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Psychophysical observations indicate that the spatial profile of visuospatial attention includes a central enhancement around the attentional focus, encircled by a narrow zone of reduced excitability in the immediate surround. This inhibitory ring optimally amplifies relevant target information, likely stemming from top-down frontoparietal recurrent activity modulating early visual cortex activations. However, the mechanisms through which neural suppression gives rise to the surrounding attenuation and any potential hemispheric specialization remain unclear. We used transcranial magnetic stimulation to evaluate the role of two regions of the dorsal attention network in the center-surround profile: the frontal eye field and the intraparietal sulcus. Participants performed a psychophysical task that mapped the entire spatial attentional profile, while transcranial magnetic stimulation was delivered either to intraparietal sulcus or frontal eye field on the right (Experiment 1) and left (Experiment 2) hemisphere. Results showed that stimulation of right frontal eye field and right intraparietal sulcus significantly changed the center-surround profile, by widening the inhibitory ring around the attentional focus. The stimulation on the left frontal eye field, but not left intraparietal sulcus, induced a general decrease in performance but did not alter the center-surround profile. Results point to a pivotal role of the right dorsal attention network in orchestrating inhibitory spatial mechanisms required to limit interference by surrounding distractors.

Due to the multitasking nature of driving, drivers are physiologically distracted by both relevant and irrelevant environmental stimuli. The ability to select relevant stimuli and suppress irrelevant distractors during driving are two relevant factors for safety. There is a lot of evidence suggesting that the frontal eye field (FEF) plays an important role in target selection and distractors suppression, as well as in attentional mechanisms crucial for safety driving performance. Taking these two points into account, this study was designed to examine the effects of different transcranial direct current stimulation (tDCS) montages over right FEF to determine whether stimulation of FEF could improve attentional mechanisms in a simulated driving environment. Twenty-seven adult participants took part in the study. A specific driving simulator task was developed in which participants had to respond to brake light events of a preceding car in front of them while driving. The second distracting task consisted of road signs of countries and cities that appeared together with braking lights or alone. Participants were required to respond to one of the two categories with their right hand. These two tasks could be performed alone or in a combined condition. Each participant completed three sessions comparing the effects of different tDCS montages, i.e. conventional, focal 4*1 ring high-definition (HD-tDCS) and sham stimulations over the right FEF. Results indicated an overall better performance under the focal HD-tDCS condition. In particular, participants improved their performance both in braking light RTs and in the second distracting task. Taken together these results are interesting from a theoretical and methodological point of view, by demonstrating a direct effect of anodal focal HD-tDCS on FEF in attentional response during an ecological driving task.

The assessment of attention in neuropsychological patients could be performed with visual search tests. The Broken Rings enVision Search test (BReViS) here proposed represents a novel open access paper-and-pencil tool in which layout and crowding are varied among four cards. These manipulations allow the assessment of different components of attention: a selective component, the visuo-spatial orientation of attention, and the focal attention, involved in a crowding phenomenon. Our purpose was to determine the characteristics of the BReViS test, provide specific normative data, and assess these components across the lifespan. The test was administered to a sample of 550 participants aged between 20 and 79 years old and to a series of patients. Three indexes targeting different components of visuo-spatial attention (selective attention, strategic orientation of visual attention, focal attention) were obtained by combining execution times and accuracy together with the total errors. The results showed that age, education and gender influenced, in different combinations, the four indexes, for which specific norms were developed. Regression-based norms were provided in percentiles and equivalent scores. All patients showed pathological scores and specific patterns of attentional deficits. The BreViS test proved to be a free and easy valuable tool which can be used in the clinical environment to assess attentional deficits in neuropsychological patients.

La prosopagnosia è un disturbo diffuso sia nella sua forma congenita che acquisita. Tuttavia, non esistono ancora protocolli unitari per la sua riabilitazione. Di consequenza, nello studio 1 è stata svolta una revisione sistematica della letteratura per avere una panoramica sugli studi esistenti sulla riabilitazione dell’agnosia per gli oggetti e della prosopagnosia. I risultati riguardanti la prosopagnosia mostrano che trattamenti basati su un’elaborazione olistica dei volti sono più efficaci e vengono generalizzati a nuove prospettive dei volti. Tuttavia, esistono pochi articoli sull’argomento ed è necessario sviluppare nuovi studi. Questo potrebbe essere dovuto alla poca chiarezza sui meccanismi di elaborazione dei volti. Per questo motivo, abbiamo deciso di approfondirli. Innanzitutto, abbiamo indagato la relazione tra espressioni facciali e riconoscimento di identità. L’obiettivo dello studio 2 era quello di indagare se c’è una relazione tra le abilità di riconoscimento individuali e l’elaborazione di espressioni facciali. Gli attuali modelli di riconoscimento volti postulano che elaboriamo i volti tramite due sistemi separati in interazione: uno elabora le caratteristiche del volto e l’altro le espressioni facciali. Di conseguenza, nello studio 2 ci aspettavamo di osservare una facilitazione delle espressioni sul riconoscimento di identità. I risultati confermano che espressioni facciali dinamiche non emotive aiutano nel riconoscimento di identità, ma solamente in chi ha delle scarse abilità di riconoscimento volti. L’obiettivo dello studio 3 era quello di approfondire le basi neurali di questa relazione. Per farlo, abbiamo stimolato STS, preSMA e un’area Sham con la TMS mentre i partecipanti dovevano riconoscere volti codificati tramite espressioni facciali dinamiche non emotive, un movimento rigido o come neutri. I risultati ottenuti nella condizione sham replicano quelli ottenuti nello studio 2: espressioni facciali non emotive aiutano il riconosc, Prosopagnosia is a diffuse deficit both in its acquired and developmental forms. However, no unitary protocols for its rehabilitation have been developed yet. Thus, a systematic review of the literature on the topic (Study 1) has been performed to understand the state of the art of rehabilitation of object agnosia and prosopagnosia. Results regarding developmental and acquired prosopagnosia, reveal that treatments involving holistic perceptual processing of faces are the most effective and can be generalized to new views and perspectives of faces. However, few papers were obtained and new studies addressing the topic are required. This might be due to the scarce clarity about the mechanisms subserving face processing. Thus, we decided to deepen our understanding of the mechanisms subserving face recognition. First, we wanted to shed light on the relationship between facial expression and identity processing. The aim of study 2 was that of assessing whether there is a relation between individual face recognition abilities and facial expression processing. Indeed, according to models of face recognition, we recognize faces through two partially independent systems which process respectively, facial features and facial expressions. Based on that, we expected expressions, even when non-emotional to aid identity recognition. Results of study 2 showed that when the system used to elaborate facial identity is deficient, dynamic facial expressions, even when non-emotional, help recognition. Study 3 aimed at deepening our understanding of the neural bases subserving the relation between facial expression and identity processing. To do so, we stimulated STS, preSMA and a Sham area with repetitive TMS while administering a task of identity matching of faces encoded through non-emotional facial expressions, rigid head movement or as neutral. Results of the Sham condition replicate findings from study 2 confirming that expressions, even when non-emotional, aid recognition in poo

Normative data of neuropsychological tests typically consider the effect of demographic variables like age and education on performance. However, a broad literature has shown that, after the school age, other cognitively stimulating experiences (e.g., occupational attainment and a variety of leisure-time activities) may increase and build up cognitive reserve (CR), which is positively associated with better performance in many neuropsychological tests. With these premises, we investigated the predictive capability of education and a life-experience proxy of CR on a widely used cognitive screening, i.e., the Montreal Cognitive Assessment (MoCA). Results show that models including the more comprehensive life-experience CR proxy performed better than models including Education. Based on the results of our analyses we provide normative data and cut-offs on 440 Italian individuals aged 50-90 years, by taking into account, for the first time for the Italian population, a CR index, together with demographic variables and Education, in the calculation of regression-based norms. Accounting for life-experience CR proxies can improve the accuracy of normative data and allow a finer estimation of cognitive performance, which lead to a more tailored approach to patient assessment.

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.

Agnosia for objects is often overlooked in neuropsychology, especially with respect to rehabilitation. Prosopagnosia has been studied more extensively, yet there have been few attempts at training it. The lack of training protocols may partially be accounted for by their relatively low incidence and specificity to sensory modality. However, finding effective rehabilitations for such deficits may help to reduce their impact on the social and psychological functioning of individuals.

Background:Agnosia for objects is often overlooked in neuropsychology, especially with respect to rehabilitation. Prosopagnosia has been studied more extensively, yet there have been few attempts at training it. The lack of training protocols may partially be accounted for by their relatively low incidence and specificity to sensory modality. However, finding effective rehabilitations for such deficits may help to reduce their impact on the social and psychological functioning of individuals. Objective:Our aim in this study was to provide clinicians and researchers with useful information with which to conduct new studies on the rehabilitation of object agnosia and prosopagnosia. To accomplish this, we performed a systematic and comprehensive review of the effect of neuropsychological rehabilitation on visual object and prosopagnosia. Methods:The Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were followed. In addition, the Single-Case Experimental Design (SCED) and the Critical Appraisal Skills Programme (CASP) scales were used to assess the quality of reporting. Results:Seven articles regarding object agnosia, eight articles describing treatments for prosopagnosia, and two articles describing treatments for both deficits were included. Conclusions:In the light of the studies reviewed, treatments based on analysis of parts seem effective for object agnosia, while prosopagnosia appears to benefit most from treatments relying on holistic/configural processing. However, more attempts at rehabilitation of face and object agnosia are needed to clarify the mechanisms of these processes and possible rehabilitations. Moreover, a publication bias could mask a broader attempt to find effective treatments for visual agnosia and leaving out studies that are potentially more informative.

Acquired Neglect Dyslexia is often associated with right-hemisphere brain damage and is mainly characterized by omissions and substitutions in reading single words. Martelli et al. proposed in 2011 that these two types of error are due to different mechanisms. Omissions should depend on neglect plus an oculomotor deficit, whilst substitutions on the difficulty with which the letters are perceptually segregated from each other (i.e., crowding phenomenon). In this study, we hypothesized that a deficit of focal attention could determine a pathological crowding effect, leading to imprecise letter identification and consequently substitution errors. In Experiment 1, three brain-damaged patients, suffering from peripheral dyslexia, mainly characterized by substitutions, underwent an assessment of error distribution in reading pseudowords and a T detection task as a function of cue size and timing, in order to measure focal attention. Each patient, when compared to a control group, showed a deficit in adjusting the attentional focus. In Experiment 2, a group of 17 right-brain-damaged patients were asked to perform the focal attention task and to read single words and pseudowords as a function of inter-letter spacing. The results allowed us to confirm a more general association between substitution-type reading errors and the performance in the focal attention task.

In brain damage patients with unilateral spatial neglect (USN), the differential diagnosis between the presence and absence of a unilateral visual half-field deficit (VHFD) is hampered by the similarity of their phenomenology. The absence of stimuli detection in the contralateral visual field, indeed, can be due to the co-occurrence of USN and VHFD or the sole presence of the USN. The disentangling of the two conditions is required to devise more specific rehabilitation programmes. Daini et al. [2002. Exploring the syndrome of spatial unilateral neglect through an illusion of length. Experimental Brain Research, 144(2), 224-237.] reported a difference in performance for the two conditions when the tasks required the bisection of Brentano illusory stimuli. Only when USN and VHFD co-occurred, the leftward illusory effect was disrupted. Based on previous findings, in this cross-sectional study, we developed the Brentano Illusion Test (BRIT), a clinical tool that helps the identification of VHFD in USN patients. The BRIT is a simple behavioural test of lines bisection aimed at verifying the presence or absence of implicit processing in USN and thus helping the diagnosis of VHFD in USN patients; it also provides normative data for the line bisection task and the length effect.

Dal 2002, anno in cui l’Organizzazione mondiale della Sanità ha sancito i principi per promuovere politiche economiche e di welfare orientate all’Active Ageing, anche la letteratura in campo psicologico operante nel settore dell’invecchiamento si è mossa in accordo con questi principi. La tesi di dottorato presenta degli studi inerenti l’invecchiamento che vertono su due tematiche principali: da un lato i fattori psicosociali nell’invecchiamento intesi come atteggiamento e percezione della propria età; dall’altro i processi cognitivi maggiormente colpiti nell’invecchiamento sano, in particolar modo gli aspetti di memoria episodica, e gli strumenti per allenarli e valutarli. La tesi è dunque divisa in due sezioni. Nella prima parte saranno approfonditi i temi dell’ageismo e degli atteggiamenti verso il proprio processo di invecchiamento, attraverso due studi che utilizzano la realtà virtuale come metodologia e approccio in grado di simulare il processo di invecchiamento: in un primo studio attraverso l’utilizzo della realtà virtuale abbiamo indagato l’impatto di una stimolazione di embodiment visuo-tattile nel modificare gli atteggiamenti negativi verso gli anziani in tre gruppi di età differenti. Nel secondo studio, data l’importanza delle caratteristiche degli avatar negli studi di realtà virtuale, abbiamo creato un dataset di corpi e volti digitali che potranno essere utilizzati successivamente per studi che combinano la realtà virtuale e gli atteggiamenti verso gli anziani. Nella seconda parte saranno invece approfondito il dominio della memoria episodica come componente relativa al self e indirettamente legata ai benessere e ai vissuti di preoccupazione e ansia relativi alla perdita di memoria. Verranno presentati due studi: un training cognitivo da noi creato con l’obiettivo di stimolare le componenti di memoria episodica e un compito che, sfruttando la rappresentazione della mental time line e del distance effect, ha l’obiettivo di studiare i meccanis, Since 2002, when the World Health Organisation laid down the principles for promoting active ageing-oriented economic and welfare policies, psychological literature in ageing has also been developed following these principles. The doctoral thesis provides studies on ageing that focused on two main themes: on the one hand, the psychosocial factors in ageing comprehensive of attitudes and perception of one's age; on the other hand, cognitive processes most affected in healthy ageing, especially episodic memory, and tools to train and evaluate them. The thesis is, therefore, divided into two sections. In the first part, the themes of ageism and attitudes towards one's ageing process will be explored through two studies that use virtual reality as a methodology and approach capable of simulating the ageing process. In a first study, we investigated the impact of a visuo-tactile embodiment stimulation in modifying negative attitudes towards the elderly in three different age groups through the use of virtual reality. In a second study, given the importance of avatar characteristics in virtual reality studies, we aimed to create a dataset of digital bodies and faces that can be used later for studies that combine virtual reality and attitudes towards the elderly. In the second part, we will focus on episodic memory as a domain related to the self and well-being. Two studies will be presented: a cognitive training created by us that aims to stimulate the components of episodic memory, and a task that, exploiting the representation of mental timeline and distance effect, has the objective of studying the mechanisms of learning of similar- personal events in young and old.

Objective: Simultanagnosia, a deficit in holistic visual perception, is among the most prominent features of posterior cortical atrophy (PCA). Deficits in visuoperceptual and attentional mechanisms could contribute to simultanagnosia. In the present study, we explored the impaired visual perception of global configuration with two main hypotheses: (a) It is due to a deficit in processing low-spatial frequency stimuli, and (b) it arises from deficits in adjusting attentional focus. Method: The visuoperceptual mechanism was explored by asking participants (5 PCA patients and 20 age- and education-matched healthy controls) to report the local and global elements of incongruent hierarchical letters. Stimuli were unbiased (black letters/white background) and parvocellular biased (red letters/green background). A cued T-detection task, where the stimulus onset asynchrony and the cues' features varied, was used to explore focal attention. Results: PCA patients systematically failed in reporting the global but not the local element. The parvocellular-biased condition partially improved the performance in only 1 patient. In the T-detection task, controls responded faster to targets cued by red dots and small cues as compared to no cues. Conversely, the cue's features did not affect patients' performance. Conclusions: Results only partially support the hypothesis according to which simultanagnosia is driven by an impairment in processing low-spatial frequencies. Data indicate a deficit in the flexibility of focal attention that prevents PCA patients from adapting the attentional window to the stimulus features. Simultanagnosia in PCA can be conceptualized as a complex result of a deficit involving visuoperceptual and exogenous attentional mechanisms.

Despite a large body of evidence suggests positive effects of playing action video games and practising sports on various visual attentional skills, the impact of these activities on the ability to maintain attention over prolonged periods of time (i.e., sustained attention) has been largely neglected. Here, we first explored free-time habits on a group of 310 adolescents by means of a self-reported questionnaire. We found an inverse relationship between the time spent with sports and video games, but not with other extra-scholastic activities: the time spent practising sports and playing video games clearly competed with each other, with the more-intensive-sport practitioners being less involved in video game play. Next, we directly measured sustained attention and other attentional skills in a subgroup of 76 participants, divided as a function of their time spent in sports and action video games. In particular, sustained attention was assessed by means of two tasks: a classic exogenous task, requiring participants to attend to a flashing visual stimulus; and an internal (endogenous) sustained attention task, requiring participants to synchronise their manual responses to the rhythm of auditory pulses presented in an earlier phase. As previously documented, we found that action video game players displayed worse ability to maintain attention over time, as compared with non-action players. In striking contrast, intensive sports practice was associated with an increased ability to maintain attention over time. Overall, these findings unveil distinct cascading effects on sustained attention induced by doing sport and playing action video games.

Prism adaptation (PA) is a technique that induces a temporary change of the alignment between different reference frames. This technique has been shown to reduce many signs of unilateral spatial neglect (USN). Two procedures of prism adaptation have been used. In concurrent exposure participants can see their arm and hand during the movement trajectory, and during terminal exposure, participants can see only the most distal few centimetres. Because the two exposures elicit different proportions of visual and proprioceptive realignment, they could present different rehabilitation efficacies. We compared these procedures in 12 USN patients and 12 healthy participants who performed one session of PA with concurrent exposure and one session with terminal exposure. We compared the effects of the two exposure types on sensorimotor outcomes (visual subjective straight ahead, proprioceptive subjective straight ahead, open loop pointing, and error correction during exposure) and neglect outcomes. We found no significant differences in the effects of the two exposure types on sensorimotor performance of patients and controls, nor on patients’ neuropsychological outcomes. Compared with controls, USN patients showed a significant rightward bias in visual subjective straight ahead pre-adaptation, a slower rate of error correction during prism exposure, and some evidence that visual and proprioceptive shift could be influenced by their neglect. Based on these results, we recommend that prism adaptation be conducted with concurrent exposure for easiness of execution.

Transcranial direct current stimulation (tDCS) has been widely used for modulating sensory, motor and cognitive functions, but there are only few attempts to induce and change illusory perception. Visual illusions have been the most traditional and effective way to investigate visual processing through the comparison between physical reality and subjective reports. Here we used tDCS to modulate two different visual illusions, namely the Brentano illusion and the glare effect, with the aim of uncovering the influence of top-down mechanisms on bottom-up visual perception in two experiments. In Experiment 1, to a first group of subjects, real and sham cathodal tDCS (2 mA, 10 min) were applied over the left and right posterior parietal cortices (PPC). In Experiment 2, real and sham cathodal tDCS were applied to the left and right occipital cortices (OC) to a second group of participants. Results showed that tDCS was effective in modulating only the Brentano illusion, but not the glare effect. tDCS increased the Brentano illusion but specifically for the stimulated cortical area (right PPC), illusion direction (leftward), visual hemispace (left), and illusion length (160 mm). These findings suggest the existence of an inhibitory modulation of top-down mechanisms on bottom-up visual processing specifically for the Brentano illusion, but not for the glare effect. The lack of effect of occipital tDCS should consider the possible role of ocular compensation or of the unstimulated hemisphere, which deserves further investigations.

Background: Alongside physiological cognitive ageing, nowadays there is an alarming increase in the incidence of dementia that requires communities to invest in its prevention. The engagement in cognitively stimulating activities and strong social networks has been identified among those protective factors promoting successful cognitive ageing. One aspect regarding cognitive stimulation concerns the relevance of the frequency of an external intervention. For this reason, the aim of this study was to evaluate the efficacy of a 3-month cognitive training program, once per week, in a group of healthy elderly aged over 60 years old. Their results were compared with those of a passive control group. Methods: The training consisted of a weekly session of multi-domain and ecological cognitive exercises performed in small homogenous (i.e. same cognitive level) groups. The scores obtained in a neuropsychological assessment by the experimental and control groups were compared at pre- and post-training. In addition, by means of a questionnaire, we also evaluated the indirect effect of the program on participants' mood, socialization and perceived impact on everyday activities. Results: Overall, the experimental group showed a general improvement in cognitive functioning following the training program, even with the frequency of once per week. Greater improvements were observed mainly on executive functions and short-term memory, but general cognitive functioning and non-verbal reasoning also showed a tendency to an improvement. It is noteworthy that a majority of the participants reported to have subjectively experienced an improvement in their everyday life and a positive influence on both mood and socialization. Conclusions: These results show that even a low-intensity training program is able to promote some of the protective factors that support successful cognitive ageing. Moreover, this multi-domain approach proved to be an excellent training method to transfer gains not

La letteratura ha indagato il ruolo dei processi top-down e bottom-up nel guidare la ricerca visiva. Recenti studi hanno suggerito un ruolo modulatorio dei processi top-down sulla cattura attentiva. Tuttavia, i risultati sono contraddittori, e il ruolo dei processi top-down non è stato ancora chiaramente stabilito. In questo lavoro, abbiamo studiato se il controllo top-down fosse reclutato proattivamente quando c’è un’aspettativa di distrattori e abbiamo adottato il paradigma di Distraction Context Manipulation (DCM) per caratterizzare il loro reclutamento nella ricerca visiva. Pertanto, abbiamo combinato un compito di feature search e uno di conjunction search con il DCM (Esp 1-4). In linea con il DCM, i blocchi erano di tre tipi: un blocco Puro senza trial con distrattori, e due blocchi contenenti frequenti trial con distrattori (Mixed Feature e Conjunction). Il compito era individuare il target in ogni trial. Il confronto tra trial senza distrattori nei blocchi misti e nel blocco puro ha permesso di rilevare il reclutamento di processi top-down per l'aspettativa di distrattori. Inizialmente abbiamo indagato se i processi top-down fossero reclutati nei contesti distraenti e se il loro potenziale reclutamento fosse modulato dal tipo di ricerca (Exp 1). I risultati hanno mostrato un reclutamento proattivo dei processi top-down in caso di aspettativa di distrattori sia nel feature che nel conjunction search. Tale reclutamento è emerso come costo in termini di tempo di risposta nonché come beneficio della sensibilità di detezione del target quando i distrattori erano attesi ma non presentati. Risultati sovrapponibili sono emersi nelle varianti di ricerca visiva covert (Esp 1,3) e overt (Esp 2,4). Poiché le precedenti esperienze distraenti hanno mostrato di modellare l'aspettativa di distrattori nei trial successivi, abbiamo anche cercato di differenziare il ruolo delle aspettative da quello dell'esperienza nell'attivare i processi top-down. I risultati (Esp 1, 2, Literature has long investigated the contributions of top-down and bottom-up processes in guiding search behavior. Recent findings suggest a modulatory role of top-down processes on attentional capture. However, results are contradictory, and whether and how top-down processes intervene has not been clearly established yet. Here, we approached the issue from the perspective of proactive top-down processes of distractor expectation and leveraged the Distractor Context Manipulation (DCM) paradigm to help characterizing their recruitment in visual search. Thus, we combined a feature search (i.e., search for a high-contrast target among no-contrast distractors) and a conjunction search (i.e., search for a high-contrast target among high-contrast distractors) with the DCM paradigm (Exp 1-4). Accordingly, blocks of trials were of three types: a Pure block containing no distractor-present trials, and two blocks containing frequent distractor-present trials (i.e., Mixed Feature and Mixed Conjunction). Subjects were instructed to look for the target on each trial. The comparison of distractor-absent trials of Mixed vs Pure blocks allowed detecting proactive top-down processes of distractor expectation. First, we investigated whether proactive top-down processes were recruited in distracting contexts of visual search and whether their potential recruitment was modulated by the type of search (Exp 1). Results attested for a proactive recruitment of top-down processes of distractor expectation in both feature and conjunction search. Such recruitment entailed a response time (RT) cost as well as a beneficial enhancement of the detection sensitivity (d’) to the target when distractors were expected, yet not presented. Overlapping results emerged in covert (Exp 1, 3) and overt (Exp 2, 4) variants of visual search. Since previous distracting experience shaped distractor expectation, we, also, sought to disentangle the role of expectation and experience in the activation of top-down

Diagnosis of developmental or congenital prosopagnosia (CP) involves self-report of everyday face recognition difficulties, which are corroborated with poor performance on behavioural tests. This approach requires accurate self-evaluation. We examine the extent to which typical adults have insight into their face recognition abilities across four experiments involving nearly 300 participants. The experiments used five tests of face recognition ability: two that tap into the ability to learn and recognize previously unfamiliar faces [the Cambridge Face Memory Test, CFMT; Duchaine, B., & Nakayama, K. (2006). The Cambridge Face Memory Test: Results for neurologically intact individuals and an investigation of its validity using inverted face stimuli and prosopagnosic participants. Neuropsychologia, 44(4), 576–585. doi:10.1016/j.neuropsychologia.2005.07.001; and a newly devised test based on the CFMT but where the study phases involve watching short movies rather than viewing static faces—the CFMT-Films] and three that tap face matching [Benton Facial Recognition Test, BFRT; Benton, A., Sivan, A., Hamsher, K., Varney, N., & Spreen, O. (1983). Contribution to neuropsychological assessment. New York: Oxford University Press; and two recently devised sequential face matching tests]. Self-reported ability was measured with the 15-item Kennerknecht et al. questionnaire [Kennerknecht, I., Ho, N. Y., & Wong, V. C. (2008). Prevalence of hereditary prosopagnosia (HPA) in Hong Kong Chinese population. American Journal of Medical Genetics Part A, 146A(22), 2863–2870. doi:10.1002/ajmg.a.32552]; two single-item questions assessing face recognition ability; and a new 77-item meta-cognition questionnaire. Overall, we find that adults with typical face recognition abilities have only modest insight into their ability to recognize faces on behavioural tests. In a fifth experiment, we assess self-reported face recognition ability in people with CP and find that some people who expect to

Focusing attention on a limited space within the environment allows us to concentrate our resources selectively on that location while ignoring the rest of the space. In this study we investigated how the deployment of the focal attention in foveal vision can be affected by task and stimuli specificity. In particular, we measured the cue-size effect in four experiments: shape detection (Experiment 1), shape discrimination (Experiment 2), letter detection (Experiment 3), and letter discrimination (Experiment 4). Our results highlight that, although the focal component can be elicited by different tasks (i.e., detection or discrimination) and by using different types of stimuli (i.e., shapes or letters), those effects interact with each other. Specifically, the effect of focal attention is more noticeable when letter stimuli are used in the case of a detection task, while no difference between letters and geometrical shapes is observed in the discrimination task. Furthermore, the analysis of the cue-size effect across the four experiments confirmed that the deployment of focal attention in foveal vision is mainly reflexive

The glare effect (GE) is an illusion in which a white region appears self-luminous when surrounded by linearly decreasing luminance ramps. It has been shown that the magnitude of the luminosity effect can be modulated by manipulating the luminance range of the gradients. In the present study we tested the thresholds for the GE on two groups of adults: young (20–30 years old) and elderly (60–75 years old). Purpose of our perspective study was to test the possibility of transforming the GE into a test that could easily measure thresholds for luminosity and discomfort glare. The Glare Effect Test (GET) consisted in 101 printed cards that differed from each other for the range of luminance ramps. Participants were assessed with GET and a battery of visual tests: visual acuity, contrast sensitivity, illusion of length perception, and Ishihara test. Specifically in the GET, participants were required to classify cards on the basis of two reference cards (solid black-no gradient; full range black to white gradient). PSEs of the GE show no correlation with the other visual tests, revealing a divergent validity. A significant difference between young and elderly was found: contrary to our original expectations, luminosity thresholds of GE for elderly were higher than those for young, suggesting a non-direct relationship between luminosity perception and discomfort glare.

Diagnosis of developmental or congenital prosopagnosia (CP) involves self-report of everyday face recognition difficulties, which are corroborated with poor performance on behavioural tests. This approach requires accurate self-evaluation. We examine the extent to which typical adults have insight into their face recognition abilities across four experiments involving nearly 300 participants. The experiments used five tests of face recognition ability: two that tap into the ability to learn and recognize previously unfamiliar faces [the Cambridge Face Memory Test, CFMT; Duchaine, B., & Nakayama, K. (2006). The Cambridge Face Memory Test: Results for neurologically intact individuals and an investigation of its validity using inverted face stimuli and prosopagnosic participants. Neuropsychologia, 44(4), 576–585. doi:10.1016/j.neuropsychologia.2005.07.001 and a newly devised test based on the CFMT but where the study phases involve watching short movies rather than viewing static faces—the CFMT-Films] and three that tap face matching [Benton Facial Recognition Test, BFRT; Benton, A., Sivan, A., Hamsher, K., Varney, N., & Spreen, O. (1983). Contribution to neuropsychological assessment. New York: Oxford University Press; and two recently devised sequential face matching tests]. Self-reported ability was measured with the 15-item Kennerknecht et al. questionnaire [Kennerknecht, I., Ho, N. Y., & Wong, V. C. (2008). Prevalence of hereditary prosopagnosia (HPA) in Hong Kong Chinese population. American Journal of Medical Genetics Part A, 146A(22), 2863–2870. doi:10.1002/ajmg.a.32552]; two single-item questions assessing face recognition ability; and a new 77-item meta-cognition questionnaire. Overall, we find that adults with typical face recognition abilities have only modest insight into their ability to recognize faces on behavioural tests. In a fifth experiment, we assess self-reported face recognition ability in people with CP and find that some people who expect to p

Congenital prosopagnosia consists of the failure to develop normal face recognition ability despite intact low-level perceptual and intellectual functioning, and in the context of normal exposure to faces throughout the individual’s life. Typically, these individuals are able to perceive facial stimuli as faces but fail to identify a face as familiar or unfamiliar and to identify it. Despite the large amount of studies that have investigated face recognition in individuals with typical development and in congenital prosopagnosics over the last twenty years, we are still far from a complete understanding of the mechanisms underlying typical and atypical face recognition, and some research questions are still open. For this reason, the present dissertation investigates some perceptual effects in individuals with a selective deficit in face recognition processing in order to reach a better understanding of what happens during a successful and unsuccessful face recognition process. In particular, by using a combination of behavioural and eye-tracking methods, I investigated whether the left perceptual bias and the self-face advantage are shown by individuals with congenital prosopagnosia and are truly face-specific or not. My results demonstrate that, whereas the left perceptual bias seems to characterize the recognition of unfamiliar faces in good recognizers, individuals with congenital prosopagnosia seem to show an opposite bias (i.e., a right perceptual bias) during the recognition of the self-face. Moreover, despite their face recognition impairment, congenital prosopagnosics consistently show high accuracy in recognizing their own face (i.e., a self-face advantage). Furthermore, some of the studies I conducted on the visual scanning strategies of this population demonstrated that the self-face advantage phenomenon is not associated with a different exploration of the face stimuli, suggesting that it could reflect a more general self-advantage and not be face-speci

The Benton Facial Recognition Test (BFRT) and Cambridge Face Memory Test (CFMT) are two of the most common tests used to assess face discrimination and recognition abilities and to identify individuals with prosopagnosia. However, recent studies highlighted that participant–stimulus match ethnicity, as much as gender, has to be taken into account in interpreting results from these tests. Here, in order to obtain more appropriate normative data for an Italian sample, the CFMT and BFRT were administered to a large cohort of young adults. We found that scores from the BFRT are not affected by participants’ gender and are only slightly affected by participant–stimulus ethnicity match, whereas both these factors seem to influence the scores of the CFMT. Moreover, the inclusion of a sample of individuals with suspected face recognition impairment allowed us to show that the use of more appropriate normative data can increase the BFRT efficacy in identifying individuals with face discrimination impairments; by contrast, the efficacy of the CFMT in classifying individuals with a face recognition deficit was confirmed. Finally, our data show that the lack of inversion effect (the difference between the total score of the upright and inverted versions of the CFMT) could be used as further index to assess congenital prosopagnosia. Overall, our results confirm the importance of having norms derived from controls with a similar experience of faces as the “potential” prosopagnosic individuals when assessing face recognition abilities.

Objective: The lack of inversion effect for face recognition in congenital prosopagnosia (CP) is consistent with the hypothesis of a failure in holistic processing. However, although CPs' abnormal gaze behavior for upright faces has already been demonstrated, neither their scanning strategy for inverted faces, nor the possibility that their abnormal gaze behavior with upright faces is because of reasons other than the holistic deficit have been investigated yet. Method: We recorded the eye movements of a congenital prosopagnosic and a control group during the encoding of unknown faces, objects, and flowers. Two types of stimuli (faces and objects) were presented upright and inverted. Results: CPs explored upright and inverted faces in the same way (i.e., similar number of fixations of the same duration and similarly distributed), whereas controls increased the number of fixations and their duration during the presentation of inverted faces. By contrast, the 2 groups showed a similar inversion effect during the encoding of objects. Finally, CPs showed anomalous exploration of within-class objects (i.e., flowers) and impairment in subordinate-level object discrimination. Conclusions: Our results demonstrate that: (a) CPs use the same part-based strategy in encoding both upright and inverted faces, suggesting a possible interpretation of the lack of inversion effect in this population; (b) CPs' lack of inversion effect is face-specific and does not affect objects

Diagnosis of developmental or congenital prosopagnosia (CP) involves self-report of everyday face recognition difficulties, which are corroborated with poor performance on behavioural tests. This approach requires accurate self-evaluation. We examine the extent to which typical adults have insight into their face recognition abilities across four experiments involving nearly 300 participants. The experiments used five tests of face recognition ability: two that tap into the ability to learn and recognize previously unfamiliar faces [the Cambridge Face Memory Test, CFMT; Duchaine, B., & Nakayama, K. (2006). The Cambridge Face Memory Test: Results for neurologically intact individuals and an investigation of its validity using inverted face stimuli and prosopagnosic participants. Neuropsychologia, 44(4), 576–585. doi:10.1016/j.neuropsychologia.2005.07.001; and a newly devised test based on the CFMT but where the study phases involve watching short movies rather than viewing static faces—the CFMT-Films] and three that tap face matching [Benton Facial Recognition Test, BFRT; Benton, A., Sivan, A., Hamsher, K., Varney, N., & Spreen, O. (1983). Contribution to neuropsychological assessment. New York: Oxford University Press; and two recently devised sequential face matching tests]. Self-reported ability was measured with the 15-item Kennerknecht et al. questionnaire [Kennerknecht, I., Ho, N. Y., & Wong, V. C. (2008). Prevalence of hereditary prosopagnosia (HPA) in Hong Kong Chinese population. American Journal of Medical Genetics Part A, 146A(22), 2863–2870. doi:10.1002/ajmg.a.32552]; two single-item questions assessing face recognition ability; and a new 77-item meta-cognition questionnaire. Overall, we find that adults with typical face recognition abilities have only modest insight into their ability to recognize faces on behavioural tests. In a fifth experiment, we assess self-reported face recognition ability in people with CP and find that some people who expect to