In questa pagina trovate tutte le pubblicazioni in riviste con revisione scientifica in cui sono uno degli autori. Gli articoli sono in ordine di data di pubblicazione. Buona lettura!
Excitability of motor cortices as a function of emotional sounds
(Eccitabilità della corteccia motoria in funzione di suoni emozionali)
Autori: Komeilipoor Naeem, Pizzolato Fabio, Daffertshofer Andreas, Cesari Paola
Rivista: PLoS One, Volume 8, Fascicolo 5, Pagine e63060
Data: Maggio 2013
Abstract: We used transcranial magnetic stimulation (TMS) to clarify how non-verbal emotionally-characterized sounds modulate the excitability of the corticospinal motor tract (CST). While subjects were listening to sounds (monaurally and binaurally), single TMS pulses were delivered to either left or right primary motor cortex (M1), and electromyographic activities were recorded from the contralateral abductor pollicis brevis muscle. We found a significant increase in CST excitability in response to unpleasant as compared to neutral sounds. The increased excitability was lateralized as a function of stimulus valence: Unpleasant stimuli resulted in a significantly higher facilitation of motor potentials evoked in the left hemisphere, while pleasant stimuli yielded a greater CST excitability in the right one. Furthermore, TMS induced higher motor evoked potentials when listening to unpleasant sounds with the left than with the right ear. Taken together, our findings provide compelling evidence for an asymmetric modulation of CST excitability as a function of emotional sounds along with ear laterality.
Observing expertise-related actions leads to perfect time flow estimations
(L’osservazione di azioni relative all’esperienza consentono una stima perfetta dello scorrimento del tempo)
Autori: Chen Yin Hua, Pizzolato Fabio, Cesari Paola.
Rivista: PLoS One, Volume 8, Fascicolo 2, Pagine e55294.
Data: Febbraio 2013.
Abstract: The estimation of the time of exposure of a picture portraying an action increases as a function of the amount of movement implied in the action represented. This effect suggests that the perceiver creates an internal embodiment of the action observed as if internally simulating the entire movement sequence. Little is known however about the timing accuracy of these internal action simulations, specifically whether they are affected by the level of familiarity and experience that the observer has of the action. In this study we asked professional pianists to reproduce different durations of exposure (shorter or longer than one second) of visual displays both specific (a hand in piano-playing action) and non-specific to their domain of expertise (a hand in finger-thumb opposition and scrambled-pixels) and compared their performance with non-pianists. Pianists outperformed non-pianists independently of the time of exposure of the stimuli; remarkably the group difference was particularly magnified by the pianists’ enhanced accuracy and stability only when observing the hand in the act of playing the piano. These results for the first time provide evidence that through musical training, pianists create a selective and self-determined dynamic internal representation of an observed movement that allows them to estimate precisely its temporal duration.
Motor system modulation for movement direction and rotation angle during motor imagery
(Modulazione del sistema motorio per la direzione e la rotazione angolare durante l’immaginazione motoria)
Autori: Pizzolato Fabio, Mirta Fiorio, Paola Cesari
Rivista: Neuroscience, Volume 218, Pagine 154-160
Data: Agosto 2012
Abstract: Transcranial magnetic stimulation (TMS) studies have shown that the motor system is facilitated when we imagine performing motor actions. However, it is not clear whether the individual’s motor system modulates bilaterally and selectively for task parameters, such as movement direction and amplitude. To investigate this issue, we applied single-pulse TMS over the left and right primary motor cortex (M1) of healthy subjects, who had to imagine grasping and rotating a clock hour hand, having a starting position at noon, towards four different times: 2, 5, 7 and 10 o’clock. Rotations could be in clockwise (2 and 5 o’clock) or counter-clockwise (7 and 10 o’clock) directions and could require small (2 and 10 o’clock) or large (5 and 7 o’clock) rotation angle. TMS motor-evoked potentials were recorded for three muscles, and movements were imagined with the right and left hands. Results showed that during motor imagery a mirroring pattern was present between the right and the left motor cortices, showing selective activation of the hand-intrinsic muscles spatially close to the direction of the imagined movement. Overall a higher activation for large and a lower activation for small rotation angle were found, but no selective muscle activity was present within the hand-intrinsic muscles for this parameter. Following these results we propose that during action imagination an internally coded covariance between movement parameters is present with a muscle-specific activation for movement direction.
Kinematic analysis of soccer players in shuttle running
(Analisi cinematica di giocatori di calcio nella corsa a navetta)
Autori: Padulo Johnny , D’Ottavio S., Pizzolato Fabio, Smith L., Annino G.
Rivista: International journal of sports medicine, Volume 33, Fascicolo 6, Pagine 459-462
Data: Giugno 2012
Abstract: The intermittent shuttle running test is mainly used within soccer to assess aerobic power. For this reason we studied kinematic parameters and heart rate at both an increasing speed, [Yo-Yo Endurance Level 1 (Y₁)] and at constant velocity [95% maximal aerobic velocity (MAV(95%))]. 12 soccer players were selected for this study. A high-speed digital camera (210 Hz) was used to record motion; Dartfish5.5 Pro was used to perform 2D video analysis and heart rate was also recorded and computed during the test. The parameters considered (baseline measures with respect to the end of each test) in this study were: step length (SL), contact time (CT) and heart rate (HR). SL: 40% in Y1 and -22% in MAV(95%). CT: -31% in Y1 and 29% in MAV(95%). HR: increased 96% in Y1 and 17% in MAV(95%). These results highlight 2 different neuromechanical strategies adopted under fatigued conditions. In light of the clear changes of the CT in MAV(95%) (29%) and with respect to the moderate changes in HR (17%) it is clear that the CT is the most important parameter, as it experiences greater adaptations associated with neuromuscular patterns, under a fatigued condition as opposed to HR.
Grip-dependent cortico-spinal excitability during grasping imagination and execution
(Eccitabilità cortico-spinale dipendente dalla presa durante l’esecuzione e l’immaginazione)
Autori: Cesari Paola, Pizzolato Fabio, Fiorio Mirta.
Rivista: Neuropsychologia, Volume 49, Fascicolo 7, Pagine 2121-30.
Data: Gennaio 2011
Abstract: Studies converge in indicating a substantial similarity of the rules and mechanisms underlying execution, observation and imagery of actions, along with a large overlapping of their neural substrates. Recent transcranial magnetic stimulation (TMS) studies have demonstrated a muscle-specific facilitation of the observer’s motor system for force requirement and type of grip during grasping observation. However, whether similar fine-tuned muscle-specificity occurs even during imagination, when subjects are free to select the most convenient grip configuration, is still unknown. Here we applied TMS over the primary motor cortex and measured the corticospinal excitability (MEP) in three muscles (FDI, ADM and FDS) while subjects imagined grasping spheres of different dimensions and materials. This range of object weights and sizes (diameters) allowed subjects to freely imagine the most suitable grip configuration among several possibilities. Activation measured during grasping imagination has been also compared to that obtained during real execution (EMG recorded from the same muscles). We found that during imagination of grasping small objects, the FDI muscle was more active than the ADM and the FDS, whereas the opposite pattern was found for big objects. Imagination of medium size objects, instead, required an equal involvement of the three muscles. The same pattern was observed when subjects were asked to perform the action. This suggests that during imagination, the cortico-spinal system is modulated in a muscle-specific/grip-specific way, as if the action would be really performed. However, when force was required (i.e., for the aluminum objects), the motor activation obtained during action execution was more fine-tuned to object dimensions than the facilitation recorded during imagination, suggesting a separate control of force production.