Document type: scientific article published in Current Biology
Authors: Mary Kieseler, Marvin R. Maechler, Kelly R. Finn, Carl Harris, Jay Michael Vincelli, Zachary Hoffman, Navneet Dhanoa, Jean Fang, Scott Gies, James McHugh, Julia Valenti, Mira Ram, John O. Fitzgerald, Madison Augusto, David Edelman, Peter U. Tse
Abstract in French (translation): The octopusOctopus bimaculoidescan learn to use a mirror to locate a reward outside its field of vision. The use of mirrors to locate hidden objects is well documented in vertebrates but has never been demonstrated in invertebrates. The use of mirrors to locate objects that would otherwise be hidden constitutes a form of mediated perception, establishing a link between a visible reflection and a hidden location, and is considered by some to be a precursor to self-recognition. Cephalopods represent a fascinating case study in convergent evolution, having independently developed sophisticated perceptual and cognitive abilities similar to those of mammals after diverging from a common ancestor more than 520 million years ago. Furthermore, they respond to reflected images as if they were conspecifics. We projected a virtual crab—visible only as a reflection in a mirror—onto the wall of a tank. ThreeOctopus bimaculoidesoctopuses were trained to swim toward the projection site rather than toward the mirror. All three octopuses learned this task, successfully choosing the correct side in 73% of trials. It is important to note that the octopuses sometimes moved away from the visible reflection and climbed up the side walls of the starting chamber to reach visually obscured locations that were spatially aligned with the location of the reflected prey. This behavior suggests (1) the ability to inhibit a direct approach toward salient visual stimuli, and (2) a spatial representation that integrates information from the mirror with knowledge of the aquarium’s 3D geometry. These results extend the capacity for mirror use to invertebrates, demonstrating that cephalopods can use mirror reflections for spatial navigation. The independent evolution of the cognitive abilities underlying mirror use across various taxa suggests that common solutions may have evolved to address the challenges of spatial navigation.
Preview: Mirror-mediated localization of hidden objects is well documented in vertebrates but has never been demonstrated in invertebrates. Using mirrors to locate otherwise occluded objects is a form of mediated perception, linking a visible reflection to an occluded location and is seen by some as a precursor to self-recognition. Cephalopods offer a fascinating test case of convergent cognition, having independently evolved sophisticated perceptual and cognitive abilities that are similar to mammals, after diverging from a common ancestor over 520 million years ago. In addition, they react to mirror images as though they were conspecifics. We projected a virtual crab that was visible only via mirror reflection onto a tank wall. Three Octopus bimaculoides were trained to navigate to the projection site instead of the mirror. All three octopuses learned this task, successfully choosing the correct side in 73% of trials. Critically, octopuses sometimes moved away from the visible reflection and climbed over the side walls of the start chamber to reach visually occluded locations that were spatially aligned with the reflected prey location. This behavior suggests (1) the ability to inhibit a direct approach to salient visual stimuli, and (2) a spatial representation that integrates mirror information with knowledge of 3D tank geometry. These findings extend mirror-use capabilities to invertebrates, demonstrating that cephalopods can employ mirror reflections for spatial navigation. The independent evolution of cognitive capacities underlying mirror use across diverse taxa suggests that common solutions may have evolved to solve spatial navigation challenges.
