Brain mechanisms for time estimation and production
Rodrigo Laje, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes
The
representation of temporal information is one of the most elusive
concepts for neurobiology. Perception, estimation, and production of
time in the range of hundreds of milliseconds, known in the literature
as millisecond timing, is crucial for motor control, speech generation
and recognition, and music perception and production. Among all the
ranges of temporal processing, millisecond timing is perhaps the most
sophisticated and the least well understood.
Sensorimotor synchronization (SMS) is a spontaneous human behavior
within this timing range. Finger tapping experiments are used to probe
our cerebral mechanisms for synchronization. Almost everybody can keep
the pace with an external periodic stimulus, for instance when tapping
along with music. Although no one response is exactly coincident with
the corresponding stimulus, an average synchrony is very easy to
achieve. What is the mechanism in charge of correcting the minute time
differences between each stimulus and its response, and thus keeping
average synchrony?
In this talk I will review the latest results on the neurophysiology of
millisecond timing and point to several issues that remain open. Is
there a specialized neural region for millisecond timing? What are the
topological restrictions that the behavioral data set on the error
correction mechanism? What is the actual underlying neural mechanism? I
will describe a simple mathematical behavioral model for SMS and
consider its benefits for driving the search for structure in the data.