Space Impacts Temporal Processing via a Visual-Dependent Spatially Organized Neural Architecture

Establishing the temporal relationship between stimuli challenges the brain, requiring some tolerance for asynchronies to form coherent representations. Based on the theory of implicit causal inference, we hypothesized that temporal processing of events is influenced by spatial features as stimuli coming from the same spatial location are most likely to derive from a common source and, consequently, implicitly merged in time. As visual experience guides the formation of neural sensory maps, we expected the spatial influence on temporal processing to depend on visual experience. In Experiment 1, 41 sighted children and adults (22 females) judged the temporal order of auditory and tactile stimuli delivered to the same or different hands (somatotopic manipulation), with hands either close or far apart (spatiotopic manipulation). In Experiment 2, sighted individuals (15 females) were compared with 26 early blind children and adults (12 females) during the somatotopic manipulation with hands far apart. Results revealed an improvement of temporal resolution with age in sighted individuals, while blind children performed similarly to adults. Notably, spatial features affected the temporal processing of sighted but not blind people, regardless of age. Sighted participants showed higher temporal tolerance toward asynchronies in the case of somatotopic or spatiotopic congruence. A bioinspired neurocomputational model has been developed to unveil neural mechanisms underlying the interaction between spatial and temporal processing. The model demonstrates that temporal processing is mediated by a spatially organized synaptic architecture, which requires visual experience to develop. Without vision, spatial alignment may not be conceptualized as a prior influencing temporal processing.