Abstract
Humans are highly skilled in processing temporal information. This is particularly visible in our compelling sense of rhythm that manifests in our tendency to move to the beat of music. Deliberately or spontaneously, we have a tendency to clap our hands, tap our feet, or dance with music. These skills are sustained by a complex neuronal network involving auditory regions (auditory cortex, superior temporal gyrus), motor and pre-motor areas (basal ganglia, motor and pre-motor cortices), as well as motor coordination regions (e.g., the cerebellum). However, rhythm skills can be disrupted in neurological diseases like Parkinson’s disease or in neuro-developmental diseases such as dyslexia. Rhythm deficits are associated with movement and cognitive disorders. Another form of rhythm disability is beat deafness, a specific condition in which healthy individuals encounter particular difficulties in synchronizing to the beat.In this dissertation, I aim at addressing two questions. First, is it possible to extend our knowledge of inter-individual differences to rhythm skills in order to better understand mechanisms underlying rhythmic processing with a systematic tool? Second, can rhythm skills be trained in order to improve the associated motor and cognitive domains in patient populations revealing rhythm disorders?In the first part of the experimental section, I used the Battery for the Assessment of Auditory Sensorimotor and Timing Abilities (BAASTA) to systematically test and characterize subjects’ perceptual and sensorimotor timing skills. I found that the results of some tasks were highly correlated with the ones of other tasks and that, on the contrary, some tasks were totally independent from each other. This reveals that the battery can discriminate between tasks involving different and common mechanisms. In a further study, 20 healthy adults were submitted twice to BAASTA at a two-week interval. The performance in most of the tasks remained stable at retest. Finally, BAASTA was used in beat-deaf individuals. I showed that two individuals performed poorly on rhythm perception tasks, such as detecting or estimating whether a metronome is aligned to the beat of the music or not (Beat Alignment Test [BAT]). Yet, they could tap to the beat of the same stimuli. The fact that synchronization to a beat can occur in the presence of poor perception is reported for the first time in this study. On top of that, beat-deaf participants benefited similarly to controls from a regular temporal pattern (implicit timing) in a task in which they had to respond as fast as possible to a different target pitch after a sequence of standard tones.In the second part of the experimental section, I present a serious game for training rhythmic skills (Rhythm Workers) designed during the doctorate. I developed a progressive rhythm training protocol with stimuli varying in rhythmic difficulty. I conducted a proof-of-concept pilot study on 20 individuals who played the game for 15 days. Participants in the experimental groups showed high compliance and motivation in playing the game. Encouraging results were found on the evolution of their rhythmic skills, as tested with the BAT taken from BAASTA that was submitted to the participants before and after the training.In sum, in this dissertation contributed to the development of tools for the assessment and training of rhythmic skills. This enabled us to design studies to better understand rhythm processing mechanisms and to pave the way for the use of rhythm games in cognitive and motor remediation and rehabilitation.