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Despite wide reporting of a right ear (RE) advantage on dichotic listening tasks and a right visual field (RVF) advantage on visual half-field tasks, we know very little about the relationship between these perceptual biases. Previous studies that have investigated perceptual asymmetries for analogous auditory and visual consonant–vowel tasks have indicated a serendipitous finding: a RE advantage and a left visual field (LVF) advantage with poor cross-modal correlations. In this study, we examined the possibility that this LVF advantage for visual processing of consonant–vowel strings may be a consequence of repetition by examining perceptual biases in analogous auditory and visual tasks for both consonant–vowel strings and words. We replicated opposite perceptual biases for consonant–vowel strings (RE and LVF advantages). This did not extend to word stimuli where we found RE and RVF advantages. Furthermore, these perceptual biases did not differ across the three experimental blocks. Thus, we can firmly conclude that this LVF advantage is unique to consonant–vowel strings and is not a consequence of the repetition of a relatively limited number of stimuli. Finally, a test of covariances indicated cross-modal relationships between laterality indices suggesting that perceptual biases are dissociable within individuals and cluster on mode of presentation.

In the present study, we leveraged computational methods to explore the extent to which, relative to direct access to semantics from orthographic cues, the additional appreciation of morphological cues is advantageous while inducing the meaning of affixed pseudo-words. We re-analyzed data from a study on a lexical decision task for affixed pseudo-words. We considered a parsimonious model only including semantic variables (namely, semantic neighborhood density, entropy, magnitude, stem proximity) derived through a word-form-to-meaning approach (ngram-based). We then explored the extent to which the addition of equivalent semantic variables derived by combining semantic information from morphemes (combination-based) improved the fit of the statistical model explaining human data. Results suggest that semantic information can be extracted from arbitrary clusters of letters, yet a computational model of semantic access also including a combination-based strategy based on explicit morphological information better captures the cognitive mechanisms underlying human performance. This is particularly evident when participants recognize affixed pseudo-words as meaningful stimuli.

Despite its widespread use to measure functional lateralization of language in healthy subjects, the neurocognitive bases of the visual field effect in lateralized reading are still debated. Crucially, the lack of knowledge on the nature of the visual field effect is accompanied by a lack of knowledge on the relative impact of psycholinguistic factors on its measurement, thus potentially casting doubts on its validity as a functional laterality measure. In this study, an eye-tracking-controlled tachistoscopic lateralized lexical decision task (Experiment 1) was administered to 60 right-handed and 60 left-handed volunteers and word length, orthographic neighborhood, word frequency, and imageability were manipulated. The magnitude of visual field effect was bigger in right-handed than in left-handed participants. Across the whole sample, a visual field-by-frequency interaction was observed, whereby a comparatively smaller effect of word frequency was detected in the left visual field/right hemisphere (LVF/RH) than in the right visual field/left hemisphere (RVF/LH). In a subsequent computational study (Experiment 2), efficient (LH) and inefficient (RH) activation of lexical orthographic nodes was modelled by means of the Naïve Discriminative Learning approach. Computational data simulated the effect of visual field and its interaction with frequency observed in the Experiment 1. Data suggest that the visual field effect can be biased by word frequency. Less distinctive connections between orthographic cues and lexical/semantic output units in the RH than in the LH can account for the emergence of the visual field effect and its interaction with word frequency.

Research into second language (L2) reading is an exponentially growing field. Yet, it still has a relatively short supply of comparable, ecologically valid data from readers representing a variety of first languages (L1). This article addresses this need by presenting a new data resource called MECO L2 (Multilingual Eye Movements Corpus), a rich behavioral eye-tracking record of text reading in English as an L2 among 543 university student speakers of 12 different L1s. MECO L2 includes a test battery of component skills of reading and allows for a comparison of the participants' reading performance in their L1 and L2. This data resource enables innovative large-scale cross-sample analyses of predictors of L2 reading fluency and comprehension. We first introduce the design and structure of the MECO L2 resource, along with reliability estimates and basic descriptive analyses. Then, we illustrate the utility of MECO L2 by quantifying contributions of four sources to variability in L2 reading proficiency proposed in prior literature: reading fluency and comprehension in L1, proficiency in L2 component skills of reading, extralinguistic factors, and the L1 of the readers. Major findings included (a) a fundamental contrast between the determinants of L2 reading fluency versus comprehension accuracy, and (b) high within-participant consistency in the real-time strategy of reading in L1 and L2. We conclude by reviewing the implications of these findings to theories of L2 acquisition and outline further directions in which the new data resource may support L2 reading research.

Despite its widespread use to measure functional lateralization of language in healthy subjects, the neuro-cognitive bases of the visual field effect in lateralized reading are still debated. Crucially, the lack of knowledge on the nature of the visual field effect is accompanied by a lack of knowledge on the relative impact of psy-cholinguistic factors on its measurement, thus potentially casting doubts on its validity as a functional laterality measure. In this study, an eye-tracking-controlled tachistoscopic lateralized lexical decision task (Experiment 1) was administered to 60 right-handed and 60 left-handed volunteers and word length, orthographic neighbor-hood, word frequency, and imageability were manipulated. The magnitude of visual field effect was bigger in right-handed than in left-handed participants. Across the whole sample, a visual field-by-frequency interaction was observed, whereby a comparatively smaller effect of word frequency was detected in the left visual field/ right hemisphere (LVF/RH) than in the right visual field/left hemisphere (RVF/LH). In a subsequent computa-tional study (Experiment 2), efficient (LH) and inefficient (RH) activation of lexical orthographic nodes was modelled by means of the Naive Discriminative Learning approach. Computational data simulated the effect of visual field and its interaction with frequency observed in the Experiment 1. Data suggest that the visual field effect can be biased by word frequency. Less distinctive connections between orthographic cues and lexical/ semantic output units in the RH than in the LH can account for the emergence of the visual field effect and its interaction with word frequency.

Patients with pure alexia have major difficulties in reading aloud. However, they often perform above chance level in reading tasks that do not require overt articulation of the target word–like lexical decision or semantic judgment–a phenomenon usually known as “implicit reading.” There is no agreement in the literature on whether implicit reading should be attributed to relative sparing of some left hemisphere (LH) reading centers or rather to signs of compensatory endeavors by the right hemisphere (RH). We report the case of an 81-year-old patient (AA) with pure alexia due to a lesion involving the left occipital lobe and the temporal infero-mesial areas, as well as the posterior callosal pathways. Although AA’s reading was severely impaired and proceeded letter by letter, she showed an above-chance-level performance for frequent concrete words in a tachistoscopic lexical decision task. A structural disconnectome analysis revealed that AA’s lesion not only affected the left occipital cortex and the splenium: it also disconnected white-matter tracts meant to connect the visual word-form system to decision-related frontal areas within the LH. We suggest that the RH, rather than the LH, may be responsible for patient AA’s implicit reading.

Scientific studies of language behavior need to grapple with a large diversity of languages in the world and, for reading, a further variability in writing systems. Yet, the ability to form meaningful theories of reading is contingent on the availability of cross-linguistic behavioral data. This paper offers new insights into aspects of reading behavior that are shared and those that vary systematically across languages through an investigation of eye-tracking data from 13 languages recorded during text reading. We begin with reporting a bibliometric analysis of eye-tracking studies showing that the current empirical base is insufficient for cross-linguistic comparisons. We respond to this empirical lacuna by presenting the Multilingual Eye-Movement Corpus (MECO), the product of an international multi-lab collaboration. We examine which behavioral indices differentiate between reading in written languages, and which measures are stable across languages. One of the findings is that readers of different languages vary considerably in their skipping rate (i.e., the likelihood of not fixating on a word even once) and that this variability is explained by cross-linguistic differences in word length distributions. In contrast, if readers do not skip a word, they tend to spend a similar average time viewing it. We outline the implications of these findings for theories of reading. We also describe prospective uses of the publicly available MECO data, and its further development plans.

Introduction The advantage of the Right Visual Field/Left Hemisphere (RVF/LH) over the Left Visual Field/Right Hemisphere (LVF/RH) for reading is a ubiquitous finding in behavioral and neuropsychological enquiry (1). A Neuropsychological account (2) suggests that such advantage could depend on “two lateralized lexical stores” in the brain, which would be differently organized with respect to different lexical variables. An alternative account, grounded on half-field studies on control subjects suggests that the left and the right brain differ in the pathways they use to access a “unique lexical store”, located in the LH (3). According to this latter view, the benchmark of such different routes would be a word length effect only appearing in the LVF/RH. When hemispheric differences in the early processing steps are ironed out, no further visual field effects should be observed. Materials & Methods In the current study, 60 young healthy right-handed volunteers were administered with an eye-tracking-controlled lateralized lexical decision task, in which either words or non-words were presented for 128ms at 3.5° left or right from central fixation. Word stimuli were manipulated by word length, frequency, imageability and orthographic neighborhood (N) size. Results In line with previous evidence, we observed a RVF/LH advantage over the LVF/RH for both accuracy and reaction times. We also detected main effects of length, imageability, and frequency, as well as a frequency-by-visual field interaction. In a subsequent analysis, we observed that whereas the performance of the LH was significantly above chance level for both high- and low-frequency words, in the RH this was only true for high-frequency words. We also report a positive effect of N size on word detection accuracy in the RVF/LH but not in the LVF/RH. Discussion The emergence of a visual field effect in spite of the absence of a different length effect in the two visual fields indicates that the two hemispheres d

English serves as today's lingua franca, a role not eased by the inconsistency of its orthography. Indeed, monolingual readers of more consistent orthographies such as Italian or German learn to read more quickly than monolingual English readers. Here, we assessed whether long-lasting bilingualism would mitigate orthography-specific differences in reading speed and whether the order in which orthographies with a different regularity are learned matters. We studied high-proficiency Italian-English and English-Italian bilinguals, with at least 20 years of intensive daily exposure to the second language and its orthography and we simulated sequential learning of the two orthographies with the CDP++ connectionist model of reading. We found that group differences in reading speed were comparatively bigger with Italian stimuli than with English stimuli. Furthermore, only Italian bilinguals took advantage of a blocked presentation of Italian stimuli compared to when stimuli from both languages were presented in mixed order, suggesting a greater ability to keep language-specific orthographic representations segregated. These findings demonstrate orthographic constraints on bilingual reading, whereby the level of consistency of the first learned orthography affects later learning and performance on a second orthography. The computer simulations were consistent with these conclusions.

La dominanza dell’emisfero cerebrale sinistro (ES) sul destro (ED) nell’ambito della lettura è ampiamente riconosciuto nell’ambito delle neuroscienze cognitive. Tuttavia, non è ancora chiaro se questa dominanza sia basata sulla completa cecità verbale dell’ED (dominanza assoluta dell’ES), o sulla presenza di rappresentazioni più deboli o minori in numero nell’ED rispetto all’ES (dominanza relativa dell’ES). In linea con la prima ipotesi, leggere dovrebbe essere impossibile se il “sistema delle rappresentazioni visive delle parole” nell’ES è lesionato e sia le connessioni afferenti ed efferenti di quest’area con il resto dell’ES sono interrotte dalla lesione. Inoltre, secondo questa ipotesi, le differenze emisferiche all’interno dei compiti di lettura lateralizzata sono spiegabili in termini di una maggiore sensibilità dell’ED rispetto all’ES a fattori di elaborazione ortografici pre-lessicali. Secondo l’approccio che propone una dominanza relativa dell’ES per la lettura e che suggerisce l’esistenza di abilità lessicali più limitate nell’ED rispetto all’ES, la lettura dovrebbe essere possibile anche in caso di lesione e disconnessione del “sistema delle rappresentazioni visive delle parole” nell’ES, sebbene limitata a parole frequenti e/o concrete. In linea con questo approccio, le differenze emisferiche in compiti di lettura lateralizzata sarebbero spiegabili da variabili semantico-lessicali. Le predizioni di questi modelli sono state testate attraverso uno studio comportamentale e di disconnessione strutturale in una paziente con Alessia Pura, e tramite due studi di lettura con campo visivo diviso (condotti su soggetti destrimani e destrimani e mancini, rispettivamente) in cui fattori lessicali e pre-lessicali sono stati manipolati. La presenza di abilità di lettura residue nel caso di lesione del “sistema delle rappresentazioni visive delle parole” dell’ES e di una sua disconnessione con il resto dell’ES, insieme all’evidenza che un effetto lessicale può, The dominance of the left cerebral hemisphere (LH) over the right one (RH) for reading is widely recognized in the domain of cognitive neuroscience. However, it is still not clear whether such dominance is underlaid by a complete word blindness of the RH (absolute LH dominance) or by poorer/weaker lexical representations in the RH than in the LH (relative dominance). According to the first account, reading should be impossible when the visual word form system of the LH is lesioned and both afferent and efferent connections with the rest of the LH are interrupted by the lesion. Also, according to this account, hemispheric differences in lateralized reading in healthy subjects are explained by greater sensitivity of the RH than the LH to pre-lexical orthographic processing factors. According to the framework advocating a relative LH dominance for reading and suggesting poorer lexical orthographic abilities of the RH than the LH, reading should be possible even in case of lesion and disconnection of the LH reading system, although limited to frequent and/or concrete words. Accordingly, hemispheric differences in lateralized reading in healthy subjects should be explained by lexical-semantic factors. The predictions of these models were tested by means of a behavioral and structural disconnectome study on a patient with Pure Alexia, and two divided visual field reading studies (conducted on healthy right-handed and left-and right-handed subjects, respectively) in which pre-lexical and lexical factors were manipulated. Evidence of residual reading abilities in case of a LH visual word form system lesioned with both afferent and efferent connections with the rest of the LH being interrupted, together with evidence of a lexical effect accounting for visual field/hemisphere differences in lateralized reading supported the view of a relative LH dominance, according to the idea of the existence of a poorer/weaker orthographic lexicon in the RH. A computational modelling study

Gait control becomes more demanding in healthy older adults, yet what cognitive or motor process leads to this age-related change is unknown. The present study aimed to investigate whether it might depend on specific decay in the quality of gait motor representation and/or a more general reduction in the efficiency of lower limb motor control. Younger and older healthy participants performed in fMRI a virtual walking paradigm that combines motor imagery (MI) of walking and standing on the spot with the presence (Dynamic Motor Imagery condition, DMI) or absence (pure MI condition) of overtly executed ankle dorsiflexion. Gait imagery was aided by the concomitant observation of moving videos simulating a stroll in the park from a first-person perspective. Behaviorally, older participants showed no sign of evident depletion in the quality of gait motor representations, and absence of between-group differences in the neural correlates of MI. However, while younger participants showed increased frontoparietal activity during DMI, older participants displayed stronger activation of premotor areas when controlling the pure execution of ankle dorsiflexion, regardless of the imagery task. These data suggest that reduced automaticity of lower limb motor control in healthy older subjects leads to the recruitment of additional premotor resources even in the absence of basic gait functional disabilities.

The dysregulation of food intake in chronic obesity has been explained by different theories. To assess their explanatory power, we meta-analyzed 22 brain-activation imaging studies. We found that obese individuals exhibit hyper-responsivity of the brain regions involved in taste and reward for food-related stimuli. Consistent with a Reward Surfeit Hypothesis, obese individuals exhibit a ventral striatum hyper-responsivity in response to pure tastes, particularly when fasting. Furthermore, we found that obese subjects display more frequent ventral striatal activation for visual food cues when satiated: this continued processing within the reward system, together with the aforementioned evidence, is compatible with the Incentive Sensitization Theory. On the other hand, we did not find univocal evidence in favor of a Reward Deficit Hypothesis nor for a systematic deficit of inhibitory cognitive control. We conclude that the available brain activation data on the dysregulated food intake and food-related behavior in chronic obesity can be best framed within an Incentive Sensitization Theory. Implications of these findings for a brain-based therapy of obesity are briefly discussed.

Neuroimaging studies suggest that the increment of the cognitive load associated with a specific task may induce the recruitment of a more bilateral brain network. In most studies, however, task demand has been manipulated in a static and pre-specified way, regardless of individual cognitive resources.Here we implemented a new paradigm based on a pre-experimental assessment to set up subject-specific levels of task demand and applied tDCS (transcranial direct current stimulation) to assess each hemisphere involvement in task performance.24 young participants performed a digit span backward (DSB, complex cognitive function) and a paced finger tapping task (pFT, basic motor function) at 3 levels of subject-specific task demand ("low" 5/5 correct answers, "medium" 3/5, "high" 1/5). Anodal tDCS (20 min, 1.5 mA) was delivered through a target electrode (5 x 5 cm) positioned to stimulate both the inferior frontal gyrus and the primary motor area over left and right hemisphere and in sham condition in three different days.A 3 (left, right, sham) x 3 (low, medium, high) mixed-model with random intercept for subjects was run with R software.As expected, in both tasks accuracy decreased with the increment of subject-specific task demand. Moreover, a significant interaction between type of stimulation and subject-specific task demand was found for the reaction times recorded during the DSB and for the accuracy in the pFT: in the most demanding conditions, right anodal tDCS significantly interfered with behavioural performance.Our results suggest that hemispheric lateralization is modulated by the subject-specific level of task demand and this modulation is not task-specific