I've Got My Beady Eye On You

When we see something new, we stare at it. But given a small magnifying glass, which eye do you use. I tend use my right eye, which means the left side of my brain is given the job of processing the image. The left hemisphere is where the analytical approach is dominant and where the job of putting things into categories by evaluating differences is done. The right side being more freewheeling and creative, where we look for patterns and the like.

The pressing question for today is: “do striped dolphins have a right or left eye bias?” Humpback whales feeding at the bottom of the sea favor their right eye for the job. Does that mean that they are being carefully analytical about what they gulp down? Whales and dolphins favor their left eye when getting friendly with their kin, which seems to fit in with a freewheeling, creative thinking.

However, back to our striped friends. Siniscalchi et al from the U of Bari “Aldo Moro” have presented their study of Stenella coeruleoalba in the wild in this week's PLoSONE (1). The investigators dangled objects in front of cavorting dolphins and recorded which eye they used to check the objects out.  They tried a striped soft ball, a cuddly large-mouse toy and a life size plastic blue fish.

The obliging dolphins got down and dirty with the plastic fish giving it the eye with their left. Dolphins in the wild rarely come across striped balls or large brightly colored cuddly mice and these toys were scrutinized with the other eye that is, the right one.

All this makes perfect sense to us mammals with the right side checking out what the object looks like when compared to similar things and the left being used to process novel things such as dangling cuddly mice in the middle of the ocean. But this doesn’t seem to be the same with fish and birds who have the opposite brain-side activities. Of course, we mammals don’t have feathers or scales either. We went our own way a long time ago.
  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0030001

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