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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.