353 research outputs found

    Age-related effects on spatial memory across viewpoint changes relative to different reference frames

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    Remembering object positions across different views is a fundamental competence for acting and moving appropriately in a large-scale space. Behavioural and neurological changes in elderly subjects suggest that the spatial representations of the environment might decline compared to young participants. However, no data are available on the use of different reference frames within topographical space in aging. Here we investigated the use of allocentric and egocentric frames in aging, by asking young and older participants to encode the location of a target in a virtual room relative either to stable features of the room (allocentric environment-based frame), or to an unstable objects set (allocentric objects-based frame), or to the viewer's viewpoint (egocentric frame). After a viewpoint change of 0,circ,^{circ} (absent), 45,circ,^{circ} (small) or 135,circ,^{circ} (large), participants judged whether the target was in the same spatial position as before relative to one of the three frames. Results revealed a different susceptibility to viewpoint changes in older than young participants. Importantly, we detected a worst performance, in terms of reaction times, for older than young participants in the allocentric frames. The deficit was more marked for the environment-based frame, for which a lower sensitivity was revealed as well as a worst performance even when no viewpoint change occurred. Our data provide new evidence of a greater vulnerability of the allocentric, in particular environment-based, spatial coding with aging, in line with the retrogenesis theory according to which cognitive changes in aging reverse the sequence of acquisition in mental development

    How watching Pinocchio movies changes our subjective experience of extrapersonal space

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    The way we experience the space around us is highly subjective. It has been shown that motion potentialities that are intrinsic to our body influence our space categorization. Furthermore, we have recently demonstrated that in the extrapersonal space, our categorization also depends on the movement potential of other agents. When we have to categorize the space as "Near" or "Far" between a reference and a target, the space categorized as "Near" is wider if the reference corresponds to a biological agent that has the potential to walk, instead of a biological and non-biological agent that cannot walk. But what exactly drives this "Near space extension"? In the present paper, we tested whether abstract beliefs about the biological nature of an agent determine how we categorize the space between the agent and an object. Participants were asked to first read a Pinocchio story and watch a correspondent video in which Pinocchio acts like a real human, in order to become more transported into the initial story. Then they had to categorize the location ("Near" or "Far") of a target object located at progressively increasing or decreasing distances from a non-biological agent (i.e., a wooden dummy) and from a biological agent (i.e., a human-like avatar). The results indicate that being transported into the Pinocchio story, induces an equal "Near" space threshold with both the avatar and the wooden dummy as reference frames

    Investigating the relationship between interoceptive accuracy, interoceptive awareness, and emotional susceptibility

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    Interoception, the sense of the physiological condition of the body, provides a basis for subjective feelings and emotions. Anterior insular cortex activity represents the state of the body and varies according to personality traits, such as emotional susceptibility (ES)-the tendency to experience feelings of discomfort and vulnerability when facing emotionally-laden stimuli. The accuracy of perceiving one's own bodily signals, or interoceptive accuracy (IAc), can be assessed with the heartbeat perception task (HPT), which is the experimental measure used by most of the existing research on interoception. However, IAc is only one facet of interoception. Interoceptive awareness (IAw) is the conscious perception of sensations from inside the body, such as heart beat, respiration, satiety, and the autonomic nervous system sensations related to emotions, which create the sense of the physiological condition of the body. We developed an Italian version of the recent self-report Multidimensional Assessment of Interoceptive Awareness (MAIA), tested its psychometric properties (reliability, dimensionality, and construct validity), and examined its relationship to ES, as assessed using the Emotional Susceptibility Scale, in a sample (n = 321) of healthy Italian psychology students (293 females, mean age: 20.5 years). In a subgroup of females (n = 135), we measured IAc with the HPT. We used a series of correlation/regression analyses to examine the complex interplay between the three constructs. We provide further evidence for a substantial independence of the IAc and IAw measures, confirming previous reports and current theoretical models that differentiate between IAc and IAw. Our analyses elucidate the complex relationship between distinct dimensions of IAw and ES, highlighting the need for continued efforts to shed more light on this topic

    Resting-state connectivity and functional specialization in human medial parieto-occipital cortex

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    According to recent models of visuo-spatial processing, the medial parieto-occipital cortex is a crucial node of the dorsal visual stream. Evidence from neurophysiological studies in monkeys has indicated that the parieto-occipital sulcus (POS) contains three functionally and cytoarchitectonically distinct areas: the visual area V6 in the fundus of the POS, and the visuo-motor areas V6Av and V6Ad in a progressively dorsal and anterior location with respect to V6. Besides different topographical organization, cytoarchitectonics, and functional properties, these three monkey areas can also be distinguished based on their patterns of cortico-cortical connections. Thanks to wide-field retinotopic mapping, areas V6 and V6Av have been also mapped in the human brain. Here, using a combined approach of resting-state functional connectivity and task-evoked activity by fMRI, we identified a new region in the anterior POS showing a pattern of functional properties and cortical connections that suggests a homology with the monkey area V6Ad. In addition, we observed distinct patterns of cortical connections associated with the human V6 and V6Av which are remarkably consistent with those showed by the anatomical tracing studies in the corresponding monkey areas. Consistent with recent models on visuo-spatial processing, our findings demonstrate a gradient of functional specialization and cortical connections within the human POS, with more posterior regions primarily dedicated to the analysis of visual attributes useful for spatial navigation and more anterior regions primarily dedicated to analyses of spatial information relevant for goal-directed action

    Causal topography of visual cortex in perceptual learning.

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    Individuals are able to improve their visual skill with practice, a phenomenon called Visual Perceptual Learning (VPL). We previously observed that after training on a difficult shape identification task, the dorsal visual regions (i.e. right V2d/V3 and right lateral occipital, LO) corresponding to the trained visual quadrant, and their homologous in the opposite hemisphere, exhibited a selective activation at the end of the learning. By contrast, such modulation was not observed in the ventral visual regions, corresponding to the untrained quadrants. The causal role of the trained visual cortex was previously showed in a TMS study as its inactivation impaired behavioral performance to learned stimuli. Here, using the same experimental design, we employed TMS over the homologous of the trained area (i.e. left V2d/V3) as well as over the untrained region (i.e. right V4) to causally map the visual network during the perceptual learning. We report a decrease of accuracy after TMS over left V2d/V3 as compared to both right V4 and Sham (inactive stimulation) conditions. Importantly, TMS effect was correlated with the degree of learning, such that subjects with lower accuracy at the end of the training exhibited stronger TMS impairment. These results provide evidence that segregated regions within the visual network are causally involved in visual perceptual learning

    Selective effects of a brain tumor on the metric representation of the hand: a pre- versus post-surgery comparison

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    Body representation disorders are complex, varied, striking and very incapacitating in most cases. Deficits of body representation have been described after lesions to multimodal and sensorimotor cortical areas. A few studies have reported the effects of tumors on the representation of the body, but little is known about the changes after tumor resection. Moreover, impact of brain lesions on the hand size representation has been investigated in few clinical cases. Hands are of special importance as no other body part has the ability for movement and interaction with the environment that the hands have, and we use them for a multitude of daily activities Studies with clinical population can add further knowledge into the way hands are represented. Here, we report a single case study of a patient (AM) who was an expert bodybuilder and underwent a surgery to remove a glioblastoma in the left posterior prefrontal and precentral cortex at the level of the hand’s motor region. Pre- (20 days) and post- (4 months) surgery assessment did not show any motor or cognitive impairments. A hand localization task was used, before and after surgery (12 months), to measure possible changes of the metric representation of his right hand. Results showed a modulation on the hand representation with an overall improvement after the surgery in the accuracy of the hand representation, especially on width dimension. These findings support the direct involvement of sensorimotor areas in the implicit representation of the body size and its relevance on defining specific size representation dimensions

    Concreteness and emotional valence of episodic future thinking (EFT) independently affect the dynamics of intertemporal decisions

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    During intertemporal decisions, the value of future rewards decreases as a function of the delay of its receipt (temporal discounting, TD). Since high discount rates have been associated with a series of problematic behaviours and clinical conditions, current research has focused on possible modulators of TD. Specifically, a reduction of individual discount rates has been shown during episodic future thinking (EFT), wherein time intervals are anchored to personal future events. However, it is not entirely clear whether this effect is mediated by a change in the representation of future events (i.e., from abstract to concrete) or by a positive-emotion modulation. Here, we investigated this issue by manipulating the valence of the EFT (i.e., using negative, neutral and positive episodic tags), and by collecting explicit and implicit measures of behaviour. The results showed a significant reduction of TD in all the three emotional conditions compared to the baseline, with differences among them, thus suggesting the existence of a cumulative effect of the concreteness and affective components of the EFT. The analyses of implicit measures additionally revealed that this effect was mediated by a simultaneous increase/decrease of attraction toward the delayed/immediate alternative. Finally, these effects appeared to be modulated by participants' baseline discounting preferences. These findings provide important insights on clinical applications in reward-related disorders

    Investire in Italia? Risultati di una recente indagine empirica

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    During the past decade all industrial countries attracted sizeable inflows of foreign direct investment (FDI), excluding Italy and Japan: this fact has been interpreted as evidencing a deterioration in Italy’s structural competitiveness. This paper presents the results of a survey conducted by the Bank of Italy through its net of foreign representative offices, aimed at identifying the main factors that influenced the country’s attractiveness of FDI in the most recent years. The first section contains a brief survey of the literature on factors of attraction and obstacles to FDI. Italy’s position vis-à-vis other advanced countries is examined in the light of a wide variety of indicators: these latter include macroeconomic, qualitative and structural variables gathered from various sources (as well as other indicators expressly built for this paper), which are meant to outline circumstances relevant to different FDI strategies (“horizontal”, “vertical”, and “regional”). Italy enjoys two major “localization advantages”, namely, (1) a large, although somewhat stagnant domestic market, and (2) low unit labor costs, comparable to those prevailing in other “peripheral” European countries such as Spain, Portugal and Greece. In the backdrop of a general improvement of Italy’s qualitative and institutional indicators in recent years, one of the major obstacles to FDI in Italy pertains to the continuing low quality of its transport and product distribution infrastructures–a circumstance that cannot alone explain the very low level of FDI inflows. Another major impediment is represented by the dominance of small- and medium-sized enterprises in the Italian industry. On the one hand, this dimensional factor has been associated with the diffusion of ownership structures hostile to foreign mergers and acquisitions (M&A, the prevailing type of FDI in recent years); on the other hand, it may have clashed with the preferences of international investors, which are skewed towards the acquisition of medium- and large-sized enterprises. In either way, this circumstance may have strengthened the negative effects of “environmental barriers” that remain elevated anyhow in our country. The results of the survey are presented in the second section. The survey confirms some of the country’s improvements mentioned earlier; however, it also confirms the perception, on the part of foreign investors, of continuing institutional and structural backwardness, as well as the importance attached by these investors to such factors while formulating their investment plans.investimenti diretti e loro determinanti, fusioni e acquisizioni internazionali, competitivita' strutturale

    Effects of Individual Discount Rate and Uncertainty Perception on Compliance with Containment Measures during the COVID-19 Pandemic

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    5noopenAnti-contagion measures restricting individual freedom, such as social distancing and wearing a mask, are crucial to contain the COVID-19 pandemic. Decision-making patterns and attitudes about uncertainty can highly influence the adherence to these restrictive measures. Here we investigated the relationship between risky behavior and individual preferences for immediate vs. delayed reward, as indexed by temporal discounting (TD), as well as the association between these measures and confidence in the future, perceived risk and confidence in the containment measures. These measures were collected through an online survey administered on 353 participants at the end of the more restrictive phase of the first Italian lockdown. The results showed an unexpected inverse relationship between the individual pattern of choice preferences and risky behavior, with an overall greater adherence to containment measures in more discounter participants. These findings were interpreted in terms of a reframing process in which behaviors aimed at protecting oneself from contagion turn into immediate gains rather than losses. Interestingly, an excessive confidence in a better future was correlated with a higher tendency to assume risky behavior, thereby highlighting the downside of an overly and blindly optimistic view.openCalluso, Cinzia; Grande, Eleonora; Erario, Alessia; Tosoni, Annalisa; Committeri, GiorgiaCalluso, Cinzia; Grande, Eleonora; Erario, Alessia; Tosoni, Annalisa; Committeri, Giorgi

    Interindividual variability in functional connectivity as long-term correlate of temporal discounting

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    During intertemporal choice (IT) future outcomes are usually devaluated as a function of the delay, a phenomenon known as temporal discounting (TD). Based on task-evoked activity, previous neuroimaging studies have described several networks associated with TD. However, given its relevance for several disorders, a critical challenge is to define a specific neural marker able to predict TD independently of task execution. To this aim, we used restingstate functional connectivity MRI (fcMRI) and measured TD during economic choices several months apart in 25 human subjects.We further explored the relationship between TD, impulsivity and decision uncertainty by collecting standard questionnaires on individual trait/ state differences. Our findings indicate that fcMRI within and between critical nodes of taskevoked neural networks associated with TD correlates with discounting behavior measured a long time afterwards, independently of impulsivity. Importantly, the nodes form an intrinsic circuit that might support all the mechanisms underlying TD, from the representation of subjective value to choice selection through modulatory effects of cognitive control and episodic prospection
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