Scientists donned masks and then captured crows in a study that tested crows reactions to human faces. The crows associated negative feelings with the mask. The researchers say humans and crows both share the ability to recognize human faces and associate them with negative and positive feelings. The researchers say the new study found that the crow brain activates in a similar manner to human brains when it comes to associating feelings toward a human face.
The crows were captured by investigators wearing masks that the researchers named the threatening face. After being captured the crows were cared for by people wearing a different mask. The researchers called this mask the caring face. Both masks were of human faces with neutral expressions.
The researchers injected a glucose fluid used in brain imaging into the bodies of the crows and then exposed them to a person wearing a threatening or caring mask. The birds were then sedated and their brains were scanned. The birds were returned to wild when the experiment was finished.
The researchers found that threatening faces activated brain circuitry including amygdalar, thalamic, and brainstem regions in the crows. Caring faces activated the motivation and striatal regions of the crow brain. The researchers say in their report that these findings "indicate that, similar to humans, crows use sophisticated visual sensory systems to recognize faces and modulate behavioral responses by integrating visual information with expectation and emotion."
John Marzluff, University of Washington professor of environmental and forest sciences, said in a release, "The regions of the crow brain that work together are not unlike those that work together in mammals, including humans. These regions were suspected to work in birds but not documented until now. For example it appears that birds have a region of their brain that is analogous to the amygdala of mammals. The amygdala is the region of the vertebrate brain where negative associations are stored as memories. Previous work primarily concerned its function in mammals while our work shows that a similar system is at work in birds. Our approach could be used in other animals – such as lizards and frogs – to see if the process is similar in those vertebrates as well."
The research was published here
in the Proceedings of the National Academy of Sciences.
Images: Jack DeLap/U of Washington