Contribution of Vision and Proprioception to the Precision of Reaching Movements

Ren and colleagues (2006) found that saccades to visual targets became less accurate when somatosensory information about hand location was added, suggesting that saccades rely mainly on vision. We conducted two kinematic experiments to examine whether or not reaching movements would also show such strong reliance on vision. In Experiment 1, subjects used their dominant right hand to perform reaches, with or without a delay, to an external visual target or to their own left fingertip positioned either by the experimenter or by the participant. Unlike saccades, reaches became more accurate and precise when proprioceptive information was available. In Experiment 2, subjects reached toward external or bodily targets with differing amounts of visual information. Proprioception improved performance only when vision was limited. Our results indicate that reaching movements, unlike saccades, are improved rather than impaired by the addition of somatosensory information.

La memoria risorgimentale in Giustizia e Libertà (1929-1940)

The dissertation regards The memory on the Italian Risorgimento in “Justice and Freedom”(1929-1940) a theoretical core point in the history of the Movement, which so far has not been granted due attention. The work herewith presented is therefore aimed at filling a storiographical gap, analysing the historical events which continue to operate as traditions, raising feelings and passions and hence operating in politics, although as secondary factors. The point made is that the Justice and Freedom Movement, an antifascist political movement born in Paris in October 1929, bases its strength on the heroic choice of the antifascism movement to fight a Second Risorgimento, connecting the fight against the regime to the battles previously fought for the justice and the freedom, an entirely isolated event in the political opposition’s panorama. The dissertation, thus, attempts to explain how and why Justice and Freedom is so tightly interconnected in its political action to the Risorgimento tradition. The first chapter sets the cultural background of the foundation of the Justice and Freedom Movement. The centre of such foundation was Florence, where Gaetano Salvemini, along with a group of young people, would later on carry out some cultural experiences that ideally prepare the ground for the movement’s birth. In the second chapter are found the sites of the memory where the passage of the Risorgimento tradition between the generations takes place. The work therefore shifts from a public to a private level, concentrating on biographical paths. The choice made was for Nello Rosselli, a man very close to the Justice and Freedom Movement but who, as opposed to his comrades-in-arms, did not chose the political way to express his ethical choice, but rather the theoretical one, becoming a Risorgimento historian. The third chapter concentrates on the birth of the Justice and Freedom Movement in France, trying to reconstruct the cultural ties and the confrontation places and sites where the members of the Movement could interact with the French intellectual milieu, bringing back to light the propagandistic usage of the Risorgimento myth carried out by the Movement. Lastly, the fourth chapter focuses on the cultural debate on the Risorgimento, which took place on the press organs of the Movement, pointing out and periodizing the theoretical passages and the propagandistic uses of the myth as related to the stages of the Movement and the political needs.

Congenital Nystagmus eye movements analysis and oculomotor system models evaluation

The term Congenital Nystagmus (Early Onset Nystagmus or Infantile Nystagmus Syndrome) refers to a pathology characterised by an involuntary movement of the eyes, which often seriously reduces a subject’s vision. Congenital Nystagmus (CN) is a specific kind of nystagmus within the wider classification of infantile nystagmus, which can be best recognized and classified by means of a combination of clinical investigations and motility analysis; in some cases, eye movement recording and analysis are indispensable for diagnosis. However, interpretation of eye movement recordings still lacks of complete reliability; hence new analysis techniques and precise identification of concise parameters directly related to visual acuity are necessary to further support physicians’ decisions. To this aim, an index computed from eye movement recordings and related to the visual acuity of a subject is proposed in this thesis. This estimator is based on two parameters: the time spent by a subject effectively viewing a target (foveation time - Tf) and the standard deviation of eye position (SDp). Moreover, since previous studies have shown that visual acuity largely depends on SDp, a data collection pilot study was also conducted with the purpose of specifically identifying eventual slow rhythmic component in the eye position and to characterise in more detail the SDp. The results are presented in this thesis. In addition, some oculomotor system models are reviewed and a new approach to those models, i.e. the recovery of periodic orbits of the oculomotor system in patients with CN, is tested on real patients data. In conclusion, the results obtained within this research consent to completely and reliably characterise the slow rhythmic component sometimes present in eye position recordings of CN subjects and to better classify the different kinds of CN waveforms. Those findings can successfully support the clinicians in therapy planning and treatment outcome evaluation.