Quantity misperception by hymenopteran insects observing the solitaire illusion

Scarlett R Howard; Adrian G Dyer

doi:10.1016/j.isci.2023.108697

Quantity misperception by hymenopteran insects observing the solitaire illusion

iScience. 2023 Dec 8;27(2):108697. doi: 10.1016/j.isci.2023.108697. eCollection 2024 Feb 16.

Authors

Scarlett R Howard¹, Adrian G Dyer^{2

3}

Affiliations

¹ School of Biological Sciences, Monash University, Clayton, VIC, Australia.
² Department of Physiology, Monash University, Clayton, VIC, Australia.
³ Institute of Developmental Biology and Neurobiology (iDN), Johannes Gutenberg University, 55122 Mainz, Germany.

Abstract

Visual illusions are errors in signal perception and inform us about the visual and cognitive processes of different animals. Invertebrates are relatively less studied for their illusionary perception, despite the insight that comparative data provides on the evolution of common perceptual mechanisms. The Solitaire Illusion is a numerosity illusion where a viewer typically misperceives the relative quantities of two items of different colors consisting of identical quantity, with more centrally clustered items appearing more numerous. We trained European honeybees (Apis mellifera) and European wasps (Vespula vulgaris) to select stimuli containing a higher quantity of yellow dots in arrays of blue and yellow dots and then presented them with the Solitaire Illusion. Insects learnt to discriminate between dot quantities and showed evidence of perceiving the Solitaire Illusion. Further work should determine whether the illusion is caused by numerical cues only or by both quantity and non-numerical spatial cues.

Keywords: Behavioral neuroscience; Entomology; Evolutionary biology.