Insects are conscious, egocentric beings, according to a new paper that also helps to explain why and likely when consciousness first evolved.
Recent neuroimaging suggests insects are fully hardwired for both consciousness and egocentric behavior, providing strong evidence that organisms from flies to fleas exhibit both.
Consciousness comes in many levels, and researchers say that insects have the capacity for at least one basic form: subjective experience.
“When you and I are hungry, we don't just move towards food; our hunger also has a particular feeling associated with it,” Colin Klein, who co-authored the new paper, told Discovery News. "An organism has subjective experience if its mental states feel like something when they happen.”
Klein, a researcher at Macquarie University, and colleague Andrew Barron studied detailed neuroimaging reports concerning insect brains. They then compared the structure of such brains with those of humans and other animals. The resulting information is published in the journal Proceedings of the National Academy of Sciences.
Their work focused on the midbrain, a set of evolutionarily ancient structures that are surrounded by the gray folds of the cortex. The arrangement, they say, looks a bit like the flesh of a peach surrounding the pit.
“In humans and other vertebrates (animals with a backbone and/or spinal column) there is good evidence that the midbrain is responsible for the basic capacity for subjective experience,” Klein said. “The cortex determines much about what we are aware of, but the midbrain is what makes us capable of being aware in the first place. It does so, very crudely, by forming a single integrated picture of the world from a single point of view.”
Portions of insect brains work in a similar way to the midbrain in humans, performing the same sort of modeling of the world, the authors believe.
As for being egocentric, Barron explained that there is now compelling evidence that insects display selective attention to their processing of the world.
“They don’t pay attention to all sensory input equally," Barron explained. "The insect selectively pays attention to what is most relevant to it at the moment, hence (it is) egocentric.”