Mind the Snake: Fear Detection Relies on Low Spatial Frequencies
The privileged processing of threat stimuli, even in the absence of visual awareness, has been associated with a subcortical superior colliculus (SC)—pulvinar pathway to the amygdala, bypassing the visual cortex. However, this has been heavily disputed by studies showing that cortical activity cannot be ruled out in fear processing. A recent study using continuous flash suppression (CFS) showed that rapid detection of fear faces relies on high spatial frequencies, which involve cortical visual areas. In the present study, we also used CFS and manipulated spatial frequency in order to assess if more primitive fear stimuli—snakes—follow a similar trend. Our results show an advantage of snakes in accessing awareness based on low spatial frequency information, arguing in favor of the role of a SC-pulvinar pathway to the amygdala.