Search

How is music perceived by cochlear implant (CI) users? This question arises as "the next step" given the impressive performance obtained by these patients in language perception. Furthermore, how can music perception be evaluated beyond self-report rating, in order to obtain measurable data? To address this question, estimation of the frontal electroencephalographic (EEG) alpha activity imbalance, acquired through a 19-channel EEG cap, appears to be a suitable instrument to measure the approach/withdrawal (AW index) reaction to external stimuli. Specifically, a greater value of AW indicates an increased propensity to stimulus approach, and vice versa a lower one a tendency to withdraw from the stimulus. Additionally, due to prelingually and postlingually deafened pathology acquisition, children and adults, respectively, would probably differ in music perception. The aim of the present study was to investigate children and adult CI users, in unilateral (UCI) and bilateral (BCI) implantation conditions, during three experimental situations of music exposure (normal, distorted and mute). Additionally, a study of functional connectivity patterns within cerebral networks was performed to investigate functioning patterns in different experimental populations. As a general result, congruency among patterns between BCI patients and control (CTRL) subjects was seen, characterised by lowest values for the distorted condition (vs. normal and mute conditions) in the AW index and in the connectivity analysis. Additionally, the normal and distorted conditions were significantly different in CI and CTRL adults, and in CTRL children, but not in CI children. These results suggest a higher capacity of discrimination and approach motivation towards normal music in CTRL and BCI subjects, but not for UCI patients. Therefore, for perception of music CTRL and BCI participants appear more similar than UCI subjects, as estimated by measurable and not self-reported parameters.Asimmetria nell’attività cerebrale frontale come parametro efficace della qualità percettiva degli stimoli audiovisivi in portatori di impianto cocleare giovani e adulti.Come è percepita la musica dai portatori di impianto cocleare (CI)? Questa domanda sorge come la “prossima sfida”, date le impressionanti prestazioni ottenute da questi pazienti nella percezione del linguaggio. Inoltre, come valutare la percezione della musica oltre il dichiarato verbale, così da ottenere dati misurabili? Per rispondere a tale domanda la stima dell’asimmetria dell’attività elettroencefalografica (EEG) in banda alfa, acquisita tramite una cuffia a 19 canali, risulta un mezzo adatto a misurare la tendenza all’approccio o al rifiuto (indice AW) verso uno stimolo. Specificamente, un maggior valore di AW indica una maggiore propensione all’approccio, viceversa un minor valore di AW una tendenza ad evitare un determinato stimolo. Inoltre, a causa dell’acquisizione prelinguale e postlinguale della sordità, bambini ed adulti rispettivamente potrebbero differire nella percezione della musica. Scopo del presente studio è stato quello di indagare due popolazioni di portatori di impianto cocleare di diversa età, bambini e adulti, nelle condizioni di impianto cocleare unilaterale (UCI) e impianto cocleare bilaterale (BCI), durante l’esposizione a tre condizioni sperimentali di stimolo musicale (Normale, Distorto e Muto). Inoltre, è stato effettuato uno studio di modelli di connettività funzionale tra reti cerebrali, così da investigare eventuali pattern funzionali peculiari delle diverse popolazioni. Come risultato generale, sia negli adulti che nei bambini, è stato dimostrata una congruenza tra i pattern elettroencefalografici riportati in pazienti BCI e soggetti di controllo normoudenti (CTRL), caratterizzata da valori più bassi per la condizione Distorto (rispetto alle condizioni Normale e Muto) nell’indice AW e nell’analisi di connettività. Inoltre, la condizione Normale e Distorta risultavano differenti in modo statisticamente significativo per il gruppo degli adulti con impianto cocleare e nei CTRL, così come nel gruppo bambini CTRL, ma non nei bambini con impianto cocleare. Queste evidenze suggeriscono una maggiore capacità di discriminazione e di motivazione all’approccio verso la musica Normale per i soggetti CTRL e BCI, a causa della somiglianza nella percezione della musica per questi due gruppi, in particolare per gli adulti, ma non per i pazienti UCI. Di conseguenza soggetti CTRL e BCI appaiono più simili che gli UCI nella percezione della musica Normale, come stimato da parametri misurabili, non derivanti da dati auto-dichiarati dai pazienti.

The present work aims to investigate the electroencephalographic (EEG) activity elicited by the observation of emotional pictures selected from the International Affective Picture System (IAPS) database. We analyzed the evoked activity within time intervals of increasing duration taking into account the related ratings of Valence and Arousal. The scalp statistical maps of Power Spectral Density (PSD), related to pictures with high valence, revealed an enhanced activity across frontal areas in the theta band and the involvement of fronto-parietal circuits in the alpha band. Difference in the processing of low and high arousing pictures, however, seems to be highly dependent on the valence dimension: for low valenced pictures, the difference in arousal was processed immediately after the observation of the picture, while for the high-valenced ones the processing took part in the second part of the observation. These results appear to be congruent with the literature, while the novelty of the current study is represented by the comparison of the activity elicited in different time windows by both the Arousal and Valence dimensions. It is possible, in this way, to observe how the processing of one variable influences the other, creating a dynamic description of the Valence- Arousal space.

Controlling an aircraft during a flight is a compelling condition, which requires a strict and well coded interaction between the crew. The interaction level between the Captain and the First Officer changes during the flight, ranging from a maximum (during takeoff and landing, as well as in case of a failure of the instrumentation or other emergency situations) to a minimum during quiet mid-flight. In this study, our aim is to investigate the neural correlates of different kinds and levels of interaction between couples of professional crew members by means of the innovative technique called brain hyperscanning, i.e. the simultaneous recording of the hemodynamic or neuroelectrical activity of different human subjects involved in interaction tasks. This approach allows the observation and modeling of the neural signature specifically dependent on the interaction between subjects, and, even more interestingly, of the functional links existing between the brain activities of the subjects interacting together. In this EEG hyperscanning study, different phases of a flight were reproduced in a professional flight simulator, which allowed, on one side, to reproduce the ecological setting of a real flight, and, on the other, to keep under control the different levels of interaction induced in the crew by means of systematic and simulated failures of the aircraft instrumentation. Results of the procedure of linear inverse estimation, together with functional hyperconnectivity estimated by means of Partial Directed Coherence, showed a dense network of connections between the activity in the two brains in the takeoff and landing phases, when the cooperation between the crew is maximal, while conversely no significant links were shown during the phases in which the activity of the two pilots was independent.

Brain Hyperscanning, i.e. the simultaneous recording of the cerebral activity of different human subjects involved in interaction tasks, is a very recent field of Neuroscience aiming at understanding the cerebral processes generating and generated by social interactions. This approach allows the observation and modeling of the neural signature specifically dependent on the interaction between subjects, and, even more interestingly, of the functional links existing between the activities in the brains of the subjects interacting together. In this EEG hyperscanning study we explored the functional hyperconnectivity between the activity in different scalp sites of couples of Civil Aviation Pilots during different phases of a flight reproduced in a flight simulator. Results shown a dense network of connections between the two brains in the takeoff and landing phases, when the cooperation between them is maximal, in contrast with phases during which the activity of the two pilots was independent, when no or quite few links were shown. These results confirms that the study of the brain connectivity between the activity simultaneously acquired in human brains during interaction tasks can provide important information about the neural basis of the “spirit of the group”.

Nowadays, there is a growing interest in measuring the impact of advertisements through the estimation of cerebral reactions. Several techniques and methods are used and discussed in the consumer neuroscience. In such a context, the present paper provides a novel method to estimate the level of memorization occurred in subjects during the observation of TV commercials. In particular, the present work introduce the Peak Density Function (PDF) as an electroencephalographic (EEG) time-varying variable which is correlated with the cerebral events of memorization of TV commercials. The analysis has been performed on the EEG activity recorded on twenty healthy subjects during the exposition to several advertisements. After the EEG recordings, an interview has been performed to obtain the information about the memorized scenes for all the video clips watched by the subjects. Such information has been put in correlation with the occurrence of transient peaks of EEG synchronization in the theta band, by computing the PDF. The present results show that the increase of PDF is positively correlated, scene by scene, (R=0.46, p

The perception of the music in cochlear implanted (CI) patients is an important aspect of their quality of life. In fact, the pleasantness of the music perception by such CI patients can be analyzed through a particular analysis of EEG rhythms. Studies on healthy subjects show that exists a particular frontal asymmetry of the EEG alpha rhythm which can be correlated with pleasantness of the perceived stimuli (approach-withdrawal theory). In particular, here we describe differences between EEG activities estimated in the alpha frequency band for a monolateral CI group of children and a normal hearing one during the fruition of a musical cartoon. The results of the present analysis showed that the alpha EEG asymmetry patterns related to the normal hearing group refers to a higher pleasantness perception when compared to the cerebral activity of the monolateral CI patients. In fact, the present results support the statement that a monolateral CI group could perceive the music in a less pleasant way when compared to normal hearing children.

There is a debate in the specialized literature about the quality of fruition of music for patients that received a cochlear implant. Interestingly, very few studies have investigated the hypothesis that patients that use a bilateral cochlear implant could perceive the music in a more pleasant way as compared to unilaterally implanted patients. Previous observations in healthy subjects have indicated that variations of particular EEG rhythms correlated with the pleasantness of the perceived music. The aim of the present pilot study is then to apply the state of the art neuroelectrical imaging and the analysis of cortical representation of EEG rhythms to monitor the perceived pleasantness during the observation of a simple videoclip in one patient with a unilateral cochlear implant and in one receiving a bilateral cochlear implant. Results of this pilot study showed that on the base of such previously validated EEG rhythms, the fruition of music and video, in terms of pleasantness, is statistically higher in the bilaterally implanted patient when compared to the monolateral implanted patient.

Objective: In this paper, we propose a body of techniques for the estimation of rapidly changing connectivity relationships between EEG signals estimated in cortical areas, based on the use of adaptive multivariate autoregressive modeling (AMVAR) for the estimation of a time-varying partial directed coherence (PDC). This approach allows the observation of rapidly changing influences between the cortical areas during the execution of a task, and does not require the stationarity of the signals. Methods: High resolution EEG data were recorded from a group of spinal cord injured (SCI) patients during the attempt to move a paralyzed limb. These data were compared with the time-varying connectivity patterns estimated in a control group during the real execution of the movement. Connectivity was estimated with the use of realistic head modeling and the linear inverse estimation of the cortical activity in a series of regions of interest by using time-varying PDC. Results: The SCI population involved a different cortical network than those generated by the healthy subjects during the task performance. Such a network differs for the involvement of the parietal cortices, which increases in strength near to the movement imagination onset for the SCI when compared to the normal population. Conclusions: The application of time-varying PDC allows tracking the evolution of the connectivity between cortical areas in the analyzed populations during the proposed tasks. Such details about the temporal evolution of the connectivity patterns estimated cannot be obtained with the application of the standard estimators of connectivity.

In the present study, we propose a theoretical graph procedure to investigate the communication redundancy in brain networks. By taking into account all the possible paths between pairs of cortical regions, this method captures the network redundancy i.e. a critical resource of the brain enhancing the resilience to neural damages and dysfunctions. As an example for its potential, we apply this procedure to the cortical networks estimated from high-resolution EEG signals in a group of spinal cord injured patients during the attempt of the foot movement. Preliminary results suggest that in the high spectral contents the effects due to the spinal trauma affect the expected redundancy attitude by suppressing mainly the longer alternative pathways between the cortical regions.

Background Auto-crosslinked polysaccharide hyaluronan-based solution (Hyalobarrier®-gel) prevents postoperative adhesions. However, its effect on tumour growth is still unknown. The aim of the present study was therefore to investigate the impact on survival of intra-abdominally administered Hyalobarrier®-gel, native hyaluronan (HA) and hyaluronan/carboxymethylcellulose (HA/CMC), after intraperitoneal tumour implantation. Methods After receiving an intraperitoneal inoculum of the human HT29 colorectal cell line, 615 athymic nude mice were assigned randomly to five groups: groups 1 and 2 received Hyalobarrier®-gel 20 mg/ml (n = 124) and 40 mg/ml (n = 126) respectively; groups 3 and 4 received HA (n = 120) and HA/CMC film (Seprafilm™) (n = 123) respectively. The survival of each treated group was compared with that of group 5, the control, which had no treatment (n = 122). Results As 34 of the 615 mice were not eligible, 581 animals were considered for the analysis. At 120 days, 136 animals (23·4 per cent) were still alive. At autopsy there was macroscopic absence of tumour in 75 cases (12·9 per cent). No statistically significant differences were found between the treatment and the control groups with respect to postoperative death and absence of tumour implantation. There was no difference in survival rate between the control group and groups treated with Hyalobarrier®-gel, HA or HA/CMC. Conclusion Hyalobarrier®-gel, HA and HA/CMC had no negative impact on the survival rate in mice that received an intraperitoneal implantation of HT29 colorectal human tumour cells.

Results: Asymmetric motor representation (lateralised dominance) for pharynx was observed in 12/13 subjects with the use of TMS with significantly larger responses observed in the lateralised projection (6 left, 6 right, p < 0.001). Largest fMRI activations were observed in primary motor cortices (BA4) after water swallowing, predominantly right lateralised. By contrast, tongue elevation and saliva swallowing produced greater numbers of left lateralised brain areas, particularly preand supplementary-motor cortex (BA6) as well as areas involved with language and speech processing (BA22,40,44). Tractography revealed larger tract volumes in the TMS predicted dominant hemispheric projection for water swallowing but not for saliva swallowing or tongue tasks (p < 0.001). Conclusion: We provide further evidence for the relevance of cerebral asymmetry in the control of human swallowing and related behaviours through detailed mapping of the network of neural pathways involved.

In this paper we show how the possibility of recording simultaneously the cerebral neuroelectric activity in different subjects (EEG hyperscanning) during the execution of different tasks could return useful information about the "internal" cerebral state of the subjects. We present the results obtained by EEG hyperscannings during ecological task (such as the execution of a card game) as well as that obtained in a series of couples of subjects during the performance of the Prisoner's Dilemma Game. The simultaneous recordings of couples of interacting subjects allows to observe and to model directly the neural signature of human interactions in order to understand the cerebral processes generating and generated by social cooperation or competition. Results obtained in a study of different groups recorded during the card game revealed a larger activity in prefrontal and anterior cingulated cortex in different frequency bands for the player that leads the game when compared to other players. Results collected in a population of 10 subjects during the performance of the Prisoner's Dilemma suggested that the most consistently activated structure is the orbitofrontal region (roughly described by the Brodmann area 10) during the condition of competition in both the tasks. It could be speculated whether the pattern of cortical connectivity between different cortical areas in different subjects could be employed as a tool for assessing the outcome of the task in advance.

In the present work, we used the brain electroencephalografic activity as an alternative means to identify individuals. 50 healthy subjects participated to the study and 56 EEG signals were recorded through a high-density cap during one minute of resting state either with eyes open and eyes closed. By computing the power spectrum density (PSD) on segments of 10 seconds, we obtained a feature vector of 40 points, notably the PSD values in the standard frequency range (1-40 Hz), for each EEG channel. By using a naive Bayes classifier and K-fold cross-validations, we observed high correct recognition rates (CRR) at the parieto-occipital electrodes (~78% during eyes open, ~89% during eyes closed). Notably, the eyes closed resting state elicited the highest CRRs at the occipital electrodes (92% O2, 91% O1), suggesting these biometric characteristics as the most suitable, among those investigated here, for identifying individuals.

The aim of the present research is to investigate the EEG activity elicited by a fast observation of face of real politicians during a simulated political election. Politician's face are taken from real local election performed in Italy in the 2004 and 2008. We recorded the EEG activity of eight healthy subjects while they are asked to give a judgment on dominance, trustworthiness traits and a preference of vote on faces shown. Statistical differences of spectral EEG scalp activity have been mapped onto a realistic head model. For each experimental condition, we employed the t-test to compare the PSD values and adopted the False Discovery Rate correction for multiple comparisons. The scalp statistical maps revealed a desynchronization in the alpha band related to the politicians who lost the simulated elections and have been judged less trustworthy. Although these results might be congruent with the recent literature, the present is the first EEG study about and there is the need to extend the paradigm and the analysis on a larger number of subjects to validate these results.

Driving tasks are vulnerable to the effects of sleep deprivation and mental fatigue, diminishing driver's ability to respond effectively to unusual or emergent situations. Physiological and brain activity analysis could help to understand how to provide useful feedback and alert signals to the drivers for avoiding car accidents. In this study we analyze the insurgence of mental fatigue or drowsiness during car driving in a simulated environment by using high resolution EEG techniques as well as neurophysiologic variables such as heart rate (HR) and eye blinks rate (EBR). Results suggest that it is possible to introduce a EEG-based cerebral workload index that it is sensitive to the mental efforts of the driver during drive tasks of different levels of difficulty. Workload index was based on the estimation of increase of EEG power spectra in the theta band over prefrontal areas and the simultaneous decrease of EEG power spectra over parietal areas in alpha band during difficult drive conditions. Such index could be used in a future to assess on-line the mental state of the driver during the drive task.

The aim of the study is to analyze the variation of the EEG power spectra in theta band when a novice starts to learn a new task. In particular, the goal is to find out the differences from the beginning of the training to the session in which the performance level is good enough for considering him/her able to complete the task without any problems. While the novices were engaged in the flight simulation tasks we recorded the brain activity by using high resolution EEG techniques as well as neurophysiologic variables such as heart rate (HR) and eye blinks rate (EBR). Results show clear changes in the EEG power spectra in theta band over the frontal brain areas, either over the left, the midline and the right side, during the learning process of the task. These results are also supported by the autonomic signals of HR and EBR, by the performances' trends and by the questionnaires for the evaluation of the perceived workload level.