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In psychology, researchers often rely on face photographs to study face perception. However, finding suitable face stimuli for experiments is often challenging. Computer-generated (CG) faces have emerged as a potential solution due to their flexibility and controllability. However, it has been suggested that these stimuli are evaluated and processed differently from real faces, and their suitability as alternatives in experimental settings remains unclear. To address this, two studies were conducted to examine the impact of CG faces' realism and observers’ self-reported exposure to CG faces on faces appraisals (Study 1) and processing (Study 2). In Study 1 (n = 97), we assessed perceptions of both real and CG faces. Findings indicated that participants generally viewed CG faces less favourably, especially when these faces lacked realism. This trend was particularly pronounced among individuals less exposed to digital characters. In Study 2 (n = 33), we examined the recognition accuracy of these faces in a memory task. The data revealed that CG faces, especially those less realistic, were less accurately recognized. However, this discrepancy was primarily observed among individuals with limited exposure to digital characters, while those more familiar with such characters showed no significant difference in recognition. Overall, this work confirmed that, to date, CG faces are not an adequate alternative to real faces and that researchers should be cautious when using these stimuli in experiments involving face processing. However, as digital graphics improve and as digital characters become more commonplace in daily life, the perceptual gap between CG and real faces may diminish.

Immersive virtual reality (IVR) technology provides several educational affordances that make it a valuable tool for learning, especially from a constructivist learning perspective. Combined with the increasing availability of Metaverse social platforms, such as ENGAGE and AltSpace VR, where students and teachers can meet and work together, IVR may transform how students learn and interact with educational content. However, little is known about students’ attitudes toward IVR in education. To address this gap, we surveyed 329 undergraduate students from different universities in Italy. We used the Unified Theory of Acceptance and Use of Technology (UTAUT) to predict students’ intention to adopt IVR for learning. We further explored the role that different individual factors, including students’ learning styles, affordances perceptions, and personal innovativeness, have on their attitudes toward IVR. A hierarchical multiple regression analysis revealed that the four constructs of the UTAUT, namely performance expectancy, effort expectancy, social influence, and facilitating conditions were the strongest predictors of students’ intention to use IVR in education and that individual factors only had little impact on it. Based on these results, this study provides helpful indications for researchers and educators who wish to introduce IVR effectively in educational contexts. Given the new possibilities provided by Metaverse applications based on IVR technology for learning, it is indeed crucial to fully understand the attitudes different stakeholders in education have toward adopting this technology in educational contexts.

L'attenzione sostenuta, la capacità di mantenere l'attenzione su un compito per un periodo di tempo prolungato senza distrarsi, è alla base di molte attività quotidiane. I questionari di autovalutazione tipicamente usati per misurarla presentano notevoli limiti: valutare la propria attenzione durante lo svolgimento di un compito può interferire con il compito stesso, mentre valutarla a posteriori difficilmente permette di coglierne i cambiamenti nel tempo. Al contrario, alcuni parametri fisiologici potrebbero costituire una misura oggettiva dell’attivazione cognitiva nel tempo senza alterare l’attività svolta. La recente disponibilità di strumenti accurati e poco invasivi per registrare questi parametri permetterebbe di studiarli anche in situazioni più vicine all’esperienza quotidiana. Questo studio mira a validare, come indicatori di attenzione sostenuta, misure basate sulla variabilità della frequenza cardiaca e della conduttanza cutanea. Un gruppo di 30 partecipanti volontari (20-28 anni) ha eseguito al computer due test neuropsicologici di attenzione sostenuta: il Jumping Square Task e il Sustained-Pace Finger Tapping task, indossando contemporaneamente un device da polso per la registrazione dei parametri fisiologici. La capacità di attenzione sostenuta è stata operazionalizzata dal punto di vista comportamentale come il cambiamento in correttezza e in tempi di risposta tra la prima e la seconda metà di ciascun compito. I parametri fisiologici sono stati analizzati in modo analogo. I risultati mostrano un'associazione, anche se moderata, tra la capacità di attenzione cognitiva e il cambiamento nei parametri fisiologici.

I volti sono tra gli stimoli visivi più rilevanti per l’uomo poiché comunicano aspetti chiave per le interazioni sociali. In psicologia, i meccanismi di percezione dei volti vengono tradizionalmente studiati mostrando ai partecipanti fotografie di volti e registrando le loro risposte comportamentali e neurofisiologiche. Recentemente, in alcuni studi le fotografie sono state sostituite da volti virtuali creati attraverso programmi di grafica digitale. Tuttavia, è stato suggerito che questi stimoli potrebbero essere valutati ed elaborati diversamente dai volti reali. Alcuni studi hanno ipotizzato che queste differenze potrebbero essere legate sia al grado di realismo, definito dalla qualità grafica, con cui vengono creati i volti virtuali, sia all'esperienza degli individui con questi stimoli, in termini di frequenza di esposizione. I risultati sono limitati e inconsistenti e non è tuttora chiaro qualora l’utilizzo dei volti virtuali in studi sperimentali rappresenti una valida alternativa ai volti reali. Questa tesi di dottorato mira a fornire una visione più approfondita del ruolo del realismo e dell’esperienza sulla valutazione (Capitolo 1 e Capitolo 2) e il riconoscimento (Capitolo 3) dei volti virtuali. Nel Capitolo 1 viene descritta una revisione della letteratura condotta per stabilire il legame tra i volti virtuali e l’effetto uncanny valley, secondo cui le entità artificiali antropomorfe altamente realistiche scaturiscono delle sensazioni di spiacevolezza e repulsione in chi le osserva. I risultati hanno confermato che i volti virtuali vengono giudicati più inquietanti e meno familiari dei volti reali e che ciò potrebbe derivare da delle discrepanze nel livello di realismo dei volti virtuali percepite dagli osservatori. La revisione ha inoltre sottolineato che, ad oggi, quasi nessun studio ha considerato l’esperienza dei partecipanti con i personaggi virtuali come possibile interpretazione dei risultati. Nel Capitolo 2 sono presentati i risultati di, Faces are among the most relevant visual stimuli for humans as they communicate key aspects essential for social interactions. In psychology, the mechanisms of face perception are traditionally investigated by showing individuals photographs of faces and measuring their behavioral and neurophysiological responses. Recent studies have replaced photographs with virtual faces generated using digital graphics programs. However, it has been suggested that these stimuli might be evaluated differently and elaborated less efficiently than real faces. Some researchers have hypothesized that these differences might be related either to the realism, in terms of render quality, of the virtual faces or to individuals’ expertise with virtual face, in terms of frequency of exposure to these stimuli. However, results are limited and inconsistent and it remains unclear whether virtual faces represent suitable alternatives to real faces in experimental studies. This doctoral dissertation aimed to provide a deeper insight into the role of realism and expertise on virtual faces' evaluation (Chapter 1 and Chapter 2) and recognition (Chapter 3). Chapter 1 described a literature review conducted to establish the link between virtual faces and the uncanny valley effect, according to which highly realistic artificial entities evoke an adverse reaction in the viewer. The results confirmed that virtual faces were judged eerier and less familiar than real faces and that these differences mainly resulted from observers’ perceived inconsistencies in the level of realism of virtual faces. The review further revealed that, so far, nearly no studies considered participants’ expertise with digital characters when analyzing observers’ evaluations of virtual faces. Chapter 2 presented the results of a survey that collected individuals’ judgments of real and virtual faces. Results indicated that virtual faces were judged less reassuring, likable, attractive, trustworthy, and memorable than real faces.

Both visuo-spatial neglect and visual extinction may occur following right-brain damage. So far, studies on brain-damaged patients have not provided definite evidence about which lesion patterns may lead to the association or dissociation of these deficits. This study was set out to address this issue using Intracranial Electrical Stimulation (IES) in a group of nine patients affected by refractory epilepsy. Cerebral regions associated with visuo-spatial neglect and visual extinction were stimulated, including the right frontal, temporal, and posterior parietal areas. During IES, patients with intracranial implantation involving at least one of these cortical regions were administered with a manual line bisection task (N = 9) to assess visuo-spatial neglect, and a computerized task (N = 8) assessing visual extinction. Results showed that parietal IES induced a rightward bias at the manual bisection task, together with a general improvement in reaction times at bilateral and unilateral visual stimuli detection at the extinction task. The occurrence of visual extinction did not vary across stimulations. By adopting a complementary approach to anatomo-clinical correlation studies, our work corroborates the notion that lesions to the right inferior parietal lobule play a pivotal role in the pathogenesis of visuo-spatial neglect. Importantly, our results also suggest that temporarily interfering with the activity of this region is not sufficient per se to generate visual extinction, which instead may involve a broader and/or different network, possibly extending beyond the cerebral regions considered here, posing important theoretical and clinical implications.

The study assessed whether the auditory reference provided by a music scale could improve spatial exploration of a standard musical instrument keyboard in right-brain-damaged patients with left spatial neglect. As performing music scales involves the production of predictable successive pitches, the expectation of the subsequent note may facilitate patients to explore a larger extension of space in the left affected side, during the production of music scales from right to left. Eleven right-brain-damaged stroke patients with left spatial neglect, 12 patients without neglect, and 12 age-matched healthy participants played descending scales on a music keyboard. In a counterbalanced design, the participants' exploratory performance was assessed while producing scales in three feedback conditions: With congruent sound, no-sound, or random sound feedback provided by the keyboard. The number of keys played and the timing of key press were recorded. Spatial exploration by patients with left neglect was superior with congruent sound feedback, compared to both Silence and Random sound conditions. Both the congruent and incongruent sound conditions were associated with a greater deceleration in all groups. The frame provided by the music scale improves exploration of the left side of space, contralateral to the right hemisphere, damaged in patients with left neglect. Performing a scale with congruent sounds may trigger at some extent preserved auditory and spatial multisensory representations of successive sounds, thus influencing the time course of space scanning, and ultimately resulting in a more extensive spatial exploration. These findings offer new perspectives also for the rehabilitation of the disorder.

Rebus puzzles and compound remote associate problems have been successfully used to study problem solving. These problems are physically compact, often can be solved within short time limits, and have unambiguous solutions, and English versions have been normed for solving rates and levels of difficulty. Many studies on problem solving with sudden insight have taken advantage of these features in paradigms that require many quick solutions (e.g., solution priming, visual hemifield presentations, electroencephalography, fMRI, and eyetracking). In order to promote this vein of research in Italy, as well, we created and tested Italian versions of both of these tests. The data collected across three studies yielded a pool of 88 rebus puzzles and 122 compound remote associate problems within a moderate range of difficulty. This article provides both sets of problems with their normative data, for use in future research.

Selective attention, i.e. the ability to concentrate one's limited processing resources on one aspect of the environment, is a multifaceted concept that includes different processes like spatial attention and its subcomponents of orienting and focusing. Several studies, indeed, have shown that visual tasks performance is positively influenced not only by attracting attention to the target location (orientation component), but also by the adjustment of the size of the attentional window according to task demands (focal component). Nevertheless, the relative weight of the two components in central and peripheral vision has never been studied. We conducted two experiments to explore whether different components of spatial attention have different effects in central and peripheral vision. In order to do so, participants underwent either a detection (Experiment 1) or a discrimination (Experiment 2) task where different types of cues elicited different components of spatial attention: a red dot, a small square and a big square (an optimal stimulus for the orientation component, an optimal and a sub-optimal stimulus for the focal component respectively). Response times and cue-size effects indicated a stronger effect of the small square or of the dot in different conditions, suggesting the existence of a dissociation in terms of mechanisms between the focal and the orientation components of spatial attention. Specifically, we found that the orientation component was stronger in periphery, while the focal component was noticeable only in central vision and characterized by an exogenous nature.

The aim of this work is to predict the complexity perception of real world images.We propose a new complexity measure where different image features, based on spatial, frequency and color properties are linearly combined. In order to find the optimal set of weighting coefficients we have applied a Particle Swarm Optimization. The optimal linear combination is the one that best fits the subjective data obtained in an experiment where observers evaluate the complexity of real world scenes on a web-based interface. To test the proposed complexity measure we have performed a second experiment on a different database of real world scenes, where the linear combination previously obtained is correlated with the new subjective data. Our complexity measure outperforms not only each single visual feature but also two visual clutter measures frequently used in the literature to predict image complexity. To analyze the usefulness of our proposal, we have also considered two different sets of stimuli composed of real texture images. Tuning the parameters of our measure for this kind of stimuli, we have obtained a linear combination that still outperforms the single measures. In conclusion our measure, properly tuned, can predict complexity perception of different kind of images.

A privileged way of representing numbers in the human mind is along an oriented mental number line. Activation of this representation has been proposed to account for the impact of numbers on motor tasks, such as on grasping, pointing, and eye movements. Here we evaluated the impact of numbers on motor control, by exploiting the evidence that the speed reached by the manual connection of two points is correlated with their physical distance. We reasoned that, if irrelevant numbers induce a mis-perception of the distance between two points, this should be reflected in the movement speed. Results showed a speed difference in the manual connection of two numerically close numbers (i.e., connected slower) and two numerically distant numbers (i.e., connected faster), placed at equal physical distance. This representational length effect indicates not only that symbolic distance modulates speed movement as physical distance does, but suggests that the impact of numbers on action planning does not only involve action initiation but it extends to the definition of kinematic parameters. More generally, the reported findings show that the representation of numbers along a mental space affects our behaviour in the physical space.

How accurate are insights compared to analytical solutions? In four experiments, we investigated how participants' solving strategies influenced their solution accuracies across different types of problems, including one that was linguistic, one that was visual and two that were mixed visual-linguistic. In each experiment, participants' self-judged insight solutions were, on average, more accurate than their analytic ones. We hypothesised that insight solutions have superior accuracy because they emerge into consciousness in an all-or-nothing fashion when the unconscious solving process is complete, whereas analytic solutions can be guesses based on conscious, prematurely terminated, processing. This hypothesis is supported by the finding that participants' analytic solutions included relatively more incorrect responses (i.e., errors of commission) than timeouts (i.e., errors of omission) compared to their insight responses.

Creative ideas seem often to appear when we close our eyes, stare at a blank wall, or gaze out of a window—all signs of shutting out distractions and turning attention inward. Prior research has demonstrated that attention-related brain areas are differently active when people solve problems with sudden insight (the Aha! phenomenon), relative to deliberate, analytic solving. We directly investigated the relationship between attention deployment and problem solving by recording eye movements and blinks, which are overt indicators of attention, as people solved short, visually presented problems. In the preparation period, before problems eventually solved by insight, participants blinked more frequently and longer, and made fewer fixations, than before problems eventually solved by analysis. Immediately prior to solutions, participants blinked longer and looked away from the problem more often when solving by insight than when solving analytically. These phenomena extend prior research with a direct demonstration of dynamic differences in attention as people solve problems with sudden insight versus analytically.

In this paper we investigate if color influences the perception of image complexity. To this end we perform two different types of psycho-physical experiments on color and grayscale images. In the first experiment, images are ranked based on their complexity (image ranking), while in the second experiment the complexity of each image is assessed on a continuous scale (image scaling). Moreover, we investigate if ten image features, that measure colors as well as other spatial properties of the images, correlate with the collected subjective data. The performance of these correlations are evaluated in terms of Pearson correlation coefficients and Spearman rank-order correlation coefficients. We observe that for each type of experiment, subjective scores for color images are highly correlated with those of the corresponding grayscale versions suggesting that color is not a relevant attribute in evaluating image complexity. Moreover none of the tested simple image features seem to be adapt to predict the image complexity according to the human judgments.

Previous studies have shown that attention deployment in visual search tasks is modulated by face race and emotional expression, with a search asymmetry in favor of those faces that are less efficiently discriminated and recognized at the individual level (i.e., other-race faces and angry faces). Face age is another dimension affecting how faces are remembered, as it has been widely reported that young adults show significant deficits in recognizing other-age faces. By comparing adults' search efficiency for ownand other-age faces in a visual search task in which face age was the target feature we explored whether the mirror pattern of detection and recognition effects found for race biases generalizes to age biases, and whether search efficiency for adult and nonadult faces is modulated by experience accumulated with nonadult faces. Search efficiency was greater for adult faces than for infant (Experiment 1) or child faces (Experiment 2) in adults with limited experience with infants or children, whereas there was no sign of search asymmetry in preschool teachers who have had extensive recent experience with children (Experiment 2). Results indicate that the influence of age on attention deployment parallels the effects that this face attribute has on face recognition, and that both effects are experience-based.

Crowding is a phenomenon that characterizes normal periphery limiting letter identification when other letters surround the signal. We investigated the nature of the reading limitation of crowding by analyzing eye-movement patterns. The stimuli consisted of two items varying across trials for letter spacing (spaced, unspaced and increased size), lexicality (words or pseudowords), number of letters (4, 6, 8), and reading modality (oral and silent). In Experiments 1 and 2 (oral and silent reading, respectively) the results show that an increase in letter spacing induced an increase in the number of fixations and in gaze duration, but a reduction in the first fixation duration. More importantly, increasing letter size (Experiment 3) produced the same first fixation duration advantage as empty spacing, indicating that, as predicted by crowding, only center-to-center letter distance, and not spacing per se, matters. Moreover, when the letter size was enlarged the number of fixations did not increase as much as in the previous experiments, suggesting that this measure depends on visual acuity rather than on crowding. Finally, gaze duration, a measure of word recognition, did not change with the letter size enlargement. No qualitative differences were found between oral and silent reading experiments (1 and 2), indicating that the articulatory process did not influence the outcome. Finally, a facilitatory effect of lexicality was found in all conditions, indicating an interaction between perceptual and lexical processing. Overall, our results indicate that crowding influences normal word reading by means of an increase in first fixation duration, a measure of word encoding, which we interpret as a modulatory effect of attention on critical spacing.