Stefania Della Penna

Publications of Stefania Della Penna

• The sound of consciousness: neural underpinnings of auditory perception.

  Authors: Alfredo Brancucci, Raffaella Franciotti, Anita D'Anselmo, Stefania Della Penna, Luca Tommasi

  The Journal of neuroscience : the official journal of the Society for Neuroscience. 11/2011; 31(46):16611-8.

  The neural correlates of consciousness (NCC), i.e., patterns of brain activity that specifically accompany a particular conscious experience, have been investigated mainly in the visual system usingThe neural correlates of consciousness (NCC), i.e., patterns of brain activity that specifically accompany a particular conscious experience, have been investigated mainly in the visual system using particularly suited paradigms, such as binocular rivalry and multistable percepts in combination with neural recordings or neuroimaging. Through the same principles, we look here for possible NCC in the auditory modality exploiting the properties of the Deutsch's illusion, a stimulation condition in which a sequence of two specular dichotic stimuli presented in alternation causes an illusory segregation of pitch and side (ear of origin), which can yield up to four different auditory percepts per dichotic stimulus. Using magnetoencephalography in humans, we observed cortical activity specifically accompanying conscious experience of pitch inside an early bilateral network, including the Heschl's gyrus, the middle temporal gyrus, the right inferior, and the superior frontal gyri. The conscious experience of perceived side was instead accompanied by later activity observed bilaterally in the inferior parietal lobe and in the superior frontal gyrus. These results suggest that the NCC are not independent of stimulus features and modality and that, even at the higher cortical levels, the different aspects of a single perceptual scene may not be simultaneously processed.

• A signal-processing pipeline for magnetoencephalography resting-state networks.

  Authors: Dante Mantini, Stefania Della Penna, Laura Marzetti, Francesco de Pasquale, Vittorio Pizzella, Maurizio Corbetta, Gian Luca Romani

  Brain connectivity. 01/2011; 1(1):49-59.

  Abstract To study functional connectivity using magnetoencephalographic (MEG) data, the high-quality source-level reconstruction of brain activity constitutes a critical element. MEG resting-stateAbstract To study functional connectivity using magnetoencephalographic (MEG) data, the high-quality source-level reconstruction of brain activity constitutes a critical element. MEG resting-state networks (RSNs) have been documented by means of a dedicated processing pipeline: MEG recordings are decomposed by independent component analysis (ICA) into artifact and brain components (ICs); next, the channel maps associated with the latter ones are projected into the source space and the resulting voxel-wise weights are used to linearly combine the IC time courses. An extensive description of the proposed pipeline is provided here, along with an assessment of its performances with respect to alternative approaches. The following investigations were carried out: (1) ICA decomposition algorithm. Synthetic data are used to assess the sensitivity of the ICA results to the decomposition algorithm, by testing FastICA, INFOMAX, and SOBI. FastICA with deflation approach, a standard solution, provides the best decomposition. (2) Recombination of brain ICs versus subtraction of artifactual ICs (at the channel level). Both the recombination of the brain ICs in the sensor space and the classical procedure of subtracting the artifactual ICs from the recordings provide a suitable reconstruction, with a lower distortion using the latter approach. (3) Recombination of brain ICs after localization versus localization of artifact-corrected recordings. The brain IC recombination after source localization, as implemented in the proposed pipeline, provides a lower source-level signal distortion. (4) Detection of RSNs. The accuracy in source-level reconstruction by the proposed pipeline is confirmed by an improved specificity in the retrieval of RSNs from experimental data.

• Temporal dynamics of spontaneous MEG activity in brain networks.

  Authors: Francesco de Pasquale, Stefania Della Penna, Abraham Z Snyder, Christopher Lewis, Dante Mantini, Laura Marzetti, Paolo Belardinelli, Luca Ciancetta, Vittorio Pizzella, Gian Luca Romani, Maurizio Corbetta

  Proceedings of the National Academy of Sciences of the United States of America. 03/2010; 107(13):6040-5.

  Functional MRI (fMRI) studies have shown that low-frequency (<0.1 Hz) spontaneous fluctuations of the blood oxygenation level dependent (BOLD) signal during restful wakefulness are coherent withinFunctional MRI (fMRI) studies have shown that low-frequency (<0.1 Hz) spontaneous fluctuations of the blood oxygenation level dependent (BOLD) signal during restful wakefulness are coherent within distributed large-scale cortical and subcortical networks (resting state networks, RSNs). The neuronal mechanisms underlying RSNs remain poorly understood. Here, we describe magnetoencephalographic correspondents of two well-characterized RSNs: the dorsal attention and the default mode networks. Seed-based correlation mapping was performed using time-dependent MEG power reconstructed at each voxel within the brain. The topography of RSNs computed on the basis of extended (5 min) epochs was similar to that observed with fMRI but confined to the same hemisphere as the seed region. Analyses taking into account the nonstationarity of MEG activity showed transient formation of more complete RSNs, including nodes in the contralateral hemisphere. Spectral analysis indicated that RSNs manifest in MEG as synchronous modulation of band-limited power primarily within the theta, alpha, and beta bands-that is, in frequencies slower than those associated with the local electrophysiological correlates of event-related BOLD responses.

• Brain structures activated by overt and covert emotional visual stimuli.

  Authors: Elisabetta Sabatini, Stefania Della Penna, Raffaella Franciotti, Antonio Ferretti, Pierluigi Zoccolotti, Paolo M Rossini, Gian Luca Romani, Guido Gainotti

  Brain research bulletin. 07/2009; 79(5):258-64.

  Research data suggest that the amygdala and some related brain structures modulate the processing of emotional visual stimuli even when they are not consciously perceived. In this study, we examinedResearch data suggest that the amygdala and some related brain structures modulate the processing of emotional visual stimuli even when they are not consciously perceived. In this study, we examined neural responses to investigate whether and how other brain areas anatomically connected to the amygdala might become activated during both overt and covert presentation of conditioned emotional visual stimuli. In the covert presentation, a conditioned angry face was shown for 15 ms followed by a neutral masking face (CSmask). In the overt condition, an angry face associated with a painful stimulus (CS+), a happy (H) and a neutral face (N) were presented for 75 ms. Based on results of functional magnetic resonance imaging (fMRI) in 10 healthy volunteers, we show evidence that a network of brain structures anatomically connected to the amygdala (including the anterior insula, the fusiform gyrus and the superior temporal sulcus) are involved in the subliminal processing of visual emotional stimuli. Of particular interest was the dissociation between the anterior and posterior insula: the anterior insula responded to both overt and covert presentation of the conditioned stimulus, whereas the posterior insula responded only to the overt presentation of the face associated with a painful electrical stimulation. This response pattern suggests that the anterior insula, the fusiform gyrus and the temporal sulcus cooperate with the amygdala in the unconscious processing of pain-conditioned stimuli.

• Modulation of alpha oscillations in insular cortex reflects the threat of painful stimuli.

  Authors: Raffaella Franciotti, Luca Ciancetta, Stefania Della Penna, Paolo Belardinelli, Vittorio Pizzella, Gian Luca Romani

  NeuroImage. 04/2009;

  Pain is a sensory and emotional experience that involves numerous brain areas. Among these areas the insular cortex has been shown to be involved in the expectation and processing of pain. AlphaPain is a sensory and emotional experience that involves numerous brain areas. Among these areas the insular cortex has been shown to be involved in the expectation and processing of pain. Alpha power modulation has been associated with the experience of pain. The aim of this study was to test the hypothesis that the threat of a painful stimulus affects alpha rhythm oscillation in the insular cortex and to find the time intervals during which the insular cortex is most active. We used a beamforming method in the frequency domain to estimate alpha power associated with source activity during psychologically different conditions, namely a sequence of nonpainful somatosensory stimuli (non-threatening condition) and a sequence of nonpainful stimuli randomly intermixed with painful stimuli (threatening condition). The results revealed that the anterior insula alone was involved during the threat of painful stimuli. Conversely, the posterior insula - as well as other brain areas such as SII - was involved in the processing of somatosensory stimuli regardless their painfulness. Additionally, the involvement of the anterior insula should not be accounted for by fear, arousal, habituation effect or by the occurrence of randomly interleaved different stimuli, but it is likely to be related mainly to expectancy mechanisms enhancing activity of specific neuronal populations.

• Neuromagnetic functional coupling during dichotic listening of speech sounds.

  Authors: Alfredo Brancucci, Stefania Della Penna, Claudio Babiloni, Fabrizio Vecchio, Paolo Capotosto, Davide Rossi, Raffaella Franciotti, Kathya Torquati, Vittorio Pizzella, Paolo M Rossini, Gian Luca Romani

  Human brain mapping. 04/2008; 29(3):253-64.

  The present magnetoencephalography (MEG) study tested the hypothesis of a phase synchronization (functional coupling) of cortical alpha rhythms (about 6-12 Hz) within a "speech" cortical neuralThe present magnetoencephalography (MEG) study tested the hypothesis of a phase synchronization (functional coupling) of cortical alpha rhythms (about 6-12 Hz) within a "speech" cortical neural network comprising bilateral primary auditory cortex and Wernicke's areas, during dichotic listening (DL) of consonant-vowel (CV) syllables. Dichotic stimulation was done with the CV-syllable pairs /da/-/ba/ (true DL, yielded by stimuli having high spectral overlap) and /da/-/ka/ (sham DL, obtained with stimuli having poor spectral overlap). Whole-head MEG activity (165 sensors) was recorded from 10 healthy right-handed non-musicians showing right ear advantage in a speech DL task. Functional coupling of alpha rhythms was defined as the spectral coherence at the following bands: alpha 1 (about 6-8 Hz), alpha 2 (about 8-10 Hz), and alpha 3 (about 10-12) with respect to the peak of individual alpha frequency. Results showed an inverse pattern of functional coupling: during DL of speech sounds, spectral coherence of the high-band alpha rhythms increased between left auditory and Wernicke's areas with respect to sham DL, whereas it decreased between left and right auditory areas. The increase of functional coupling within the left hemisphere would underlie the processing of the syllable presented to the right ear, which arrives to the left auditory cortex without the interference of the other syllable presented to the left ear. Conversely, the decrease of inter-hemispherical coupling of the high-band alpha might be due to the fact that the two auditory cortices do not receive the same information from the ears during DL. These results suggest that functional coupling of alpha rhythms can constitute a neural substrate for the lateralization of auditory stimuli during DL.

• Lateralization of dichotic speech stimuli is based on specific auditory pathway interactions: neuromagnetic evidence.

  Authors: Stefania Della Penna, Alfredo Brancucci, Claudio Babiloni, Raffaella Franciotti, Vittorio Pizzella, Davide Rossi, Kathya Torquati, Paolo M Rossini, Gian Luca Romani

  Cerebral cortex (New York, N.Y. : 1991). 11/2007; 17(10):2303-11.

  Dichotic listening (DL) is a neuropsychological technique for the study of functional laterality. Based on behavioral patient studies, the "structural theory" states that lateralization of theDichotic listening (DL) is a neuropsychological technique for the study of functional laterality. Based on behavioral patient studies, the "structural theory" states that lateralization of the auditory input during DL is allowed by an inhibition of the ipsilateral pathways. We aimed here at extending this theory to provide a neurophysiological basis of verbal DL. We investigated the magnetic responses of the primary auditory cortices elicited by dichotic consonant-vowel syllables. Dichotic stimuli consisted of 2 syllables pairs, a "competing" one composed by syllables with high spectral overlap (/da/ and /ba/) and a "noncompeting" pair (/da/ and /ka/). One of the syllables in each pair was delivered at 2 intensities, whereas the other did not change. A reduced increase of source intensity in response to dichotic pairs at the 2 levels was assumed to indicate pathway inhibition effects. We obtained that the left ipsilateral pathway (i.e., the left ipsilateral signal) was strongly inhibited by the right contralateral one. Conversely, the right ipsilateral pathway did not show an inhibition larger than the left contralateral one. These results extend the notion of auditory functional asymmetries by showing that beyond hemispheric functional specialization there is an asymmetry within the ascending auditory system, which is based on a competition mechanism. The larger the competition between the left and right ear stimuli, the larger are the inhibition effects, which determine the pathway asymmetry. These findings represent as well a neurophysiological basis for the "structural theory" explaining the right ear preference usually found in verbal DL tasks.

• Temporal dynamics of plastic changes in human primary somatosensory cortex after finger webbing.

  Authors: Maria L Stavrinou, Stefania Della Penna, Vittorio Pizzella, Kathya Torquati, Francesco Cianflone, Raffaella Franciotti, Anastasios Bezerianos, Gian Luca Romani, Paolo Maria Rossini

  Cerebral cortex (New York, N.Y. : 1991). 10/2007; 17(9):2134-42.

  The primary somatosensory cortex (SI) exhibits a detailed topographic organization of the hand and fingers, which has been found to undergo plastic changes following modifications of the sensoryThe primary somatosensory cortex (SI) exhibits a detailed topographic organization of the hand and fingers, which has been found to undergo plastic changes following modifications of the sensory input. Although the spatial properties of these changes have been extensively investigated, little is known about their temporal dynamics. In this study, we adapted the paradigm of finger webbing, in which 4 fingers are temporarily webbed together, hence modifying their sensory feedback. We used magnetoencephalography, to measure changes in the hand representation in SI, before, during, and after finger webbing for about 5 h. Our results showed a decrease in the Euclidean distance (ED) between cortical sources activated by electrical stimuli to the index and small finger 30 min after webbing, followed by an increase lasting for about 2 h after webbing, which was followed by a return toward baseline values. These results provide a unique frame in which the different representational changes occur, merging previous findings that were only apparently controversial, in which either increases or decreases in ED were reported after sensory manipulation for relatively long or short duration, respectively. Moreover, these observations further confirm that the mechanisms that underlie cortical reorganization are extremely rapid in their expression and, for the first time, show how brain reorganization occurs over time.

• Evaluation of cortical connectivity during real and imagined rhythmic finger tapping.

  Authors: Maria L Stavrinou, Liviu Moraru, Laura Cimponeriu, Stefania Della Penna, Anastasios Bezerianos

  Brain topography. 02/2007; 19(3):137-45.

  Accumulating evidence suggests the existence of a shared neural substrate between imagined and executed movements. However, a better understanding of the mechanisms involved in the motor executionAccumulating evidence suggests the existence of a shared neural substrate between imagined and executed movements. However, a better understanding of the mechanisms involved in the motor execution and motor imagery requires knowledge of the way the co-activated brain regions interact to each other during the particular (real or imagined) motor task. Within this general framework, the aim of the present study is to investigate the cortical activation and connectivity sub-serving real and imaginary rhythmic finger tapping, from the analysis of multi-channel electroencephalogram (EEG) scalp recordings. A sequence of 250 auditory pacing stimuli has been used for both the real and imagined right finger tapping task, with a constant inter-stimulus interval of 1.5 s length. During the motor execution, healthy subjects were asked to tap in synchrony with the regular sequence of stimulus events, whereas in the imagery condition subjects imagined themselves tapping in time with the auditory cue. To improve the spatial resolution of the scalp fields and suppress unwanted interferences, the EEG data have been spatially filtered. Further, event related synchronization and desynchronization phenomena and phase synchronization analysis have been employed for the study of functionally active brain areas and their connectivity during real and imagery finger tapping. Our results show a fronto-parietal co-activation during both real and imagined movements and similar connectivity patterns among contralateral brain areas. The results support the hypothesis that functional connectivity over the contralateral hemisphere during finger tapping is preserved in imagery. The approach and results can be regarded as indicative evidences of a new strategy for recognizing imagined movements in EEG-based brain computer interface research.

• Human alpha rhythms during visual delayed choice reaction time tasks: a magnetoencephalography study.

  Authors: Claudio Babiloni, Fabio Babiloni, Filippo Carducci, Febo Cincotti, Claudio Del Percio, Stefania Della Penna, Raffaella Franciotti, Sandro Pignotti, Vittorio Pizzella, Paolo Maria Rossini, Elisabetta Sabatini, Kathya Torquati, Gian Luca Romani

  Human brain mapping. 04/2005; 24(3):184-92.

  Magnetoencephalography (MEG) includes fast and comfortable recording procedures very suitable for the neurophysiological study of cognitive functions in aged people. In this exploratory MEG study inMagnetoencephalography (MEG) includes fast and comfortable recording procedures very suitable for the neurophysiological study of cognitive functions in aged people. In this exploratory MEG study in normal young adults, we tested whether very simple short-term memory (STM) demands induce visible changes in amplitude and latency of surface alpha rhythms. Two delayed response tasks were used. In the STM condition, a simple cue stimulus (one bit) was memorized along a brief delay period (3.5-5.5 s). In the control (no short-term memory; NSTM) condition, the cue stimulus remained available along the delay period. To make extremely simple the tasks, the explicit demand was visuospatial but the retention could be also based on phonological and somatomotor coding. Compared to the control condition, the amplitude of the alpha 1 (6-8 Hz) ERD decreased in the left hemisphere, whereas the amplitude of the alpha 2 (8-10 Hz) and alpha 3 (10-12 Hz) event-related desynchronization (ERD) increased in right and left parietal areas, respectively. Furthermore, the latency of the alpha ERD peak was slightly but significantly (P < 0.05) later in STM compared to control condition. In conclusion, whole-head MEG technology and very simple STM demands revealed significant changes of human neuromagnetic alpha rhythms in normal young adults.

• Sampling and reconstruction schemes for biomagnetic sensor arrays.

  Authors: Adele Naddeo, Stefania Della Penna, Ciro Nappi, Emanuele Vardaci, Vittorio Pizzella

  Physics in medicine and biology. 10/2002; 47(18):N239-48.

  In this paper we generalize the approach of Ahonen et al (1993 IEEE Trans. Biomed. Eng. 40 859-69) to two-dimensional non-uniform sampling. The focus is on two main topics: (1) searching for theIn this paper we generalize the approach of Ahonen et al (1993 IEEE Trans. Biomed. Eng. 40 859-69) to two-dimensional non-uniform sampling. The focus is on two main topics: (1) searching for the optimal sensor configuration on a planar measurement surface; and (2) reconstructing the magnetic field (a continuous function) from a discrete set of data points recorded with a finite number of sensors. A reconstruction formula for Bz is derived in the framework of the multidimensional Papoulis generalized sampling expansion (Papoulis A 1977 IEEE Trans. Circuits Syst. 24 652-4, Cheung K F 1993 Advanced Topics in Shannon Sampling and Interpolation Theory (New York: Springer) pp 85-119) in a particular case. Application of these considerations to the design of biomagnetic sensor arrays is also discussed.

• Comparison between SI and SII responses as a function of stimulus intensity.

  Authors: Kathya Torquati, Vittorio Pizzella, Stefania Della Penna, Raffaella Franciotti, Claudio Babiloni, Paolo Maria Rossini, Gian Luca Romani

  Neuroreport. 06/2002; 13(6):813-9.

  In this MEG study we investigated the differences in responses to somatosensory electrical stimuli between primary (SI) and secondary (SII) sensory cortices using 10 different levels of stimulusIn this MEG study we investigated the differences in responses to somatosensory electrical stimuli between primary (SI) and secondary (SII) sensory cortices using 10 different levels of stimulus intensity, starting from below the sensory threshold up to a weak painful level. SI dipole source linearly increased in amplitude as the stimulus intensity raised up to a strong motor level and then saturated at higher stimulation levels. The contralateral and ipsilateral SII dipole source strengths followed the stimulus intensity growing up to the motor threshold, but showed a decrease at the strong motor level, followed by an increase as the stimulus intensity raised towards the weak painful threshold. These results suggest different responses of SI and SII cortices as the intensity of stimulation rises from non-painful to painful values.

• Brain structures activated by overt and covert emotional visual stimuli

  Authors: Elisabetta Sabatini, Stefania Della Penna, Raffaella Franciotti, Antonio Ferretti, Pierluigi Zoccolotti, Paolo M. Rossini, Gian Luca Romani, Guido Gainotti

  Brain Research Bulletin.

  Research data suggest that the amygdala and some related brain structures modulate the processing of emotional visual stimuli even when they are not consciously perceived.In this study, we examinedResearch data suggest that the amygdala and some related brain structures modulate the processing of emotional visual stimuli even when they are not consciously perceived.In this study, we examined neural responses to investigate whether and how other brain areas anatomically connected to the amygdala might become activated during both overt and covert presentation of conditioned emotional visual stimuli. In the covert presentation, a conditioned angry face was shown for 15 ms followed by a neutral masking face (CSmask). In the overt condition, an angry face associated with a painful stimulus (CS+), a happy (H) and a neutral face (N) were presented for 75 ms.Based on results of functional magnetic resonance imaging (fMRI) in 10 healthy volunteers, we show evidence that a network of brain structures anatomically connected to the amygdala (including the anterior insula, the fusiform gyrus and the superior temporal sulcus) are involved in the subliminal processing of visual emotional stimuli. Of particular interest was the dissociation between the anterior and posterior insula: the anterior insula responded to both overt and covert presentation of the conditioned stimulus, whereas the posterior insula responded only to the overt presentation of the face associated with a painful electrical stimulation. This response pattern suggests that the anterior insula, the fusiform gyrus and the temporal sulcus cooperate with the amygdala in the unconscious processing of pain-conditioned stimuli.