Valeria Centanino¹ (), Gianfranco Fortunato¹, Domenica Bueti¹; ¹International School for Advanced Studies (SISSA)

The duration perception of a sensory event is shaped by the statistical distribution of the durations at hand, namely the temporal context. For example, a given physical duration is reproduced differently when presented within distinct but partially overlapping duration ranges, systematically showing a bias toward the mean of the range at hand. Temporal context can also change when the frequency of presented durations varies within the same temporal range, but the effects of such manipulation are less well understood. At brain level, functional MRI studies suggested that the processing of brief visual events relies on tuning mechanisms whose properties change across the cortical hierarchy. How these tuning properties adapt to contextual biases, however, remains an open question. In this study, thirty participants reproduced eight visual durations presented under either a uniform or a positively skewed distribution. Results showed that, under the skewed condition, all durations were reproduced as longer, with the greatest bias observed for the shortest durations. However, this bias varied significantly across participants, highlighting a non-trivial and nuanced influence of temporal statistics on reproduction performance. To investigate the neural underpinnings of this effect, a separate group of eight participants performed the same task while brain activity was recorded at 7T-MRI. The blood-oxygen-level-dependent signal was then modeled with a unimodal neuronal response function. Preliminary findings showed that duration preferences in medial and lateral premotor areas and anterior insula shifted toward longer durations under the skewed condition. This shift was most pronounced in neuronal populations preferring shorter durations under the uniform condition, mirroring behavioral biases. In contrast, the sensitivity of neuronal responses remained stable across conditions. These findings suggest that temporal statistics shape our perception of visual durations by shifting neuronal preferences within higher-level regions of the cortical timing hierarchy.