The great influence of mass technologies has changed our writing modality that is moving from the traditional use of pen and paper to the domain of keyboards and recently to touchscreen tools, both in everyday life and in educational contexts. The digitalization of writing and of the texts we write, but also the ubiquity of digital technologies, should encourage a deeper understanding of the implications of the physical and sensorimotor changes in writing. It is reasonable to think that the motor-perceptual differences between different writing modalities can lead to different cognitive performances in linguistic tasks, depending on the writing movement that has to be performed but also on the experience that we have with this movement. In this work, I take into account the role of tangible devices for writing and their different haptic affordance, rarely considered in the study of language, in general, and of writing, in particular. To do so I analyzed different behaviors while we use different writing technologies and discuss the findings from a cognitive science point of view. The general aims of this thesis consists in establishing possible cognitive entailment of different types of writing modalities, in explicating their role in other linguistic tasks and in evaluating the possible implication on daily life and education. The thesis is presented like a collection of papers, results of my research activity and experiences during my participation in the doctoral school. I divided my work in three separate chapters in which different research points of views are analyzed, different experimental procedures are used and different technological devices for writing are tested. Chapter 1 present a study aimed at investigating whether technologically mediated linguistic performance reflects cross-modal interaction and whether it is modulated by the writing technology used, specifically a touchscreen and a keyboard. Chapter 2 comprises a set of studies dedicated to investigate whether it is possible that a strong experience in typing influences our linguistic abilities. Furthermore, typing and mobile typing are compared testing if the two writing modalities share the same motor behaviors. Mobile technologies are also the argument of Chapter 3 in which I present two theoretical papers dedicated to the potential of these devices for learning, in general, and for second language learning, in particular.

This thesis investigated the crossmodal interactions occurring between hearing and touch. Chapters 1 to 6 present the background to this topic and an introduction to the underlying mechanisms of crossmodal perception. Chapter 1 provides a historical overview on the pioneering studies in this issue, whereas in the successive ones the main behavioural evidence on is described. Specific aspects are presented across the chapters, with Chapter 2 presenting the studies using detection/discrimination tasks, intensity tasks, or investigating texture perception or crossmodal sensory illusions and pseudosynaesthetic correspondences. In the subsequent chapters, more specific aspects are taken into consideration, such as the temporal (Chapter 3) and the spatial (Chapter 4) constraints characterizing audiotactile interactions. In Chapter 5, special attention is given to the neural substrates of the audiotactile sensory interplay, in both humans and monkeys. Since there is considerable evidence showing that visual deprivation influences how touch and hearing interact, Chapter 6 will be devoted to explore this topic in more detail. The following chapters present the experimental studies designed to empirically investigate different aspects of audiotactile interactions. Chapter 7 contains experimental studies examining the potential existence of a sensory dominance between hearing and touch, by investigating different portions of the peripersonal space and/or spatial arrangement of the stimuli. Chapter 8 is focused on evaluate the capability of humans in matching the frequency pattern of auditory, tactile and crossmodal stimuli. The spatial factors affecting audiotactile interactions will be explored in Chapter 9, by evaluating how the perception of apparent motion in one modality is biased by the presentation of apparent moving stream in the other modality. The investigation of crossmodal compatibility effects is the topic of Chapter 10. Since visual deprivation has been proved to influence how touch and hearing interact, the last chapter (Chapter 11) will be devoted to compare either spatial or temporal perception, as well as the construction of frames of reference for tactile processing - in relation with auditory stimulation- in blind and sighted individuals.

All'interno dell'annoso dibattito sulla razionalità del ragionamento umano il fenomeno della fallacia della congiunzione (CF) riveste un ruolo di estremo interesse (Tversky & Kahneman, 1983). La CF rappresenta una particolare tipologia di errore logico e probabilistico ed è uno dei fenomeni maggiormente studiati nell'ambito del ragionamento probabilistico. Essa consiste nel valutare come maggiormente probabile l'occorrenza della congiunzione di due eventi (h1&h2) rispetto alla probabilità di presentazione di uno dei due costituenti (h2), giudizio che contravviene ai dettami normativi della regola di congiunzione. Nel Capitolo 1 verrà presentato il problema della fallacia della congiunzione e la sua rilevanza per la spiegazione del ragionamento umano. Nel Capitolo 2 verranno presente le principali proposte esplicative analizzandone i maggiori punti di forza e le limitazioni, in particolare per quanto riguarda la loro forza predittiva. Nonostante i numerosi tentativi di spiegazione, a tutt'oggi difettiamo di una teoria esaustiva in grado di predire l'occorrere del fenomeno. Tra le spiegazioni avanzate particolare rilevanza ai fini della nostra indagine assumono l'insieme della Averaging Rule Hypotheses, che assumono che la CF sia il risultato di una valutazione della probabilità di una congiunzione effettuata attraverso regole non normative del calcolo della media applicate alle probabilità dei congiunti (Nilsson, 2008). Una più recente interpretazione, la Random Variation Hypothesis, descrive invece la CF come l'effetto di un errore casuale insito nel processo valutativo (Costello, 2009). Entrambe queste teorie descrivono e prevedono l'incidenza della CF come funzione della probabilità degli eventi componenti la congiunzione, in particolare l'incidenza dell'errore aumenterà all'aumentare della probabilità assegnata al congiunto aggiunto h2. Queste teorie forniranno il termine di paragone contro cui confrontare il valore esplicativo e predittivo dell'ipotesi che presenteremo nel capitolo successivo. Nel Capitolo 3 si avanzerà una nuova lettura del fenomeno, proposta inizialmente da Crupi, Fitelson & Tentori, 2008 e basata sulla teoria bayesiana della conferma, per cui si ipotizza che le stime probabilistiche erronee tipiche della CF siano in realtà connesse con valutazioni sulla relazione di conferma, intesa come l'apporto informativo che una evidenza conferisce ad una ipotesi. Più in dettaglio, in accordo con questa analisi l'incidenza dell'errore della congiunzione è descritto come funzione dell'aumento del supporto fornito all'ipotesi aggiunta h2. La parte più prettamente sperimentale del presente lavoro è contenuta nel Capitolo 4 dove verranno presentati quattro studi sperimentali finalizzati ad una maggiore comprensione del fenomeno della fallacia della congiunzione, in particolare confrontando empiricamente la spiegazione basata sulla nozione di conferma induttiva con le principali teorie alternative. Il termine di confronto privilegiato sarà fornito dall'insieme delle Averaging Hypotheses e dalla Random variation hypothesis: questi due approcci esplicativi presentano infatti forti similitudini, per quanto concerne le predizioni, con la teoria basata sulla nozione di conferma bayesiana, in quanto grado di conferma e grado di probabilità sono strettamente correlati e spesso mutano in maniera congiunta. Per dimostrare la validità della nozione basata sulla conferma occorre quindi separare le responsabilità dei due fattori, e quindi creare contesti sperimentali in cui le due teorie forniscono predizioni divergenti. I risultati mostrano che la proposta teorica basata sulla conferma si dimostra un buon predittore del verificarsi del fenomeno. In conclusione questi risultati verranno ripresi in considerazione dal punto di vista teorico, per saggiarne la rilevanza nei confronti della ricerca empirica sulla CF, per tentare di gettare una luce sul ruolo della CF stessa nel quadro dell'indagine sulla natura del ragionamento e per suggerire nuovi percorsi di riflessione.

Inductive reasoning is of remarkable interest as it plays a crucial role in many human activities, including hypotheses evaluation in scientific inquiry, learning processes, prediction of future events, and diagnosis of a phenomenon (e.g., medical diagnosis). Despite the relevance of these cognitive processes in a variety of settings, there still remains much to understand about the basis of human inductive inferences. For example, it is not yet clear whether the same psychological mechanisms underlie both inductive reasoning and deductive reasoning or, on the contrary, whether induction and deduction correspond to distinct mental processes. The study of inductive reasoning has been a traditional topic in epistemology, and is more recently being explored in cognitive psychology as well. In the present contribution, I focus on both the epistemological and the psychological accounts. To begin with, I illustrate the state-of-art of research on inductive reasoning. On one hand, epistemologists have been working to develop normative theories in which the notion of inductive strength (or confirmation) is formalized. I discuss some of the alternative Bayesian measures of confirmation proposed in the literature on inductive logic. On the other hand, psychologists have been empirically investigating inductive reasoning, discovering important phenomena such as systematic effects of similarity, typicality, and diversity. I illustrate some of the most significant models of induction proposed in the psychological literature to account for such phenomena. Both lines of inquiry – epistemological and psychological – have focused on a restricted kind of induction problem: when assessing the inductive strength of arguments, premises are assumed to be true, that is, ascertained with the maximum degree of probability. However, inductive arguments occurring in real settings often depart from this pattern. Indeed, in a variety of situations, one may need to assess the impact of a piece of evidence whose probability may have significantly changed while not attaining certainty. Evidential uncertainty in inductive inferences is at the core of the present research. After exploring a selection of psychological phenomena concerning uncertainty, I address the epistemological problem of how to extend Bayesian confirmation theory to include cases where the evidence is not certain. A straightforward solution is proposed for a major class of confirmation measures called P-incremental. The solution proposed is based on Jeffrey conditionalization, an essential formal principle discussed below in greater detail. On the psychological account, I discuss two experimental studies conducted to test whether and how people’s judgments of inductive strength depend on the degree of evidential uncertainty. In the first study the uncertainty of evidence is explicitly manipulated by means of numerical values, whereas in the second study uncertainty is implicitly manipulated by means of ambiguous pictures. The results show that people’s judgments are highly correlated with those predicted by two normatively sound Bayesian measures of confirmation. This sensitivity to the degree of evidential uncertainty supports the centrality of inductive reasoning in cognition, and opens the path to further investigations on induction in real contexts.

The work presented here is at the meeting point of two branches of visual search research, one of which focuses on the proposition that visual search is guided by preparatory internal representations of targets (i.e., search templates: e.g., Bravo & Farid, 2009; 2012; Castelhano & Heaven, 2010; Duncan & Humphreys, 1989; Malcolm & Henderson 2009; 2010; Schmidt & Zelinsky, 2009; Vickery, King, & Jiang, 2005; Wolfe, 2007; Wolfe, Cave, & Franzel, 1989; Yang & Zelinsky, 2009), and the other of which focuses on investigating target detection in naturalistic search environments (e.g., Delorme, Richard, & Fabre-Thorpe, 2010; Delorme, Rousselet, Macé, & Fabre-Thorpe, 2004; Li, VanRullen, Koch, & Perona, 2002; Peelen, Fei-Fei, & Kastner, 2009; Peelen & Kastner, 2011; Thorpe, Fize, & Marlot, 1996; VanRullen & Thorpe, 2001). The search template for objects presented in naturalistic scenes is relatively unknown in terms of its content and characteristics, neural underpinnings, and individual differences in its representation. This thesis explores these topics in depth using behavioral and neurostimulation methods in four experimental chapters.

In everyday situations humans are continuously confronted with complex and cluttered visual environments that contain a large number of objects. Despite this complexity, performance in real-life tasks is surprisingly efficient. As a novel explanation for this efficiency, we propose that the brain uses typical regularities between objects (e.g., lamps are typically appearing above dining tables) to group these objects to reduce complexity and thereby facilitate behavioral performance. In a series of experiments, we show that object regularities reduce competitive interactions in visual cortex, and we relate this benefit to improved detection of target objects among regular distracter groups. Furthermore, we show that this inter-object grouping also enhances performance in visual working memory and determines how fast objects enter visual awareness in the first place. Altogether, our findings demonstrate that inter-object grouping effectively reduces the number of competing objects and thus can facilitate perception in cluttered, but regular environments.

Interacting with the external environment is an inherently multisensory experience. Therefore, understanding how unisensory deprivations occurring early in life affect this interaction has always been a hot topic of research. In this thesis I aim to contribute to this prolific debate by further investigating the effects on behavior exerted by early-acquired bilateral deafness. In the past decades many studies have extensively investigated this topic, focusing mainly on explaining the changes occurring within the visual modality of deaf people, ultimately aiming at understanding to what extent the intuitive assumption that deaf adults ‘see better’ than hearing controls is really true. This approach proved highly informative, yet many fundamental aspects of behavior remained largely overlooked. The aim of this thesis was to identify these missing aspects and try to address them as systematically as possible. In particular I focused on four critical domains: (i) the investigation of the behavioral reorganization that occurs within the tactile modality of deaf adults (Chapter 2, Study 1; Study 2); (ii) the possible modifications of the interactions between two intact sensory systems (i.e., vision and touch) as a consequence of auditory deprivation (Chapter 3); (iii) the finer-grained definition of which mechanisms of visual attention are modified by bilateral deafness (Chapter 4, Study 1; Chapter 5); (iv) the further understanding of the role of extensive visual training in driving the behavioral improvements reported in the deaf population compared to hearing controls (Chapter 2, Study 3; Chapter 4, Study 1; Study 2; Chapter 5). This set of results highlight that deafness-related plasticity exerts multifaceted effects on behavior, which extend selectively to certain functions but not to others, and that even produced selective aspects of impaired behaviors. Importantly, these data also provide initial evidence that vision and touch might to a certain extent, reorganize independently from one another as a consequence of early bilateral deafness and that also the way they interact with each other shows some modified aspects. Finally, the majority of the behavioral modifications I documented in this thesis depended from deafness per se and was not ascribable to training-related effects. Unexpectedly but very interestingly, what clearly emerged from this set of results is the remarkable flexibility of which are capable the reorganized sensory systems, and in particular the reorganized visual system of deaf adults.

For decades, works in psychology of thinking and decision making have been reporting suboptimal performance and systematic departures from the axioms of probability theory in people’s probability judgments. In these first works, poor performance was often attributed to people making normatively wrong intuitions because of their limited cognitive resources and lack of statistical skills. Over the last years, studies that considered various Bayesian models of inductive reasoning but also other high and lower-level cognitive processes provided a more optimistic picture by showing that, despite departing from the normative benchmark, people’s reasoning skills lead to adaptive and sound performance in everyday life. Different explanatory accounts for this suboptimal but sound reasoning have been proposed, some being more compelling than others. The present thesis is aimed at exploring one of these accounts that is based on confirmation relations and suggests that human inductive ability might rely more on estimating evidential impact than posterior probability. So far, this account has been applied to classical probabilistic reasoning errors, linguistic and psycholinguistic phenomena and probabilistic inferences with verbal stimuli. In this study, we tried to see whether the implicit estimation of confirmation relations can affect probability judgments also when the link between evidence and hypotheses is operationalized as the arbitrary association between visual features in briefly presented figures. First, we expected participants to consider confirmed hypotheses more probable than corresponding (in terms of posterior probability) disconfirmed ones; second, we expected them to choose the more likely option (i.e. the normatively correct one) more often when it was confirmed by the evidence provided than when it was disconfirmed. Four computer-based experiments were conducted using the same methodology. Experimental stimuli consisted of inductive arguments concerning 40 sets of figures composed of two features with two possible values each. By varying the probabilistic association between the two values of the features, sets were generated to have, for each possible combination of the two features, two arguments with the same posteriors and opposite impacts. In each trial, participants first looked at a set of figures. One of these figures was then randomly drawn. Participants were informed about the value of one feature of the drawn figure (e.g., that it was a “circle”) and had to guess the value of the other feature (“white” vs. “black”). Throughout the four experiments, we used three different combinations of features: color and shape (exp.1: black/white; exp 2: light/dark grey), pattern and shape (exp 3) and type and orientation of line (exp 4). In all four experiments, participants systematically chose the confirmed alternative over the equally probable, but disconfirmed one, and chose the normatively incorrect (i.e. less likely) alternative more often when it was confirmed (vs. disconfirmed) by the evidence provided. These results provided a first empirical evidence of the effect of confirmation relations on probability judgment with perceptual stimuli, but also highlighted a significant influence of the experimental material itself on choice patterns. In fact, in experiments 1 to 3 the obtained results showed that color (or pattern) was a more compelling evidence than shape in determining participants’ choices. The combination of line curvature and orientation used in experiment 4 proved to be the more balanced among those employed in the present research. Only in this last experiment, indeed, the type of evidence did not affect the choice for the confirmed alternative, nor the amount of errors. The results we found supported our experimental claims showing that confirmation relations can affect probability judgments even in absence of any semantic element, but also suggested the existence of a mutual influence between perceptual features and probability judgments. Our experimental results have theoretical as well as applied implications. On a theoretical level, they extend the results coming from works involving verbal and linguistic material to perceptual stimuli with no semantic background. Additionally, they show that high-level relations, which are completely unknown to the subject, affect the way people perceive relations within a visual set of perceptual items. This might have interesting and noteworthy implications for studies on visual cognition, and, on a broader level, contingency learning and stereotypical judgments.

The current thesis aims to investigate cascaded processing in visual word recognition by testing the predictions of the Dual Route Cascaded (DRC) model of reading. Despite widespread acceptance of the idea that visual language processing is cascaded, there are circumstances in which such an account is not easily reconciled with the data produced by skilled readers. Recent experiments involving factorial manipulations in reading showed, in particular, additive effects of stimulus quality (i.e., clear vs. degraded stimuli) with letter string length and orthographic neighbourhood size in nonword reading and with word frequency and lexicality when words and nonwords were mixed in the task, thus suggesting that information processing implicated in visual word recognition must be at least partially thresholded. Six experiments have been presented in this thesis: on one hand, a new variable that has a role when the stimuli are degraded – the Total Letter Confusability – has been introduced; on the other hand, the effects due to list composition have been analyzed when the stimuli were degraded in the task. In general, the results obtained suggest a novel interpretation of the additivities previously observed; these findings have been explained within the DRC model which also correctly simulates a significant amount of the data. The empirical evidence collected so far clearly indicates that there is currently no need to assume thresholded processing in the reading system.

Reward is a strong determinant of human and non-human behavior, influencing the exploration of the world around us and our interactions with it. Interestingly, the impact of reward and reward-associated objects is not limited to strategic changes in approach behavior or attention deployment, but also extends to situations in which prioritizing processing of such objects is not necessarily advantageous for current goals. In spite of converging evidence for the automatic influence of reward on attentional deployment, less is known about the impact of reward on other cognitive processes. In this thesis I describe a first attempt to investigate the influence of reward in encoding and maintenance of visual representations in working memory. Throughout this thesis I argue that once objects have been associated with a positive outcome in past encounters, they are preferentially encoded and maintained in visual working memory (VWM) even when reward is no longer provided or when there is no consistent pairing between reward feedback and target identity. In Chapters 2 and 3 I demonstrate that reward associated objects interfere with the visual representations of less valuable items maintained in VWM. This interference was already present starting 10 ms from the offset of the memory display suggesting that valuable objects directly affected the encoding of less valuable items. This robust phenomenon was observed at different delays, both when reward-associated objects were task-relevant and when they were not, and was independent of object salience. However, the interference disappeared when task requirements for target selection increased suggesting that items with a positive reward history can effectively capture attention and interfere with VWM representations only when cognitive resources are not exhausted by the main task (Chapter 3). In the last study presented in this thesis I explored the possibility that reward could impact VWM beyond target selection and encoding, namely influencing the active maintenance process. To investigate this hypothesis I measured reward priming effects on event-related potential (ERP) indices of selective attention – the N2pc - and visual working memory maintenance – the CDA (contralateral delay activity). Results indicate that reward modulated CDA only, speaking for a discrete effect of reward on VWM maintenance. While the precise nature of such modulation is still unknown, these results suggest that reward history might influence the precision or the duration of visual representations maintained in VWM. Further studies are necessary to directly test this hypothesis, but these initial results suggest an interesting direction for future research in better characterizing the nature and extent of the influence of reward history on visual cognition.