The scope and role of deduction in infant cognition.

The origins of the human capacity for logically structured thought are still a mystery. Studies on young humans, which can be particularly informative, present conflicting results. Infants seem able to generate competing hypotheses1,2,3 and monitor the certainty or probability of one-shot outcomes,4,5,6,7,8 suggesting the existence of an articulated language of thought.9 However, sometimes toddlers10 and even children younger than 411,12,13,14 fail tasks seemingly requiring the same representational abilities. One fundamental test for the presence of logical abilities is the concept of disjunction as a way into the conception of alternative possibilities, and of disjunctive elimination as a way to prune them. Here, we document their widespread presence in 19-month-old infants. In a word-referent association task, both bilingual and monolingual infants display a pattern of oculomotor inspection previously found to be a hallmark of disjunctive reasoning in adults and children,15,16 showing that the onset of logical reasoning is not crucially dependent on language experience. The pattern appears when targets are novel, but also when both objects and words are known, though likely not yet sedimented into a mature lexicon. Disjunctive reasoning also surfaces in a non-linguistic location search task, not prompted by violated expectations, showing that infants reason by elimination spontaneously. Together, these results help answer long-standing empirical and philosophical puzzles about the role of logic in early knowledge development, suggesting that by increasing confidence in some options while eliminating alternatives, logic provides scaffolding for the organization of knowledge about the world, language, and language-world relations.

Natural logic and baby LoTH.

Language-of-thought hypothesis (LoTH) is having a profound impact on cognition studies. However, much remains unknown about its basic primitives and generative operations. Infant studies are fundamental, but methodologically very challenging. By distilling potential primitives from work in natural-language semantics, an approach beyond the corset of standard formal logic may be undertaken. Still, the road ahead is challenging and long.

QM/Classical Modeling of Surface Enhanced Raman Scattering Based on Atomistic Electromagnetic Models.

We present quantum mechanics (QM)/frequency dependent fluctuating charge (QM/ωFQ) and fluctuating dipoles (QM/ωFQFµ) multiscale approaches to model surface-enhanced Raman scattering spectra of molecular systems adsorbed on plasmonic nanostructures. The methods are based on a QM/classical partitioning of the system, where the plasmonic substrate is treated by means of the atomistic electromagnetic models ωFQ and ωFQFµ, which are able to describe in a unique fashion and at the same level of accuracy the plasmonic properties of noble metal nanostructures and graphene-based materials. Such methods are based on classical physics, i.e. Drude conduction theory, classical electrodynamics, and atomistic polarizability to account for interband transitions, by also including an ad-hoc phenomenological correction to describe quantum tunneling. QM/ωFQ and QM/ωFQFµ are thus applied to selected test cases, for which computed results are compared with available experiments, showing the robustness and reliability of both approaches.

Seeing inferences: brain dynamics and oculomotor signatures of non-verbal deduction.

We often express our thoughts through words, but thinking goes well beyond language. Here we focus on an elementary but basic thinking process, disjunction elimination, elicited by elementary visual scenes deprived of linguistic content, describing its neural and oculomotor correlates. We track two main components of a nonverbal deductive process: the construction of a logical representation (A or B), and its simplification by deduction (not A, therefore B). We identify the network active in the two phases and show that in the latter, but not in the former, it overlaps with areas known to respond to verbal logical reasoning. Oculomotor markers consistently differentiate logical processing induced by the construction of a representation, its simplification by deductive inference, and its maintenance when inferences cannot be drawn. Our results reveal how integrative logical processes incorporate novel experience in the flow of thoughts induced by visual scenes.

Strain-Induced Plasmon Confinement in Polycrystalline Graphene.

Terahertz spectroscopy is a perfect tool to investigate the electronic intraband conductivity of graphene, but a phenomenological model (Drude-Smith) is often needed to describe disorder. By studying the THz response of isotropically strained polycrystalline graphene and using a fully atomistic computational approach to fit the results, we demonstrate here the connection between the Drude-Smith parameters and the microscopic behavior. Importantly, we clearly show that the strain-induced changes in the conductivity originate mainly from the increased separation between the single-crystal grains, leading to enchanced localization of the plasmon excitations. Only at the lowest strain values explored, a behavior consistent with the deformation of the individual grains can instead be observed.

Do We Really Need Quantum Mechanics to Describe Plasmonic Properties of Metal Nanostructures?

Optical properties of metal nanostructures are the basis of several scientific and technological applications. When the nanostructure characteristic size is of the order of few nm or less, it is generally accepted that only a description that explicitly describes electrons by quantum mechanics can reproduce faithfully its optical response. For example, the plasmon resonance shift upon shrinking the nanostructure size (red-shift for simple metals, blue-shift for d-metals such as gold and silver) is universally accepted to originate from the quantum nature of the system. Here we show instead that an atomistic approach based on classical physics, ωFQFµ (frequency dependent fluctuating charges and fluctuating dipoles), is able to reproduce all the typical "quantum" size effects, such as the sign and the magnitude of the plasmon shift, the progressive loss of the plasmon resonance for gold, the atomistically detailed features in the induced electron density, and the non local effects in the nanoparticle response. To support our findings, we compare the ωFQFµ results for Ag and Au with literature time-dependent DFT simulations, showing the capability of fully classical physics to reproduce these TDDFT results. Only electron tunneling between nanostructures emerges as a genuine quantum mechanical effect, that we had to include in the model by an ad hoc term.

In silico design of graphene plasmonic hot-spots.

We propose a route for the rational design of engineered graphene-based nanostructures, which feature enormously enhanced electric fields in their proximity. Geometrical arrangements are inspired by nanopatterns allowing single molecule detection on noble metal substrates, and are conceived to take into account experimental feasibility and ease in fabrication processes. The attention is especially focused on enhancement effects occurring close to edge defects and grain boundaries, which are usually present in graphene samples. There, very localized hot-spots are created, with enhancement factors comparable to noble metal substrates, thus potentially paving the way for single molecule detection from graphene-based substrates.

Pudendal nerve block: a safe, simple and effective approach in surgical proctological patients.

BACKGROUND: Pudendal nerve block (PNB) is commonly used in pudendal neuralgia (PN) and, as anesthesiological technique, in obstetrical and urological procedures. The purpose of this retrospective study was to compare the efficacy of PNB with other anesthesiolocal techniques in proctological surgery. METHODS: A total of 362 patients were seen from a 22-month-time interval. Surgical indication was placed after a conservative therapy. Seventy-eight patients underwent surgery: 42 with spinal anesthesia with PNB and 36 with PNB alone according to their anatomical characteristics. All the patients underwent PNB in lithotomy position and with a perirectal approach. The success rate of PNB was evaluated in postoperative pain control with the VAS score, after the first and the second evacuation. The follow-up also included a third check on the seventh day after surgery. RESULTS: In postoperative period, the mean VAS score found after the first evacuation in patients undergoing PNB was 2.66, after the second evacuation was 1.55, while the VAS score on the seventh day was 0.38. The mean VAS score in the group who underwent spinal anesthesia and PNB were respectively 3.71 and 1.80 after the first and second evacuation. The VAS score calculated on the seventh day was 0.50. There were no statistically significant differences in the VAS score between the 2 groups (P>0.05). CONCLUSIONS: PNB may be a valid alternative to spinal anesthesia in proctological patients. PNB has proven to be both safe and effective technique.

Intestinal malrotation in one adult patient affected by SARS-CoV-2 infection: occlusion misdiagnosed as COVID gastroenteritis. Case report and literature review.

Malrotation of the gut is a rare occurrence, commonly diagnosed during childhood, but occasionally diagnosed in adults. In children, intestinal obstruction is the most common manifestation, whereas in adult patients, the diagnosis is more challenging since the symptoms are less specific with several episodes of abdominal pain and vomit. In a particular epidemic period, like the one we are going through, these generic symptoms may mislead to a wrong diagnosis. We present the case of a young man in which occlusion due to intestinal malrotation has been misinterpreted as gastroenteric symptoms of severe acute respiratory syndrome coronavirus 2 infection, and we also overview the correct Ladd's technique, commonly performed by pediatrical surgeon, but unusual operation for adult general surgeons.

Appendiceal mucocele: three cases with different clinical presentation and review of literature.

Mucinous lesions of appendix are a rare clinical entity and may be neoplastic or non-neoplastic. The diagnosis is usual incidental during computed tomography scan or colonoscopy performed for general abdominal symptoms or occasional finding during operation for acute appendicitis. For this reason, initial treatment should be tailored to the situation, aiming at complete resection of the appendix with disease-free margins: this can be achieved by simple appendectomy or more extensive resection. The pathological examination of the specimen is the key to offer the patient a correct and complete treatment, and, if a neoplastic pathology is found, the case should be discussed in multidisciplinary group. We describe three cases with different clinical presentation leading to different surgical treatment: one elective case, in which the diagnosis was suspected preoperatively; and two urgent cases, one mimicking an intussusception and another one presenting as an acute appendicitis.

Graphene Plasmonics: Fully Atomistic Approach for Realistic Structures.

We demonstrate that the plasmonic properties of realistic graphene and graphene-based materials can effectively and accurately be modeled by a novel, fully atomistic, yet classical, approach, named ωFQ. Such a model is able to reproduce all plasmonic features of these materials and their dependence on shape, dimension, and fundamental physical parameters (Fermi energy, relaxation time, and two-dimensional electron density). Remarkably, ωFQ is able to accurately reproduce experimental data for realistic structures of hundreds of nanometers (∼370k atoms), which cannot be afforded by any ab initio method. Also, the atomistic nature of ωFQ permits the investigation of complex shapes, which can hardly be dealt with by exploiting widespread continuum approaches.

Plasmonic Resonances of Metal Nanoparticles: Atomistic vs. Continuum Approaches.

The fully atomistic model, ωFQ, based on textbook concepts (Drude theory, electrostatics, quantum tunneling) and recently developed by some of the present authors in Nanoscale, 11, 6004-6015 is applied to the calculation of the optical properties of complex Na, Ag, and Au nanostructures. In ωFQ, each atom of the nanostructures is endowed with an electric charge that can vary according to the external electric field. The electric conductivity between nearest atoms is modeled by adopting the Drude model, which is reformulated in terms of electric charges. Quantum tunneling effects are considered by letting the dielectric response of the system arise from atom-atom conductivity. ωFQ is challenged to reproduce the optical response of metal nanoparticles of different sizes and shapes, and its performance is compared with continuum Boundary Element Method (BEM) calculations.

Precursors of logical reasoning in preverbal human infants.

Infants are able to entertain hypotheses about complex events and to modify them rationally when faced with inconsistent evidence. These capacities suggest that infants can use elementary logical representations to frame and prune hypotheses. By presenting scenes containing ambiguities about the identity of an object, here we show that 12- and 19-month-old infants look longer at outcomes that are inconsistent with a logical inference necessary to resolve such ambiguities. At the moment of a potential deduction, infants' pupils dilated, and their eyes moved toward the ambiguous object when inferences could be computed, in contrast to transparent scenes not requiring inferences to identify the object. These oculomotor markers resembled those of adults inspecting similar scenes, suggesting that intuitive and stable logical structures involved in the interpretation of dynamic scenes may be part of the fabric of the human mind.

Infants anticipate probabilistic but not deterministic outcomes.

Infants look at physically impossible events longer than at physically possible events, and at improbable events longer than at probable events. Such behaviors are generally interpreted as showing that infants have expectations about future events and are surprised to see them violated. It is unknown, however, whether and under what conditions infants form proactive expectations about the future, as opposed to realizing post hoc that outcomes do not comply with their previous knowledge or experience. Here we investigate the relation between expectation and surprise at probabilistic or deterministic events in preverbal infants. When a situation is uncertain, 12-month-olds anticipate probable outcomes and are surprised at improbable continuations of the scene. However, they do not anticipate the only possible outcome of a physically deterministic situation, although they are surprised when it does not occur. The results suggest that infants are sensitive to the tradeoff between information gain and programming efforts, showing higher propensity to anticipate those future events that carry novel knowledge.

Words, rules, and mechanisms of language acquisition.

We review recent artificial language learning studies, especially those following Endress and Bonatti (Endress AD, Bonatti LL. Rapid learning of syllable classes from a perceptually continuous speech stream. Cognition 2007, 105:247-299), suggesting that humans can deploy a variety of learning mechanisms to acquire artificial languages. Several experiments provide evidence for multiple learning mechanisms that can be deployed in fluent speech: one mechanism encodes the positions of syllables within words and can be used to extract generalization, while the other registers co-occurrence statistics of syllables and can be used to break a continuum into its components. We review dissociations between these mechanisms and their potential role in language acquisition. We then turn to recent criticisms of the multiple mechanisms hypothesis and show that they are inconsistent with the available data. Our results suggest that artificial and natural language learning is best understood by dissecting the underlying specialized learning abilities, and that these data provide a rare opportunity to link important language phenomena to basic psychological mechanisms. For further resources related to this article, please visit the WIREs website.

Numerical representations and intuitions of probabilities at 12 months.

Recent research shows that preverbal infants can reason about single-case probabilities without relying on observed frequencies, adapting their predictions to relevant dynamic parameters of the situation (Téglás, Vul, Girotto, Gonzalez, Tenenbaum & Bonatti, ; Téglás, Girotto, Gonzalez & Bonatti, ). Here we show that intuitions of probabilities may derive from the ability to represent a limited number of possibilities. After watching a scene containing moving objects of two ensembles, 12-month-olds looked longer at an unlikely than at a likely single-case outcome when the objects were within the parallel individuation range. However, they did not do so when the scene contained the same ratio between ensembles but a larger number of objects. At the same time, they could form rational expectations about single-case outcomes in scenes containing the same large number of objects when they could exploit subtle physical parameters induced by the objects' movements and their spatial configuration. Our findings demonstrate that at early stages of development the mental representations involved in probability estimations of future individual situations are powerful and sophisticated, but at the same time they depend on infants' overall cognitive architecture, being constrained by the numerical representations spontaneously induced by the situations.

Finding words and word structure in artificial speech: the development of infants' sensitivity to morphosyntactic regularities.

To achieve language proficiency, infants must find the building blocks of speech and master the rules governing their legal combinations. However, these problems are linked: words are also built according to rules. Here, we explored early morphosyntactic sensitivity by testing when and how infants could find either words or within-word structure in artificial speech snippets embodying properties of morphological constructions. We show that 12-month-olds use statistical relationships between syllables to extract words from continuous streams, but find word-internal regularities only if the streams are segmented. Seven-month-olds fail both tasks. Thus, 12-month-olds infants possess the resources to analyze the internal composition of words if the speech contains segmentation information. However, 7-month-old infants may not possess them, although they can track several statistical relations. This developmental difference suggests that morphosyntactic sensitivity may require computational resources extending beyond the detection of simple statistics.

Words and possible words in early language acquisition.

In order to acquire language, infants must extract its building blocks-words-and master the rules governing their legal combinations from speech. These two problems are not independent, however: words also have internal structure. Thus, infants must extract two kinds of information from the same speech input. They must find the actual words of their language. Furthermore, they must identify its possible words, that is, the sequences of sounds that, being morphologically well formed, could be words. Here, we show that infants' sensitivity to possible words appears to be more primitive and fundamental than their ability to find actual words. We expose 12- and 18-month-old infants to an artificial language containing a conflict between statistically coherent and structurally coherent items. We show that 18-month-olds can extract possible words when the familiarization stream contains marks of segmentation, but cannot do so when the stream is continuous. Yet, they can find actual words from a continuous stream by computing statistical relationships among syllables. By contrast, 12-month-olds can find possible words when familiarized with a segmented stream, but seem unable to extract statistically coherent items from a continuous stream that contains minimal conflicts between statistical and structural information. These results suggest that sensitivity to word structure is in place earlier than the ability to analyze distributional information. The ability to compute nontrivial statistical relationships becomes fully effective relatively late in development, when infants have already acquired a considerable amount of linguistic knowledge. Thus, mechanisms for structure extraction that do not rely on extensive sampling of the input are likely to have a much larger role in language acquisition than general-purpose statistical abilities.