Non-invasive deep brain stimulation is a novel field of research that aims to affect deep brain r... more Non-invasive deep brain stimulation is a novel field of research that aims to affect deep brain regions’ activity through non-invasive stimulation. Recent computational and clinical findings have fostered the interest on transcranial direct current stimulation as non-invasive deep brain stimulation techniques, and several optimization strategies have been tested. Multi-electrode transcranial direct current stimulation has shown the potential to selectively affect deep brain structures. Here, we assess whether arbitrarily chosen monopolar multi-electrode transcranial direct current stimulation montages might selectively affect deep brain structures through computational predictions and neurophysiological assessment. Electric field distribution in deep brain structures (i.e., thalamus and midbrain) were estimated through computational models simulating transcranial direct current stimulation with two monopolar and two monopolar multi-electrode montages. Monopolar multi-electrode trans...
Local field potentials (LFPs) recorded from implanted deep brain electrodes demonstrated the osci... more Local field potentials (LFPs) recorded from implanted deep brain electrodes demonstrated the oscillatory nature of human basal ganglia. LFP rhythms were mainly characterized by means od power spectral analysis, thus loosing information related to rhythm phase synchronization and to event related phase modulations. Because the application of higher-order spectral analysis methodology can overcome such limitation, here we review the present applications of bispectral and cross-bispectral analysis to LFP recordings. The results obtained up to now showed that higher-order spectral analysis was able to clarify detect different rhythm synchronizations and interactions characterizing different pathologies and patient's states.
Clinical findings suggest that transcutaneous spinal direct current stimulation (tsDCS) can modul... more Clinical findings suggest that transcutaneous spinal direct current stimulation (tsDCS) can modulate ascending sensitive, descending corticospinal, and segmental pathways in the spinal cord (SC). However, several aspects of the stimulation have not been completely understood, and realistic computational models based on MRI are the gold standard to predict the interaction between tsDCS-induced electric fields and anatomy. Here, we review the electric fields distribution in the SC during tsDCS as predicted by MRI-based realistic models, compare such knowledge with clinical findings, and define the role of computational knowledge in optimizing tsDCS protocols. tsDCS-induced electric fields are predicted to be safe and induce both transient and neuroplastic changes. This could support the possibility to explore new clinical applications, such as spinal cord injury. For the most applied protocol (2–3 mA for 20–30 min, active electrode over T10–T12 and the reference on the right shoulder)...
The systematic observation and imagination of actions promotes acquisition of motor skills. Furth... more The systematic observation and imagination of actions promotes acquisition of motor skills. Furthermore, studies demonstrated that early sleep after practice enhances motor learning through an offline stabilization process. Here, we investigated behavioral effects and neurodynamical correlates of early sleep after action observation and motor imagery training (AO + MI-training) on motor learning in terms of manual dexterity. Forty-five healthy participants were randomized into three groups receiving a 3 week intervention consisting of AO + MI-training immediately before sleeping or AO + MI-training at least 12 h before sleeping or a control stimulation. AO + MI-training implied the observation and motor imagery of transitive manual dexterity tasks, whereas the control stimulation consisted of landscape video-clips observation. Manual dexterity was assessed using functional tests, kinematic and neurophysiological outcomes before and after the training and at 1-month follow-up. AO + M...
Transcranial electrical stimulation (tES) techniques, such as direct current stimulation (tDCS) a... more Transcranial electrical stimulation (tES) techniques, such as direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), cause neurophysiological and behavioral modifications as responses to the electric field are induced in the brain. Estimations of such electric fields are based mainly on computational studies, and in vivo measurements have been used to expand the current knowledge. Here, we review the current tDCS- and tACS-induced electric fields estimations as they are recorded in humans and non-human primates using intracerebral electrodes. Direct currents and alternating currents were applied with heterogeneous protocols, and the recording procedures were characterized by a tentative methodology. However, for the clinical stimulation protocols, an injected current seems to reach the brain, even at deep structures. The stimulation parameters (e.g., intensity, frequency and phase), the electrodes’ positions and personal anatomy determine whether ...
Typical seizure prediction models aim at discriminating interictal brain activity from pre-seizur... more Typical seizure prediction models aim at discriminating interictal brain activity from pre-seizure electrographic patterns. Given the lack of a preictal clinical definition, a fixed interval is widely used to develop these models. Recent studies reporting preictal interval selection among a range of fixed intervals show inter- and intra-patient preictal interval variability, possibly reflecting the heterogeneity of the seizure generation process. Obtaining accurate labels of the preictal interval can be used to train supervised prediction models and, hence, avoid setting a fixed preictal interval for all seizures within the same patient. Unsupervised learning methods hold great promise for exploring preictal alterations on a seizure-specific scale. Multivariate and univariate linear and nonlinear features were extracted from scalp electroencephalography (EEG) signals collected from 41 patients with drug-resistant epilepsy undergoing presurgical monitoring. Nonlinear dimensionality r...
Music-based interventions seem to enhance motor, sensory and cognitive functions in Parkinson’s d... more Music-based interventions seem to enhance motor, sensory and cognitive functions in Parkinson’s disease (PD), but the underlying action mechanisms are still largely unknown. This electroencephalography (EEG) study aimed to investigate the effective connectivity patterns characterizing PD in the resting state and during music listening. EEG recordings were obtained from fourteen non-demented PD patients and 12 healthy controls, at rest and while listening to three music tracks. Theta- and alpha-band power spectral density and multivariate partial directed coherence were computed. Power and connectivity measures were compared between patients and controls in the four conditions and in music vs. rest. Compared to controls, patients showed enhanced theta-band power and slightly enhanced alpha-band power, but markedly reduced theta- and alpha-band interactions among EEG channels, especially concerning the information received by the right central channel. EEG power differences were parti...
Several studies have suggested that the auditory mismatch-response (MMR) elicited in infants is a... more Several studies have suggested that the auditory mismatch-response (MMR) elicited in infants is a predictor of later language skills (Choudhury & Benasich, 2011;van Zuijen et al. 2013). However, there is little knowledge of what brain source activities the infant MMR reflects (Näätänen et al., 2014) and Independent Component Analysis (ICA) has not been used to address this issue. Scalpchannel averaged EEG and MMRs may sum volume-conducted contributions from many cortical source areas. ICA applied to the unaveraged EEG data can be used to identify the complex spatiotemporal dynamics underlying the MMR, allowing identification of the contributions of the cortical generators that contribute to the scalp averages (Rissling et al., 2014). We recorded 60channel EEG data in 34 typically developing six-month-old infants during a passive acoustic oddball paradigm involving ‘standard’ interspersed with occasional pitchor duration-deviant tonepairs. Adaptive-Mixture-ICA (Palmer et al., 2006, 2...
OPPORTUNITIES AND CHALLENGES for European Projects, 2018
The goal of LiNK is to discover and define research tracks in the area of intelligent processing ... more The goal of LiNK is to discover and define research tracks in the area of intelligent processing to support cardiovascular disease management in Personalized Healthcare (PHC). The strategy was based on a twofold approach. First, using a status assessment of the current research on PHC and an international research forum. From this roadmap, specific innovative research tracks were developed by common workgroups. Knowledge transfer methodologies between partners by using a "learn by doing" approach increased the research excellence momentum. These research tracks supported concept definition activities that will be the basis for new project, network and PhD grant proposals, leading to a continuum of widening. Second, existing links to international leading organizations and key actors in PHC (academic, industrial and users) were exploited to launch a research and innovation forum in which the definition of a research agenda and curricula for advanced training was completed.
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2017
Two key ingredients of a successful neurorehabilitative intervention have been identified as inte... more Two key ingredients of a successful neurorehabilitative intervention have been identified as intensive and repetitive training and subject's active participation, which can be coupled in an active robot-assisted training. To exploit these two elements, we recorded electroencephalography, electromyography and kinematics signals from 9 healthy subjects performing a 2×2 factorial design protocol, with subject's volitional intention and robotic glove assistance as factors. We quantitatively evaluated primary sensorimotor, premotor and supplementary motor areas activation during movement execution by computing Event-Related Desynchronization (ERD) patterns associated to mu and beta rhythms. ERD patterns showed a similar behavior for all investigated regions: statistically significant ERDs began earlier in conditions requiring subject's volitional contribution; ERDs were prolonged towards the end of movement in conditions in which the robotic assistance was present. Our study suggests that the combination between subject volitional contribution and movement assistance provided by the robotic device (i.e., active robot-assisted modality) is able to provide early brain activation (i.e., earlier ERD) associated with stronger proprioceptive feedback (i.e., longer ERD). This finding might be particularly important for neurological patients, where movement cannot be completed autonomously and passive/active robot-assisted modalities are the only possibilities of execution.
Multimodal human brain mapping has been proposed as an integrated approach capable of improving t... more Multimodal human brain mapping has been proposed as an integrated approach capable of improving the recognition of the cortical correlates of specific neurological functions. We used simultaneous EEG-fMRI (functional magnetic resonance imaging) and EEG-TD-fNIRS (time domain functional near-infrared spectroscopy) recordings to compare different hemodynamic methods with changes in EEG in ten patients with progressive myoclonic epilepsy and 12 healthy controls. We evaluated O 2 Hb, HHb and Blood oxygen level-dependent (BOLD) changes and event-related desynchronization/synchronization (ERD/ERS) in the a and b bands of all of the subjects while they performed a simple motor task. The general linear model was used to obtain comparable fMRI and TD-fNIRS activation maps. We also analyzed cortical thickness in order to evaluate any structural changes. In the patients, the TD-NIRS and fMRI data significantly correlated and showed a significant lessening of the increase in O 2 Hb and the decrease in BOLD. The post-movement b rebound was minimal or absent in patients. Cortical thickness was moderately reduced in the motor area of the patients and correlated with the reduction in the hemodynamic signals. The fMRI and TD-NIRS results were consistent, significantly correlated and showed smaller hemodynamic changes in the patients. This finding may be partially attributable to mild cortical thickening. However, cortical hyperexcitability, which is known to generate myoclonic jerks and probably accounts for the lack of EEG b-ERS, did not reflect any increased energy requirement. We hypothesize that this is due to a loss of inhibitory neuronal components that typically fire at high frequencies.
The combined application of different investigating techniques is helpful for studying reading me... more The combined application of different investigating techniques is helpful for studying reading mechanisms, since they found on the integration among visual, auditory, motor, attentive and cognitive processes. Electrophysiological scalp recordings and functional magnetic resonance provide significantly correlated measures of brain function and are characterized by complementary spatiotemporal resolution. This work describes an event-related experimental design for studying grapheme-phoneme association mechanisms naturally active while reading. ERPs and fMRI were separately acquired from healthy volunteers during passive observation and overt reading of single letters and non-alphabetic symbols visually presented. Concatenated EEG single trials were preprocessed using Independent Component Analysis (ICA) decomposition: current density distribution inside the brain was estimated applying Low Resolution Electromagnetic Tomography (LORETA) to artefact-free independent components. Multiple regression with a set of triangular basis functions was performed for time series images analysis. LORETA and fMRI local maxima were considered functionally connected if they were not farther than 30 mm. Results of application to a single subject are presented as an example. The method is promising for the study of cognitive functions that involve complex brain networks, each working at different spatial and temporal scales.
The problem of the automatic measurement of amplitudes and latencies in reading related potential... more The problem of the automatic measurement of amplitudes and latencies in reading related potentials (RRPs) is here addressed. Our approach based on the Dynamic Time Warping technique, shows promising results for the development of an automatic measuring procedure.
2016 IEEE 2nd International Forum on Research and Technologies for Society and Industry Leveraging a better tomorrow (RTSI), 2016
The color-word Stroop paradigm is a neuropsychological test often employed for the evaluation of ... more The color-word Stroop paradigm is a neuropsychological test often employed for the evaluation of the cognitive processing when a conflict between different attributes of the same visual stimulus is present. In clinical environments, the standard practice for the Stroop test administration is still based on paper supports and stopwatches. Thus, the aim of the present pilot study was to investigate the usability in clinical practice of a completely computerized system for the Stroop test administration. The computerized system developed for this study was made up of the following modules: i) a PC for stimuli administration and data acquisition connected to two monitors (one for the user, the other for the experimenter); ii) a response system composed of three colored electronic buttons; iii) a wireless electroencephalography (EEG) acquisition module (i.e. headset and dedicated software). The system was installed in the IRCCS Don Carlo Gnocchi Foundation and tested on 7 subjects hospitalized in the neurorehabilitation Unit. The developed system was able to provide information about the subjects' reaction time to stimuli in addition to the traditional behavioral scores. Moreover, the integrated EEG acquisition module allowed monitoring the user's engagement during the test through the computation of a simple EEG-based evaluation index. We believe that this pilot study could set a further step towards the clinical use of computerized systems to monitor cognitive functions.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2018
In this work we are interested in analyzing any correlations between physiological parameters, ex... more In this work we are interested in analyzing any correlations between physiological parameters, extracted from signals such as Electrocardiogram, respiratory signal and Skin Conductance, and self-reported indices related to emotional or cognitive stimulations. For this purpose, an experiment involving twenty participants with a mean age of 25±5 years of both sexes (13 males and 7 females) was carried out. The protocol included the navigation in simulated web-sites and the vision of two different commercial products (utilitarian and hedonistic). At the end of the navigation, a questionnaire was submitted to the subject in order to measure his/her feelings and emotions in a qualitative and subjective way. Quantitative features were extracted from the physiological signals recorded during the execution of the protocol. We performed a correlation analysis between self-reported and physiological responses related to Arousal, Pleasure, Expectancy and Situational Involvement. Findings showe...
... Fabio Dercole3, Luca Di Rienzo4, Diego Liberati5, Luca Mainardi1, Paolo Ravazzani6, Sergio Ri... more ... Fabio Dercole3, Luca Di Rienzo4, Diego Liberati5, Luca Mainardi1, Paolo Ravazzani6, Sergio Rinaldi3, Maria Gabriella Signorini1, Alessandro ... De-convolution (De Nicolao and Liberati, 1993) has been successfully applied in reconstructing from blood concentration the course ...
The increasingly widespread diffusion of wearable devices makes possible the continuous monitorin... more The increasingly widespread diffusion of wearable devices makes possible the continuous monitoring of vital signs, such as heart rate (HR), heart rate variability (HRV), and breath signal. However, these devices usually do not record the “gold-standard” signals, namely the electrocardiography (ECG) and respiratory activity, but a single photoplethysmographic (PPG) signal, which can be exploited to estimate HR and respiratory activity. In addition, these devices employ low sampling rates to limit power consumption. Hence, proper methods should be adopted to compensate for the resulting increased discretization error, while diverse breath-extraction algorithms may be differently sensitive to PPG sampling rate. Here, we assessed the efficacy of parabola interpolation, cubic-spline, and linear regression methods to improve the accuracy of the inter-beat intervals (IBIs) extracted from PPG sampled at decreasing rates from 64 to 8 Hz. PPG-derived IBIs and HRV indices were compared with th...
Non-invasive deep brain stimulation is a novel field of research that aims to affect deep brain r... more Non-invasive deep brain stimulation is a novel field of research that aims to affect deep brain regions’ activity through non-invasive stimulation. Recent computational and clinical findings have fostered the interest on transcranial direct current stimulation as non-invasive deep brain stimulation techniques, and several optimization strategies have been tested. Multi-electrode transcranial direct current stimulation has shown the potential to selectively affect deep brain structures. Here, we assess whether arbitrarily chosen monopolar multi-electrode transcranial direct current stimulation montages might selectively affect deep brain structures through computational predictions and neurophysiological assessment. Electric field distribution in deep brain structures (i.e., thalamus and midbrain) were estimated through computational models simulating transcranial direct current stimulation with two monopolar and two monopolar multi-electrode montages. Monopolar multi-electrode trans...
Local field potentials (LFPs) recorded from implanted deep brain electrodes demonstrated the osci... more Local field potentials (LFPs) recorded from implanted deep brain electrodes demonstrated the oscillatory nature of human basal ganglia. LFP rhythms were mainly characterized by means od power spectral analysis, thus loosing information related to rhythm phase synchronization and to event related phase modulations. Because the application of higher-order spectral analysis methodology can overcome such limitation, here we review the present applications of bispectral and cross-bispectral analysis to LFP recordings. The results obtained up to now showed that higher-order spectral analysis was able to clarify detect different rhythm synchronizations and interactions characterizing different pathologies and patient's states.
Clinical findings suggest that transcutaneous spinal direct current stimulation (tsDCS) can modul... more Clinical findings suggest that transcutaneous spinal direct current stimulation (tsDCS) can modulate ascending sensitive, descending corticospinal, and segmental pathways in the spinal cord (SC). However, several aspects of the stimulation have not been completely understood, and realistic computational models based on MRI are the gold standard to predict the interaction between tsDCS-induced electric fields and anatomy. Here, we review the electric fields distribution in the SC during tsDCS as predicted by MRI-based realistic models, compare such knowledge with clinical findings, and define the role of computational knowledge in optimizing tsDCS protocols. tsDCS-induced electric fields are predicted to be safe and induce both transient and neuroplastic changes. This could support the possibility to explore new clinical applications, such as spinal cord injury. For the most applied protocol (2–3 mA for 20–30 min, active electrode over T10–T12 and the reference on the right shoulder)...
The systematic observation and imagination of actions promotes acquisition of motor skills. Furth... more The systematic observation and imagination of actions promotes acquisition of motor skills. Furthermore, studies demonstrated that early sleep after practice enhances motor learning through an offline stabilization process. Here, we investigated behavioral effects and neurodynamical correlates of early sleep after action observation and motor imagery training (AO + MI-training) on motor learning in terms of manual dexterity. Forty-five healthy participants were randomized into three groups receiving a 3 week intervention consisting of AO + MI-training immediately before sleeping or AO + MI-training at least 12 h before sleeping or a control stimulation. AO + MI-training implied the observation and motor imagery of transitive manual dexterity tasks, whereas the control stimulation consisted of landscape video-clips observation. Manual dexterity was assessed using functional tests, kinematic and neurophysiological outcomes before and after the training and at 1-month follow-up. AO + M...
Transcranial electrical stimulation (tES) techniques, such as direct current stimulation (tDCS) a... more Transcranial electrical stimulation (tES) techniques, such as direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), cause neurophysiological and behavioral modifications as responses to the electric field are induced in the brain. Estimations of such electric fields are based mainly on computational studies, and in vivo measurements have been used to expand the current knowledge. Here, we review the current tDCS- and tACS-induced electric fields estimations as they are recorded in humans and non-human primates using intracerebral electrodes. Direct currents and alternating currents were applied with heterogeneous protocols, and the recording procedures were characterized by a tentative methodology. However, for the clinical stimulation protocols, an injected current seems to reach the brain, even at deep structures. The stimulation parameters (e.g., intensity, frequency and phase), the electrodes’ positions and personal anatomy determine whether ...
Typical seizure prediction models aim at discriminating interictal brain activity from pre-seizur... more Typical seizure prediction models aim at discriminating interictal brain activity from pre-seizure electrographic patterns. Given the lack of a preictal clinical definition, a fixed interval is widely used to develop these models. Recent studies reporting preictal interval selection among a range of fixed intervals show inter- and intra-patient preictal interval variability, possibly reflecting the heterogeneity of the seizure generation process. Obtaining accurate labels of the preictal interval can be used to train supervised prediction models and, hence, avoid setting a fixed preictal interval for all seizures within the same patient. Unsupervised learning methods hold great promise for exploring preictal alterations on a seizure-specific scale. Multivariate and univariate linear and nonlinear features were extracted from scalp electroencephalography (EEG) signals collected from 41 patients with drug-resistant epilepsy undergoing presurgical monitoring. Nonlinear dimensionality r...
Music-based interventions seem to enhance motor, sensory and cognitive functions in Parkinson’s d... more Music-based interventions seem to enhance motor, sensory and cognitive functions in Parkinson’s disease (PD), but the underlying action mechanisms are still largely unknown. This electroencephalography (EEG) study aimed to investigate the effective connectivity patterns characterizing PD in the resting state and during music listening. EEG recordings were obtained from fourteen non-demented PD patients and 12 healthy controls, at rest and while listening to three music tracks. Theta- and alpha-band power spectral density and multivariate partial directed coherence were computed. Power and connectivity measures were compared between patients and controls in the four conditions and in music vs. rest. Compared to controls, patients showed enhanced theta-band power and slightly enhanced alpha-band power, but markedly reduced theta- and alpha-band interactions among EEG channels, especially concerning the information received by the right central channel. EEG power differences were parti...
Several studies have suggested that the auditory mismatch-response (MMR) elicited in infants is a... more Several studies have suggested that the auditory mismatch-response (MMR) elicited in infants is a predictor of later language skills (Choudhury & Benasich, 2011;van Zuijen et al. 2013). However, there is little knowledge of what brain source activities the infant MMR reflects (Näätänen et al., 2014) and Independent Component Analysis (ICA) has not been used to address this issue. Scalpchannel averaged EEG and MMRs may sum volume-conducted contributions from many cortical source areas. ICA applied to the unaveraged EEG data can be used to identify the complex spatiotemporal dynamics underlying the MMR, allowing identification of the contributions of the cortical generators that contribute to the scalp averages (Rissling et al., 2014). We recorded 60channel EEG data in 34 typically developing six-month-old infants during a passive acoustic oddball paradigm involving ‘standard’ interspersed with occasional pitchor duration-deviant tonepairs. Adaptive-Mixture-ICA (Palmer et al., 2006, 2...
OPPORTUNITIES AND CHALLENGES for European Projects, 2018
The goal of LiNK is to discover and define research tracks in the area of intelligent processing ... more The goal of LiNK is to discover and define research tracks in the area of intelligent processing to support cardiovascular disease management in Personalized Healthcare (PHC). The strategy was based on a twofold approach. First, using a status assessment of the current research on PHC and an international research forum. From this roadmap, specific innovative research tracks were developed by common workgroups. Knowledge transfer methodologies between partners by using a "learn by doing" approach increased the research excellence momentum. These research tracks supported concept definition activities that will be the basis for new project, network and PhD grant proposals, leading to a continuum of widening. Second, existing links to international leading organizations and key actors in PHC (academic, industrial and users) were exploited to launch a research and innovation forum in which the definition of a research agenda and curricula for advanced training was completed.
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2017
Two key ingredients of a successful neurorehabilitative intervention have been identified as inte... more Two key ingredients of a successful neurorehabilitative intervention have been identified as intensive and repetitive training and subject's active participation, which can be coupled in an active robot-assisted training. To exploit these two elements, we recorded electroencephalography, electromyography and kinematics signals from 9 healthy subjects performing a 2×2 factorial design protocol, with subject's volitional intention and robotic glove assistance as factors. We quantitatively evaluated primary sensorimotor, premotor and supplementary motor areas activation during movement execution by computing Event-Related Desynchronization (ERD) patterns associated to mu and beta rhythms. ERD patterns showed a similar behavior for all investigated regions: statistically significant ERDs began earlier in conditions requiring subject's volitional contribution; ERDs were prolonged towards the end of movement in conditions in which the robotic assistance was present. Our study suggests that the combination between subject volitional contribution and movement assistance provided by the robotic device (i.e., active robot-assisted modality) is able to provide early brain activation (i.e., earlier ERD) associated with stronger proprioceptive feedback (i.e., longer ERD). This finding might be particularly important for neurological patients, where movement cannot be completed autonomously and passive/active robot-assisted modalities are the only possibilities of execution.
Multimodal human brain mapping has been proposed as an integrated approach capable of improving t... more Multimodal human brain mapping has been proposed as an integrated approach capable of improving the recognition of the cortical correlates of specific neurological functions. We used simultaneous EEG-fMRI (functional magnetic resonance imaging) and EEG-TD-fNIRS (time domain functional near-infrared spectroscopy) recordings to compare different hemodynamic methods with changes in EEG in ten patients with progressive myoclonic epilepsy and 12 healthy controls. We evaluated O 2 Hb, HHb and Blood oxygen level-dependent (BOLD) changes and event-related desynchronization/synchronization (ERD/ERS) in the a and b bands of all of the subjects while they performed a simple motor task. The general linear model was used to obtain comparable fMRI and TD-fNIRS activation maps. We also analyzed cortical thickness in order to evaluate any structural changes. In the patients, the TD-NIRS and fMRI data significantly correlated and showed a significant lessening of the increase in O 2 Hb and the decrease in BOLD. The post-movement b rebound was minimal or absent in patients. Cortical thickness was moderately reduced in the motor area of the patients and correlated with the reduction in the hemodynamic signals. The fMRI and TD-NIRS results were consistent, significantly correlated and showed smaller hemodynamic changes in the patients. This finding may be partially attributable to mild cortical thickening. However, cortical hyperexcitability, which is known to generate myoclonic jerks and probably accounts for the lack of EEG b-ERS, did not reflect any increased energy requirement. We hypothesize that this is due to a loss of inhibitory neuronal components that typically fire at high frequencies.
The combined application of different investigating techniques is helpful for studying reading me... more The combined application of different investigating techniques is helpful for studying reading mechanisms, since they found on the integration among visual, auditory, motor, attentive and cognitive processes. Electrophysiological scalp recordings and functional magnetic resonance provide significantly correlated measures of brain function and are characterized by complementary spatiotemporal resolution. This work describes an event-related experimental design for studying grapheme-phoneme association mechanisms naturally active while reading. ERPs and fMRI were separately acquired from healthy volunteers during passive observation and overt reading of single letters and non-alphabetic symbols visually presented. Concatenated EEG single trials were preprocessed using Independent Component Analysis (ICA) decomposition: current density distribution inside the brain was estimated applying Low Resolution Electromagnetic Tomography (LORETA) to artefact-free independent components. Multiple regression with a set of triangular basis functions was performed for time series images analysis. LORETA and fMRI local maxima were considered functionally connected if they were not farther than 30 mm. Results of application to a single subject are presented as an example. The method is promising for the study of cognitive functions that involve complex brain networks, each working at different spatial and temporal scales.
The problem of the automatic measurement of amplitudes and latencies in reading related potential... more The problem of the automatic measurement of amplitudes and latencies in reading related potentials (RRPs) is here addressed. Our approach based on the Dynamic Time Warping technique, shows promising results for the development of an automatic measuring procedure.
2016 IEEE 2nd International Forum on Research and Technologies for Society and Industry Leveraging a better tomorrow (RTSI), 2016
The color-word Stroop paradigm is a neuropsychological test often employed for the evaluation of ... more The color-word Stroop paradigm is a neuropsychological test often employed for the evaluation of the cognitive processing when a conflict between different attributes of the same visual stimulus is present. In clinical environments, the standard practice for the Stroop test administration is still based on paper supports and stopwatches. Thus, the aim of the present pilot study was to investigate the usability in clinical practice of a completely computerized system for the Stroop test administration. The computerized system developed for this study was made up of the following modules: i) a PC for stimuli administration and data acquisition connected to two monitors (one for the user, the other for the experimenter); ii) a response system composed of three colored electronic buttons; iii) a wireless electroencephalography (EEG) acquisition module (i.e. headset and dedicated software). The system was installed in the IRCCS Don Carlo Gnocchi Foundation and tested on 7 subjects hospitalized in the neurorehabilitation Unit. The developed system was able to provide information about the subjects' reaction time to stimuli in addition to the traditional behavioral scores. Moreover, the integrated EEG acquisition module allowed monitoring the user's engagement during the test through the computation of a simple EEG-based evaluation index. We believe that this pilot study could set a further step towards the clinical use of computerized systems to monitor cognitive functions.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2018
In this work we are interested in analyzing any correlations between physiological parameters, ex... more In this work we are interested in analyzing any correlations between physiological parameters, extracted from signals such as Electrocardiogram, respiratory signal and Skin Conductance, and self-reported indices related to emotional or cognitive stimulations. For this purpose, an experiment involving twenty participants with a mean age of 25±5 years of both sexes (13 males and 7 females) was carried out. The protocol included the navigation in simulated web-sites and the vision of two different commercial products (utilitarian and hedonistic). At the end of the navigation, a questionnaire was submitted to the subject in order to measure his/her feelings and emotions in a qualitative and subjective way. Quantitative features were extracted from the physiological signals recorded during the execution of the protocol. We performed a correlation analysis between self-reported and physiological responses related to Arousal, Pleasure, Expectancy and Situational Involvement. Findings showe...
... Fabio Dercole3, Luca Di Rienzo4, Diego Liberati5, Luca Mainardi1, Paolo Ravazzani6, Sergio Ri... more ... Fabio Dercole3, Luca Di Rienzo4, Diego Liberati5, Luca Mainardi1, Paolo Ravazzani6, Sergio Rinaldi3, Maria Gabriella Signorini1, Alessandro ... De-convolution (De Nicolao and Liberati, 1993) has been successfully applied in reconstructing from blood concentration the course ...
The increasingly widespread diffusion of wearable devices makes possible the continuous monitorin... more The increasingly widespread diffusion of wearable devices makes possible the continuous monitoring of vital signs, such as heart rate (HR), heart rate variability (HRV), and breath signal. However, these devices usually do not record the “gold-standard” signals, namely the electrocardiography (ECG) and respiratory activity, but a single photoplethysmographic (PPG) signal, which can be exploited to estimate HR and respiratory activity. In addition, these devices employ low sampling rates to limit power consumption. Hence, proper methods should be adopted to compensate for the resulting increased discretization error, while diverse breath-extraction algorithms may be differently sensitive to PPG sampling rate. Here, we assessed the efficacy of parabola interpolation, cubic-spline, and linear regression methods to improve the accuracy of the inter-beat intervals (IBIs) extracted from PPG sampled at decreasing rates from 64 to 8 Hz. PPG-derived IBIs and HRV indices were compared with th...
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Papers by Anna Bianchi