Cognitive load but not immersion plays a significant role in embodied cognition as seen through the spontaneous act of leaning.

An important aspect of embodied approaches to cognition is the idea that human cognition does not occur simply in the brain, but is influenced by a complex bi-directional interplay between the brain, body, and external environment. Though embodied cognition is often studied in a controlled laboratory setting, by its very nature it can arise spontaneously in everyday life (e.g., gesturing). A recent paper by Chisholm et al. suggested that leaning while playing a video game may be another instance of a natural spontaneous expression of embodied cognition that can be studied to gain insight into a person's ongoing covert cognition. Consistent with this proposal, Chisholm et al. found that, like gestures, leaning increases when cognitive demand is increased. However, in Chisholm et al., immersion also increased with cognitive demand. We argue that their test to exclude it as a contributing factor-by holding cognitive demand constant while manipulating immersion-was limited. Despite their test, it remains possible and plausible that cognitive demand has an effect on leaning only when immersion increases. To address this issue, the present study systematically varied demand and immersion. We replicate Chisholm et al.'s finding that leaning increases with cognitive load. We also show that the effect of load is not influenced by a robust and reliable change in immersion. Collectively our results provide new and converging evidence that spontaneous overt embodiment of an individual's intention is modulated by cognitive demand, and emphasises the utility of using natural behaviours to understand the embodiment of cognition.