Quantitative modeling of perception and production of time intervals

The accurate perception/production of durations in the seconds and minutes range is important in a number of everyday activities, but the lack of dire ct experimental evidence on the neural circuits that could be involved has precluded the detailed elucidation of the underlying physiological mechanis ms. We show, using a basic biophysical model of a timekeeping system and ex perimental data on time intervals produced or estimated under different con ditions, that experimental values, variability, and distributions can be qu antitatively explained in terms of a background synaptic activity such as t hat generated by attention. The model provides a plausible neural substrate for encoding time intervals, and the findings suggest how it may interplay at the single neuron level with the attentional system, to elaborate a sub jective representation of the elapsing time.