Publications

Abstract

People with grapheme-colour synaesthesia experience colour for letters of the alphabet or digits; A can be red and B can be green. How can it be, that people automatically see a colour where only black letters are printed on the paper? With brain scans (fMRI) I showed that (black) letters activate the colour area of the brain (V4) and also a brain area that is important for combining different types of information (SPL). We found that the location where synaesthetes subjectively experience their colours is related to the order in which these brain areas become active. Some synaesthetes see their colour ‘projected onto the letter’, similar to real colour experiences, and in this case colour area V4 becomes active first. If the colours appear like a strong association without a fixed location in space, SPL becomes active first, similar to what happens for normal memories. In a last experiment we showed that in synaesthetes, attention is captured by real colour very strongly, stronger than for control participants. Perhaps this attention effect of colour can explain how letters and colours become coupled in synaesthetes.

Abstract

The linguistic category of irrealis does not show stable semantics across languages. This makes it difficult to formulate general statements about this category, and it has led some researchers to reject irrealis as a cross-linguistically valid category. In this paper we look at the semantics of the irrealis category of Yurakaré, an unclassified language spoken in central Bolivia, and compare it to irrealis semantics of a number of other languages. Languages differ with respect to the subcategories they subsume under the heading of irrealis. The variable subcategories are future tense, imperatives, negatives, and habitual aspect. We argue that the cross-linguistic variation is not random, and can be stated in terms of an implicational scale.

Abstract

Marieke van der Linden investigated the neural mechanisms underlying category formation in the human brain. The research in her thesis provides novel insights in how the brain learns, stores, and uses category knowledge, enabling humans to become skilled in categorization. The studies reveal the neural mechanisms through which perceptual as well as conceptual category knowledge is created and shaped by experience. The results clearly show that neuronal sensitivity to object features is affected by categorization training. These findings fill in a missing link between electrophysiological recordings from monkey cortex demonstrating learning-induced sharpening of neuronal selectivity and brain imaging data showing category-specific representations in the human brain. Moreover, she showed that it is specifically the features of an object that are relevant for its categorization that induce selectivity in neuronal populations. Category-learning requires collaboration between many different brain areas. Together these can be seen as the neural correlates of the key points of categorization: discrimination and generalization. The occipitotemporal cortex represents those characteristic features of objects that define its category. The narrowly shape-tuned properties of this area enable fine-grained discrimination of perceptually similar objects. In addition, the superior temporal sulcus forms associations between members or properties (i.e. sound and shape) of a category. This allows the generalization of perceptually different but conceptually similar objects. Last but not least is the prefrontal cortex which is involved in coding behaviourally-relevant category information and thus enables the explicit retrieval of category membership.

Abstract

Yurakaré (unclassified, central Bolivia) has five subordination strategies (on the basis of a morphosyntactic definition). In this paper I argue that the use of these different strategies is conditioned by the degree of conceptual synthesis of the two events, relating to temporal integration and participant integration. The most integrated events are characterized by shared time reference; morphosyntactically they are serial verb constructions, with syntactically fused predicates. The other constructions are characterized by less grammatical integration, which correlates either with a low degree of temporal integration of the dependent predicate and the main predicate, or with participant discontinuity.

Abstract

The seemingly effortless switching between languages and the merging of two languages into a coherent utterance is a hallmark of bilingual language processing, and reveals the flexibility of human speech and skilled cognitive control. That skill appears to be available not only to speakers when they produce language-switched utterances, but also to listeners and readers when presented with mixed language information. In this chapter, we review electrophysiological studies in which Event-Related Potentials (ERPs) are derived from recordings of brain activity to examine the neurocognitive aspects of comprehending and producing mixed language. Topics we discuss include the time course of brain activity associated with language switching between single stimuli and language switching of words embedded in a meaningful sentence context. The majority of ERP studies report that switching between languages incurs neurocognitive costs, but –more interestingly- ERP patterns differ as a function of L2 proficiency and the amount of daily experience with language switching, the direction of switching (switching into L2 is typically associated with higher switching costs than switching into L1), the type of language switching task, and the predictability of the language switch. Finally, we outline some future directions for this relatively new approach to the study of language switching.

Abstract

This chapter explores grammatical gender as a linguistic phenomenon. First, I define gender in terms of agreement, and look at the parts of speech that can take gender agreement. Because it relates to assumptions underlying much psycholinguistic gender research, I also examine the reasons why gender systems are thought to emerge, change, and disappear. Then, I describe the gender system of Dutch. The frequent confusion about the number of genders in Dutch will be resolved by looking at the history of the system, and the role of pronominal reference therein. In addition, I report on three lexical- statistical analyses of the distribution of genders in the language. After having dealt with Dutch, I look at whether the genders of Dutch and other languages are more or less randomly assigned, or whether there is some system to it. In contrast to what many people think, regularities do indeed exist. Native speakers could in principle exploit such regularities to compute rather than memorize gender, at least in part. Although this should be taken into account as a possibility, I will also argue that it is by no means a necessary implication.

Abstract

This thesis investigates the processing of words written in Japanese kanji and Chinese hànzì, i.e. logographic scripts. Special attention is given to the fact that the majority of Japanese kanji have multiple pronunciations (generally depending on the combination a kanji forms with other characters). First, using masked priming, it is established that upon presentation of a Japanese kanji multiple pronunciations are activated. In subsequent experiments using word naming with context pictures it is concluded that both Chinese hànzì and Japanese kanji are read out loud via a direct route from orthography to phonology. However, only Japanese kanji become susceptible to semantic or phonological context effects as a result of a cost due to the processing of multiple pronunciations. Finally, zooming in on the size of the articulatory planning unit in Japanese it is concluded that the mora as a phonological unit best complies with the observed data pattern and not the phoneme or the syllable

Abstract

Mutations of the human FOXP2 gene have been shown to cause severe difficulties in learning to make coordinated sequences of articulatory gestures that underlie speech (developmental verbal dyspraxia or DVD). Affected individuals are impaired in multiple aspects of expressive and receptive linguistic processing and ­display abnormal grey matter volume and functional activation patterns in cortical and subcortical brain regions. The protein encoded by FOXP2 belongs to a divergent subgroup of forkhead-box transcription factors, with a distinctive DNA-binding domain and motifs that mediate hetero- and homodimerization. This chapter describes the successful use of FOXP2 as a unique molecular window into neurogenetic pathways that are important for speech and language development, adopting several complementary strategies. These include direct functional investigations of FOXP2 splice variants and the effects of etiological mutations. FOXP2’s role as a transcription factor also enabled the development of functional genomic routes for dissecting neurogenetic mechanisms that may be relevant for speech and language. By identifying downstream target genes regulated by FOXP2, it was possible to identify common regulatory themes in modulating synaptic plasticity, neurodevelopment, and axon guidance. These targets represent novel entrypoints into in vivo pathways that may be disturbed in speech and language disorders. The identification of FOXP2 target genes has also led to the discovery of a shared neurogenetic pathway between clinically distinct language disorders; the rare Mendelian form of DVD and a complex and more common form of language ­disorder known as Specific Language Impairment.

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.