PT - JOURNAL ARTICLE AU - Ghaith Tarawneh AU - Vivek Nityananda AU - Ronny Rosner AU - Steven Errington AU - William Herbert AU - Sandra Arranz-Paraíso AU - Natalie Busby AU - Jimmy Tampin AU - Jenny Read AU - Ignacio Serrano-Pedraza TI - Contrast thresholds reveal different visual masking functions in humans and praying mantises AID - 10.1101/135970 DP - 2017 Jan 01 TA - bioRxiv PG - 135970 4099 - http://biorxiv.org/content/early/2017/05/09/135970.short 4100 - http://biorxiv.org/content/early/2017/05/09/135970.full AB - Recently, we showed a novel property of the Hassenstein-Reichardt detector: namely, that insect motion detection can be masked by “invisible” noise, i.e. visual noise presented at spatial frequencies to which the animals do not respond when presented as a signal. While this study compared the effect of noise on human and insect motion perception, it used different ways of quantifying masking in two species. This was because the human studies measured contrast thresholds, which were too time-consuming to acquire in the insect given the large number of stimulus parameters examined. Here, we run longer experiments in which we obtained contrast thresholds at just two signal and two noise frequencies. We examine the increase in threshold produced by noise at either the same frequency as the signal, or a different frequency. We do this in both humans and praying mantises (Sphodromantis lineola), enabling us to compare these species directly in the same paradigm. Our results confirm our earlier finding: whereas in humans, visual noise masks much more effectively when presented at the signal spatial frequency, in insects, noise is roughly equivalently effective whether presented at the same frequency or a lower frequency. In both species, visual noise presented at a higher spatial frequency is a less effective mask.Summary Statement We here show that despite having similar motion detection systems, insects and humans differ in the effect of low and high spatial frequency noise on their contrast thresholds.