Something to crow about: PET Bird Brains

This post was the impetus to resume work on my #CHMedicalImagingSeries and add PET imaging.

Medical Imaging 101 pt 4: PET

http://goo.gl/YNAVhX

You have probably seen plenty of posts/articles about the Cockatoos picking locks. Well as Buddhini Samarasinghe Rajini Rao and others have discussed, that’s a bit misleading to sensationalize what’s already pretty cool. In the two links below, you’ll see that it isn’t the traditional lock that is being “picked”. It’s more like solving a mechanical puzzle. A pin has to be removed, before the nut can be unscrewed, before the latch can slide, etc. What’s amazing is that one of the 10 birds figured it out on it’s own while the other 9 needed the researchers to demonstrate each step. When the “locks” were reordered, the birds had no problem remembering how to solve each step. In one of the pictures below you can see that the crow has figured out that it needs to raise the string to get the food and the cockatoo has fashioned a tool to get the cashew. The importance of the string test is that not all bird are smart enough to hold the string with their foot so as to free up their beak to pull another segment of the string closer. On of the questions is, are they mentally visualizing the food being closer by pulling up a segment of string, one segment at a time? Conversely, are they using a feedback loop, i.e., the food gets closer each time the lift a segment of the string.

Bird brains

http://goo.gl/9IWlD

via Kevin Clift

Lock-picking Cockatoos

http://goo.gl/0hMB5

⌘What’s on your mind?⌘

Following up on the cockatoo story, Virginia Morell wrote the article below and was interviewed in the podcast. The podcast should be available to the public. However the article, I think, is behind a paywall. One of the suggestions from the cockatoo study is that the bird must have a mental image of the outcome, i.e., that the nut is available after each part of the lock is undone. Likewise, researchers wondered if crows had a mental image of the end result, after watching one crow fashion a tool to retrieve some food. 

⌘Something to crow about⌘

Crows in the wild often caw at perceived threats and even mob them. The Science article shows a group of crows chasing an American bald eagle. The image below with the women in a mask demonstrates part of the study. Why the mask? These are crows caught in the  wild and will be released after the study.The crows will remember the faces of the researchers and mob them if seen later. The researchers noted that the crows blink less when presented with a dead crow by the women in the mask or a stuffed hawk. Blinking less is a sign of nervousness in the crows. However, are the two “threats” equal?

⌘My PET image⌘

Well if you want to see into the brain while someone or some animal is alive, you need medical imaging, PET in this case. The crows were given a radiotracer before being presented with one of the threats. F-18 FDG was likely used (I’ll see if I can access the article at work). An example PET image is shown below. They found that different regions of the brain were activated depending on the threat. So the answer is that the crows were likely calculating the nuances between the masked person and the stuffed hawk. You can see the anesthetized crow being placed in the PET scanner.  The bed has a heating element to keep the bird warm. Note that the bed is made of carbon fiber so as to be nearly invisible for the CT scan.

Podcast Interview

http://www.sciencemag.org/content/341/6141/22/suppl/DC1

Reference and image source (behind paywall)

http://www.sciencemag.org/content/341/6141/22.short

PET study:

Distinct neural circuits underlie assessment of a diversity of natural dangers by American crows.

Cross et al

Proc Biol Sci. 2013 Jul 3;280(1765):20131046. doi: 10.1098/rspb.2013.1046

http://www.ncbi.nlm.nih.gov/pubmed/23825209

#ScienceSunday