1,249 research outputs found
Peripersonal space representation in the first year of life: a behavioural and electroencephalographic investigation of the perception of unimodal and multimodal events taking place in the space surrounding the body
Full text linkIn my PhD research project, I wanted to investigate infants’ representation of the peripersonal space, which is the portion of environment between the self and the others. In the last three decades research provided evidence on newborns’ and infants’ perception of their own bodies and of other individuals, whereas not many studies investigated infants’ perception of the portion of space where they can interact with both others and objects, namely the peripersonal space. Considering the importance of the peripersonal space, especially in light of its defensive and interactive functions, I decided to investigate the development of its representation focusing on two aspects. On one side, I wanted to study how newborns and infants processed the space around them, if they differentiated between near and far space, possibly perceiving and integrating depth cues across sensory modalities and when and how they started to respond to different movements occurring in the space surrounding their bodies. On the other side, I was interested in understanding whether already at birth the peripersonal space could be considered as a delimited portion of space with special characteristics and, relatedly, if its boundaries could be determined. In order to respond to my first question, I investigated newborns’ and infants’ looking behaviour in response to visual and audio-visual stimuli depicting different trajectories taking place in the space immediately surrounding their body. Taken together, the results of these studies demonstrated that humans show, since the earliest stages of their development, a rudimentary processing of the space surrounding them. Newborns seemed, in fact, to already differentiate the space around them, through an efficient discrimination of different moving trajectories and a visual preference for those directed towards their own body, possibly due to their higher adaptive relevance. They also seemed to integrate multimodal, audio-visual information about stimuli moving in the near space, showing a facilitated processing of congruent audio-visual approaching stimuli. Furthermore, the results of these studies could help understand the development of the integration of multimodal stimuli with an adaptive valence during infancy. When newborns’ and infants were presented with unimodal, visual stimuli, they all directed their visual preferences to the stimuli moving towards their bodies. Conversely, their pattern of looking times was more complex when they were presented with congruent and incongruent audiovisual stimuli. Right after birth infants showed a spontaneous visual preference for congruent audio-visual stimuli, which was challenged by a similarly strong visual preference for adaptively important visual stimuli moving towards their bodies. The looking behaviours of 5-month-old infants, instead, seemed to be driven only by a spontaneous preference for multimodal congruent stimuli, i.e. depicting motion along the same trajectory, irrespective of the adaptive value of the information conveyed by either of the two sensory components of the stimulus. Nine-month-old infants, finally, seemed to flexibly integrate multisensory integration principles with the necessity of directing their attention to ethologically salient stimuli, as shown by the fact that their visual preference for unexpected, incongruent audio-visual stimuli was challenged by the simultaneous presence of adaptively relevant stimuli. Similarly to what happened with newborns, presenting 9-month-old infants with the two categories of preferred stimuli simultaneously led to the absence of a visual preference. Within my project I also investigated the electroencephalographic correlates of the processing of unimodal, visual and auditory, stimuli depicting different trajectories in a sample of 5-month-old infants. The results seemed to provide evidence in support of the role of the primary sensory cortices in the processing of crossmodal stimuli. Furthermore, they seemed to support the possibility that infants’ brain could allocate, already during the earliest stages of processing, different amounts of attention to stimuli with different adaptive valence. Two further studies addressed my second question, namely whether already at birth the peripersonal space could be considered as a delimited portion of space with special characteristics and if its boundaries could be determined. In these studies I measured newborns’ saccadic reaction times (RTs) to tactile stimuli presented simultaneously to a sound perceived at different distances from their body. The results showed that newborns’ RTs were modulated by the perceived position of the sound and that their modulation was very similar to that shown by adults, suggesting that the boundary of newborns’ peripersonal space could be identified in the perceived sound position in whose correspondence the drop of RTs happened. This suggested that at birth the space immediately surrounding the body seems to be already invested of a special salience and characterised by a more efficient integration of multimodal stimuli. As a consequence, it might be considered as a rudimentary representation of the peripersonal space, possibly serving, as a working space representation, early interactions between newly born humans and their environment. Overall, these findings provide a first understanding of how humans start to process the space surrounding them, which, importantly, is the space linking them with others and the space where their first interactions will take place
Multisensory perception of looming and receding objects in human newborns
Full text linkWhen newborns leave the enclosed spatial environment of the uterus and arrive in the outside world, they are faced with a new audiovisual environment of dynamic objects, actions and events both close to themselves and further away. One particular challenge concerns matching and making sense of the visual and auditory cues specifying object motion [1-5]. Previous research shows that adults prioritise the integration of auditory and visual information indicating looming (for example [2]) and that rhesus monkeys can integrate multisensory looming, but not receding, audiovisual stimuli [4]. Despite the clear adaptive value of correctly perceiving motion towards or away from the self - for defence against and physical interaction with moving objects - such a perceptual ability would clearly be undermined if newborns were unable to correctly match the auditory and visual cues to such motion. This multisensory perceptual skill has scarcely been studied in human ontogeny. Here we report that newborns only a few hours old are sensitive to matches between changes in visual size and in auditory intensity. This early multisensory competence demonstrates that, rather than being entirely naïve to their new audiovisual environment, newborns can make sense of the multisensory cue combinations specifying motion with respect to themselves
Identifying peripersonal space boundaries in newborns
Full text linkPeripersonal space immediately surrounds the body and can be represented in the brain as a multisensory and sensorimotor interface mediating physical and social interactions between body and environment. Very little consideration has been given to the ontogeny of peripersonal spatial representations in early postnatal life, despite the crucial roles of peripersonal space and its adaptive relevance as the space where infants’ earliest interactions take place. Here, we investigated whether peripersonal space could be considered a delimited portion of space with defined boundaries soon after birth. Our findings showed for the first time that newborns’ saccadic reaction times to a tactile stimulus simultaneous to sounds with different intensities changed based on the sound intensity. In particular, they were significantly faster when the sound was lounder than a critical intensity, in a pattern that closely resembled that showed by adults. Therefore, provided that sound intensity on its own can cue newborns’ sound distance perception, we speculate that this critical distance could be considered the boundary of newborns’ rudimentary peripersonal space. Altogether, our findings suggest that soon after birth peripersonal space may be already considered as a bounded portion of space, perhaps instrumental to drive newborns’ attention towards events and people within it
1485-1490, Pietro di Francesco Orioli, Florence, Galleria Moretti (NH 908)
No full textDate 1485-90 Peintre Pietro di Francesco Orioli Dates/activité 1480s 1490s Formation amont/aval Formé dans l’atelier de Matteo di Giovanni, puis auprès de Francesco di Giorgio Martini Lieu de conservation Florence, Galleria Moretti Dimensions 74,3 x 51 c
Giulia Veronica Varisco
No full textThe headword explains the biography and the contribution of the author Giulia Varisco to the children's literatur
Neural correlates of tactile expectation in infancy
No full textAs adults, we can accurately predict the timing and location of an impending touch specified by a looming visual object (Clery et al., 2015, Kandula et al., 2015). The developmental origins of this adaptively important ability, likely underpinned by multisensory neurons representing peripersonal space, have not yet been investigated. To address this, we presented 4-, 8- and 10-month- old infants with visual stimuli either looming towards their hands or receding towards the background, followed by a brief tactile stimulus delivered on their hands at the expected time-to-contact of the visual looming stimulus. We recorded infants’ spontaneous brain activity during the stimulus presentation using scalp electroencephalography (EEG) and we measured their somatosensory evoked potentials (SEPs) in response to the touches. Preliminary results suggest that already at 4 months of life the tactile stimuli that have been preceded by a visual looming stimulus (i.e. anticipated touches) are processed differently from those that have been preceded by a visual receding stimulus. In particular, the SEPs showed a consistently larger amplitude of the potential in response to the anticipated vs non anticipated touches. However, this difference seems to disappear at 8 and 10 months of life. More complete results will be presented and discussed
Sudden sensorineural hearing loss and polymorphisms in iron homeostasis genes: New insights from a case-control study
Full text linkBackground. Even if various pathophysiological events have been proposed as explanations, the putative cause of sudden hearing loss remains unclear. Objectives. To investigate and to reveal associations (if any) between the main iron-related gene variants and idiopathic sudden sensorineural hearing loss. Study Design. Case-control study. Materials and Methods. A total of 200 sudden sensorineural hearing loss patients (median age 63.65 years; range 10-92) were compared with 400 healthy control subjects. The following genetic variants were investigated: the polymorphism c.-8CG in the promoter of the ferroportin gene (FPN1; SLC40A1), the two isoforms C1 and C2 (p.P570S) of the transferrin protein (TF), the amino acidic substitutions p.H63D and p.C282Y in the hereditary hemochromatosis protein (HFE), and the polymorphism c.-582AG in the promoter of the HEPC gene, which encodes the protein hepcidin (HAMP). Results. The homozygous genotype c.-8GG of the SLC40A1 gene revealed an OR for ISSNHL risk of 4.27 (CI 95%, 2.65-6.89; P = 0.001), being overrepresented among cases. Conclusions. Our study indicates that the homozygous genotype FPN1 -8GG was significantly associated with increased risk of developing sudden hearing loss. These findings suggest new research should be conducted in the field of iron homeostasis in the inner ear
Trajectory Discrimination and Peripersonal Space Perception in Newborns
Full text linkThe ability to discriminate the trajectories of moving objects is highly adaptive and fundamental for physical and social interactions. Therefore, we could reasonably expect sensitivity to different trajectories already at birth, as a precursor of later communicative and defensive abilities. To investigate this possibility, we measured newborns' looking behavior to evaluate their ability to discriminate between visual stimuli depicting motion along different trajectories happening within the space surrounding their body. Differently from previous studies, we did not take into account defensive reactions, which may not be elicited by impending collision as newborns might not categorize approaching stimuli as possible dangers. In two experiments, we showed that newborns display a spontaneous visual preference for trajectories directed toward their body. We found this visual preference when visual stimuli depicted motion in opposite directions (approaching vs. receding) as well as when they both moved toward the peripersonal space and differed only in their specific target (i.e., the body vs. the space around it). These findings suggest that at birth human infants seem to be already equipped with visual mechanisms predisposing them to perceive their presence in the environment and to adaptively focus their attention on the peripersonal space and their bodily self
Dihydrofolate reductase (DHFR) 19-bp ins/del polymorphism and methylenetetrahydrofolate reductase (MTHFR) C677T in coronary heart disease patients: potential intracellular folate unbalancing.
No full textElevated homocysteine (Hcy) due to common gene variants is correlated with coronary heart disease (CHD), but definite causality remains uncertain. Hcy increases due to genetic and environment interactions. Assuming no direct effects of folate on CHD except via increased Hcy, and that folate drives Hcy metabolism, investigating on how genes influence folate balancing is strongly useful. DHFR and MTHFR fully activate diet folate. Common polymorphisms influence activity/level of enzymes. MTHFR677TT reduces enzyme efficiency yielding ~20% higher Hcy. Less definitive is the role ascribed to DHFR 19bp ins/del; some authors reported ~50% higher mRNA in del/del genotype. We selected 14 CHD patients from our Center carrying opposite DHFR/MTHFR genotypes. We hypothesized that patients (n=7) carrying both polymorphisms in homozygous condition (DHFRdel/del and MTHFR677TT) might have different folate status and respond differently, than double wildtypes (n=7), under controlled in vitro folate levels. So, we put whole blood in culture (t0, t48, t96-120 hours) containing 10ng/ml folate. DD/TT patients had significant lower basal folate levels (plasma and RBC) versus wildtypes. Interestingly, in vitro culture showed DD/TT genotype rapidly gained folate stores, to completely cancel the gap at ~96h. These results are partially in contrast with previous reports in which DHFR properties were tested without consider MTHFR, and strongly advice to analyze these two common variants before ascribing disease risk and public health implications
Osmosis Theme Park: piano per la rigenerazione urbana della ex discarica di Küçükçekmece ad Istanbul
No full textQuesta tesi di laurea nasce dall’approfondimento del progetto che abbiamo sviluppato nel laboratorio di progettazione architettonica frequentato presso la Middle East Technical University, METU, di Ankara, Turchia, durante l’anno accademico 2011-12.
La prima parte del corso, tenuto dai professori S. Özkan e Z. Mennan, consisteva nello studio e analisi critica dei progetti in concorso per il bando “Istanbul Theme Park” e nella riproposizione, da presentare a gruppi, di uno dei masterplan studiati, con le modifiche ritenute necessarie a fronte delle considerazioni fatte e di nuove idee progettuali.
Lo step successivo è stato quello di approfondire individualmente la progettazione architettonica di un area di almeno 100.000 mq in scala 1:500 e di un edificio in dettaglio 1:200.
Date le tempistiche molto ridotte del corso, che si completava in tredici settimane, abbiamo scelto di continuare il lavoro e approfondire, con l’aiuto della prof.ssa V. Orioli e dell’arch. E. Brighi, l’elaborazione del masterplan arrivando ad una definizione maggiore di tutta l’area e non solamente delle aree di interesse approfondite durante la permanenza in Turchia.
Il progetto presentato è quindi il frutto di un anno di lavoro sulla riqualificazione di un area di 150 ettari precedentemente adibita a discarica, situata nella parte occidentale di Istanbul.
L’obiettivo che abbiamo perseguito è stato quello di ricreare nella periferia della metropoli turca uno stralcio di città con caratteri più “europei”, comprendendo in un solo grande ambito di progetto tutte le funzioni necessarie alla vita di un quartiere cittadino ma anche le grandi strutture attrattive richieste dal concorso. Durante il nostro percorso abbiamo cercato anche di non perdere di vista il contesto in cui lavoravamo e le abitudini della società turca con cui ci andavamo a confrontare.
Nonostante la forte occidentalizzazione delle zone ricche delle grandi città come Istanbul, Ankara e Izmir, gli stili di vita europeo e turco sono fondamentalmente differenti e progettare una città, o uno stralcio di essa, per un popolo diverso necessita la conoscenza dei suoi valori fondamentali e delle abitudini che ne scandiscono le giornate
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