PMC

From the snake skin microstructure to the SIMPS. a) Photograph of the California King Snake (Lampropeltis getula californiae). SEM-micrographs of the snake skin of a ventral scale (b) and the SIMPS made of epoxy resin (c).

Both (A) fear scores and (B) disgust scores of fear- and disgust-eliciting snake stimuli closely correlated with the average of skin resistance amplitude. The venomous Viperid snakes (the variable bush viper Atheris squamigera, Fea’s viper Azemiops feae, Gaboon viper Bitis gabonica, rhinoceros viper Bitis nasicornis, Sahara sand viper Cerastes vipera, eastern diamondback rattlesnake Crotalus adamanteus, multiscale saw-scaled viper Echis carinatus mutlisquamata, Sochurek’s saw-scaled viper Echis carinatus sochureki, Jerdon’s pitviper Protobothrops jerdonii, and the Orlov’s viper Vipera orlovi) were scored as more fear-eliciting (and less disgust-eliciting) and also elicited stronger physiological reactions than harmless fossorial snakes (the Bibron’s blind snake Afrotyphlops bibronii, northern blind snake Anilios diversus, rotund blind snake Austrotyphlops pinguis, brown-snouted blind snake Anilios wiedii, Bahamian slender blind snake Cubatyphlops biminiensis, northern rubber boa Charina bottae, brahminy blind snake Indotyphlops braminus, Hong Kong blind snake Indotyphlops lazelli, Madagascar blind snake Xenotyphlops grandidieri, and the Eurasian blind snake Xerotyphlops vermicularis). Depicted species: eastern diamondback rattlesnake as a fear-eliciting snake and Madagascar blind snake as a disgust-eliciting snake. Illustrations by Pavel Procházka.

From snake skin to SIMPS. a) Photograph of L. g. californiae , the California King Snake; b) SEM micrograph of a ventral scale of L. g. californiae; c) SEM micrograph of the snake-inspired microstructured polymer surface – SIMPS. Scale bars: 10 µm. 3-dimensional image of d) snake skin from L. g. californiae and e) SIMPS based on AFM data.

(A) Grand-average waveforms for the early posterior negativity (EPN) in response to pictures of snake skin (red line), lizard skin (blue line), and bird plumage (black line) at the occipito-parietal cluster (collapsed across O1, Oz, O2, PO3, PO4, P7, P8). The vertical bar depicts the EPN time window. (B) Grand-average topographic maps of the differences in the 225–300 ms mean area amplitudes between pictures of snake skin vs. bird plumage (left), snake skin vs. lizard skin (middle), and lizard skin vs. bird plumage (right). 3D head view created with BrainVision Analyzer 2.1, Brain Products GmbH, Gilching, Germany.