Neuroscience of Rhythm
Current work in the neuroscience of rhythm perception and rhythmic synchronization mechanisms has produced results in 3 major areas:
- Empirical data and computational modeling of how the brain synchronizes rhythmic movement to external rhythm
- Evidence for subliminal perception of auditory timing information below the level of conscious perception, which the brain nevertheless uses to guide the timing of rhythmic movement
- Brain mapping using PET and fMRI technology to describe neural networks involved in rhythmic synchronization
In conjunction with groups in Germany (Duesseldorf University: Department of Neurology and Neurological Therapy Center; Federal Research Center Juelich)and Italy (IRCCS Santa Lucia and IESS-CNR, Rome) we have been able to map the cortical and subcortical areas in the brain, involving parieto-thalamic, cerebellar, and frontal networks, that are active and contribute to the process of auditory rhythm perception and rhythmic motor synchronization. These studies into brain function have also revealed the different neuroanatomical areas active during different levels of perceptual awareness and consciousness in the brain when processing external sensory information. The different levels of human consciousness appear to be linked to differential activation patterns in the prefrontal cortex. We showed how even subliminal auditory timing information is processed in the auditory cortex and translated into precise changes in the timing of movement without cognitive awareness and learning. We recently developed a data driven model, which models mathematically the strong and fast physiological attractor or ‘magnet’ function of auditory rhythm to influence the timing of movement. All these studies, employing neurophysiological data recording such as PET, fMRI and Magnetic and Electric Encephalography, contributed new knowledge to the study of sensorimotor integration in the brain, the role of perception in action, and how the brain perceives and produces rhythm.
In neurologic rehabilitation our research findings have focused on 3 areas:
- The application of rhythm and music to facilitate and improve the long-term mobility of patients with stroke, Parkinson’s disease, cerebral palsy, and traumatic brain injury; etc.
- Evidence for NMT in the rehabilitation of speech/language
- Data and computational models of the mechanisms showing why auditory rhythm stabilizes and optimizes movement kinematics in therapeutic training
Our group (associate faculty, postdoctoral fellows, graduate students from neurology, physical and music therapy, biomechanics, mathematics, electrical engineering, physics at The Center for Biomedical Research in Music) discovered, in first experiments in 1990, that the strong synchronization effect of rhythm on gait movements has a profound facilitating effect on the gait ability of stroke patients. Research experiments synchronizing gait patterns to auditory rhythm led to dramatic gait improvements in speed, symmetry, and muscle activation patterns in patients whose gait ability was severely compromised. Further rehabilitation studies have shown by now that rhythmic training can also produce sustainable improvements in gait recovery over longer periods of time. Since then, other patient groups have been successfully researched as well, most notably patients with Parkinson’s disease, traumatic brain injury, and cerebral palsy. Most recent studies show that the use of the upper extremities can also be improved with rhythmically patterned movement training. This research has been introduced at numerous international medical and rehabilitation conferences, and is being practiced all over the world. At the 2009 World Congress of Neurologic Rehabilitation, the rhythmic model of rehabilitative motor training developed in our lab was recognized as one of 6 current evidence-based motor training techniques.