Development of mental disorders after removal of pituitary tumors.

Thermal perception and regulation are crucial for physical exercise. It is widely known that performance in exercise is affected by the ambient temperature. A large body of research shows that performance is impaired while cycling in the heat. Racinais et al., for example, showed that cyclists had a reduced power output when cycling during an environmental temperature of 36.0C compared to 8.2C. While the exact underlying mechanisms still need to be explored, previous work suggests that during exercise in the heat, an increase in body temperature directly influences central nervous functions. Consequently, the central nervous system activates anticipatory protective mechanisms to naturally protect the body from overheating by reducing muscle activation. In addition, higher body temperature increases skin blood flow to dissipate heat. This creates competition for blood between working muscles that need oxygen and the skin that needs cooling. Hence, increasing the body temperature through ambient temperature adds additional thermal strain to the body beyond the heat produced during exercise, leading to higher perceived exertion and reduced performance. Previous work found that the body temperature can even be increased by visual cues without actually changing the ambient temperature. The hue-heat hypothesis posits that color temperature influences thermal perception, e.g., warmer colors result in warmer thermal perception. Whether the hue-heat hypothesis holds has been debated for decades, but Wang et al. recently concluded, based on a systematic review, that the results confirmed the long-held hypothesis. Accordingly, Takakura et al. showed that watching videos showing a desert on a regular display increased participants’ skin temperature while videos showing a snowy environment decreased their skin temperature. While the hue-heat hypothesis poses one explanation for such effects, the authors argue that classical conditioning causes them. Seeing videos of a hot desert activates associations of how it feels in that place. This cognitive process activates the thermoregulatory mechanisms one would experience in a hot environment, resulting in increased body temperature. Thus, real and virtual environment’s color temperature indeed influence thermal perception and thermoregulation. Virtual reality (VR) enables immersion in any possible environment. Consequently, previous work investigated whether virtual environments can also influence thermal perception. Multiple studies confirmed the hue-heat hypothesis for VR and found effects of color temperature on thermal perception and even skin temperature. Wührl et al., for example, consistently found that being immersed in a fire virtual environment in VR increases skin temperature compared to being in an ice environment. These findings suggest that the visual characteristics of virtual environments must be carefully considered when designing VR experiences. However, previous studies examined static or sedentary scenarios, for example participants sitting for several minutes while being immersed in a fire or ice-themed virtual environment. It, therefore, remains unclear whether these effects also occur and persist during sustained physical activity.