Phd in PHD PROGRAM IN BEHAVIORAL NEUROSCIENCE

Thesis title: From perception to action and back: Finding harmony in time-space domains of human behaviour

This PhD thesis was aimed at studying the organization of human behavior through a series of experiments that fall within the perception-action topic. This investigation had two levels of analysis: on the one hand, the concept of harmony was used as a method of analysis; on the other hand, harmony was the subject of investigation. However, within the human behavioral repertoire, it was chosen to focus on a specific behavior: human walking. This choice is motivated by the fact that some of its harmonic properties are well known, which are also common to dynamic systems, namely fractality. In fact, human locomotion represents a stable, repeatable behavior, characterized by sub-phases that mark the gait cycle that have the property of self-similarity. This property can also be found in the relationship between the duration of the gait cycle phases and has recently been identified in the irrational number phi (φ) 1.618032 ... In the first chapters, this proportion was investigated in a psychophysical task of visual stimuli perception (Chapter 1) and in the gait ratio of different locomotor tasks (Chapter 2). In the following experiments, the study of another harmonic property of the gait, the fluidity, has been deepened, in relation to the production of a cognitive rhythm mimicking the locomotor one (Chapter 3); and of the perception of an external rhythm that can instead regulate the progress of walking (Chapter 4). In the final part of this thesis, the investigation of walking complexity was made in relation to the entrainment between physiological and cognitive systems (Chapter 5) and, finally, considering it as a phenomenon emerging from the interaction between man-environment, comparing two possible development trajectories (Chapter 6).