Modulation Of Threating Information On The Processing Of The Ebbinghaus Illusion

Threatening information can modulate visual perception.However,previous studies indicate that the modulation of threatening information on visual perception varies with the spatial frequency content of threatening stimuli and stimulus type.To verify this hypothesis,they used two types of threatening stimuli,i.e.,social threatening stimuli(i.e.,fearful faces)and biological threatening stimuli(i.e.,snakes and spiders).Moreover,the threatening stimuli were spatially filtered to contain either low-(LSF)or high-spatial-frequency(HSF)information.In Experiment 1,they adopted a priming paradigm to investigate the priming effect of threatening information on the processing of the Ebbinghaus illusion.Results revealed that in both LSF and HSF conditions,fearful faces compared to neutral ones had a negligible effect on the magnitude of the Ebbinghaus illusion.However,in the LSF condition,threatening animals relative to neutral ones(i.e.,horses and rabbits)significantly decreased the magnitude of the Ebbinghaus illusion.Moreover,this threat-related modulation was not observed in the HSF condition.It has been found that the temporal-occipital junction(TPJ)is involved in the processing of spatial frequency information in a hemispheric asymmetry manner,with left and right TPJ being associated with HSF and LSF information,respectively.In Experiment 2,they adopted the technique of TMS to investigate the contribution of TPJ to the modulation of LSF threatening information on the processing of visual size illusion.The procedure was the same as that in Experiment 1,and only face stimuli were used.A double-pulse TMS was applied to the left or right TPJ when the face stimuli were presented.The results showed that when TMS was applied to the left TPJ,LSF fearful faces significantly decreased the illusion magnitude compared to LSF neutral faces.In contrary,when TMS was applied to the right TPJ,LSF fearful faces significantly increased the illusion magnitude relative to LSF neutral faces.However,in the HSF condition,the disparity of illusion magnitude between the fearful and neutral face primes was not observed no matter TMS was applied to the left or the right TPJ.In conclusion,our results provide clear evidence that threat shapes visual perception in spatial frequency-and stimulus-specific manners,and TPJ plays a crucial role in this LSF threat-related modulation of visual size perception.