1,720,975 research outputs found
EEG indices of performance monitoring activity and error predictability: embodying the actions of an avatar in immersive virtual reality
No full textElectro-cortical signatures of performance errors are thought to indicate the need for top-down control. Mid-frontal Theta oscillatory activity (4-8Hz) is a well-established marker of committed or observed errors. By combining EEG and immersive virtual reality, we reported that observing errors in reach-to-grasp actions of an avatar seen from a first-person perspective elicited greater theta oscillations over fronto-central electrodes (Pavone et al., 2016). Previous studies on committed or observed errors used sequences of trials were erroneous actions were less frequent than correct actions (e.g. 30% vs 70%). Therefore, it was not possible to disentangle whether the activation of the performance system was due to error per se or to surprise/novelty effect associated with rare and less predictable events. To address this issue, we recorded the EEG signal of 20 participants observing correct or erroneous actions performed by an avatar. Importantly, at variance with Pavone et al, (2016) the proportion of erroneous vs correct actions was 70% vs 30%. The results show that observation of erroneous actions enhanced Theta power compared to correct actions. Our data suggest that error per se, and not its percentage of occurrence, triggered the activity of the performance monitoring system, likely with the aim of flexibly adapting actions to the challenges of the external environment
Predicting the fate of basketball throws: a psychophysics and EEG study in healthy and paraplegics athletes
No full textElite athletes can predict successful free shots more rapidly and accurately, with cues of
body kinematics, also reflected in their motor activation for successful and unsuccessful
shots (Aglioti et al., 2008). Psychophysics studies indicate that paraplegic athletes may
fine tune their ability to process pictures of body parts involved in the practiced sport
(Pernigo et al, 2012). Here we explored the behavioral and electrocortical
underpinnings of wheelchair athletes who predict the fate of throws to basket
performed by paraplegic athletes. Using EEG, we searched for the possible
electrocortical correlates of observing domain specific actions and predicting their
outcome. Expert wheelchair basketball (WCB) players with two levels of physical
movement capability were chosen (Points 1 and 4; former with most severe disability,
least trunk movement and latter with least severe disability, most trunk movement).
Thus far no study has focused on the AON modulation contingent upon expertise and
severity injury in people with body-brain somatosensory and motor disconnection.
10 athletes and 19 healthy participants observed free throw videos (“IN” – correct
movement execution; "OUT" – incorrect movement execution). They were asked to
predict the outcome of the shot which was occluded by a black screen. Preliminary
behavioral results highlight a significantly higher performance for the expert players to
detect the error in OUT shots, while the healthy subjects only were able to predict shot
outcomes at chance level. Furthermore, the players had significantly stronger P300
response compared to naïve healthy subjects over parietal electrodes, both for IN and
for OUT videos. Moreover, the P300 response was greater for Point 4 players, which are
not only experts, but also have a wider range of motor representations due to less
injury, compared to Point 1 players. This suggests that the P300 modulation might be a
correlate of motor expertise during action observation
Perceived Social Support and Well-Being of International Students at an Italian University
No full textThe present study aims at exploring international students’ well-being in relation to their perception of social support and dispersion of dependency on various resources. The participants were 139 international students at an Italian university who completed the WHO-5 Well-being Index, Symptom Checklist 90-R, Multidimensional Scale of Perceived Social Support, and Dependency Grids. The results show that higher well-being is correlated with higher support and lower distress and that higher dispersion of dependency was associated with higher perceived support. International students who seek professional psychological help also report lower well-being, higher distress, and fewer resources compared with those who do not seek psychological support. Further, coming from collectivist cultures (rather than individualist ones) as well as being a long-term (rather than short-term) student was mostly associated with higher distress and less perceived support. These results suggest that counseling services for international students should help them find new sources of social support
Effects of the social context on the neurophysiological correlates of observed error monitoring
No full textMonitoring the motor performance of others, including the correctness of their actions, is crucial for the human
behavior. However, while performance (and error) monitoring of the own actions has been studied extensively at
the neurophysiological level, the corresponding studies on monitoring of others’ errors are scarce, especially for
ecological actions. Moreover, the role of the context of the observed action has not been sufficiently explored. To
fill this gap, the present study investigated electroencephalographic (EEG) indices of error monitoring during
observation of images of interrupted reach-to-grasp actions in social (an object held in another person’s hand)
and non-social (an object placed on a table) contexts. Analysis in time- and time-frequency domain showed that,
at the level of conscious error awareness, there were no effects of the social context (observed error positivity was
present for erroneous actions in both contexts). However, the effects of the context were present at the level of
hand image processing: observing erroneous actions in the non-social context was related to larger occipito-
temporal N1 and theta activity, while in the social context this pattern was reversed, i.e., larger N1 and theta
activity were present for the correct actions. These results suggest that, in case of easily predictable ecological
actions, action correctness is processed as early as at the level of hand image perception, since the hand posture
conveys information about the action (e.g., motor intention). The social context of actions might make the
correct actions more salient, possibly through the saliency of the correctly achieved common goal
Cinquanta di questi giorni. Per pensare la sessualità del disabile intellettivo
No full textQuesto testo nasce come allegato del cortometraggio Cinquanta di questi giorni, scritto e diretto dai registi Matteo Maffesanti e Davide Pachera, con la mia supervisione scientifica, e prodotto da Paolo Filippini. Si tratta di una breve raccolta di brani tratti da autori esperti sui temi della sessualità in presenza di disabilità. La raccolta è preceduta da un mio capitolo che illustra come il DVD e il materiale antologico possano essere utilizzati per progettare percorsi di formazione mirata.
L'idea di produrre un cortometraggio sulla realtà e le problematiche del bisogno-diritto alla sessualità della persona con disabilità intellettiva nasce nel 2007 dall'incontro con il regista Matteo Maffesanti ed il suo gruppo di lavoro. Ricordo di avere apprezzato fin da subito la qualità dei cortometraggi realizzati da Maffesanti, per la delicatezza nell'approccio agli argomenti e l'intrinseca forza narrativa. All'inizio, ho provato a presentarne qualche spezzone agli studenti, durante le mie lezioni di Pedagogia speciale all'Università di Verona, per introdurre il tema della qualità della vita della persona con disabilità intellettiva. Ben presto mi sono accorto che tale scelta didattica, oltre a riscuotere un generale interesse verso gli argomenti trattati, aveva importanti ricadute anche sul piano degli apprendimenti. Infatti, come ho potuto constatare in sede d'esame, diversi studenti presenti alle proiezioni, nel rispondere ai miei quesiti, utilizzavano (in forme più o meno consapevoli) i contenuti dei cortometraggi per dare un volto ed una concretezza ai concetti presenti nei testi di studio. Tale fenomeno, che dapprima mi ha solo incuriosito, mi ha portato poi a ritenere che avrei potuto utilizzare, in forme più approfondite, lo "strumento" cortometraggio per migliorare l'azione didattica. Premetto che nel passato avevo già notato che la proiezione di spezzoni di film riguardanti la disabilità, aveva provocato negli studenti maggior interesse verso i temi e le problematiche trattate, attivando in più occasioni disponibilità al confronto e alla discussione. La forma del cortometraggio, però, mi dava l'impressione di porsi al servizio della discussione e della rielaborazione critica dei contenuti mediati in modo ancor più efficace, in quanto è proprio la brevità della storia (in sè conclusa) che consente di mantenere il fuoco dell'attenzione sull'aspetto particolare della realtà narrata.
Nel costruire le lezioni ho chiesto al regista di presentare il suo lavoro e di esplicitare le motivazioni che lo avevano spinto ad affrontare determinate problematiche sociali. L'incontro con Maffesanti, seguito dalla proiezione del cortometraggio, ha avuto il merito di generare una riflessione, una discussione e un confronto costruttivo con gli studenti. In particolare, si è potuta cogliere nei ragazzi una progressiva presa di coscienza che la disabilità non è un "mondo a parte" lontano dal proprio, costituito da una "categoria" di esseri umani "diversi" dagli altri, oggetto di azioni per lo più assistenziali e di solidarietà umana. Tale presa di coscienza si è evidenziata nella generale considerazione che il "fenomeno disabilità" si può declinare non solo nelle forme del pietismo o della rassegnata presa d'atto dell'esistenza di esseri umani "meno fortunati di altri", ma si coniuga correttamente anche con pensieri intelligenti e - soprattutto - interessanti, con azioni sociali creative, con approfondimenti culturali capaci di abbracciare e dare significato a tutte le dimensioni dell'umano.
Queste e altre considerazioni mi hanno portato a costituire un gruppo di lavoro per la produzione del cortometraggio dedicato al delicato tema della sessualità e della disabilità intellettiva, allo scopo di offrie uno strumento da utilizzare in contesti formativi, per la costruzione di percorsi didattici e culturali di approfondimento sulla disabilità intellettiva
Age differences in sustained attention tasks: A meta-analysis
Full text linkMany aspects of attention decline with aging. There is a current debate on how aging also affects sustained attention. In this study, we contribute to this debate by meta-analytically comparing performance on the go/no-go Sustained Attention to Response Task (SART) in younger and older adults. We included only studies in which the SART had a low proportion of no-go trials (5%–30%), there was a random or quasirandom stimulus presentation, and data on both healthy younger and older adults were available. A total of 12 studies were suitable with 832 younger adults and 690 older adults. Results showed that older adults were slower than younger adults on go trials (g = 1, 95% CI [.72, 1.27]) and more accurate than younger adults on no-go trials (g = .59, 95% CI [.32, .85]). Moreover, older adults were slower after a no-go error than younger adults (g = .79, 95% CI [.60, .99]). These results are compatible with an age-related processing speed deficit, mostly suggested by longer go RTs, but also with an increased preference for a prudent strategy, as demonstrated by fewer no-go errors and greater posterror slowing in older adults. An inhibitory deficit account could not explain these findings, as older adults actually outperformed younger adults by producing fewer false alarms to no-go stimuli. These findings point to a more prudent strategy when using attentional resources in aging that allows reducing the false-alarm rate in tasks producing a tendency for automatic responding
Trial-by-trial fluctuations of pre-stimulus alpha power predict language ERPs
No full textAnticipatory mechanisms are known to play a key role in language, but they have been mostly investigated with violation paradigms, which only consider what happens after predictions have been (dis)confirmed. Relatively few studies focused on the pre-stimulus interval and found that stronger expectations are associated with lower pre-stimulus alpha power. However, alpha power also fluctuates spontaneously, in the absence of experimental manipulations; and in the attention and perception domains, spontaneously low pre-stimulus power is associated with better behavioral performance and with event-related potential (ERPs) with shorter latencies and higher amplitudes. Importantly, little is known about the role of alpha fluctuations in other domains, as it is in language. To this aim, we investigated whether spontaneous fluctuations in pre-stimulus alpha power modulate language-related ERPs in a semantic congruence task. Electrophysiology data were analyzed using Generalized Additive Mixed Models to model nonlinear interactions between pre-stimulus alpha power and EEG amplitude, at the single-trial level. We found that the N400 and the late posterior positivity/P600 were larger in the case of lower pre-stimulus alpha power. Still, while the N400 was observable regardless of the level of pre-stimulus power, a late posterior positivity/P600 effect was only observable for low pre-stimulus alpha power. We discuss these findings in light of the different, albeit connected, functional interpretations of pre-stimulus alpha and the ERPs according to both a nonpredictive interpretation focused on attentional mechanisms and under a predictive processing framework
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Brain Dynamics of Action Monitoring in Higher-Order Motor Control Disorders: The Case of Apraxia
Full text linkLimb apraxia (LA) refers to a high-order motor disorder characterized by the inability to reproduce transitive actions on commands or after observation. Studies demonstrate that action observation and action execution activate the same networks in the human brain, and provides an onlooker's motor system with appropriate cognitive, motor and sensory-motor cues to flexibly implementing action-sequences and gestures. Tellingly, the temporal dynamics of action monitoring has never been explored in people suffering from LA. To fill this gap, we studied the electro-cortical signatures of error observation in human participants suffering from acquired left-brain lesions with (LA+) and without (LA-) LA, and in a group of healthy controls (H). EEG was acquired while participants observed from a first-person perspective (1PP) an avatar performing correct or incorrect reach-to-grasp a glass action in an immersive-virtual environment. Alterations of typical EEG signatures of error observation in time (early error positivity; Pe) and time-frequency domain (theta band-power) were found reduced in LA+ compared with H. Connectivity analyses showed that LA+ exhibited a decreased theta phase synchronization of both the frontoparietal and frontofrontal network, compared with H and LA-. Moreover, linear regression analysis revealed that the severity of LA [test of upper LA (TULIA) scores] was predicted by mid-frontal error-related theta activity, suggesting a link between error monitoring capacity and apraxic phenotypes. These results provide novel neurophysiological evidence of altered neurophysiological dynamics of action monitoring in individuals with LA and shed light on the performance monitoring changes occurring in this disorder
- …
