Abstract: PURPOSE: Fast detection of threatening information is crucial for survival. There is still controversy regarding the roles of low- and high-spatial-frequency information (LSF and HSF) in the fast detection of threat.
METHODS: Here we probed this issue by using a prime procedure together with the transcranial direct current stimulation (tDCS) technique. Participants were prior exposed to LSF or HSF faces before the detection of approaching or receding spheres. In the meantime, tDCS was applied to the left or right temporo-parietal junction (TPJ), which has been preferentially associated with the processing of the LSF and HSF information, respectively.
RESULTS: Significant LSF-related facilitation of threat detection was observed when anodal tDCS was applied to the right TPJ. However, HSF-related facilitation of threat detection was not observed when anodal tDCS was applied to the left TPJ.
CONCLUSIONS: Our findings support the idea that LSF information can facilitate threat detection, and provide direct evidence that right TPJ is vital for the LSF-related facilitation of threat detection.

Key words: spatial frequencies, threat detection, tDCS, TPJ