. Considering grammaticalisation and lexicalisation processes linking some of these constructions is also important for a better understanding of reciprocity in IPSL.

Abstract

Word learning happens in everyday contexts with many words and many potential referents for those words in view at the same time. It is challenging for young learners to find the correct referent upon hearing an unknown word at the moment. This problem of referential uncertainty has been deemed as the crux of early word learning (Quine, 1960). Recent empirical and computational studies have found support for a statistical solution to the problem termed cross-situational learning. Cross-situational learning allows learners to acquire word meanings across multiple exposures, despite each individual exposure is referentially uncertain. Recent empirical research shows that infants, children and adults rely on cross-situational learning to learn new words (Smith & Yu, 2008; Suanda, Mugwanya, & Namy, 2014; Yu & Smith, 2007). However, researchers have found evidence supporting two very different theoretical accounts of learning mechanisms: Hypothesis Testing (Gleitman, Cassidy, Nappa, Papafragou, & Trueswell, 2005; Markman, 1992) and Associative Learning (Frank, Goodman, & Tenenbaum, 2009; Yu & Smith, 2007). Hypothesis Testing is generally characterized as a form of learning in which a coherent hypothesis regarding a specific word-object mapping is formed often in conceptually constrained ways. The hypothesis will then be either accepted or rejected with additional evidence. However, proponents of the Associative Learning framework often characterize learning as aggregating information over time through implicit associative mechanisms. A learner acquires the meaning of a word when the association between the word and the referent becomes relatively strong. In this chapter, we consider these two psychological theories in the context of cross-situational word-referent learning. By reviewing recent empirical and cognitive modeling studies, our goal is to deepen our understanding of the underlying word learning mechanisms by examining and comparing the two theoretical learning accounts.