Saturday, September 22, 2012

Crow and Faces: Part II

We posted earlier about how crows and their relatives have been found to hold grudges (http://tinyurl.com/97yssm6) but how do they do this? A recent study reveals that we are not as different as you may think...

Building on his previous research using masks, Dr. John Marzluff and his team (of the University of Washington) captured crows using a "threatening" mask and kept
them in captivity for four weeks. During this time they used a different mask to feed them, known as the "caring" mask. Both masks had a neutral expression to ensure any associations crows made were because of their treatment. After this four weeks the crows were injected with a glucose fluid and spent 15 minutes with a researcher wearing either the threatening mask or the caring mask. They were then sedated and scanned.

The results yielded striking similarities between how human and crow brains function. Crows who had been exposed to the threatening mask showed activity in amygdalar, thalamic and brainstem regions - regions that in humans indicate emotion and conditioned fear learning. By contrast, those exposed to the caring face showed more activity related to motivation and in striatal regions (in humans, one of the functions of the striatum is involvement in stimuli associated with reward).

“The regions of the crow brain that work together are not unlike those that work together in mammals, including humans. For example it appears that birds have a region of their brain that is analogous to the amygdala of mammals", said Marzluff. ”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."

Image credit: Jack DeLap/University of Washington.

http://www.washington.edu/news/2012/09/10/crows-react-to-threats-in-human-like-way/

http://www.livescience.com/23090-crows-grudges-brains.html

http://www.pnas.org/content/early/2012/09/05/1206109109.short

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