We understand the structural features of the corvid brain
Of course, the most important feature of corvids is their intelligence. Moreover, the history of the study of the bird’s brain is full of dramas and painful attempts to pull the owl of theory onto the globe of practical observations.
The problem was this: since the study of the psyche was based primarily on the materiel of homo sapiens (for obvious reasons), secondly on primates (as close relatives), and thirdly on mammals in general, for a long time it was considered a self-evident thing that GNI is responsible for the neocortex. No neocortex – no GNI. And since the neocortex is absent in birds as a phenomenon, the issue of bird intelligence was closed without really opening it. The CPU architecture does not allow. Dot.
Diagram of the structure of the hemispheres of the telencephalon of the gray crow. Designations: HA – hyperstriatum accessorium, HD – hyperstriatum dorsale, HV – hyperstriatum ventrale, N – neostriatum, LPO – lobus olfactorius, CHp – hippocamous, lfm – lamina frontalis suprema, lfs – lamina frontalis superior, lh – lamina hyperstriatica, lmd – lamina medialis dorsalis, APH – parahippocampus, ES – ectostriatum, PA – paleostriatum accessorium, Spt – septum, PP – paleostriatum primitivum, CDL – lamina corticoidalis, AS – archistriatum, Tel – telencephalon, Wall – vallecula, Cer – cerebellum
The approach had to be changed: since there is a developed cognitive ability, it is necessary to reconsider the issues of materiel. Birds do not have a neocortex, never have been, and are not expected to. It is a fact. In mammals, the neocortex is responsible for intelligence. This is also a fact. Intelligence and other complex mental functions are present in birds. And this is also a fact. From these three facts, the conclusion is obvious: the architecture of the brain in birds is fundamentally different than in mammals. It remains only to find out what it is.
Fortunately, the twenty-first century was approaching, and, in addition to saws, chisels and hammers, scientists had at their disposal various tomographs, encephalographs and other non-destructive testing tools that made it possible to track the activity of various areas of the bird’s brain in real time without having to first remove it from the bird. The results obtained looked quite unexpected.
The bird brain is small. Since most of the birds are sharpened for flight, aviation specificity imposes its own limitations, primarily in terms of mass. Well, in terms of energy consumption, where without it. Two large eyes have already been stuffed into the already small bird’s skull (in relation to the size of the body, bird’s eyes are much larger than those of mammals). There they also drilled a couple of holes for the ears, which, I must say, are also rather big. And the bird eats in this head. Find a place to attach the beak muscles in front and neck muscles in the back. And in the remaining space, shove the brain, but such that it does not consume too much energy, and weighs real garbage – after all, all of the above must be carried through the air solely by muscle power. Like TK? Run AutoCAD, calculate…
So, besides the primitive structure, the bird’s brain is too small to fit even one smart thought. Scientists cautiously bypassed the familiar rake (since the materiel does not allow it, it means that GNI is impossible) and began to figure out how something that should not work at all works. So far, they’ve been able to figure out something like this.
Firstly, most birds do not shine with intelligence (however, with mammals – and with some people, to be honest – this rule also works). Pigeons, for example, are really stupid. Most of their processor power is consumed by GPS, the rest is barely enough to understand that food needs to be shove in the beak, and not somewhere else. But even here there are nuances: even a dove with a small intellect is capable of learning some simple commands. They say that at Skinner’s, the pigeons pecked at the iron scrap on the whistle, long, hard, until the command “stop” came. However, among the birds, two families stand out – corvids and parrots – whose intelligence catches up, and in some places even surpasses monkeys and is quite comparable to human.
Corvids are capable of predicting, abstracting, using and making tools, counting, distinguishing colors, using a complex communication system – in general, they have a bunch of goodies that a developed intellect gives. At the same time, their brain in terms of mass, size and energy consumption is not even close to a human one. Such impressive characteristics of the crow CPU are due to its very specific structure.
The first reason for achieving such impressive optimization performance is the size of a single neuron. Bird neurons are much smaller, therefore, other things being equal, much more of them will fit into the allotted volume.
The second is denser packing. Neurons in birds are not only small – they are packed into the available volume denser than herring in a barrel. This way we can win a little more in their numbers.
Third. Let’s move from quantity to quality. In addition to their size and packing density, avian neurons have another feature: they have more dendrites, and therefore more connections with neighboring cells.
Fourth. These compact, branched, densely packed neurons aggregate into highly efficient neuroglial complexes, structurally distinct from those found in mammals. If mammals are characterized by the so-called “columns”, then for birds – spherical clusters.
As a result, the main wise men of the bird world (corvids and parrots) are doing monkeys both in terms of the number of neurons (and this is in a brain the size of a hazelnut!), And in terms of the efficiency of their use. It is not surprising that with such a progressive processor architecture, a four-month-old raven on benchmarks in all respects catches up with an adult (!) Chimpanzee. Respect the corvids, guys. When we do jump to a nuclear war, it is they who will have to revive civilization on the ruins of the planet. And let’s hope they’re smart enough to get along peacefully with rats, parrots and octopuses. See you soon!
Author and photographer: Daniel Lee
More on the topic of corvids:
– A few observations about crow vision