An investigation on humans’ sensitivity to environmental temperature

According to the grounded cognition perspective, our perception depends on the re-activation of sensorimotor experiences, as well as on our current bodily states and on the environment (Barsalou, 2008). Our environment provides us with a lot of cues but, above all, temperature appears of great importance for the survival and wellbeing of our body (Kelly, 2007). Nonetheless, research on human perception lacks a quantitative result on thermal perception when the full body is involved. We developed an innovative experimental paradigm to address this question with four climate chambers set at varied temperatures between 24 °C ± 1 °C. 26 participants moved from a reference chamber to a target chamber and noted whether this was warmer or colder than the former. Data has been analysed by adopting the generalised linear mixed-effects models (GLMM). The results showed a PSE of -0.13 °C and a JND of 0.38 °C (Figure 1). These results point out both the high accuracy of participants’ performance and the small variability between them, with the latter suggesting that this sensitivity could be an intrinsic mechanism in our body. In light of these findings, we further investigated the possible multisensory interactions between temperature and vision. Considering the ongoing literature controversy (e.g., see Table 1 Brambilla et al., 2020), we specifically looked into the impact that the colour of the lights might have on thermal sensitivity. In conclusion, these experiments answer a still-open question revealing our body's ability to accurately perceive the environment, even without participants’ awareness of this capability.