Posts tagged animal cognition
Articles and news from the latest research reports.
Brain size matters when it comes to animal self-control
Chimpanzees may throw tantrums like toddlers, but their total brain size suggests they have more self-control than, say, a gerbil or fox squirrel, according to a new study of 36 species of mammals and birds ranging from orangutans to zebra finches.
Scientists at Duke University, UC Berkeley, Stanford, Yale and more than two-dozen other research institutions collaborated on this first large-scale investigation into the evolution of self-control, defined in the study as the ability to inhibit powerful but ultimately counter-productive behavior. They found that the species with the largest brain volume – not volume relative to body size – showed superior cognitive powers in a series of food-foraging experiments.
Moreover, animals with the most varied diets showed the most self-restraint, according to the study published in the journal of the Proceedings of the National Academy of Sciences.
“The study levels the playing field on the question of animal intelligence,” said UC Berkeley psychologist Lucia Jacobs, a co-author of this study and of its precursor, a 2012 paper in the journal, Animal Cognition.
This latest study was led by evolutionary anthropologists Evan MacLean, Brian Hare and Charles Nunn of Duke University. The findings challenge prevailing assumptions that “relative” brain size is a more accurate predictor of intelligence than “absolute” brain size. One possibility, they posited, is that “as brains get larger, the total number of neurons increases and brains tend to become more modularized, perhaps facilitating the evolution of new cognitive networks.”
While participating researchers all performed the same series of experiments, they did so on their own turf and on their own animal subjects. Data was provided on bonobos, chimpanzees, gorillas, olive baboons, stump-tailed macaques, golden snub-nosed monkeys, brown, red-bellied and aye-aye lemurs, coyotes, dogs, gray wolves, Asian elephants, domestic pigeons, orange-winged amazons, Eurasian jays, western scrub jay, zebra finches and swamp sparrows.
Food inside a tube used as bait
In one experiment, creatures large and small were tested to see if they would advance toward a clear cylinder visibly containing food – showing a lack of self-restraint – after they had been trained to access the food through a side opening in an opaque cylinder. Large-brained primates such as gorillas quickly navigated their way to the treat or “bait.” Smaller-brained animals did so with mixed results.
Jacobs and UC Berkeley doctoral student Mikel Delgado contributed the only rodent data in the study, putting some of the campus’s fox squirrels and some Mongolian gerbils in their lab through food-foraging tasks.
Mixed results on campus squirrels’ self-restraint
In the case of the fox squirrels, the red-hued, bushy-tailed critters watched as the food was placed in a side opening of an opaque cylinder. Once they demonstrated a familiarity with the location of the opening, the food was moved to a transparent cylinder and the real test began. If the squirrels lunged directly at the food inside the bottle, they had failed to inhibit their response. But if they used the side entrance, the move was deemed a success.
“About half of the squirrels and gerbils did well and inhibited the direct approach in more than seven out of 10 trials,” Delgado said. “The rest didn’t do so well.”
In a second test, three cups (A, B and C) were placed in a row on their sides so the animals could see which one contained food. It was usually cup A. The cups were then turned upside down so the “baited” cup could no longer be seen. If the squirrels touched the cup with the food three times in a row, they graduated to the next round. This time, the food was moved from cup A to cup C at the other end of the row.
“The question was, would they approach cup A, where they had originally learned the food was placed, or could they update this learned response to get the food from a new location?” Delgado said. “The squirrels and gerbils tended to go to the original place they had been trained to get food, showing a failure to inhibit what they originally learned.” Click here for video showing other animals doing the cup test.
“It might be that a squirrel’s success in life is affected the same way as in people,” Jacobs said. “By its ability to slow down and think a bit before it snatches at a reward.”
(Source: newscenter.berkeley.edu)
Study finds pigeons and other animals, like humans, can place everyday things in categories
Pinecone or pine nut? Friend or foe? Distinguishing between the two requires that we pay special attention to the telltale characteristics of each. And as it turns out, us humans aren’t the only ones up to the task.
According to researchers at the University of Iowa, pigeons share our ability to place everyday things in categories. And, like people, they can hone in on visual information that is new or important and dismiss what is not.
“The basic concept at play is selective attention. That is, in a complex world, with its booming, buzzing confusion, we don’t attend to all properties of our environment. We attend to those that are novel or relevant,” says Ed Wasserman, UI psychology professor and secondary author on the paper, published in the Journal of Experimental Psychology: Animal Learning and Cognition.
Selective attention has traditionally been viewed as unique to humans. But as UI research scientist and lead author of the study Leyre Castro explains, scientists now know that discerning one category from another is vital to survival.
“All animals in the wild need to distinguish what might be food from what might be poison, and, of course be able to single out predators from harmless creatures,” she says.
More than that, other creatures seem to follow the same thought process humans do when it comes to making these distinctions. Castro and Wasserman’s study reveals that learning about an object’s relevant characteristics and using those characteristics to categorize it go hand-in-hand.
When observing pigeons, “We thought they would learn what was relevant (step one) and then learn the appropriate response (step two),” Wasserman explains. But instead, the researchers found that learning and categorization seemed to occur simultaneously in the brain.
To test how, and indeed whether, animals like pigeons use selective attention, Wasserman and Castro presented the birds with a touchscreen containing two sets of four computer-generated images—such as stars, spirals, and bubbles.
The pigeons had to determine what distinguished one set from the other. For example, did one set contain a star while the other contained bubbles?
By monitoring what images the pigeons pecked on the touchscreen, Wasserman and Castro were able to determine what the birds were looking at. Were they pecking at the relevant, distinguishing characteristics of each set—in this case the stars and the bubbles?
The answer was yes, suggesting that pigeons—like humans—use selective attention to place objects in appropriate categories. And according to the researchers, the finding can be extended to other animals like lizards and goldfish.
“Because a pigeon’s beak is midway between its eyes, we have a pretty good idea that where it is looking is where it is pecking,” Wasserman says. “This could be true of any bird or fish or reptile.
“However, we can’t assume our findings would hold true in an animal with appendages—such as arms—because their eyes can look somewhere other than where their hand or paw is touching,” he explains.
Physics-minded crows bring Aesop’s fable to life
Eureka! Like Archimedes in his bath, crows know how to displace water, showing that Aesop’s fable The Crow and the Pitcher isn’t purely fictional.
To see if New Caledonian crows could handle some of the basic principles of volume displacement, Sarah Jelbert at the University of Auckland in New Zealand and her colleagues placed scraps of meat just out of a crow’s reach, floating in a series of tubes that were part-filled with water. Objects potentially useful for bringing up the water level, like stones or heavy rubber erasers, were left nearby.
The crows successfully figured out that heavy and solid objects would help them get a treat faster. They also preferred to drop objects in tubes where they could access a reward more easily, picking out tubes with higher water levels and choosing tubes of water over sand-filled ones.
Monkeys can point to objects they do not report seeing
Are monkeys, like humans, able to ascertain where objects are located without much more than a sideways glance? Quite likely, says Lau Andersen of the Aarhus University in Denmark, lead author of a study conducted at the Yerkes National Primate Research Center of Emory University, published in Springer’s journal Animal Cognition. The study finds that monkeys are able to localize stimuli they do not perceive.
Humans are able to locate, and even side-step, objects in their peripheral vision, sometimes before they perceive the object even being present. Andersen and colleagues therefore wanted to find out if visually guided action and visual perception also occurred independently in other primates.
The researchers trained five adult male rhesus monkeys (Macaca mulatta) to perform a short-latency, highly stereotyped localization task. Using a touchscreen computer, the animals learned to touch one of four locations where an object was briefly presented. The monkeys also learned to perform a detection task using identical stimuli, in which they had to report the presence or absence of an object by pressing one of two buttons. These techniques are similar to those used to test normal humans, and therefore make an especially direct comparison between humans and monkeys possible. A method called “visual masking” was used to systematically reduce how easily a visual target was processed.
Andersen and his colleagues found that the monkeys were still able to locate targets that they could not detect. The animals performed the tasks very accurately when the stimuli were unmasked, and their performance dropped when visual masking was employed. But monkeys could still locate targets at masking levels for which they reported that no target had been presented. While these results cannot establish the existence of phenomenal vision in monkeys, the discrepancy between visually guided action and detection parallels the dissociation of conscious and unconscious vision seen in humans.
“Knowing whether similar independent brain systems are present in humans and nonverbal species is critical to our understanding of comparative psychology and the evolution of brains,” explains Andersen.
(Source: springer.com)
Why don’t apes have musical talent, while humans, parrots, small birds, elephants, whales, and bats do? Matz Larsson, senior physician at the Lung Clinic at Örebro University Hospital, attempts to answer this question in the scientific publication Animal Cognition.
In his article, he asserts that the ability to mimic and imitate things like music and speech is the result of the fact that synchronised group movement quite simply makes it possible to perceive sounds from the surroundings better.
The hypothesis is that the evolution of vocal learning, that is musical traits, is influenced by the need of a species to deal with the disturbing sounds that are created in connection with locomotion. These sounds can affect our hearing only when we move.
“When several people with legs of roughly the same length move together, we tend to unconsciously move in rhythm. When our footsteps occur simultaneously, a brief interval of silence occurs. In the middle of each stride we can hear our surroundings better. It becomes easier to hear a pursuer, and perhaps easier to conduct a conversation as well,” explains Larsson.
A behaviour that has survival value tends to produce dopamine, the “reward molecule”. In dangerous terrain, this could result in the stimulation of rhythmic movements and enhanced listening to surrounding sounds in nature. If that kind of synchronized behaviour was rewarding in dangerous environments it may as well have been rewarding for the brain in relative safety, resulting in activities such as hand- clapping, foot-stamping and yelping around the campfire. From there it is just a short step to dance and rhythm. The hormone dopamine flows when we listen to music.
New research reveals how elephants ‘see’ the world
Think Elephants International, a not-for-profit organization that strives to promote elephant conservation through scientific research, education programming and international collaborations, today announced its latest study, “Visual Cues Given by Humans are Not Sufficient for Asian Elephants (Elephas Maximus) to Find Hidden Food.”
This study has been published in the April 17, 2013 issue of PLOS ONE, an international publication that reports original research from all disciplines within science and medicine. Designed in collaboration with and co-authored by 12-14 year old students from East Side Middle School in NYC, the study revealed that elephants were not able to recognize visual cues provided by humans, although they were more responsive to vocal commands. These findings may directly impact protocols for future efforts to conserve elephants, which are in danger of extinction in this century due to increased poaching and human/elephant conflict.
The publication of this paper is the climax of a three-year endeavor to create a comprehensive middle school curriculum that brings elephants into classrooms as a way to educate young people about conservation by getting them directly involved in work with endangered species. This research tested whether elephants could follow visual, social cues (pointing and gazing) to find food hidden in one of two buckets. The elephants failed at this task, but were able to follow vocal commands telling them which bucket contained the food. These results suggest that elephants may navigate their physical world in ways that primates and dogs, prior subjects of animal cognition studies, do not.
"Dogs have a great sense of smell, but appear to be able to follow human pointing as a way of finding food," said Joshua Plotnik, PhD, founder and CEO of Think Elephants. "Perhaps elephants’ sense of smell is one of their primary sensory modalities, meaning that they may use it preferentially when navigating their physical worlds."
In the field of animal cognition, there has been considerable attention focused on how animals interact with each other and humans. Particularly, there is a lot of interest in how dogs are able to read social cues to understand what people see, know or want. Remarkably, non-human primates such as chimpanzees are not good at this, suggesting it may be that through domestication or long-term human contact, dogs have developed a capacity for following social cues provided by people. Think Elephants aimed to test elephants on this because they are a wild, non-domesticated species that, in captivity in Thailand, are in relatively constant contact with humans.
The study’s findings have important implications for future protection protocols for wild elephants.
According to Dr. Plotnik, “If elephants are not primarily using sight to navigate their natural environment, human-elephant conflict mitigation techniques must consider what elephants’ main sensory modalities are and how elephants think so that they might be attracted or deterred effectively as a situation requires. The loss of natural habitat, poaching for ivory, and human-elephant conflict are serious threats to the sustainability of elephants in the wild. Put simply, we will be without elephants, and many other species in the wild, in less than 50 years if the world does not act.”
To mitigate this, Dr. Plotnik suggests further attention to research on elephant behavior and an increase in educational programming are needed, particularly in Asia where the market for ivory is so strong. Think Elephants’ education program in NYC is a pilot that will be expanding to Thai schools later in 2013.
The students were integrally involved in the development of this study, even helping to design some of the experimental control conditions. The study was carried out at Think Elephants’ field site in northern Thailand, and students participated via webcam conversation and direct web-links to the elephant camp.
This shows that collaborations that include both academics and young students can be productive, informative and exciting.
According to Jen Pokorny, PhD, Think Elephants’ head of education programs, “We are so proud of our pilot program with East Side Middle School and hope to use this as a model for other schools throughout the state and country. This wonderful group of students had an opportunity that very few young people have and, as a result, are now published co-authors on a significant piece of animal behavior research. They were integrally involved in the development of the study, even helping to design some of the experimental control conditions. Think Elephants is committed to showcasing these productive, informative and exciting student collaborations, and we believe similar studies can help to change the way in which young people observe and appreciate their global environment.”
Brainless robots swarm just like animals
Swarming patterns and herding behaviours have been observed throughout the animal kingdom. Scientists and mathematicians have pondered the cause of complex relationships and group dynamics at work that allow schools of fish, such as herring, and flocks of birds, such as starlings, to move together in apparent unity — and now, in an interesting twist to the discussion, a team of engineers from Harvard University has observed apparent collective behaviour in brainless robots.
The robot research team was looking for a way to investigate the transition that swarming groups make from random behaviour into collective motion. In order to observe a randomly moving collective, they built the simplest of “self-propelled automatons”, the charmingly named Bristle-Bot (BBots).