Do animals have reflective minds?

According to one of the leading scholars in the field, there is an emerging consensus among scientists that animals share functional parallels with humans' conscious metacognition -- that is, our ability to reflect on our own mental processes and guide and optimize them. 

Scientists concur that when it comes to this Old World macaque: monkey see, monkey do, monkey think about what monkey do, monkey maybe do something else [Credit: University at Buffalo]

In two new contributions to this influential field of comparative psychology, David Smith, PhD, of the University at Buffalo and his fellow researchers report on continuing advances in this domain. 

Smith is a professor in the Department of Psychology at UB, and a member of the university's graduate program in evolution, ecology and behavior and its Center for Cognitive Science. His co-authors on the articles are Justin J. Couchman, PhD, visiting assistant professor of psychology, State University of New York at Fredonia, and Michael J. Beran, PhD, senior research scientist, Language Research Center, Georgia State University. 

In "The Highs and Lows of Theoretical Interpretation in Animal-Metacognition Research," in press at the journal Philosophical Transactions of the Royal Society, Smith, Couchman and Beran examine the theoretical and philosophical problems associated with the attribution of self-reflective, conscious mind to nonverbal animals. 

"The possibility of animal metacognition has become one of the research focal points in comparative psychology today," Smith says, "but, of course, this possibility poses difficult issues of scientific interpretation and inference." In this article, they evaluate the standards that science brings to making difficult interpretations about animal minds, describing how standards have been applied historically and as they perhaps should be applied. The article concludes that macaques do show uncertainty-monitoring capacities that are similar to those in humans. 

The other contribution, "Animal Metacognition," will be published in March by Oxford University Press in the volume "Comparative Cognition: Experimental Explorations of Animal Intelligence." 

In this article, Smith and his colleagues provide a comprehensive review of the current state of the animal-metacognition literature. They describe how Smith inaugurated animal metacognition as a new field of study in 1995 with research on a bottlenosed dolphin. The dolphin assessed correctly when the experimenter's trials were too difficult for him, and adaptively declined to complete those trials. 

The dolphin also showed his own distinctive set of hesitation, wavering and worrying behaviors when the trials were too difficult. In sharp contrast, when the trials were easy, he swam to the responses so fast that he would make a bow-wave around himself that would swamp Smith's delicate electronics. Smith says: "We finally had to buy condoms to protect the equipment." 

Subsequently, Smith and many collaborators also explored the metacognitive capacities of joystick-trained macaques. These Old-World monkeys, native to Africa and Asia, can make specific responses to declare uncertainty about their memory. They can respond, "Uncertain," to gain hints from the experimenters of what to do on the first trial of new tasks. They can even respond, "Uncertain," when their memory has been erased by trans-cranial magnetic stimulation. Accordingly, this second article by Smith and colleagues also supports the consensus that animals share with humans a form of the self-reflective, metacognitive capacity. 

"In all respects," says Smith, "their capacity for uncertainty monitoring, and for responding to uncertainty adaptively, show close correspondence to the same processes in humans. 

"At present," he says, "members of South-American monkey species or New World monkeys have not shown the same robust capacities for uncertainty monitoring, a possible species difference that has intriguing implications regarding the emergence of reflective mind in monkeys, apes and humans." 

Smith's ongoing research in this area is supported by generous grants from both the National Institutes of Health and the National Science Foundation. 

Source: University at Buffalo [March 22, 2012]

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Denying mental qualities to animals in order to eat them

New research by Dr Brock Bastian from UQ's School of Psychology highlights the psychological processes that people engage in to reduce their discomfort over eating meat. 

This paper will be published in an upcoming edition of the Personality and Social Psychology Bulletin, where Dr Bastian and his co-authors show that people deny mental qualities to animals they eat. 

"Many people like eating meat, but most are reluctant to harm things that have minds. Our studies show that this motivates people to deny minds to animals," Dr Bastian said. 

The research demonstrates when people are confronted with the harm that their meat-eating brings to food animals they view those animals as possessing fewer mental capacities compared to when they are not reminded. 

The findings also reveal that this denial of mind to food animals is especially evident when people expect to eat meat in the near future. 

Dr Bastian said it shows that denying mind to animals that are used for food makes it less troublesome for people to eat them. 

"Meat is central to most people's diets and a focus of culinary enjoyment, yet most people also like animals and are disturbed by harm done to them; therefore creating a 'meat paradox' - people's concern for animal welfare conflicts with their culinary behavior. 

"For this reason, people rarely enjoy thinking about where meat comes from, the processes it goes through to get to their tables, or the living qualities of the animals from which it is extracted," he said. 

Dr Bastian's research argues that meat eaters go to great lengths to overcome these inconsistencies between their beliefs and behaviours. 

"In our current research we focus on the processes by which people facilitate their practice of eating meat. People often mentally separate meat from animals so they can eat pork or beef without thinking about pigs or cows. 

"Denying minds to animals reduces concern for their welfare, justifying the harm caused to them in the process of meat production," he added. 

Meat is pleasing to the palate for many, and although the vegetarian lifestyle is increasingly popular, most people continue to make meat a central component of their diet. 

"In short, our work highlights the fact that although most people do not mind eating meat, they do not like thinking of animals they eat as having possessed minds," Dr Bastian said.  

Source: University of Queensland [November 25, 2011]

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Adolescent sex linked to adult body, mood troubles... in hampsters

A new study suggests that sex during adolescence can have lasting negative effects on the body and mood well into adulthood, most likely because the activity occurs when the nervous system is still developing. 

While the research used laboratory animals, the findings provide information that may be applicable to understanding human sexual development. 

Researchers paired adult female hamsters with male hamsters when the males were 40 days old, the equivalent of a human's mid-adolescence. They found that these male animals with an early-life sexual experience later showed more signs of depressive-like behaviors as well as lower body mass, smaller reproductive tissues and changes to cells in the brain than did hamsters that were first exposed to sex later in life or to no sex at all. 

Among the cell changes observed in the animals that had sex during adolescence were higher levels of expression of a gene associated with inflammation in their brain tissue and less complex cellular structures in key signaling areas of the brain. 

They also showed signs of a stronger immune response to a sensitivity test, suggesting their immune systems were in a heightened state of readiness even without the presence of infection – a potential sign of an autoimmune problem. 

The combination of physiologic responses in adulthood don't necessarily cause harm, but do suggest that sexual activity during the nervous system's development might be interpreted by the body as a stressor, researchers say. 

"Having a sexual experience during this time point, early in life, is not without consequence," said John Morris, a co-author of the study and a doctoral student in psychology at Ohio State University. "It could be affecting males' susceptibility to symptoms of depression, and could also expose males to some increase in inflammation in adulthood." 

Morris presented the research Tuesday (11/15) at the Society for Neuroscience annual meeting in Washington, D.C. He conducted the study with Zachary Weil, research assistant professor, and Randy Nelson, professor and chair, both from Ohio State's Department of Neuroscience. 

Previous research has most often examined the effects of adolescent sex on young women, and for ethical reasons must be done in humans as retrospective explorations of behavior. The Ohio State scientists used hamsters, which have physiologic similarities to humans, to learn specifically how the body responds to sexual activity early in life. 

"There is a time in nervous system development when things are changing very rapidly, and part of those changes are preparations for adult reproductive behaviors and physiology," Weil said. "There is a possibility that environmental experiences and signals could have amplified effects if they occur before the nervous system has settled down into adulthood." 

The scientists worked with five groups of male hamsters: two groups that had sex at age 40 days and were assessed at 40 days and 80 days after exposure to sex, two groups that had adult sex at age 80 days and were assessed at the same time intervals, and hamsters that had no sexual experience. Male hamsters reach puberty at age 21 days. 

The researchers placed the adolescent and adult males in environments with in-heat female hamsters for six hours and recorded their encounters to ensure that sexual activity occurred. 

The animals were subjected to a variety of tests when they all had reached adulthood. They were placed in mazes with options to explore open areas or hide in isolation; those that chose not to explore were showing signs of anxiety. Animals placed in water showed signs of depressive-like behavior if they stopped swimming vigorously. 

"Both groups of sexually active hamsters showed an increase in anxiety-like behavior compared to the control group, but the increase in a depressive-like response was specific to the adolescent sexually paired group," Morris said. 

A test of immune system sensitivity suggested that the hamsters with adolescent sexual experiences were at risk for excess inflammation as part of an enhanced immune response. In addition, these same hamsters had higher levels of a pro-inflammatory cytokine called interleukin-1, or IL-1, in their brain tissue than did the other hamsters. IL-1 is one of several chemical messengers that cause inflammation, most often to fight infection or repair injury; when it circulates without an infection to fight, the body experiences excess inflammation. 

This elevated gene expression was seen in areas of the brain known not to reach maturity until well into adulthood – including the amygdala, prefrontal cortex, hippocampus and striatum. In some of these same areas of the brain, animals with adolescent sexual experience also showed less complexity in the dendrites, the branching segments from nerve cells that house the synapses, which carry signals to the brain from the rest of the body. 

Without further research, the scientists don't know exactly what these brain differences mean. But because they are seen most prominently in the animals that were exposed to sex in adolescence, the scientists say, there is a clear association with that activity. "Sex is doing something physiological that these cells are interpreting and responding to with shorter dendrites," Weil said. 

Finally, the hamsters that had adolescent sex had a smaller total body mass as well as a decrease in accessory reproductive tissue, including the seminal vesicles, vas deferens and epididymis, as adults. 

"This suggests to us that maybe this process is causing the animals to have a maladaptive response reproductively, as well," Morris said. 

Source: Ohio State University [November 15, 2011]

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Chromosomal “Breakpoints” Linked to Canine Cancer

North Carolina State University researchers have uncovered evidence that evolutionary “breakpoints” on canine chromosomes are also associated with canine cancer. Mapping these “fragile” regions in dogs may also have implications for the discovery and treatment of human cancers. 

When new species evolve, they leave genetic evidence behind in the form of “breakpoint regions.” These regions are sites on the genome where chromosomes broke during speciation (when new species of dogs developed). Dr. Matthew Breen, professor of genomics at NC State, and graduate student Shannon Becker looked at the breakpoint regions that occurred when the canid (dog) species differentiated during evolution. They compared the genomes of several wild canine species with those of the domestic dog. By overlaying the genomes, they found shared breakpoints among 11 different canid species – the so-called evolutionary breakpoints. 

“The interesting thing about the breakpoint areas in the canid chromosome is that they are the same regions that we have shown to be associated with chromosome breaks in spontaneously occurring cancers,” Breen says. “It is possible that the re-arrangement of chromosomes that occurred when these species diverged from one another created unstable regions on the chromosome, and that is why these regions are associated with cancer.” 

The researchers’ results appear in Chromosome Research. 

“As species evolve, genetic information encoded on chromosomes can be restructured – resulting in closely related species having differently organized genomes,” says Becker. “In some cases, species acquire extra chromosomes, called B chromosomes. We looked at these extra B chromosomes in three canid species and found that they harbor several cancer-associated genes. Our work adds to the growing evidence that there is an association between cancer-associated genomic instability and genomic rearrangement during speciation.” 

“The presence of clusters of cancer- associated genes on canid B chromosomes suggests that while previously though to be inert, these chromosomes may have played a role in sequestering excess copies of such genes that were generated during speciation,” adds Breen. “We now need to determine whether these stored genes are active or inert – that information could give us new tools in cancer detection and treatment.” 

Source: North Carolina State University [November 03, 2011]

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