Roberto Almeida

Studies have suggested that metaphors (Lawyers are sharks) and similes (Lawyers are like sharks) have distinct representations: metaphors engender more figurative and abstract properties, whereas similes engender more literal properties. We investigated to what extent access to such representations occurs automatically, during on-line reading. In particular, we examined whether similes convey a more literal meaning by following the metaphors and similes with explanations that expressed either a figurative (dangerous) or a literal property (fish) of the vehicle. In a self-paced reading with a moving window paradigm, we presented participants with negated simile and metaphor main clauses (Lawyers are not (like) sharks) followed by explanations that also negated either a figurative (because lawyers are not dangerous) or a literal property of the vehicle (because lawyers are not fish). We found that vehicles (sharks) in metaphors were read significantly faster than those in similes. In addition, explanations negating a figurative property were read faster after metaphors, whereas explanations negating a literal property were read faster after similes. These results support the hypothesis that metaphors and similes rely on different interpretive processes, suggesting that similes access literal representations while metaphor access figurative ones in real time.

What are the roles of semantic and pragmatic processes in the interpretation of sentences in context? And how do we attain such interpretations when sentences are deemed indeterminate? Consider a sentence such as “Lisa began the book” which does not overtly express the activity that Lisa began doing with the book. Although it is believed that individuals compute a specified event to enrich the sentential representation – yielding, e.g., “began [reading] the book” – there is no evidence that a default event meaning is attained. Moreover, if indeterminate sentences are enriched, it is not clear where the information required to generate enriched interpretations come from. Experiment 1 showed that, in isolation, there is no default interpretation for indeterminate sentences. The experiment also showed that biasing contexts constrain event interpretations and improve plausibility judgments, suggesting that event representations for indeterminate sentences are generated by context. In Experiment 2, participants heard biasing discourse contexts and later falsely recognized foil sentences containing the biased events at the same proportion and with the same confidence as the original indeterminate sentence. We suggest that indeterminate sentences trigger event-enriching inferences but only in sufficiently constraining contexts. We also suggest that indeterminate sentences create two memory traces, one for the proposition consistent with the denotational, compositional meaning, and another for the proposition that is enriched pragmatically over time.

As Macnamara (1978) once asked, how can we talk about what we see? We report on a study manipulating realistic dynamic scenes and sentences aiming to understand the interaction between linguistic and visual representations in real-world situations. Specifically, we monitored participants’ eye movements as they watched video clips of everyday scenes while listening to sentences describing these scenes. We manipulated two main variables. The first was the semantic class of the verb in the sentence and the second was the action/motion of the agent in the unfolding event. The sentences employed two verb classes—causatives (e.g., break) and perception/psychological (e.g., notice)—which impose different constraints on the nouns that serve as their grammatical complements. The scenes depicted events in which agents either moved towards a target object (always the referent of the verb-complement noun), away from it, or remained neutral performing a given activity (such as cooking). Scenes and sentences were synchronized such that the verb onset corresponded to the first video frame of the agent motion towards or away from the object. Results show effects of agent motion but weak verb-semantic restrictions: causatives draw more attention to potential referents of their grammatical complements than perception verbs only when the agent moves towards the target object. Crucially, we found no anticipatory verb-driven eye movements toward the target object, contrary to studies using non-naturalistic and static scenes. We propose a model in which linguistic and visual computations in real-world situations occur largely independent of each other during the early moments of perceptual input, but rapidly interact at a central, conceptual system using a common, propositional code. Implications for language use in real world contexts are discussed.

Sentences such as "The author started the book" are indeterminate because they do not make explicit what the subject (the author) started doing with the object (the book). In principle, indeterminate sentences allow for an infinite number of interpretations. One theory, however, assumes that these sentences are resolved by semantic coercion, a linguistic process that forces the noun "book" to be interpreted as an activity (e.g., writing the book) or by a process that interpolates this activity information in the resulting enriched semantic composition. An alternative theory, pragmatic, assumes classical semantic composition, whereby meaning arises from the denotation of words and how they are combined syntactically, with enrichment obtained via pragmatic inferences beyond linguistic-semantic processes. Cognitive neuroscience studies investigating the neuroanatomical and functional correlates of indeterminate sentences have shown activations either at the ventromedial pre-frontal cortex or at the left inferior frontal gyrus. These studies have supported the semantic coercion theory assuming that one of these regions is where enriched semantic composition takes place. Employing fMRI, we found that indeterminate sentences activate bilaterally the superior temporal gyrus, the right inferior frontal gyrus, and the anterior cingulate cortex, more so than control sentences ("The author wrote the book"). Activation of indeterminate sentences exceeded that of anomalous sentences ("…drank the book") and engaged more left- and right-hemisphere areas than other sentence types. We suggest that the widespread activations for indeterminate sentences represent the deployment of pragmatic-inferential processes, which seek to enrich sentence content without necessarily resorting to semantic coercion.

Vector transmission of bacterial plant pathogens involves three steps: pathogen acquisition from an infected host, retention within the vector, and inoculation of cells into susceptible tissue of an uninfected plant. In this study, a combination of plant and artificial diet systems were used to determine the importance of several genes on the initial adhesion and retention of the bacterium Xylella fastidiosa to an efficient insect vector. Mutant strains included fimbrial and afimbrial adhesins and three loci involved in regulatory systems. Transmission assays with variable retention time indicated that HxfA and HxfB were primarily important for early adhesion to vectors, while FimA was necessary for both adhesion and retention. The long pilus protein PilB was not deficient in initial adhesion but may be important for retention. Genes upregulated under the control of rpfF are important for both initial adhesion and retention, as transmission rates of this mutant strain were initially low and decreased over time, while disruption of rpfC and cgsA yielded trends similar to that shown by the wild-type control. Because induction of an X. fastidiosa transmissible state requires pectin, a series of experiments were used to test the roles of a polygalacturonase and the pectin and galacturonic acid carbohydrates on the transmission of X. fastidiosa. Results show that galacturonic acid, or PglA activity breaking pectin into its major subunit, is required for X. fastidiosa vector transmission using an artificial diet system. This study shows that early adhesion and retention of X. fastidiosa are mediated by different factors. It also illustrates that the interpretation of results of vector transmission experiments, in the context of vector-pathogen interaction studies, is highly dependent on experimental design. © 2014, American Society for Microbiology.

Experimental studies have suggested that variables such as aptness or conventionality are predictors of people’s preference for expressing a particular topic–vehicle pair as either a metaphor or a simile. In the present study, we investigated if such variables would also be predictive within a more naturalistic context, where other variables, such as the intention to include an explanation, may also influence people’s decision. Specifically, we investigated the production of metaphor and simile expressions on the Internet via the Google search engine and checked for accompanying explanations, as well as the properties they expressed, to examine whether ratings such as aptness, conventionality, as well as participants’ own stated preference or the intention to produce an explanation, would predict which topic–vehicle pairs appeared more often as metaphor. We found that participants’ stated preference predicted metaphor dominance on the Internet, and that apt topic–vehicles occurred more often as metaphors. The explanations collected, however, occurred 82% of the time after similes, and familiar expressions were the most explained. Finally, comparing the properties expressed in these explanations to normed property lists, we found that simile explanations typically expressed a novel conception of the topic–vehicle relationship. Therefore, we found that Internet posters use metaphors to convey an apt relationship, as found in previous laboratory studies, but prefer using a simile frame when they want to express a relationship that readers will find novel.