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Tesi etd-02062013-125119


Thesis type
Tesi di dottorato di ricerca
Author
BERNARDI, GIULIO
URN
etd-02062013-125119
Title
Brain functional and structural reorganization induced by intensive training and exposition to extreme conditions: a study on professional race-car drivers
Settore scientifico disciplinare
BIO/12
Corso di studi
NEUROSCIENZE E SCIENZE ENDOCRINOMETABOLICHE
Commissione
tutor Prof. Pietrini, Pietro
Parole chiave
  • expertise
  • drivers
  • connectivity
  • brain plasticity
  • bold variability
  • athletes
  • fMRI
  • intersubject correlation
  • skills
Data inizio appello
11/02/2013;
Consultabilità
completa
Riassunto analitico
The present work was designed to investigate the brain functional and structural correlates subserving top-level performances in highly skilled individuals. Specifically, we studied a particular class of elite athletes exposed to intensive psycho-physical trainings and extremely demanding conditions, namely Formula racing car drivers. As a matter of fact, these athletes ordinarily undergo intensive physical and mental trainings, and are exposed to extreme competitive conditions (e.g., accelerations 0-100 km/h in less than 2 seconds, top speeds up to 360 km/h, need for sustained attention and accurate sensorimotor control, etc.), and therefore represent an exceptional sample to study the brain correlates of skills acquisition. <br>In a first experiment, we used functional magnetic resonance imaging (fMRI) to measure brain activity while professional drivers and a matched group of ‘naïve’ volunteers performed two relatively simple visuo-motor tasks. Three different aspects have been examined to characterize the brain functional organization of these subjects: regional brain response, inter-regional interaction and blood oxygen level dependent (BOLD) signal variability. We demonstrated that, while behavioral performance levels were similar in the two samples, race-car drivers recruited to a smaller extent task-related areas, as compared to naïve drivers. Moreover, professional drivers showed reinforced connections among task-related areas and increased brain operative efficiency as reflected by a higher signal variability. The described results indicate that, during visuo-spatial and motor processing, professional drivers are characterized by distinctive functional correlates, with both ‘quantitative’ and ‘qualitative’ modifications, as compared to naïve drivers. <br>To further explore the brain functional organization developed as a consequence of expertise acquisition of a specific behavior, we designed a second experiment during which ten professional race-car drivers and nine healthy naïve volunteers underwent fMRI scans while presented with four video-clips depicting a Formula One car racing on different official circuits. Analyses of functional brain response and inter-regional interaction revealed that professional drivers were characterized by a stronger recruitment of prefrontal and motor control devoted areas as compared to non-expert drivers. On the other hand, naïve drivers showed a robust response only in brain regions involved in visual information processing. As a matter of fact, previous studies demonstrated that passive observation of complex motor behaviors elicits a brain functional response that essentially overlaps with the one revealed during actual execution of the same activities, but only if the observer has acquired a certain degree of expertise in the specific task. In this perspective, our findings indicate that only professional drivers, that have been trained specifically in car racing, were able to effectively compare their motor repertoire with specific situations presented in a race-car driving task. <br>Finally, we investigated brain anatomical differences between expert and naïve drivers. Specifically, we measured and compared gray matter cortical thickness in the two groups, revealing that professional drivers are characterize by an increased gray matter volume in areas involved in visuo-spatial processing and motor control.<br>Overall, findings described in the present work indicate that skilled race-car drivers are characterized by distinctive functional and structural correlates as compared to ‘common’ individuals with an ordinary driving experience. We concluded that expertise acquisition is founded on a series of plastic changes that allow the storing of new motor and cognitive repertoires and the refinement of the existing ones. Specifically, we demonstrated the existence of at least three different potential markers of superior skills and expertise levels: an increased neural efficiency during relatively simple tasks in which experts show a higher degree of automaticity, a more distributed functional response during passive observation of complex behavior in which only the professional group was specifically trained, and a greater cortical thickness in brain areas devoted to sensorimotor processing.
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