Humans interact with the environments through their senses. Since Helmholtz’s classical concept, it is well known in psychology and cognitive neuroscience that human perception and action are influenced by an individual’s prior sensory and learning experiences, as well as by other factors, such as task-specific goals or contexts. Focusing on human perception and action as one of the target primary research fields for the new transdisciplinary research of Tactile Internet with Human-in-the-Loop (TaHiL), this chapter reviews neurocognitive processes for multisensory perception, as well as how these processes are affected by age-related effects across the lifespan and individual differences. Neural information processing in brain circuitries that underlie the different senses not only operate very fast (on the order of <20 ms), but also at very different speeds. Whereas hearing and seeing operate, respectively, in the range of 3 ms or 15 ms, the tactile sense operates in the 1 ms time range. Furthermore, neuronal gain control of neural information processing and uncertainty reduction are key mechanisms of human multisensory perception. Empirical data from lifespan developmental psychology and cognitive neuroscience show that the one-size-fits-all assumption, which is commonly adopted in the engineering fields, cannot by default be applied to user populations covering broad age ranges. Empirical evidence indicates that mechanisms of brain development and aging can substantially impact neuronal gain control with consequences for the speed and robustness of human perception and action. Furthermore, prominent age-related differences pertaining to the development and aging of the frontal-parietal brain network affect multiple cognitive functions, such as attention, executive control, and valuation. These effects on cognition would further influence goal-directed multisensory perception and action across the lifespan. Thus the Human-in-the-Loop approach emphasized by the research of TaHiL requires systematic investigations of the effects of development, aging, and skill acquisition on the dynamic interplay between multisensory perception, goal anticipation, and action. Basic experimental research with population-based samples is indispensable for understanding age- and expertise-sensitive psychophysical and neurocognitive factors. Such knowledge can guide theoretical developments of computational models as well as engineering innovations of key technologies (e.g., sensors and actuators, data coding and compression methods, communication networks and human-inspired machine learning) for the advancement of next generation quasi-real-time human-machine interactions in the Tactile Internet.