The syntactic side of Time: processing Adverb-Verb Temporal Agreement

The aim of this thesis deals with the investigation of the cognitive mechanisms underlying the online processing of adverb-verb temporal agreement, namely the coherence in temporal features between the verb and a deictic temporal adverb (e.g. YesterdayPAST I wentPAST/*will goFUT to the jazz concert), during sentence comprehension. There are at least two reasons that make the investigation of this phenomenon interesting and challenging at the same time. The first reason is more theoretical. Differently from well-studied phenomena such as subject-verb agreement or anaphora, the nature of the adverb-verb relation is still debated in theoretical linguistics. The debated nature of the adverb-verb temporal agreement probably relies on the peculiar properties of the constituents involved in the relation. The relation between temporal adverbs and verbs has been traditionally defined anaphoric in nature, since verbs can be bound to temporal antecedents (e.g. adverb) which allow to set a reference time that the event expressed by the verb must refer to. However, other accounts have hypothesized a structural parallelism between the adverb-verb and the subject-verb relation. One question is thus whether this similarities or dissimilarities between subject-verb agreement and temporal agreement at the theoretical level can mirror a similarity/dissimilarity at the cognitive level. The second reason is more empirical and comes from past experimental literature investigating the processing of temporal agreement. Basically, experimental evidence mainly comes from ERPs studies and results are rather sparse and heterogeneous. These ERP studies report an early detection of the temporal violation (around 200 milliseconds after the stimulus onset) but qualitatively different ERP waveforms were elicited by the target word (i.e. the verb) in the different experiments (e.g. LAN, N400, right lateralized negativities). One licit question is thus where the source of heterogeneity resides and how this phenomenon can be better investigated. Given the debated theoretical and experimental past evidence on the processing of this relation, the current work was conducted (i) investigating the pattern elicited by adverb-verb temporal violations compared to other better-studied agreement phenomena, as the one between the subject and the verb, during sentence comprehension (ii) adopting only behavioral techniques since a detailed investigation of the behavioral costs elicited by a temporal violation needs to be established prior to facing the detailed neurophysiological correlates of these processes, which are known to be subject to a larger interpretive freedom with respect to reading time differences. The core of the thesis, namely six empirical studies investigating the processing of temporal violations through different designs and techniques, is preceded by a theoretical chapter which deals with the description of Tense and deictic temporal adverbs from a semantic and syntactic point of view. The main aim of the theoretical chapter is to give a brief overview of the main linguistic theories which have investigated the nature of Tense and temporal adverbs, but also a motivation for considering the syntactic interaction between Tense and temporal adverbs, which is fundamental to preserve the grammaticality of the sentence.The first set of self-paced reading studies, in Italian, addressed two main questions: how different is the processing of adverb-verb temporal agreement with respect to other better-studied phenomena such as subject-verb number agreement? Is the different configuration between the verb and the temporal adverb that has led to heterogeneous results in past experimental literature? In the second (eye-tracking) study, in Spanish, three other questions were addressed: how differently the parser deals with the processing of number, tense and (crucially) person features when encountering a violation on the inflected verb? Does the distance between the two constituents of the dependency play any role in the detection of the violation? Finally, in the third set of eye-tracking studies in English, the processing of the adverb-verb temporal relation was tested in a more complex sentential environment, namely in sentence where the temporal adverb and the verb are separated by an embedded relative clause containing a distracting temporal element. In this set of studies, several questions were addressed: how different can be the processing of adverb-verb temporal agreement at a conspicuous distance? Is the temporal adverb-verb relation sensitive to interference effects from an illicit intervener? How differently this relation behaves with respect to subject-verb agreement and anaphora during memory retrieval? All findings collected in this work provide further evidence for a differentiation in the processing of agreement mechanisms entailing a covariance of features between two constituents within a sentence. This evidence is in line with previous accounts showing a differentiation in the processing of different features (i.e. number, person) within the same relation such as subject-verb agreement (Mancini et al. 2013), and in the processing of the same feature (e.g. number) across different relations such as subject-verb agreement and anaphora (Dillon et al. 2013). This evidence can be particularly relevant for the development of a new model of sentence parsing. In fact, among mainstream models of parsing, only Construal (Frazier & Clifton, 1996) model assumes a relation-sensitive language system. However, a differentiation in the processing of agreement phenomena is not explicitly addressed in terms of feature-related properties. On the other hand, some recent accounts have proposed different processing mechanisms depending on the feature under computation (e.g. Mancini et al., 2013; Carminati, 2005) but a specific formalization of the role of different features properties within a model of parsing has not been provided yet. The second challenge that this current work tried to face was to add more complexity into the agreement configuration testing the adverb-verb agreement relation at different linear distance. The findings here collected seems to give positive evidence on the role played by word order in the processing of the adverb-verb relation, but further investigation needs to address whether other factors may play a role and whether adverb-verb agreement is the only agreement relation which is sensitive to word order. This puzzle thus opens new questions about whether the agreement relation may change even being both the relation and the feature under computation equal. The role played by linear distance in the detection of adverb-verb temporal anomalies also suggests that parsing routines are not “stagnant†, and the language system can deal with redundant information in a very dynamic fashion.