Summary and Outlook

2.4.1 Summary

To summarize, agreement is a widespread phenomenon which occurs in various forms. What these various instances of agreement have in common is the system-atic co-variation of grammsystem-atical forms. They differ with respect to the categories involved (e.g., in terms of word categories), the syntactic relation (e.g., two heads or a head and some dependent), which typically entails a difference in locality, and the kind of features which co-vary. This dissertation is concerned with subject–

verb agreement, and in particular number agreement between a subject NP and the corresponding finite verb. Number is an interesting feature since is relevant for morphology, syntax and semantics. It is relevant for morphology since it de-termines the form of a noun or a verb. It is relevant for semantics since it is potentially interpretable. More precisely, number is interpretable with respect to nouns or actually noun phrases but not with respect to verbs. And finally, num-ber is relevant for syntax as witnessed by the phenomenon of numnum-ber agreement.

Furthermore, grammatical number has to be distinguished from notional number.

Though the two usually coincide, this is not necessary. Discrepancies between grammatical number and notional number occur with so-called summation plu-rals like scissors, mass nouns like furniture and collective nouns like committee.⁵⁴ In particular collective nouns figured prominently in the discussion of agreement in both the linguistic and the psycholinguistic literature. The reason for their de-cisive role lies in the multilayered agreement patterns they elicit. They allow both grammatical agreement—co-variation with respect to grammatical number—and notional concord—co-variation in terms of notional number—and they do so dif-ferently for different agreement targets. The latter finding has been taken as evi-dence for the Agreement Hierarchy, though individual languages choose different points on that scale to allow for notional concord.

Theoretical approaches of agreement can be classified as to where they locate agreement and as to whether they treat agreement as a symmetrical or asymmetri-cal relation. Symmetriasymmetri-cal approaches assume that controller and target contribute equally to the final result whereas asymmetrical approaches give the controller a logically prior status. In asymmetric approaches, agreement is reached through some sort of feature transfer although not necessarily in the literal sense of trans-fer. Recent versions of the minimalist program, for instance, assume a feature valuation process.

54These three categories are not mutually exclusive. Collective nouns are often treated as a sub-type of mass nouns (e.g., Krifka, 1991) though not all collective nouns behave alike with respect to the standard tests (e.g., plural formation: families vs.^?staffs).

2.4.2 The psycholinguistic perspective

Psycholinguistic approaches to agreement commensurate to the two principal views on agreement. Theoretical approaches of agreement emphasizing the syntactic and asymmetrical nature of the agreement relation find their correspondence in psycholinguistic accounts assuming some sort of feature transfer from the subject to the verb. On this view, agreement is computed during grammatical encoding and not affected by non-syntactic information, at least not directly. Subject–verb agreement is established via feature transfer, though the exact mechanism varies across different models. The most elaborated instantiation of such an account is the MARKING AND MORPHING MODEL proposed in Bock et al. (2001) and extended in Bock et al. (2004); Eberhard et al. (2005). Marking links concep-tual features to linguistic objects, e.g., the notional number of event participant(s) to the corresponding NPs. Crucially, this linking process is constrained to lin-guistically relevant features and corresponding linguistic objects. For instance, a referent corresponds to an NP but not to a verb, hence, notional number is linked to NPs but not to verbs. Verbs receive their number value through the second mechanism, called morphing (for details see chapter 3, section 3.4.3). Further examples for this sort of account are the PERCOLATION ACCOUNT(Nicol, 1995;

Vigliocco and Nicol, 1998) and the FEATURE SELECTION ANDFEATURE COPY

-ING MODEL (Franck et al., 2008).⁵⁵ Supporting evidence for informational en-capsulation comes from experiments demonstrating that non-syntactic factors do not modulate the incidence of agreement errors. In the last decade, however, an increasing number of studies found non-syntactic effects on agreement processing (for semantic effects see Eberhard, 1999; Haskell and MacDonald, 2003; Solomon and Pearlmutter, 2004; Thornton and MacDonald, 2003; Vigliocco et al., 1996; for morphophonological effects see Haskell and MacDonald, 2003). These findings challenge modular approaches though there are ways to incorporate them (Bock et al., 2001, 2004; Eberhard et al., 2005; Franck et al., 2008).

Theoretical approaches of agreement advocating that both controller and target contribute to the computation of agreement have their equivalent in constraint-satisfaction approaches. Agreement accounts of this sort are characterized by interactivity among different types of information. Interactivity paves way for an impact of conceptual features like notional number on the computation of agreement. The issue of interactivity versus modularity in language production is discussed in extenso in Vigliocco and Hartsuiker (2002). Based on an ex-haustive examination the evidence for and against a modular view⁵⁶ the authors

55The Feature Selection and Feature Copying Model actually represents a synthesis of modular and interactive approaches. Yet, the interactive component is related to lexical retrieval whereas the core agreement processes are assumed to be strictly syntactically driven.

56Vigliocco and Hartsuiker’s term is ‘minimalist view’ emphasizing informational

encapsula-argue for what they call ‘the maximalist view’. This view is characterized by the assumption of multiple levels of integration, cascading activation and a bidi-rectional flow of information. At each level, several types of information are available but certain types are more important than others. Put differently, the weight of a given information type varies across levels of representation. For the computation of agreement at the functional level, the subject’s formal num-ber specification is the primary source of information. Conceptual information is also available and can be used though it is not necessary for the computation of agreement. In related publications, Vigliocco and colleagues proposed that the agreement features of both subject and verb originate at the message level (Vigliocco et al., 1995, 1996; Vigliocco and Franck, 1999; Vigliocco et al., 1996).

The conceptual features are linked to subject and verb independently allowing for early morphophonological encoding of the verb even before it is integrated with the subject NP. Constraints on unification then ensure that agreement is in fact obeyed. Another example for an interactive approach to agreement computa-tion is the constraint-satisfaccomputa-tion approach laid out by MacDonald and colleagues (Haskell and MacDonald, 2003; Thornton and MacDonald, 2003). Their approach is close to constraint-satisfaction approaches as developed for sentence compre-hension. In addition to interactivity, the approach is characterized by competition between verb forms and sensitivity to distributional factors.

The issue of modularity versus interactivity has been debated in the domain of sentence comprehension as well. An influential modular approach is the GARDEN -PATH MODELdeveloped by Frazier and colleagues (Frazier, 1979, 1987a; Frazier and Rayner, 1982; Rayner et al., 1983). The model dissociates parsing and se-mantic interpretation.⁵⁷ The initial analysis the parser computes is exclusively based on syntactic information. Non-syntactic information comes only later into play and can trigger reanalysis of the initial parse. This view has been questioned by findings that both discourse context and lexical semantics have an effect on parsing preferences in syntactic ambiguity resolution (e.g., Altmann and Steed-man, 1988; Crain and SteedSteed-man, 1985; Trueswell et al., 1994). Reduced relative clauses, for instance, commonly give rise to garden path effects because they are locally compatible with a main clause analysis as in the famous example The horse raced past the barn fell (Bever, 1970). The garden-path, however, vanishes when the initial NP is no potential agent for the subsequent verb as in (65) (Trueswell et al., 1994).⁵⁸

(65) a. The defendant examined by the lawyer turned out to be unreliable.

tion of different levels of language processing.

57A third step preceding the other two is lexical access.

58For an overview of findings with respect to this particular construction see MacDonald and Seidenberg, 2006.

b. The evidence examined by the lawyer turned out to be unreliable.

Constraint-satisfaction approaches—assuming that the parser uses all informa-tion available, that is syntactic and non-syntactic informainforma-tion— predict such find-ings (e.g., MacDonald et al., 1994; McRae et al., 1998; Tanenhaus et al., 2000;

Trueswell et al., 1994; for a recent overview see MacDonald and Seidenberg, 2006). However, the debate is still ongoing.

Other than in the production literature, agreement played no crucial role to de-cide between modular and interactive parsing architectures. Agreement received little attention by itself but was rather used as a tool. Disambiguation by agree-ment was used to study attachagree-ment preferences for relative clauses (e.g., Cuetos and Mitchell, 1988; Frazier and Clifton, 1996) as well as to study parsing pref-erence in face of syntactic function ambiguity (for recent overviews on German see Bader and Bayer, 2006; Bornkessel and Schlesewsky, 2006). Besides, agree-ment violations have been contrasted with other violation types, mostly semantic anomalies, to demonstrate the dissociation of various types of syntactic process-ing as well as of syntax and semantics. Kutas and Hillyard (1983) found that distinct brain responses to agreement violations compared to semantic violations.

This finding was repeated in a great number of subsequent studies demonstrating that semantic anomalies are associated with a centroparietal negativity in compar-ison to unimpaired control sentences while morphosyntactic violations including agreement violations evoke either an anterior negativity or a late positivity, or both. Though the latter components show some variability in terms of latency, scalp distribution and other aspects, morphosyntactic violations consistently do not evoke an N400 or at least not just an N400 (for details see chapter 4 and the overviews in Bornkessel-Schlesewsky and Schlesewsky, 2009; Kutas et al., 2006). But how exactly agreement is computed or rather checked during sentence comprehension only lately attracted psycholinguists’ attention (e.g., Nicol et al., 1997; Pearlmutter et al., 1999) and is still relatively underexplored. The aim of this study is therefore to make a contribution to a better understanding of agree-ment processes in this domain of language processing.

2.4.3 Preview of the Upcoming Experiments

The upcoming experiments explore the processing of agreement during sentence comprehension. More precisely, the experiments scrutinize patterns and determi-nants of attraction errors in comprehension. The experiments take a closer look at the four constructions exemplified below (repeated from chapter 1).

(66) Ich

‘I know that the mother of the children has called.’

(67) Ich

‘I know that the mother comforted the children.’

(68) Ich

‘I know that the mother whose children I care for called.’

(69) Da

‘Then came the mother whose children cried.’

For each construction, the experiments examine four number combinations—

singular subject and singular distractor, singular subject and plural distractor, plu-ral subject and pluplu-ral distractor, pluplu-ral subject and singular distractor. In addition, the experiments explore the role of grammaticality, distance, ambiguity of case marking and animacy.

Before presenting the experiments, chapter 3 addresses the computation of agreement during language production. Taking a look at production is valuable since most work on attraction has been done in the field of production. This bulk of research has shown a variety of factors that affect the incidence of attraction errors in sentence production. Those factors will be reviewed in chapter 3 and later taken up for sentence comprehension.

This is a man who knows how to naz.

He is nazzing. He does it every day.

Every day he

(Berko, 1958: 156)

3