Crows Zero Full Movie Eng Sub
Claribel Szwaja
The concept of zero, as used in a number system, fully developed in human society around the fifth century A.D., or potentially a few centuries earlier, Live Science previously reported. For instance, the notion of multiplying 8 by 0, or adding 0 to 10, didn't emerge until then. The concept of "none," or the absence of any quantity, likely emerged earlier, but this differs from using zero as a distinct "quantity," in and of itself.
Zero represents that emptiness, the absence of apples, and "that obviously requires very abstract thinking ... thinking that is detached from empirical reality," Nieder said. And now, by peering into the brains of crows, Nieder and his colleagues have discovered that the birds' nerve cells, or neurons, encode "zero" as they do other numbers. The birds' brain activity patterns also support the idea that zero falls before "1" on crows' mental number line, so to speak.
In the new study, published June 2 in The Journal of Neuroscience, the team ran experiments with two male carrion crows (Corvus corone), during which the birds sat on a wooden perch and interacted with a computer monitor in front of them. In each trial, a grey screen containing zero to four black dots popped up in front of the crows; this "sample" image was followed by a "test" image containing either the same or a different number of dots.
In a previous study using the same setup, the group showed that crows could successfully identify the matched and unmatched pairs of images about 75% of the time after undergoing extensive training for the experiment, according to a report published in 2015 in the journal Proceedings of the National Academy of Sciences. This previous study did not include an empty screen, standing in for zero, but it did demonstrate that the crows could differentiate an image containing three dots from a screen containing five, for instance.
The greater the difference between the two sets of dots, the more accurately the birds responded; in other words, the birds mixed up closer quantities, such as two and three, more often than more divergent quantities, such as one and four. This phenomenon is known as the "numerical distance effect," which can also be observed in monkeys and humans during similar tests, Nieder told Live Science.
In the more recent study, which included a blank screen, "what we found is that the crows, after this training, could discriminate zero from the other countable numerosities," Nieder said. However, importantly, the birds still demonstrated the numerical distance effect in trials that included the empty screen.
That means that the birds mixed up the zero-dot image with the one-dot image more often than with two-, three- or four-dot images, Nieder explained. "This is an indication that they treat the empty set, not just as 'nothing' versus 'something,' but really as a numerical quantity," in that they perceive zero dots as proximal to one dot.
To better understand the brain activity behind these behaviors, the team implanted tiny, glass-coated wires into the birds' brains to record electrical activity while the crows repeated the behavioral tests. The chosen neurons sat within a region known as the pallium, which is located toward the back of the bird brain and handles high-level cognitive functions.
The avian pallium belongs to a larger brain region called the telencephalon; humans also have a telencephalon, of which the cerebral cortex, the wrinkled outer layer of the human brain, is one part. But although both the pallium and cortex lie in the telencephalon, there's where many similarities end between the two structures. While the cerebral cortex contains six distinct layers of brain tissue, connected by crisscrossing wires, the avian pallium contains no layers and instead arranges neurons in nuclear clusters, Nieder said.
In the prior 2015 study, the team also gathered recordings from the pallium and specifically zoomed in on one key region, known as the nidopallium caudolaterale (NCL). The NCL receives sensory information, including that from the eyes, processes that data and sends it to areas of the brain related to motor functions, to coordinate physical behaviors. (In primates, the prefrontal cortex plays the same role.)
In the NCL, the team found that certain subgroups of neurons went wild when specific numbers of dots appeared on the screen. Some would begin rapidly firing in response to two dots, while others kicked off for four, for example. These neurons appeared "tuned" to a specific number. And interestingly, the greater the distance between that preferred number and the number of on-screen dots, the less active those neurons became.
These patterns of brain activity hinted at how the crows perceive numerical values in relation to each other, Nieder said. "They are inherently representing this ordinality aspect of numbers, this ordering along a number line, so that after one comes two and after two comes three, and so on," he said.
In combination, the observed patterns of behavior and brain activity suggest that, yes, crows indeed grasp the concept of zero, the authors concluded. What utility this holds for the animals, if any, remains unclear, Nieder told Live Science. While being able to distinguish one piece of fruit from two can be useful for survival, for instance, "I don't see an immediate advantage for these animals to understand nothing as a quantity," he said.
Other behavioral studies have shown that rhesus macaques and honeybees also demonstrate an understanding of zero. In terms of brain activity linked to zero, multiple studies have shown that monkeys carry specially tuned neurons for the number zero, just like crows. And more recently, Nieder and his colleagues demonstrated the same in humans, as described in a 2018 report in the journal Neuron.
"I think that initially it sounds a little crazy to ask whether animals understand zero, because zero is a very, very special, almost magical, number that we have," Nieder said. But now, growing evidence hints that more animals may understand the concept of zero than scientists originally realized.
Even so, Nieder said he'd be surprised if animals like amphibians or reptiles could do mathematical calculations that rely on an understanding of zero, since their learning capabilities don't match that of mammals and birds. But given that birds and mammals split off from their common ancestor well before the extinction of the dinosaurs, the fact that they share overlapping cognitive abilities is also remarkable, Nieder said.
Nicoletta Lanese is the health channel editor at Live Science and was previously a news editor and staff writer at the site. She holds a graduate certificate in science communication from UC Santa Cruz and degrees in neuroscience and dance from the University of Florida. Her work has appeared in The Scientist, Science News, the Mercury News, Mongabay and Stanford Medicine Magazine, among other outlets. Based in NYC, she also remains heavily involved in dance and performs in local choreographers' work."}), " -0-10/js/authorBio.js"); } else console.error('%c FTE ','background: #9306F9; color: #ffffff','no lazy slice hydration function available'); Nicoletta LaneseSocial Links NavigationChannel Editor, HealthNicoletta Lanese is the health channel editor at Live Science and was previously a news editor and staff writer at the site. She holds a graduate certificate in science communication from UC Santa Cruz and degrees in neuroscience and dance from the University of Florida. Her work has appeared in The Scientist, Science News, the Mercury News, Mongabay and Stanford Medicine Magazine, among other outlets. Based in NYC, she also remains heavily involved in dance and performs in local choreographers' work.
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Different species of animals can discriminate numerosity, the countable number of objects in a set. The representations of countable numerosities have been deciphered down to the level of single neurons. However, despite its importance for human number theory, a special numerical quantity, the empty set (numerosity zero), has remained largely unexplored. We explored the behavioral and neuronal representation of the empty set in carrion crows. Crows were trained to discriminate small numerosities including the empty set. Performance data showed a numerical distance effect for the empty set in one crow, suggesting that the empty set and countable numerosities are represented along the crows' "mental number line." Single-cell recordings in the endbrain region nidopallium caudolaterale (NCL) showed a considerable proportion of NCL neurons tuned to the preferred numerosity zero. As evidenced by neuronal distance and size effects, NCL neurons integrated the empty set in the neural number line. A subsequent neuronal population analysis using a statistical classifier approach showed that the neuronal numerical representations were predictive of the crows' success in the task. These behavioral and neuronal data suggests that the conception of the empty set as a cognitive precursor of a zero-like number concept is not an exclusive property of the cerebral cortex of primates. Zero as a quantitative category cannot only be implemented in the layered neocortex of primates, but also in the anatomically distinct endbrain circuitries of birds that evolved based on convergent evolution.SIGNIFICANCE STATEMENT The conception of "nothing" as number "zero" is celebrated as one of the greatest achievements in mathematics. To explore whether precursors of zero-like concepts can be found in vertebrates with a cerebrum that anatomically differs starkly from our primate brain, we investigated this in carrion crows. We show that crows can grasp the empty set as a null numerical quantity that is mentally represented next to number one. Moreover, we show that single neurons in an associative avian cerebral region specifically respond to the empty set and show the same physiological characteristics as for countable quantities. This suggests that zero as a quantitative category can also be implemented in the anatomically distinct endbrain circuitries of birds that evolved based on convergent evolution.
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