Human sensory perception and action are important elements of closed-loop digitally transmitted human-human and human-machine interactions in virtual and remote environments. Taking the Human-in-the-Loop approach, mechanisms underlying noise regulation of neural information processing are introduced first in this chapter, since they affect the precision of sensory perception and action and may interface with theories of information technology. The remaining sections highlight results of recent research that address several questions relevant to future developments of the Tactile Internet. Concrete examples of utilising human perceptual judgements to evaluate and compare tactile codecs, as well as the role of haptic actuation in enhancing multisensory perception, are showcased. Neurocognitive studies exploring the principles of human expectations are emphasised to inform the design of plausible sensory augmentation technologies that are inclusive across different age groups. Extending these studies, research on the sense of smell and social touch is also discussed. Regarding human actions, we present our open-source kinematic datasets of hand, locomotion, and full-body movements to illustrate the potential of using such data to predict human behaviour. Together, the research reviewed in this chapter illustrates fruitful interdisciplinary research that integrates empirical studies of human perception and action into the development of Tactile Internet technologies.