Simona Amenta

Morphological processing as we know it: an analytical review of morphological effects in visual word identification.

The last 40 years have witnessed a growing interest in the mechanisms underlying the visual identification of complex words. A large amount of experimental data has been amassed, but although a growing number of studies are proposing explicit theoretical models for their data, no comprehensive theory has gained substantial agreement among scholars in the field. We believe that this is due, at least in part, to the presence of several controversial pieces of evidence in the literature and, consequently, to the lack of a well-defined set of experimental facts that any theory should be able to explain. With this review, we aim to delineate the state of the art in the research on the visual identification of complex words. By reviewing major empirical evidences in a number of different paradigms such as lexical decision, word naming, and masked and unmasked priming, we were able to identify a series of effects that we judge as reliable or that were consistently replicated in different experiments, along with some more controversial data, which we have tried to resolve and explain. We concentrated on behavioral and electrophysiological studies on inflected, derived, and compound words, so as to span over all types of complex words. The outcome of this work is an analytical summary of well-established facts on the most relevant morphological issues, such as regularity, morpheme position coding, family size, semantic transparency, morpheme frequency, suffix allomorphy, and productivity, morphological entropy, and morpho-orthographic parsing. In discussing this set of benchmark effects, we have drawn some methodological considerations on why contrasting evidence might have emerged, and have tried to delineate a target list for the construction of a new all-inclusive model of the visual identification of morphologically complex words.

From sound to meaning : phonology-to-semantics mapping in visual word recognition

In the present study, the role of phonological information in visual word recognition is investigated by adopting a large-scale data-driven approach that exploits a new consistency measure based on distributional semantics methods. A recent study by Marelli, Amenta, and Crepaldi (2015) showed that the consistency between an orthographic string and the meanings to which it is associated in a large corpus is a relevant predictor in lexical decision experiments. Exploiting irregular mappings between orthography and phonology in English, we were able to compute a phonology-to-semantics consistency measure that dissociates from its orthographic counterpart and tested both measures on lexical decision data taken from the British Lexicon Project (Keuleers et al., 2012). Results showed that both orthography and phonology are activated during visual word recognition. However, their contribution is crucially determined by the extent to which they are informative of the word semantics, and phonology plays a crucial role in accessing word meaning.

Eye movement and online bisection task in unilateral patients with neglect: a new look to the 'gradient effect'.

Primary objective: The present study explored the behavioural and eye-movement measures in spatial unilateral neglect in response to a bisection task. Research design: Four right neglect patients were considered and compared with 11 control subjects during an online task (segment bisection). Methods and procedures: Eye-movements (fixation count and duration) and behavioural responses were monitored during an online bisection task, consisting of unfilled segments (two ending points) to be bisected by subjects. Segment length (six levels) and spatial dislocation (five levels) were modulated to explore a possible ‘gradient effect’” (left-to-right) in neglect bias. Main outcomes and results: Consistent spatial biases were found for both bisection position and eye fixations as a function of segment length (from shorter to longer) and segment spatial dislocation (from right to left). However, only the more eccentric left-positions induced a greater rightward bias in patients, with increasing more right-side bisection and visual right-directed fixations. Also segment length produced significant differences between-groups for behavioural responses, with more right-side bisection for longer segment in patients, and eye movement behaviour, with increased fixation count and duration rightward oriented in response to longer segments. Conclusions: Although a left-to-right and longer-to-shorter ‘continuous-gradient effect’ was not supported by the results, an ‘extreme left-gradient effect’ was suggested and discussed.

From pragmatics to neuropragmatics

Two metaphors coined by Reddy [1], the conduit metaphor and the toolmaker’s paradigm, can be used to introduce several observations on the nature of communication and its pragmatic properties. The conduit metaphor depicts linguistic expression as channels carrying ideas and meanings: mental representations are poured into the conduit and are extracted from it, without undergoing modifications. Seen in this light, communication is nothing more than the exchange of information among individuals. The toolmaker’s paradigm, by contrast, explains communication through a more complex scenario, in which speakers live in distant worlds; no one knows anything about their language, culture, and characteristics, and the only means of communication is through the exchange of blueprints of tools. Inhabitants of these worlds are proud of their projects and are disappointed when they are misunderstood. In fact, it is reason enough to rejoice when, on occasion, the blueprints are received correctly, without further specifications.

Isn’t it ironic? An analysis on the elaboration of ironic sentences with ERPs

Although frequent in our everyday conversations, irony is a complex pragmatic phenomenon involving specific linguistic, communicative and cognitive abilities in order to be fully understood. In this study we examined the pragmatic comprehension of ironical and non ironical language by analysing event-related potentials (ERPs) of irony decoding proc- ess. We asked 12 subjects to listen to 240 sentences with a counterfactual vs. non-counterfactual content and spoken with ironical vs. neutral prosody. ERPs morphological analysis showed a negative deflection peaking in central-frontal and pa- rietal areas at about 460ms post stimulus onset (N400) for all the conditions. Statistical analyses applied to peak ampli- tudes showed no statistically significant differences between the conditions as a function of the type of sentence (ironical vs. non ironical) and the content of ironical sentences (counterfactual vs. non counterfactual). An increase of N400 related to ironical sentences was nonetheless observed. The absence of an N400 effect may indicate that irony is not treated as a semantic anomaly, although, the observed differences in amplitude could be probably attributed to a higher requirement for the cognitive system in order to integrate contrasting and complex lexical, prosodic and contextual cues.

Statistical learning and language (in spite of arbitrariness)

It has long been known that the relationship between form and meaning is generally arbitrary in human languages, that is, forms have no inherent relationships with their meanings (Hockett, 1963). However, it has also been shown that the cumulative cultural evolution of languages does introduce regularities in form–to– meaning mapping (Kirby, Cornish, & Smith, 2008), and that systematicity in this mapping helps learnability, at least in terms of word categorization (Monaghan, Christiansen, & Fitneva, 2011). One apparent end product of this structure– oriented “invisible hand” is linguistic morphology—families of words emerge whose relationship in form predicts their relationship in meaning (e.g., DEAL and DEALER, HUNT and HUNTER). Here we complement this evolutionary evidence with data from Cognitive Neuroscience, showing that the brain codes for these form–to–meaning regularities in a probabilistic way, and uses this information as we process words, either in isolation or embedded in sentence context.

A database of orthography-semantics consistency (OSC) estimates for 15,017 English words

Orthography–semantics consistency (OSC) is a measure that quantifies the degree of semantic relatedness between a word and its orthographic relatives. OSC is computed as the frequency-weighted average semantic similarity between the meaning of a given word and the meanings of all the words containing that very same orthographic string, as captured by distributional semantic models. We present a resource including optimized estimates of OSC for 15,017 English words. In a series of analyses, we provide a progressive optimization of the OSC variable. We show that computing OSC from word-embeddings models (in place of traditional count models), limiting preprocessing of the corpus used for inducing semantic vectors (in particular, avoiding part-of-speech tagging and lemmatization), and relying on a wider pool of orthographic relatives provide better performance for the measure in a lexical-processing task. We further show that OSC is an important and significant predictor of reaction times in visual word recognition and word naming, one that correlates only weakly with other psycholinguistic variables (e.g., family size, word frequency), indicating that it captures a novel source of variance in lexical access. Finally, some theoretical and methodological implications are discussed of adopting OSC as one of the predictors of reaction times in studies of visual word recognition.