Towards an integrated study of camouflage and cognition in cephalopods

The coleoid cephalopods (i.e., octopus, squid, and cuttlefish) are notable for their complex cognition and dynamic camouflage, but the two processes have rarely been considered in conjunction. Here, we argue that camouflage and cognition likely coevolved and should therefore be studied as linked processes, which we term the “camocognitive hypothesis”. We suggest that camouflage serves as a “self-report” measure of a cephalopod’s subjective inner world, and is therefore a critical innate tool for studying complex cognition in cephalopods. We draw a comparison between camouflage in cephalopods and food caching in corvids, suggesting that camouflaging cephalopods may “cache” themselves in the environment; in doing so, they may draw upon complex cognitive processes similar to those used by caching corvids. With a focus on cuttlefish of genus Sepia, we briefly review knowledge arising from the interaction of camouflage and cognition, including visual perception, amodal completion, visual perspective taking, and flexible control of camouflage. Moving beyond the widespread view that camouflage is a reflexive behaviour based solely on visual input, we suggest that it may be subject to cognitive control in certain contexts, much like mammalian breathing is largely automatic but subject to volitional control. Finally, we discuss barriers to using camouflage as a method to study cognition and provide two hypothetical paradigms using camouflage to study object permanence and predator deception.