Cognitive processes supporting interoception and the influence of activation states

Interoception encompasses both the processing and the perception of signals from inside the body. While the processing of afferent signals occurs par
tially at an automatic, pre-conscious level, their conscious perception involves sev
eral higher cognitive processes that affect each other bi-directionally. The current chapter focuses on cognitive processes that support the conscious perception of interoceptive signals. We first present examples of influential deterministic and probabilistic models of interoception. Deterministic models assume that an intero
ceptive percept is fully determined by objectifiable steps of interoceptive signal processing, whereas in probabilistic models, the generation of percepts are thought to occur at different probabilities based on observed and expected sensations. From these models, it can be inferred that attention, learning, and memory, as well as interpretation and attribution play an important role for conscious interoception. Furthermore, we address different states of activation, such as sleep, relaxation, physical exercise, and stress, as they may affect the processing of bodily signals both along bottom-up (e.g., by an increase or decrease in interoceptive signal strength) and top-down pathways (e.g., by modulation of attention). We argue that states of activation are inherently bound to cognitive processes that are necessary for conscious interoception, based on deterministic and probabilistic models.