Hyperthermia exposure impaired the early stage of face recognition: an ERP study

We investigated the effect of hyperthermia exposure on the early stages of face processing by recording event-related potentials (ERPs) elicited by faces and non-face stimuli presented in upright and inverted orientations. Across all conditions, both the peak latencies of P1 and N170 components were earlier in the hyperthermia group than in the control participants. Although no effects of P1 amplitudes were influenced by hyperthermia, the face effect (larger amplitude for faces relative to other object categories) of the N170 was modulated by hyperthermia, whereas the face effect was significant in the control group, it was minimised in the hyperthermia group. The inversion effect of faces on N170 amplitudes, however, was not affected by hyperthermia. These data suggest that the detection of faces in the visual field and their initial streaming to face-specific structural encoding mechanisms are impaired by hyperthermia. However, subsequent face-specific configural processing revealed by the N170 inversion effect is not affected by hyperthermia. In addition, hyperthermia accelerates the early stage of visual perception, regardless of faces or non-face objects.