Cross-linguistic variation in the neurophysiological response to semantic processing: evidence from anomalies at the borderline of awareness.

The N400 event-related brain potential (ERP) has played a major role in the examination of how the human brain processes meaning. For current theories of the N400, classes of semantic inconsistencies which do not elicit N400 effects have proven particularly influential. Semantic anomalies that are difficult to detect are a case in point ("borderline anomalies", e.g. "After an air crash, where should the survivors be buried?"), engendering a late positive ERP response but no N400 effect in English (Sanford, Leuthold, Bohan, & Sanford, 2011). In three auditory ERP experiments, we demonstrate that this result is subject to cross-linguistic variation. In a German version of Sanford and colleagues' experiment (Experiment 1), detected borderline anomalies elicited both N400 and late positivity effects compared to control stimuli or to missed borderline anomalies. Classic easy-to-detect semantic (non-borderline) anomalies showed the same pattern as in English (N400 plus late positivity). The cross-linguistic difference in the response to borderline anomalies was replicated in two additional studies with a slightly modified task (Experiment 2a: German; Experiment 2b: English), with a reliable LANGUAGE×ANOMALY interaction for the borderline anomalies confirming that the N400 effect is subject to systematic cross-linguistic variation. We argue that this variation results from differences in the language-specific default weighting of top-down and bottom-up information, concluding that N400 amplitude reflects the interaction between the two information sources in the form-to-meaning mapping.

The processing of good-fit semantic anomalies: an ERP investigation.

The failure-to-detect good-fit semantic anomalies is taken as evidence for shallow semantic processing, however the cognitive mechanisms involved are not well understood. To investigate this we recorded event-related potentials (ERPs) to sentences that contained good and poor-fit semantic anomalies and non-anomalous controls. Detected good-fit anomalies elicited an N400 effect when detection accuracy was stressed, indicating the registration of the anomaly. ERP analyses further ruled out that anomaly non-/detection is due to differences in initial word encoding or in processing prior contextual information. In addition, starting in the P2 interval, the ERP waveform was less positive for non-detected than detected anomalies and non-anomalous controls, presumably reflecting a language-driven modulation of visual input processing. And finally, detection of good-fit anomalies may also depend on the integration of sentential information into the discourse model at the end of the critical sentence. Overall, present findings support the shallow processing account of anomaly detection failure.

Reading in healthy ageing: the influence of information structuring in sentences.

In three experiments, we investigated the cognitive effects of linguistic prominence to establish whether focus plays a similar or different role in modulating language processing in healthy ageing. Information structuring through the use of cleft sentences is known to increase the processing efficiency of anaphoric references to elements contained with a marked focus structure. It also protects these elements from becoming suppressed in the wake of subsequent information, suggesting selective mechanisms of enhancement and suppression. In Experiment 1 (using self-paced reading), we found that focus enhanced (faster) integration for anaphors referring to words contained within the scope of focus; but suppressed (slower) integration for anaphors to words contained outside of the scope of focus; and in some cases, the effects were larger in older adults. In Experiment 2 (using change detection), we showed that older adults relied more on the linguistic structure to enhance change detection when the changed word was in focus. In Experiment 3 (using delayed probe recognition and eye-tracking), we found that older adults recognized probes more accurately when they were made to elements within the scope of focus than when they were outside the scope of focus. These results indicate that older adults' ability to selectively attend or suppress concepts in a marked focus structure is preserved.

Anaphoric reference to quantified antecedents: an event-related brain potential study.

We report an event-related brain potential (ERP) study examining how readers process sentences containing anaphoric reference to quantified antecedents. Previous studies indicate that positive (e.g. many) and negative (e.g. not many) quantifiers cause readers to focus on different sets of entities. For example in Many of the fans attended the game, focus is on the fans who attended (the reference set), and subsequent pronominal reference to this set, as in, Their presence was a boost to the team, is facilitated. In contrast, if many is replaced by not many, focus shifts to the fans who did not attend (the complement set), and reference to this set, as in, Their absence was disappointing, is preferred. In the current studies, the electroencephalogram (EEG) was recorded while participants read positive or negative quantified statements followed by anaphoric reference to the reference set or complement set. Results showed that the pronoun their elicited a larger N400 following negative than positive quantifiers. There was also a larger N400 on the disambiguating word (presence/absence) for complement set reference following a positive quantifier, and for reference set reference following a negative quantifier. Findings are discussed in relation to theoretical accounts of complement anaphora.

Anomalies at the borderline of awareness: an ERP study.

Behaviorally, some semantic anomalies, such as those used to demonstrate N400 effects in ERPs, are easy to detect. However, some, such as "after an air crash, where should the survivors be buried?" are difficult. The difference has to do with the extent to which the anomalous word fits the general context. We asked whether anomalies that are missed elicit an ERP that could be taken as indicating unconscious recognition, and whether both types elicit an N400 effect when they are detected. We found that difficult anomalies having a good fit to general context did not produce an N400 effect, whereas control "easy-to-detect" anomalies did. For difficult anomalies, there was no evidence for unconscious detection occurring. The results support a qualitative distinction in the way the two types of anomalies are processed, and the idea that semantic information is simply not utilized (shallow processing) when difficult anomalies are missed.

Enhancement and suppression effects resulting from information structuring in sentences.

Information structuring through the use of cleft sentences increases the processing efficiency of references to elements within the scope of focus. Furthermore, there is evidence that putting certain types of emphasis on individual words not only enhances their subsequent processing, but also protects these words from becoming suppressed in the wake of subsequent information, suggesting mechanisms of enhancement and suppression. In Experiment 1, we showed that clefted constructions facilitate the integration of subsequent sentences that make reference to elements within the scope of focus, and that they decrease the efficiency with reference to elements outside of the scope of focus. In Experiment 2, using an auditory text-change-detection paradigm, we showed that focus has similar effects on the strength of memory representations. These results add to the evidence for enhancement and suppression as mechanisms of sentence processing and clarify that the effects occur within sentences having a marked focus structure.

Eye-movements and ERPs reveal the time course of processing negation and remitting counterfactual worlds.

The ability to update our current knowledge using contextual information is a vital process during every-day language comprehension. To understand a negated statement, readers are required to cancel real-world expectations, but are not explicitly provided with an alternative model. Thus, the question of how and when a negative context influences interpretation of later events arises. We report one eye-movement study (Exp. 1) and one ERP study (Exp. 2) investigating the effects of negation on discourse processing. Prior context depicted a real-world (RW), or negated-world (NW), while the second sentence was manipulated to create RW anomalous continuations, where events included a violation of RW knowledge, and RW-congruent continuations, where the events described were congruent with RW knowledge. Results from Experiment 1 showed that the negated discourse context did not influence initial processing of the target sentence, as reflected in participants' eye-movement behaviour. Similarly, Experiment 2 revealed that the typical N400 effect to semantic violations has not been reversed by introducing a negated-world context. However, in later processing, Experiment 1 demonstrated that the negated-world context is eventually incorporated into the representation of the sentence meaning. Thus, we suggest that discourse does not always have an immediate effect on language comprehension and discuss the results in terms of a variety of accounts of representing negation.

Processing pronouns without antecedents: evidence from event-related brain potentials.

Pronouns that do not have explicit antecedents typically cause processing problems. We investigate a specific example in which this may not be the case, as in "At the interview, they asked really difficult questions," where the plural pronoun they has no explicit antecedent, yet is intuitively easy to process. Some unspecified but constrained set of individuals (the interview panel or the company) can be inferred as the referent, but it is not crucial to determine specifically which entities are being referred to. We propose that this contrasts with the processing of singular pronouns (he or she), for which it is necessary to determine a specific referent. We used event-related brain potentials to investigate how readers process the pronoun (they vs. he/she) in these cases. Sentences were placed in a context that either did or did not contain an explicit antecedent for the pronoun. There were two key findings. Firstly, when there was no explicit antecedent, a larger fronto-central positivity was observed 750 msec after pronoun onset for he/she than they, possibly reflecting the additional difficulty involved in establishing a referent for he/she than for they when no explicit referent is available. Secondly, there was a larger N400-like deflection evoked by he/she than they, regardless of whether there was an explicit antecedent for the pronoun. We suggest that this is due to the singular pronouns bringing about a greater integration effort than the plural pronoun. This observation adds to a growing body of research revealing fundamental differences in the way these pronouns are handled by the language processor.

When is cataphoric reference recognised?

Pronouns typically have explicit antecedents in the prior discourse otherwise processing difficulty is experienced. However, it has been argued [Gordon, P. C., & Hendrick, R. (1997). Intuitive knowledge of linguistic co-reference. Cognition, 62, 325-370; Gordon, P. C., & Hendrick, R. (1998). The representation and processing of co-reference in discourse. Cognitive Science, 22, 389-424] that when a pronoun appears in a preposed subordinate clause (as in, Before she began to sing, Susan stood up), incremental interpretation is suspended and no antecedent is immediately sought, since the pronoun cannot be resolved until the main clause is encountered. We report results from an eye-tracking study showing that on encountering a pronoun that has no prior antecedent (compared to cases where there is an explicit prior antecedent), readers experience immediate difficulty whether or not the pronoun appears in a preposed subordinate clause, suggesting that attempted incremental interpretation is not suspended in these cases.

They're digging up the road again: the processing cost of institutional they.

It is commonplace to use the pronoun they to refer to agents in certain situations without ever providing a referent, as in On the train, they served really bad coffee. Such an example we call "Institutional They", because such defaults typically represent the actions of some agent tied stereotypically to a situation. These cases represent an important subset of unheralded pronouns (Gerrig, 1986), pronouns without any explicit antecedent. While in many situations, the occurrence of referential pronouns without explicit antecedents entails a processing cost, an eye-tracking experiment revealed no reliable detectable costs associated with Institutional They. However, there were for singular pronouns without antecedents in the same situations. We argue that Institutional They cases result from properties of plural pronouns (they and them). These will accept underspecified type-referents, while singular pronouns require specified token-referents. Failure to identify token-referents results in disruption of processing in the case of singulars, but not in the case of the plurals.

"They" as a gender-unspecified singular pronoun: eye tracking reveals a processing cost.

The plural pronouns they and them are used to refer to individuals with unknown gender and when a random allocation of gender is undesirable. Despite this apparently felicitous usage, "singular they/them" should raise processing problems under the theory that pronouns seek gender- and number-matched antecedents. Using eye-tracking, we investigated whether there was any processing cost associated with using singular they/them. There was a clear cost of number incompatibility for they/them. Thus, although singular they/them is in current usage, it does not appear that they/them is immediately tolerant of a plural antecedent, though such may be rapidly accommodated. The data are consistent with the search account of pronoun resolution and preserve the semantics of they/them as denoting plurality.

Covariation and quantifier polarity: what determines causal attribution in vignettes?

Tests of causal attribution often use verbal vignettes, with covariation information provided through statements quantified with natural language expressions. The effect of covariation information has typically been taken to show that set size information affects attribution. However, recent research shows that quantifiers provide information about discourse focus as well as covariation information. In the attribution literature, quantifiers are used to depict covariation, but they confound quantity and focus. In four experiments, we show that focus explains all (Experiment 1) or some (Experiment 2-4) of the impact of covariation information on the attributions made, confirming the importance of the confound. Attribution experiments using vignettes that present covariation information with natural language quantifiers may overestimate the impact of set size information, and ignore the impact of quantifier-induced focus.

Linguistic focus and good-enough representations: an application of the change-detection paradigm.

A number of lines of study suggest that word meanings are not always fully exploited in comprehension. In two experiments, we used a text-change paradigm to study depth of semantic processing during reading. Participants were instructed to detect words that changed across two consecutive presentations of short texts. The results suggest that the full details of word meanings are not always incorporated into the interpretation and that the degree of semantic detail in the representation is a function of linguistic focus. The results provide evidence for the idea that representations are only good enough for the purpose at hand (Ferreira, Bailey, & Ferraro, 2002).

Perspective in statements of quantity, with implications for consumer psychology.

We demonstrate that presentation of information about quantities, whether expressed in natural language or by using numbers, induces a perspective that influences subsequent processing. Experiment 1 shows this to be true for natural language quantifiers, with negative and positive expressions inducing different perspectives. In Experiment 2, we examined the application of this idea to the specific case of perspectives induced by describing products as containing x% fat or as being x% fat free. We found that the percentage-fat description appears to induce a perspective that is sensitive to the level offat being depicted, with products being judged as less healthy at higher amounts of fat. However, this effect was lessened (Experiment 2) or eliminated (Experiment 3) with the percentage-fat-free description. The experiments suggest the fat-free perspective blocks access to assumptions about healthy fat levels.