Bird-brains of Britain: Pigeons have an understanding of space and time

Alan Martin December 4, 2017

In the great World Cup of animal minds, the pigeon is just happy to make the final tournament. Blinking passively, they seem to be the very dictionary definition of dim: there’s a reason the expression “bird-brained” has entered our lexicon, and it’s not a flattering one.

Bird-brains of Britain: Pigeons have an understanding of space and time

But it seems a lot more may be going on in their walnut-sized brains than we previously gave them credit for. Specifically, they’ve put those tiny minds to the abstract concepts of space and time – and they seem to understand them.

This is a bit of a surprise, as previous research into the subject suggests that animals – including us – process both concepts through the parietal cortex: part of the cerebral cortex which is associated with higher thought processes such as speech and decision making. The trouble is that pigeons don’t have a parietal cortex, so they must be doing this somewhere else.

Of course, without said parietal cortex, questioning the pigeons on their understanding of space and time will also get you nowhere. So how exactly do you test a pigeon’s ability to understand?

Winging it

The researchers tested the birds with a quiz and the prospect of food for picking the correct answer. The pigeons were shown a horizontal line on a computer screen, with two variables for space and time: the line could either be 6cm or 24cm, and it could be onscreen for either two or eight seconds. The birds would then pick one of four visual symbols indicating a possible length or duration, and if they picked right, they’d get a snack.

But this only gets you so far, so the researchers added in other lengths and different time periods to mix things up a bit. “The task now forces pigeons to process time and space simultaneously because they cannot know on which dimension they’re going to be tested,” explains Professor Edward Wasserman from the University of Iowa’s department of psychology and brain science.

The results were clear: variation in line length affected the pigeons’ judgement of distance, while different timings affected their perception of time. The pigeons were analysing space and time somewhere, so it must be in a different part of the brain.

So what is going on here? If the birds have no parietal cortex, where is the analysis happening? “It’s a very good question,” replies Benjamin De Corte, a graduate student from the University of Iowa, and one of the paper’s authors, via email. “If I had to guess, it would be something called the nidopallium caudolaterale. That area seems to be critical for complex cognitive processing in pigeons and birds in general. However, no one’s evaluated this yet with respect to space-time interactions as far as I know.”

How could that be tested? “I’d train pigeons on the task we employed and assess what neurons in the nidopallium caudolaterale are doing during the task,” De Corte offers. “Basically, looking for neurons that seem to be encoding both the length and duration of the line.”

Whatever future research finds, these results should figuratively put the cat amongst the pigeons. Though cats apparently have a complex understanding of physics, so who knows how that intellectual clash of the titans would play out?