Brain activity underlying American crow processing of encounters with dead conspecifics
Kaeli N. Swifta,*, John M. Marzluffa, Christopher N. Templetonb, Toru Shimizuc, and Donna J. Crossd

aSchool of Environmental and Forest Sciences, Seattle, WA; bDepartment of Biology, Pacific University Oregon, Forest Grove, OR; cDepartment of Psychology, University of South Florida, Tampa, Fl; dDepartment of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT
Research synopsis: Animals utilize a variety of auditory and visual cues to navigate the landscape of fear.  For some species, including some corvids, dead conspecifics appear to act as one such visual cue of danger, and prompt alarm calling by attending conspecifics. Which brain regions mediate responses to dead conspecifics, and how this compares to other threats, has so far only been speculative. Using 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) we contrast the metabolic response to visual and auditory cues associated with a dead conspecific among five a priori selected regions in the American crow (Corvus brachyrhynchos) brain: the hippocampus, nidopallium caudolaterale, striatum, amygdala, and the septum. Using a longitudinal, fully balanced approach, we exposed crows to four stimuli: a dead conspecific, a dead song sparrow (Melospiza melodia), conspecific alarm calls given in response to a dead crow, and conspecific food begging calls. We find that in response to observations of a dead crow, crows show significant activity in areas associated with higher-order decision-making (NCL), but not in areas associated with social behaviors or fear learning. We do not find strong differences in activation between hearing alarm calls and food begging calls; both activate the NCL. Lastly, repeated exposures to negative stimuli had a marginal effect on the subjects’ sensitivity in response to control stimuli, suggesting that crows might quickly learn from such experiences. 
Data synopsis: Excel files contain volume of interest (VOI), meaning relative FDG uptake, in the five brain regions of interst.  The first tab (All_values) shows the VOI data for each subject’s 5 focal brain regions under all 5 stimulus possibilities (dead crow, dead sparrow, crow begging, crow scolding and empty room).  The following 5 tabs are the data for each separate region and include the number of dangerous or neutral exposures prior to the corresponding stimulus.  In these tabs, the empty room column shows the global normal values for 3 birds from a previous study who were exposed to an empty room. These birds only received the empty room stimulus and therefore have no previous dangerous or neutral exposures.