Promotion Of Low Spatial Frequency Information On Threat Detection

Rapid threat detection is critical for survival.Previous studies have shown that spatial frequency information is involved in the process of threat detection.However,the specific role it plays in this process is still controversial.The current study investigated two issues through five experiments: whether the TPJ is invovled in the promotion of high or low spatial frequency information(HSF/LSF)on threat detection;and whether the contribution of HSF/LSF information to threat detection varied with response manners.Experiments 1 and 2 used a priming paradigm in which subjects passively viewed HSF/LSF pictures of faces and subsequently judged the trajectory of the sphere(looming: threatening information;receding: non-threatening information).During the task,transcranial direct current stimulation(t DCS)was applied to the right temporo-parietal junction(TPJ;Experiment 1)and the left TPJ(Experiment 2)which are associated with the preferential processing of LSF and HSF information,respectively.The results showed significant LSF-related facilitation of threat detection when anodal t DCS was applied to the right TPJ.However,HSF-related facilitation of threat detection was not observed when anodal t DCS was applied to the left TPJ.The findings support the idea that LSF information can facilitate threat detection,and r TPJ plays a crucial role in this process.A priming paradigm was also used for Experiments 3,4,and 5.The primes were HSF/LSF gratings.Subjects passively viewed the gratings and subsequently judged whether a target(threatening/non-threatening pictures)appeared on the left or right of the screen.Three responses manners were adopted: manual response(Experiment 3),saccade movement(Experiment 4),and reaching movement(Experiment 5).The results showed that when using saccade and reaching responses,LSF primes significantly facilitated threat detection,while HSF primes did not.When using manual response,no facilitation effect was observed for neither LSF or HSF primes.The results suggested that LSF-related facilitation of threat detection varied with response manners.In summary,LSF information can facilitate threat detection,and r TPJ plays a crucial role to this process.Furthermore,this facilitation effect varies with response manners.