Silvia Seghezzi ha conseguito con lode la Laurea Magistrale in Psicologia Clinica, dello Sviluppo e Neuropsicologia presso l’Università degli Studi di Milano Bicocca, nell’Ottobre 2016. È attualmente dottoranda di ricerca in Neuropsicologia Clinica sotto la supervisione del Professor Eraldo Paulesu. Il suo principale ambito di interesse attiene alla fisiologia – normale e patologica – del controllo motorio, con particolare attenzione allo studio dei processi motori intenzionali e al senso di agentività. L’indagine di questi costrutti è condotta attraverso tecniche di meta-analisi, neuroimaging funzionale (fMRI) e di stimolazione cerebrale non invasiva (TMS), in soggetti sani e patologici (Tourette Syndrome). Si occupa, inoltre, dell’indagine dei correlati neurali dell’immaginazione motoria in soggetti ortopedici.
PROGETTO DI RICERCA
The sense of agency in normal and pathological populations: meta-analytical, behavioural and neurofunctional evidence
- Curriculum: Neuroscienze Cliniche
- Tutor: Prof. Eraldo Paulesu
- Supervisor: Dott.ssa Laura Zapparoli
AIMS: The aim of this project is to provide new knowledge in the area of intentional motor control and agency by means of behavioural tests combined with advanced fMRI and non-invasive brain stimulation methods (TMS), in both healthy controls and neurological patients characterized by deficits in the domain of intentional actions (e.g. Tourette Syndrome).
BACKGROUND: Willed Action can be divided in a number of phenomena: from the emergence of intention and the ensuing motor plans and action; to the monitoring of action outcomes and their congruency with intention; to the final emergence of a sense of agency. In this framework, intentionality and sense of agency should occur at different stages in the normal generation of willed actions: the former should be associated with cognitive processes occurring before action execution; the sense of agency should arise after the comparison between intentions and some evidence about the performed action, when it becomes available. Both intentionality and sense of agency have been associated with a fronto-parietal motor network. However, no study has investigated whether the two processes can be dissociated at the neural level. Furthermore, despite a large number of behavioural studies, there is limited and unsatisfactory evidence on the functional anatomical underpinnings of the sense of agency itself. A systematization might contribute to better understand all the facets of the agency experience, as well as the actual role of different cortical structures in relation to the different aspects of the agency-related processes, in both healthy subjects and pathological population. For example, the several impaired aspects of volitional motor control suggest an abnormal sense of agency in Tourette Syndrome patients. TSs patients’ life is impaired by unwanted movements and a varying degree of obsessive-compulsive symptoms: I expect TSs to show condition-specific deficits of the sense of agency and a perturbed task-dependent sensorial modulation of it.
METHODS: The present research project is divided in four different sub-experiments, each one partially independent from the others.
First, I will perform a systematic review of the literature with a meta-analytic approach using a hierarchical clustering algorithm. The meta-analysis will be based on neuroimaging articles investigating the neurofunctional correlates of intentionality and agency I will test the hypothesis of distinct neural correlates for motor intentionality and sense of agency.
The second experiment will be based on an implicit measurement of the sense of agency, the intentional binding phenomenon (IB), and its neurofunctional modulations. IB, as defined by Haggard in 2002, refers to the subjective compression of the temporal interval between a voluntary action and its consequence. 24 adult healthy subjects will perform a temporal-judgment-task in an event-related fMRI setting. I will test the interaction between agency and causality and their modulatory effect within premotor and somatosensory cortices which have been previously associated with explicit attributions of self-agency. This will be assessed by using the trial by trial judgement error as a parametric regressor over the fMRI BOLD response.
In the third experiment non-invasive brain stimulation will be used in order to provide insight into the specific causal role of the cortical structures identified by the previous meta-analytical and fMRI experiments. High frequency rTMS will be used in order to investigate the neural substrates involved in SoA by measuring the effects of locally disrupting brain activity on the IB effect during the previous temporal-judgment-task that I’m going to use in the fMRI experiment. I aim to stimulate specific areas within premotor and somatosensory cortices, by placing the coil above activation peaks which will be found in the fMRI study using the same behavioural task.
Finally, the behavioural and fMRI paradigm will be administered to adult Tourette Syndrome patients (TSs). Patients’ performance in specific scales for tics and OCD symptoms will be correlated with the fMRI patterns.
The results will be discussed with regard to a more comprehensive neuro-cognitive model of motor awareness.
PUBBLICAZIONI E PARTECIPAZIONI A CONGRESSI RECENTI
- Zapparoli L, Seghezzi S, Paulesu E. The What, the When, and the Whether of Intentional Action in the Brain: A Meta-Analytical Review. Front Hum Neurosci 2017; 11: 238. DOI: 10.3389/fnhum.2017.00238
- Zapparoli L, Seghezzi S, Scifo P, Zerbi A, Banfi G, Tettamanti M, Paulesu E. Dissecting the neurofunctional bases of intentional action. PNAS. 2018 Jul 10;115(28):7440-7445.
- Seghezzi S., Zapparoli L. and Paulesu E. Agency and Intentionality in the brain: a meta-analytical review. European Workshop of Cognitive Neuropsychology. Brixen, 21-26 January 2018. Oral presentation.
- Zapparoli L., Seghezzi S., Zirone E., Sconfienza L.M., Banfi G. and Paulesu E. The sense of agency: behavioural and neurofunctional correlates. European Workshop of Cognitive Neuropsychology. Brixen, 21-26 January 2018. Poster session.
- Seghezzi S., Sacheli L.M., Zapparoli L., Stucovitz E., Preti M., Pelosi C., Ursino N., Zerbi A., Banfi G. and Paulesu E. Behavioral, clinical and neuro-functional effects of motor imagery in the rehabilitation of walking. 6th Conference of the SINP, Palermo, 24-25 November 2017. Poster Session.