Is temporal reproduction independent of judgment certainty?

In a recent article by Martin Riemer, Myself and Thomas Wolbers published in Neural Plasticity we uncovered evidence that uncertainty about the timing of intervals is independent of temporal reproduction. 

​Martin has published a few papers recently along the idea of time being the 'view from nowhen', That is, due to the way time flows, there are necessary peculiarities when measuring temporal properties. A common finding in the literature is that, on average, subjects reproduce intervals as slightly shorter than what they are. This is usually called the 'negative error', and has been explained by Martin as due to a general judgment bias towards earlier responses, instead of reflecting a genuine misperception of temporal intervals. 

We applied transcranial magnetic stimulation (TMS) to inhibit neuronal processes in the right posterior parietal cortex (PPC) and tested its effects on time discrimination and reproduction tasks. The results show increased certainty for discriminative time judgments after PPC inhibition. They suggest that the right PPC plays an inhibitory role for time perception, possibly by mediating the multisensory integration between temporal stimuli and other quantities. Importantly, this increased judgment certainty had no influence on the degree of temporal underreproduction. We conclude that the systematic underreproduction of time is not caused by uncertainty for temporal judgments. 

​Paper can be found here: