A sensory integration account for time perception

Alessandro Toso, Arash Fassihi, Luciano Paz, Francesca Pulecchi, Mathew E. Diamond

Abstract: Author summary The challenge to neuroscience posed by the sense of time lies, first and foremost, in the fact there do not exist dedicated receptors–the passage of time is a sensory experience constructed without sensors. In the present study, we have found that the perceived duration of a vibration applied to the skin increases not only in relation to actual elapsed time but also in relation to the intensity of the vibration. Our data uncover this robust relationship–“stronger is judged as longer”–in the psychophysical results both of human subjects and rats, indicating a general mechanism linking stimulus features to perceived time. We propose a computational model where the experience of the elapsed time accompanying a stimulus is generated when the activity of the sensory cortical neuronal populations encoding that stimulus is integrated by a downstream accumulator. We test the plausibility of the model by simulating the time percept that would emerge through integration of the neuronal firing of real spike trains recorded from the sensory cortex of rats receiving the vibratory stimulus. The close match of the model’s prediction of perceived time to actual perceived time for the same stimuli supports the proposed sensory integration account for time perception.