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Brain topography, connectivity dynamics and coding mechanisms underlying the subjective experience of affective states

Lettieri, Giada (2019) Brain topography, connectivity dynamics and coding mechanisms underlying the subjective experience of affective states. Advisor: Pietrini, Prof. Pietro. Coadvisor: Cecchetti, Dr. Luca . pp. 178. [IMT PhD Thesis]

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Abstract

The present dissertation focuses on the behavioral and neural substrates of socio-affective abilities involved in the subjective emotional experience. Socio-affective abilities are the building blocks of the more general domain of social cognition, which represents the cornerstone of human interactions. In particular, understanding, predicting and responding to others’ emotional signals are fundamental aspects necessary for the optimal functioning of human’s daily life. Emotions are pervasively present in dyadic interactions, give color to individual experiences, and can rapidly change over time, as they are the consequence of an active interplay between an individual and the environment. Despite their relevance, however, emotions are still an open question for researchers. Indeed, which mechanisms link descriptions of affective states to brain activity is still unclear, with evidence supporting either local or distributed processing. Moreover, the majority of neuroimaging studies so far did not take into account the dynamism of affective states and their unfolding over time. For this reason, how the temporal characteristics of emotions (e.g., duration, onset, resurgence) are represented in the brain, with the dynamics between specific regions related to different emotional experiences is an open question. In light of all this, the studies reported in the present dissertation aimed to overcome previous limitations and answer these questions. In the first study we used brain hemodynamic activity evoked by an emotionally charged movie and continuous ratings of the perceived emotion intensity to reveal the topographic organization of affective states. In the second study, we explored the dynamic interplay between different brain regions throughout a naturalistic situation. To do so, we related continuous ratings of the perceived intensity of various emotional states to changes in functional connectivity among distinct brain regions during the watching of the same movie employed before. Our results showed that moment-by-moment ratings of perceived emotions explain brain activity recorded in independent subjects. Most importantly, we demonstrated the existence of orthogonal and spatially overlapping right temporo-parietal gradients encoding emotion dimensions, a mechanism that we named emotionotopy. We also unveiled the central role of the right precentral sulcus during the subjective emotional experience, with changes in the functional connectivity dynamics of this region being modulated by three cardinal emotion dimensions.

Item Type: IMT PhD Thesis
Subjects: R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
PhD Course: Cognitive, Computational and Social Neurosciences
Identification Number: 10.6092/imtlucca/e-theses/294
NBN Number: urn:nbn:it:imtlucca-27316
Date Deposited: 27 Feb 2020 14:16
URI: http://e-theses.imtlucca.it/id/eprint/294

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