Using time reversal symmetry for sensitive incoherent matter-wave Sagnac interferometry

We present a theory of the transmission of incoherent guided matter-waves through Sagnac interferometers. Interferometer configurations with only one input and one output port have a property similar to the phase rigidity observed in the transmission through Aharonov-Bohm interferometers in coherent mesoscopic electronics. This property is connected to the existence of counterpropagating paths of equal length and enables the operation of such matter-wave interferometers with incoherent sources. High finesse interferometers of this kind have a rotation sensitivity inversely proportional to the square root of the finesse

The role of left and right hemispheres in the comprehension of idiomatic language: an electrical neuroimaging study

<p>Abstract</p> <p>Background</p> <p>The specific role of the two cerebral hemispheres in processing idiomatic language is highly debated. While some studies show the involvement of the left inferior frontal gyrus (LIFG), other data support the crucial role of right-hemispheric regions, and particularly of the middle/superior temporal area. Time-course and neural bases of literal vs. idiomatic language processing were compared. Fifteen volunteers silently read 360 idiomatic and literal Italian sentences and decided whether they were semantically related or unrelated to a following target word, while their EEGs were recorded from 128 electrodes. Word length, abstractness and frequency of use, sentence comprehensibility, familiarity and cloze probability were matched across classes.</p> <p>Results</p> <p>Participants responded more quickly to literal than to idiomatic sentences, probably indicating a difference in task difficulty. Occipito/temporal N2 component had a greater amplitude in response to idioms between 250-300 ms. Related swLORETA source reconstruction revealed a difference in the activation of the left fusiform gyrus (FG, BA19) and medial frontal gyri for the contrast idiomatic-minus-literal. Centroparietal N400 was much larger to idiomatic than to literal phrases (360-550 ms). The intra-cortical generators of this effect included the left and right FG, the left cingulate gyrus, the right limbic area, the right MTG (BA21) and the left middle frontal gyrus (BA46). Finally, an anterior late positivity (600-800 ms) was larger to idiomatic than literal phrases. ERPs also showed a larger right centro-parietal N400 to associated than non-associated targets (not differing as a function of sentence type), and a greater right frontal P600 to idiomatic than literal associated targets.</p> <p>Conclusion</p> <p>The data indicate bilateral involvement of both hemispheres in idiom comprehension, including the right MTG after 350 ms and the right medial frontal gyrus in the time windows 270-300 and 500-780 ms. In addition, the activation of left and right limbic regions (400-450 ms) suggests that they have a role in the emotional connotation of colourful idiomatic language. The data support the view that there is direct access to the idiomatic meaning of figurative language, not dependent on the suppression of its literal meaning, for which the LIFG was previously thought to be responsible.</p

A Dataset of Metaphors from the Italian Literature: Exploring Psycholinguistic Variables and the Role of Context

<div><p>Defining the specific role of the factors that affect metaphor processing is a fundamental step for fully understanding figurative language comprehension, either in discourse and conversation or in reading poems and novels. This study extends the currently available materials on everyday metaphorical expressions by providing the first dataset of metaphors extracted from literary texts and scored for the major psycholinguistic variables, considering also the effect of context. A set of 115 Italian literary metaphors presented in isolation (Experiment 1) and a subset of 65 literary metaphors embedded in their original texts (Experiment 2) were rated on several dimensions (word and phrase frequency, readability, cloze probability, familiarity, concreteness, difficulty and meaningfulness). Overall, literary metaphors scored around medium-low values on all dimensions in both experiments. Collected data were subjected to correlation analysis, which showed the presence of a strong cluster of variables—mainly familiarity, difficulty, and meaningfulness—when literary metaphor were presented in isolation. A weaker cluster was observed when literary metaphors were presented in the original contexts, with familiarity no longer correlating with meaningfulness. Context manipulation influenced familiarity, concreteness and difficulty ratings, which were lower in context than out of context, while meaningfulness increased. Throughout the different dimensions, the literary context seems to promote a global interpretative activity that enhances the open-endedness of the metaphor as a semantic structure constantly open to all possible interpretations intended by the author and driven by the text. This dataset will be useful for the design of future experimental studies both on literary metaphor and on the role of context in figurative meaning, combining ecological validity and aesthetic aspects of language.</p></div