Paolo Canal

Predictive mechanisms in idiom comprehension

Prediction is pervasive in human cognition and plays a central role in language comprehension. At an electrophysiological level, this cognitive function contributes substantially in determining the amplitude of the N400. In fact, the amplitude of the N400 to words within a sentence has been shown to depend on how predictable those words are: The more predictable a word, the smaller the N400 elicited. However, predictive processing can be based on different sources of information that allow anticipation of upcoming constituents and integration in context. In this study, we investigated the ERPs elicited during the comprehension of idioms, that is, prefabricated multiword strings stored in semantic memory. When a reader recognizes a string of words as an idiom before the idiom ends, she or he can develop expectations concerning the incoming idiomatic constituents. We hypothesized that the expectations driven by the activation of an idiom might differ from those driven by discourse-based constraints. To this aim, we compared the ERP waveforms elicited by idioms and two literal control conditions. The results showed that, in both cases, the literal conditions exhibited a more negative potential than the idiomatic condition. Our analyses suggest that before idiom recognition the effect is due to modulation of the N400 amplitude, whereas after idiom recognition a P300 for the idiomatic sentence has a fundamental role in the composition of the effect. These results suggest that two distinct predictive mechanisms are at work during language comprehension, based respectively on probabilistic information and on categorical template matching.

Are complex function words processed as semantically empty strings? A reading time and ERP study of collocational complex prepositions

Collocational complex prepositions (CCPs, e.g., in the hands of) are prefabricated strings of words that play a prepositional role in natural language. Typically, CCPs are formed by a first preposition (P1) followed by a content word (N1) and a second, final preposition (P2) (in the - P1 - hands - N1 - of - P2). Despite their default structure stored in semantic memory, some CCPs allow internal modification (e.g., adjective insertion). In this study, two experiments tested the comprehension of CCPs in which we modified their default structure inserting an adjective before the noun. This modification preserved the semantic well-formedness of the string. The self-paced reading time study (Experiment 1) showed that readers took significantly longer to read the CCP constituents after the inserted adjective (N1 and P2). The ERP (Experiment 2) showed a smaller N400 response to the noun when preceded by the adjective, suggesting that the insertion did not disrupt the online processing of the CCP. Critically, the adjective insertion increased the processing load of the prepositional phrase introduced by the CCP, as evidenced by a LAN in response to the complement noun (N2). Overall, these findings showed that processing CCPs was not disrupted by insertions despite their predefined default word order. Rather, their interpretation was semantically enriched, correlating with an increase in the processing load when the CCP was integrated with the complement noun.

Norms on the gender perception of role nouns in Czech, English, French, German, Italian, Norwegian, and Slovak

We collected norms on the gender stereotypicality of an extensive list of role nouns in Czech, English, French, German, Italian, Norwegian, and Slovak, to be used as a basis for the selection of stimulus materials in future studies. We present a Web-based tool (available at https://www.unifr.ch/lcg/) that we developed to collect these norms and that we expect to be useful for other researchers, as well. In essence, we provide (a) gender stereotypicality norms across a number of languages and (b) a tool to facilitate cross-language as well as cross-cultural comparisons when researchers are interested in the investigation of the impact of stereotypicality on the processing of role nouns.

Cloze probability does not only affect N400 amplitude: The case of complex prepositions

Cloze-probability levels are inversely correlated with N400 amplitude, indicating an easier integration for expected words in semantic-pragmatic contexts. Here we exploited the prespecified standard order of complex prepositions and measured the ERPs time-locked to the last preposition in sentences in which complex prepositions were presented in their standard form or with the last preposition changed. The expected preposition elicited an N280 followed by an N400-700, two ERP components previously associated to the processing of closed-class words. The unexpected preposition elicited only an N280, and the N400-700 was reduced. These results reflect the specificity of the contextual constraints linked to the complex preposition word sequence.

Presupposition of new information as a pragmatic garden path: Evidence from Event-Related Brain Potentials

Abstract This study investigates the processing of presupposition in discourse through the Event-Related Brain Potential technique. While theoretical linguistics has largely described the phenomenon of presupposition, there is little empirical investigation, mainly from behavioural studies. Here we employed the Event Related Potential (ERP) technique to search for the brain signature of presupposition as opposed to assertion in discourse. Based on theoretical accounts, we hypothesized that presupposing new information should elicit higher efforts due to the mismatch between the information packaging and the actual knowledge, and to the need of accommodating the presupposed content in the mental model of discourse. We also hypothesized that these efforts could reflect in enhanced N400, similarly to other mechanisms operating at the discourse-context level. Twenty-seven participants were presented with passages containing new information packaged either as presupposition or as assertion. Two types of presupposition triggers were selected: definite descriptions and temporal subordinate clauses. Results evidenced a difference between the processing of presuppositions and that of assertions, reflected in a more enhanced N400 for the former. Results also showed that the temporal development of the presupposition effect is earlier for subordinate clauses than for definite descriptions. Differently from some behavioural studies on presupposition, but consistently with the theoretical literature and with other ERP studies on discourse processing, our data offer the first neurophysiological evidence that presupposition is more costly than assertion when new information is presented, with differences in the time development of the effect across trigger types. We proposed to account for the N400 effect induced by new presuppositions as stemming from a pragmatic “garden path” effect, in that, being presented with a new presupposition, the receiver is led down a mismatch between information packaging and discourse representation.

Beyond Gender Stereotypes in Language Comprehension: Self Sex-Role Descriptions Affect the Brain's Potentials Associated with Agreement Processing.

We recorded Event-Related Potentials to investigate differences in the use of gender information during the processing of reflexive pronouns. Pronouns either matched the gender provided by role nouns (such as “king” or “engineer”) or did not. We compared two types of gender information, definitional information, which is semantic in nature (a mother is female), or stereotypical (a nurse is likely to be female). When they followed definitional role-nouns, gender-mismatching pronouns elicited a P600 effect reflecting a failure in the agreement process. When instead the gender violation occurred after stereotypical role-nouns the Event Related Potential response was biphasic, being positive in parietal electrodes and negative in anterior left electrodes. The use of a correlational approach showed that those participants with more “feminine” or “expressive” self sex-role descriptions showed a P600 response for stereotype violations, suggesting that they experienced the mismatch as an agreement violation; whereas less “expressive” participants showed an Nref effect, indicating more effort spent in linking the pronouns with the possible, although less likely, counter-stereotypical referent.

Basic Composition and Enriched Integration in Idiom Processing: An EEG Study

We investigated the extent to which the literal meanings of the words forming literally plausible idioms (e.g., break the ice) are semantically composed and how the idiomatic meaning is integrated in the unfolding sentence representation. Participants read ambiguous idiom strings embedded in highly predictable, literal, and idiomatic contexts while their EEG was recorded. Control sentences only contained the idiom-final word whose cloze values were as high as in literal and idiomatic contexts. Event-related potentials data showed that differences in the amplitude of a frontal positivity (PNP) emerged at the beginning and at the end of the idiom strings, with the idiomatic context condition associated with more positive voltages. The time frequency analysis of the EEG showed an increase in power of the middle gamma frequency band only in the literal context condition. These findings suggest that sentence revision mechanisms, associated with the frontal PNP, are involved in idiom meaning integration, and that the literal semantic composition of the idiomatic constituents, associated with changes in gamma frequency, is not carried out after idiom recognition.

N400 and P600 modulation in presupposition accommodation: The effect of different trigger types

Abstract This study investigates the neurophysiological correlates of presupposition processing in conditions of satisfaction and accommodation, comparing two types of triggers: definite descriptions and change-of-state verbs. Results showed that, for both types, the accommodation of presuppositions is associated with a biphasic N400-P600 pattern at the processing point. With definite descriptions, we observed a more clear involvement of the N400, while for change-of-state verbs the costs of accommodation were associated with a more pronounced P600. Moreover, when conveyed by change of state predicates, presuppositions seem to elicit also a P200 visible already at the trigger verb. The data nicely fit into the Linking-Updating model and support two main conclusions. First, presupposition accommodation is a sequential process unfolding through a biphasic ERP pattern presumably related to search for antecedent and discourse update. Second, the kind of presupposition trigger seems to affect the cognitive cost of presupposition accommodation at different processing times, with definite description capitalizing more on the earlier search for antecedent and change-of-state verbs capitalizing more on the later updating of the discourse mental model with the presupposed information. Overall, our findings suggest that the brain understands information taken for granted by going through a process whose time course involves several phases, differently modulated based on specific linguistic expressions.

Time Course and Neurophysiological Underpinnings of Metaphor in Literary Context

ABSTRACT Several theoretical proposals tried to account for the meaning open-endedness of metaphors in literature and for the effortful process they trigger in readers. However, very few experiments have tackled the neurophysiological underpinnings of literary metaphor. Here we used Event-Related brain Potentials (ERPs) to explore the temporal dynamics of comprehending metaphors from Italian poems and novels (e.g., grass of velvet), presented in their original context, as compared with literal expressions (e.g., throne of velvet). Results evidence a more negative ERP response for metaphors, unfolding in an N400 followed by a sustained negativity over frontal sites, suggesting a long-lasting effort in elaborating figurative meanings. Whereas the N400 might be indicative of lexical/semantic processes typical of metaphors and amplified by the literary context, the sustained negativity might reflect the manipulation of multiple meanings in working memory, possibly responsible for the poetic effect. Interestingly, the late negativity effect is driven by familiarity, with a more negative response for those metaphors that are less familiar. These findings offer material to discuss ideas put forward in pragmatics, literary studies, and cognitive neuroscience of literature, like the condensation of weak implicatures, the foregrounding, and the relation between a metaphor and its context.

Anticipatory Mechanisms in Idiom Comprehension: Psycholinguistic and Electrophysiological Evidence

Idiomatic expressions are highly pervasive in everyday language: as Jackendoff [1] pointed out, in American English there are as many words as there are multi-word expressions (i.e., word strings listed in semantic memory, as proverbs, cliches, idioms, phrasal verbs, etc.), roughly around 80 000 [2]. If, indeed, multi-word expressions are so pervasive in everyday language, no theory of language can ignore them. In fact, during the last few decades a consistent body of research on the comprehension and production of idioms has accumulated in psycholinguistics [3, 4, 5] and, more recently, in the cognitive neurosciences (e.g., [6], Mado Proverbio, this volume).