Publications

Abstract

Descriptive grammars are our main vehicle for documenting and analysing the linguistic structure of the world's 6,000 languages. They bring together, in one place, a coherent treatment of how the whole language works, and therefore form the primary source of information on a given language, consulted by a wide range of users: areal specialists, typologists, theoreticians of any part of language (syntax, morphology, phonology, historical linguistics etc.), and members of the speech communities concerned. The writing of a descriptive grammar is a major intellectual challenge, that calls on the grammarian to balance a respect for the language's distinctive genius with an awareness of how other languages work, to combine rigour with readability, to depict structural regularities while respecting a corpus of real material, and to represent something of the native speaker's competence while recognising the variation inherent in any speech community. Despite a recent surge of awareness of the need to document little-known languages, there is no book that focusses on the manifold issues that face the author of a descriptive grammar. This volume brings together contributors who approach the problem from a range of angles. Most have written descriptive grammars themselves, but others represent different types of reader. Among the topics they address are: overall issues of grammar design, the complementary roles of outsider and native speaker grammarians, the balance between grammar and lexicon, cross-linguistic comparability, the role of explanation in grammatical description, the interplay of theory and a range of fieldwork methods in language description, the challenges of describing languages in their cultural and historical context, and the tensions between linguistic particularity, established practice of particular schools of linguistic description and the need for a universally commensurable analytic framework. This book will renew the field of grammaticography, addressing a multiple readership of descriptive linguists, typologists, and formal linguists, by bringing together a range of distinguished practitioners from around the world to address these questions.

Abstract

Language comprehension involves two basic operations: the retrieval of lexical information (such as phonologic, syntactic, and semantic information) from long-term memory, and the unification of this information into a coherent representation of the overall utterance. Neuroimaging studies using hemo¬dynamic measures such as PET and fMRI have provided detailed information on which areas of the brain are involved in these language-related memory and unification operations. However, much less is known about the dynamics of the brain's language network. This chapter presents a literature review of the oscillatory neuronal dynamics of EEG and MEG data that can be observed during language comprehen¬sion tasks. From a detailed review of this (rapidly growing) literature the following picture emerges: memory retrieval operations are mostly accompanied by increased neuronal synchronization in the theta frequency range (4-7 Hz). Unification operations, in contrast, induce high-frequency neuronal synchro¬nization in the beta (12-30 Hz) and gamma (above 30 Hz) frequency bands. A desynchronization in the (upper) alpha frequency band is found for those studies that use secondary tasks, and seems to correspond with attentional processes, and with the behavioral consequences of the language comprehension process. We conclude that it is possible to capture the dynamics of the brain's language network by a careful analysis of the event-related changes in power and coherence of EEG and MEG data in a wide range of frequencies, in combination with subtle experimental manipulations in a range of language comprehension tasks. It appears then that neuronal synchrony is a mechanism by which the brain integrates the different types of information about language (such as phonological, orthographic, semantic, and syntactic infor¬mation) represented in different brain areas.

Abstract

Impersonal verbs in Greek ‒ as in the other Indo-European languages ‒ exclusively feature 3rd person singular finite forms and convey one of three types of meaning: (a) meteorological conditions; (b) emotional and physical state/experience; (c) modality. In Greek, impersonal verbs predominantly convey meteorological conditions and modality.

Impersonal verbs in Greek, as in the other Indo-European languages, exclusively feature 3rd person singular finite forms and convey one of three types of me…

Abstract

This book examines Latin word order, its historical origins in Proto-Indo-European and the shift in ordering patterns that took place in syntax and morphology in the history of Latin and (early) French (OV or left branching giving way to VO or right branching). Subsequently, analysis of the acquisition of ordering patterns shows that the archaic structuration—when complex—is acquired with difficulty. Diachronic and psycholinguistic analysis therefore demonstrates that the order of grammatical structures in Modern French, for example, is the result of a long-lasting development that psycholinguistic data can account for.

Abstract

Fictive Motion is the metaphoric use of path relators in the expression of spatial relations or configurations that are static, or at any rate do not in any obvious way involve physical entities moving in real space. The goal is to study the expression of such relations or configurations in the target language, with an eye particularly on whether these expressions exclusively/preferably/possibly involve motion verbs and/or path relators, i.e., Fictive Motion. Section 2 gives Talmy’s (2000: ch. 2) phenomenology of Fictive Motion construals. The researcher’s task is to “distill” the intended spatial relations/configurations from Talmy’s description of the particular Fictive Motion metaphors and elicit as many different examples of the relations/configurations as (s)he deems necessary to obtain a basic sense of whether and how much Fictive Motion the target language offers or prescribes for the encoding of the particular type of relation/configuration. As a first stab, the researcher may try to elicit natural translations of culturally appropriate adaptations of the examples Talmy provides with each type of Fictive Motion metaphor.

Abstract

Landscape terms reflect the relationship between geographic reality and human cognition. Are ‘mountains’, ‘rivers, ‘lakes’ and the like universally recognised in languages as naturally salient objects to be named? The landscape subproject is concerned with the interrelation between language, cognition and geography. Specifically, it investigates issues relating to how landforms are categorised cross-linguistically as well as the characteristics of place naming.

Abstract

Prosodic juncture concerns the compartmentalization and partitioning of syntactic entities in spoken discourse by means of prosody. It has been argued that the Intonation Unit, defined by internal criteria and prosodic boundary phenomena (e.g., final lengthening, pitch reset, pauses), encapsulates the basic structural unit of spoken Modern Hebrew.

Abstract

Fricative consonants in Hebrew can be divided into bgdkpt and sibilants (ז, ס, צ, שׁ, שׂ). Hebrew sibilants have been argued to stem from Proto-Semitic affricates, laterals, interdentals and /s/. In standard Israeli Hebrew the sibilants are pronounced as [s] (ס and שׂ), [ʃ] (שׁ), [z] (ז), [ʦ] (צ).

Abstract

Reprinted from; Bowerman, M. (1989). Learning a semantic system: What role do cognitive predispositions play? In M.L. Rice & R.L Schiefelbusch (Ed.), The teachability of language (pp. 133-169). Baltimore: Paul H. Brookes.

Abstract

Reprinted from: Bowerman, M. (1990). Mapping thematic roles onto syntactic functions: Are children helped by innate linking rules? Linguistics, 28, 1253-1289.

Abstract

Kids’ Cut & Break is a task inspired by the original Cut & Break task (see MPI L&C Group Field Manual 2001), but designed for use with children as well as adults. There are fewer videoclips to be described (34 as opposed to 61), and they are “friendlier” and more interesting: the actors wear colorful clothes, smile, and act cheerfully. The first 2 items are warm-ups and 4 more items are fillers (interspersed with test items), so only 28 of the items are actually “test items”. In the original Cut & Break, each clip is in a separate file. In Kids’ Cut & Break, all 34 clips are edited into a single file, which plays the clips successively with 5 seconds of black screen between each clip.

Abstract

In a famous paper Harvey Sacks (1974) argued that the sequential properties of greeting conventions, as well as those governing the flow of information, mean that 'everyone has to lie'. In this paper I show this dictum to be equally true in the Tzeltal Mayan community of Tenejapa, in southern Mexico, but for somewhat different reasons. The phenomenon of interest is the practice of routine fearsome threats to small children. Based on a longitudinal corpus of videotaped and tape-recorded naturally-occurring interaction between caregivers and children in five Tzeltal families, the study examines sequences of Tzeltal caregivers' speech aimed at controlling the children's behaviour and analyzes the children's developing pragmatic skills in handling such controlling utterances, from prelinguistic infants to age five and over. Infants in this society are considered to be vulnerable, easily scared or shocked into losing their 'souls', and therefore at all costs to be protected and hidden from outsiders and other dangers. Nonetheless, the chief form of control (aside from physically removing a child from danger) is to threaten, saying things like "Don't do that, or I'll take you to the clinic for an injection," These overt scare-threats - rarely actually realized - lead Tzeltal children by the age of 2;6 to 3;0 to the understanding that speech does not necessarily convey true propositions, and to a sensitivity to the underlying motivations for utterances distinct from their literal meaning. By age 4;0 children perform the same role to their younger siblings;they also begin to use more subtle non-true (e.g. ironic) utterances. The caretaker practice described here is related to adult norms of social lying, to the sociocultural context of constraints on information flow, social control through gossip, and the different notion of 'truth' that arises in the context of non-verifiability characteristic of a small-scale nonliterate society.

Abstract

This is an appropriate moment to review the state of the art in cognitive anthropology, construed broadly as the comparative study of human cognition in its linguistic and cultural context. In reaction to the dominance of universalism in the 1970s and '80s, there have recently been a number of reappraisals of the relation between language and cognition, and the field of cognitive anthropology is flourishing in several new directions in both America and Europe. This is partly due to a renewal and re-evaluation of approaches to the question of linguistic relativity associated with Whorf, and partly to the inspiration of modern developments in cognitive science. This review briefly sketches the history of cognitive anthropology and surveys current research on both sides of the Atlantic. The focus is on assessing current directions, considering in particular, by way of illustration, recent work in cultural models and on spatial language and cognition. The review concludes with an assessment of how cognitive anthropology could contribute directly both to the broader project of cognitive science and to the anthropological study of how cultural ideas and practices relate to structures and processes of human cognition.

Abstract

This paper surveys the lexical and grammatical resources for talking about spatial relations in the Mayan language Tzeltal - for describing where things are located, where they are moving, and how they are distributed in space. Six basic sets of spatial vocabulary are presented: i. existential locative expressions with ay ‘exist’, ii. deictics (demonstratives, adverbs, presentationals), iii. dispositional adjectives, often in combination with (iv) and (v), iv. body part relational noun locatives, v. absolute (‘cardinal’) directions, and vi. motion verbs, directionals and auxiliaries. The first two are used in minimal locative descriptions, while the others constitute the core resources for specifying in detail the location, disposition, orientation, or motion of a Figure in relation to a Ground. We find that Tzeltal displays a relative de-emphasis on deixis and left/right asymmetry, and a detailed attention to the spatial properties of objects.

Abstract

This paper surveys the concept of culture as used in recent work in cognitive science, assessing the very different (and sometimes minimal) role 'culture' plays in different branches and schools of linguistics: generative approaches, descriptive/comparative linguistics, typology, cognitive linguistics, semantics, pragmatics, psycholinguistics, linguistic and cognitive anthropology. The paper then describes research on one specific topic, spatial language and conceptualization, describes a methodology for studying it cross-linguistically and cross-culturally. Finally, it considers the implications of results in this area for how we can fruitfully conceptualize 'culture', arguing for an approach which shifts back and forth between individual mind and collective representations, between universals and particulars, and ties 'culture' to our biological roots.

Abstract

Interaction, for all that it has an ethological base, is culturally constituted, and how new social members are enculturated into the interactional practices of the society is of critical interest to our understanding of interaction – how much is learned, how variable is it across cultures – as well as to our understanding of the role of culture in children’s social-cognitive development. The goal of this task is to document the nature of caregiver infant interaction in different cultures, especially during the critical age of 9-15 months when children come to have an understanding of others’ intentions. This is of interest to all students of interaction; it does not require specialist knowledge of children.

Abstract

This is a translation of the Brown 1998 article in Journal of Linguistic Anthropology, 'Conversational structure and language acquisition: The role of repetition in Tzeltal adult and child speech'.

Abstract

This paper presents results of a comparative project documenting the development of verbal agreement inflections in children learning four different Mayan languages: K’iche’, Tzeltal, Tzotzil, and Yukatek. These languages have similar inflectional paradigms: they have a generally agglutinative morphology, with transitive verbs obligatorily marked with separate cross-referencing inflections for the two core arguments (‘ergative’ and ‘absolutive’). Verbs are also inflected for aspect and mood, and they carry a ‘status suffix’ which generally marks verb transitivity and mood. At a more detailed level, the four languages differ strikingly in the realization of cross-reference marking. For each language, we examined longitudinal language production data from two children at around 2;0, 2;6, 3;0, and 3;6 years of age. We relate differences in the acquisition patterns of verbal morphology in the languages to 1) the placement of affixes, 2) phonological and prosodic prominence, 3) language-specific constraints on the various forms of the affixes, and 4) consistent vs. split ergativity, and conclude that prosodic salience accounts provide th ebest explanation for the acquisition patterns in these four languages.

Abstract

In this paper I take up the idea that human thinking is systematically biased in the direction of interactive thinking (E. Goody's anticipatory interactive planning), that is, that humans are peculiarly good at, and inordinately prone to, attributing intentions and goals to one other (as well as to non-humans), and that they routinely orient to presumptions about each other's intentions in what they say and do. I explore the implications of that idea for an understanding of politeness in interaction, taking as a starting point the Brown and Levinson (1987) model of politeness, which assumes interactive thinking, a notion implicit in the formulation of politeness as strategic orientation to face. Drawing on an analysis of the phenomenon of conventionalized ‘irony’ in Tzeltal, I emphasize that politeness does not inhere in linguistic form per se but is a matter of conveying a polite intention, and argue that Tzeltal irony provides a prime example of one way in which humans' highly-developed intellectual machinery for inferring alter's intentions is put to the service of social relationships.

Abstract

In this chapter, we survey the processes of recognizing and producing words and of understanding and creating sentences. Theory and research on these topics have been shaped by debates about how various sources of information are integrated in these processes, and about the role of language structure, as analyzed in the discipline of linguistics. In this chapter, we describe current views of fluent language users' comprehension of spoken and written language and their production of spoken language. We review what we consider to be the most important findings and theories in psycholinguistics, returning again and again to the questions of modularity and the importance of linguistic knowledge. Although we acknowledge the importance of social factors in language use, our focus is on core processes such as parsing and word retrieval that are not necessarily affected by such factors. We do not have space to say much about the important fields of developmental psycholinguistics, which deals with the acquisition of language by children, or applied psycholinguistics, which encompasses such topics as language disorders and language teaching. Although we recognize that there is burgeoning interest in the measurement of brain activity during language processing and how language is represented in the brain, space permits only occasional pointers to work in neuropsychology and the cognitive neuroscience of language. For treatment of these topics, and others, the interested reader could begin with two recent handbooks of psycholinguistics (Gaskell, 2007; Traxler & Gemsbacher, 2006) and a handbook of cognitive neuroscience (Gazzaniga, 2004).

Abstract

Rudolf Meringer (1859–1931), Indo-European philologist, published two collections of slips of the tongue, annotated and interpreted. From 1909, he was the founding editor of the cultural morphology movement's journal Wörter und Sachen. Meringer was the first to note the linguistic significance of speech errors, and his interpretations have stood the test of time. This work, rather than his mainstream philological research, has proven his most lasting linguistic contribution

Abstract

Speech segmentation procedures may differ in speakers of different languages. Earlier work based on French speakers listening to French words suggested that the syllable functions as a segmentation unit in speech processing. However, while French has relatively regular and clearly bounded syllables, other languages, such as English, do not. No trace of syllabifying segmentation was found in English listeners listening to English words, French words, or nonsense words. French listeners, however, showed evidence of syllabification even when they were listening to English words. We conclude that alternative segmentation routines are available to the human language processor. In some cases speech segmentation may involve the operation of more than one procedure.

Abstract

This chapter highlights that most language behavior consists of speaking and listening. The chapter also reveals differences and similarities between speaking and listening. The laboratory study of word production raises formidable problems; ensuring that a particular word is produced may subvert the spontaneous production process. Word production is investigated via slips and tip-of-the-tongue (TOT), primarily via instances of processing failure and via the technique of via the picture-naming task. The methodology of word production is explained in the chapter. The chapter also explains the phenomenon of interaction between various stages of word production and the process of speech recognition. In this context, it explores the difference between sound and meaning and examines whether or not the comparisons are appropriate between the processes of recognition and production of spoken words. It also describes the similarities and differences in the structure of the recognition and production systems. Finally, the chapter highlights the common issues in recognition and production research, which include the nuances of frequency of occurrence, morphological structure, and phonological structure.

Abstract

Different linguistic structures allow us to highlight distinct aspects of a situation. The aim of this survey is to investigate similarities and differences in the expression of situations or events as “stative” (maintaining a state), “inchoative” (adopting a state) and “agentive” (causing something to be in a state). The questionnaire focuses on the encoding of stative, inchoative and agentive possibilities for the translation equivalents of a set of English verbs.

Abstract

Expressions of human activities and states are a rich area for cross-linguistic comparison. Some languages of the world treat human posture verbs (e.g., sit, lie, kneel) as a special class of predicates, with distinct formal properties. This survey examines lexical, semantic and grammatical patterns for posture verbs, with special reference to contrasts between “stative” (maintaining a posture), “inchoative” (adopting a posture), and “agentive” (causing something to adopt a posture) constructions. The enquiry is thematically linked to the more general questionnaire 'Intransitive Predicate Form Class Survey'.

Abstract

This chapter argues that an evolutionary cultural approach to language not only has already proven fruitful, but it probably holds the key to understand many puzzling aspects of language, its change and origins. The chapter begins by highlighting several still common misconceptions about language that might seem to call into question a cultural evolutionary approach. It explores the antiquity of language and sketches a general evolutionary approach discussing the aspects of function, fi tness, replication, and selection, as well the relevant units of linguistic evolution. In this context, the chapter looks at some fundamental aspects of linguistic diversity such as the nature of the design space, the mechanisms generating it, and the shape and fabric of language. Given that biology is another evolutionary system, its complex coevolution with language needs to be understood in order to have a proper theory of language. Throughout the chapter, various challenges are identifi ed and discussed, sketching promising directions for future research. The chapter ends by listing the necessary data, methods, and theoretical developments required for a grounded evolutionary approach to language.

Abstract

The complex inter-relationships between genetics and linguistics encompass all four scales highlighted by the contributions to this book and, together with cultural transmission, the genetics of language holds the promise to offer a unitary understanding of this fascinating phenomenon. There are inter-individual differences in genetic makeup which contribute to the obvious fact that we are not identical in the way we understand and use language and, by studying them, we will be able to both better treat and enhance ourselves. There are correlations between the genetic configuration of human groups and their languages, reflecting the historical processes shaping them, and there also seem to exist genes which can influence some characteristics of language, biasing it towards or against certain states by altering the way language is transmitted across generations. Besides the joys of pure knowledge, the understanding of these three aspects of genetics relevant to language will potentially trigger advances in medicine, linguistics, psychology or the understanding of our own past and, last but not least, a profound change in the way we regard one of the emblems of being human: our capacity for language.

Abstract

The papers in this volume focus on the impact of information structure on language acquisition, thereby taking different linguistic approaches into account. They start from an empirical point of view, and examine data from natural first and second language acquisition, which cover a wide range of varieties, from early learner language to native speaker production and from gesture to Creole prototypes. The central theme is the interplay between principles of information structure and linguistic structure and its impact on the functioning and development of the learner's system. The papers examine language-internal explanatory factors and in particular the communicative and structural forces that push and shape the acquisition process, and its outcome. On the theoretical level, the approach adopted appeals both to formal and communicative constraints on a learner’s language in use. Two empirical domains provide a 'testing ground' for the respective weight of grammatical versus functional determinants in the acquisition process: (1) the expression of finiteness and scope relations at the utterance level and (2) the expression of anaphoric relations at the discourse level.

Abstract

Words evolve not as blobs of ink on paper but in face to face interaction. The nature of language as fundamentally interactive and multimodal is shown by the study of ideophones, vivid sensory words that thrive in conversations around the world. The ways in which these Lautbilder enable precise communication about sensory knowledge has for the first time been studied in detail. It turns out that we can paint with language, and that the onomatopoeia we sometimes classify as childish might be a subset of a much richer toolkit for depiction in speech, available to us all.

Abstract

Conclusion In this study we have examined the evidence for the exact genetic position of the Awetí language in the large Tupí family, especially evidence for an internal classification of the larger branch of Tupí called “Mawetí-Guaraní” which comprises the Tupí-Guaraní family, Awetí and Sateré-Mawé. As it turns out, we did not find any clear example of an uncommon sound change which would have happened after the separation of the antecessor of one branch but before the split between the other two. There is some just probability that Awetí belongs somewhat closer to Tupí-Guaraní within Mawetí-Guaraní (configuration A in Table 1), but we did not find any conclusive evidence. All we have are some weak indications the majority of which, however, point in this direction: • a higher number of cognates found between Awetí and proto-Tupí-Guarani; • lexicostatistic results (number of cognates in a 100-item-word-list proposed by Swadesh); • loss of long vowels in Awetí and Tupí-Guaraní, but not in Sateré-Mawé; • some sound changes suggest that in the development to Awetí and to proto-Tupí-Guaraní velar segments changes to dental segments (cf. the discussion of the correspondence set j : t : w); • possibly some of the correspondence sets given in Table 20. We consider it to be too soon to conclude that there is a branch Awetí + Tupí-Guaraní of Mawetí-Guaraní, opposed to Sateré-Mawé, but if there is any grouping, this hypothesis is most promising. 29

Abstract

The Island Melanesia project was initiated to collect data on the little-known Papuan languages of Island Melanesia, and to explore the origins of and relationships between these languages. The project materials from the 2003 field season focus on language related to cultural domains (e.g., material culture) and on targeted grammatical description. Five tasks are included: Proto-Oceanic lexicon, Grammatical questionnaire and lexicon, Kinship questionnaire, Domains of likely pre-Austronesian terminology, and Botanical collection questionnaire.

Abstract

This task is designed to elicit virtual 3D ‘models’ created in gesture space using iconic and other representational gestures. This task has been piloted with Lao speakers, where two speakers were asked to explain the meaning of terms referring to different kinds of fish trap mechanisms. The task elicited complex performances involving a range of iconic gestures, and with especially interesting use of (a) the ‘model/diagram’ in gesture space as a virtual object, (b) the non-dominant hand as a prosodic/semiotic anchor, (c) a range of different techniques (indexical and iconic) for evoking meaning with the hand, and (d) the use of nearby objects and parts of the body as semiotic ‘props’.

Abstract

Laos features a high level of linguistic diversity, with more than 70 languages from four different major language families (Tai, Mon-Khmer, Hmong-Mien, Tibeto-Burman). Mon-Khmer languages were spoken in Laos earlier than other languages, with incoming migrations by Tai speakers (c. 2000 years ago) and Hmong-Mien speakers (c. 200 years ago). There is widespread language contact and multilingualism in upland minority communities, while lowland-dwelling Lao speakers are largely monolingual. Lao is the official national language. Most minority languages are endangered, with a few exceptions (notably Hmong and Kmhmu). There has been relatively little linguistic research on languages of Laos, due to problems of both infrastructure and administration.

Abstract

Introduction

A comparison of conversation in twenty-one languages from around the world reveals commonalities and differences in the way that people do open-class other-initiation of repair (Schegloff, Jefferson, and Sacks, 1977; Drew, 1997). We find that speakers of all of the spoken languages in the sample make use of a primary interjection strategy (in English it is Huh?), where the phonetic form of the interjection is strikingly similar across the languages: a monosyllable featuring an open non-back vowel [a, æ, ə, ʌ], often nasalized, usually with rising intonation and sometimes an [h-] onset. We also find that most of the languages have another strategy for open-class other-initiation of repair, namely the use of a question word (usually “what”). Here we find significantly more variation across the languages. The phonetic form of the question word involved is completely different from language to language: e.g., English [wɑt] versus Cha'palaa [ti] versus Duna [aki]. Furthermore, the grammatical structure in which the repair-initiating question word can or must be expressed varies within and across languages. In this chapter we present data on these two strategies – primary interjections like Huh? and question words like What? – with discussion of possible reasons for the similarities and differences across the languages. We explore some implications for the notion of repair as a system, in the context of research on the typology of language use.

The general outline of this chapter is as follows. We first discuss repair as a system across languages and then introduce the focus of the chapter: open-class other-initiation of repair. A discussion of the main findings follows, where we identify two alternative strategies in the data: an interjection strategy (Huh?) and a question word strategy (What?). Formal features and possible motivations are discussed for the interjection strategy and the question word strategy in order. A final section discusses bodily behavior including posture, eyebrow movements and eye gaze, both in spoken languages and in a sign language.

Abstract

Research on video- and audio-recordings of spontaneous naturally-occurring conversation in English has shown that conversation is a rule-guided, practice-oriented domain that can be investigated for its underlying mechanics or structure. Systematic study could yield something like a grammar for conversation. The goal of this task is to acquire a corpus of video-data, for investigating the underlying structure(s) of interaction cross-linguistically and cross-culturally

Abstract

We want to know how people think about their field of kin, on the supposition that it is quasi-spatial. To get some insights here, we need to video a discussion about kinship reckoning, the kinship system, marriage rules and so on, with a view to looking at both the linguistic expressions involved, and the gestures people use to indicate kinship groups and relations. Unlike the task in the 2001 manual, this task is a direct interview method.

Abstract

This chapter contains sections titled: Introduction Lexical Selection in Reference: Introductory Examples of Reference to Times Multiple “Preferences” Future Directions Conclusion