Our daily movements are made of statistical behaviors that can be
studied at different time and length scales: For example, most people
can easily achieve the simple task of reaching a cup in front them, but
no two people will have exactly the same movements when we zoom in their
trajectories at millisecond time scales. Most current movement studies
are mainly based on visual observations of performances in motor tasks,
which may leave out important information at finer time scales, often
considered as noise. Atypical behaviors are actually highly
heterogeneous in people with neurological disorders, e.g. like Autism
Spectrum Disorders (ASD), Parkinson and Schizophrenia. This
heterogeneity has particularly impeded developing efficient and
quantitative biological diagnoses for these disorders when they are only
based on human eye observations. There is thus a critical need to
identify objective and data-driven biomarkers for these disorders as
guides for basic biological research studies. Recent advent of
high-resolution wearable sensing devices enable continuous motion
recordings at milliseconds time scales, away from detection of the naked
eye. Using this technology, we asked the question as to whether we could
extract information leading to quantitative biomarkers for these
disorders based on natural movement studies at millisecond time scales.
Here I will only discuss our results for ASD individuals. By studying
the movement statistics of human natural hand movements, we unraveled
a new data-type characterized by the smoothness levels of the dynamics.
We used correlation functions, nearest neighbor speed-spike statistics
plus other statistical metrics to quantitatively characterize each
individual within the spectrum. Our statistical analysis led to a
parameter plane that provides an automatic screening of different ASD
subjects linking it, a posteriori, with their verbal speaking abilities.
We also found unexpected similarities of the ASD's movement statistics
to that of their parents. Our studies are presently being used as part
of a clinical trial testing for a special genetically generated Autism.