October 13, 2008

Cephalopod consciousness: Behavioural evidence

animal minds — alice @ 12:00 am

Building on past investigations of the possibility of a form of consciousness in birds and cephalopod molluscs, Jennifer Mather reports on cephalopod consciousness in an article in Consciousness and Cognition.  Using global workspace as a criterion for consciousness, Mather concludes that cephalopods appear to have primary consciousness.

Abstract:

Behavioural evidence suggests that cephalopod molluscs may have a form of primary consciousness. First, the linkage of brain to behaviour seen in lateralization, sleep and through a developmental context is similar to that of mammals and birds. Second, cephalopods, especially octopuses, are heavily dependent on learning in response to both visual and tactile cues, and may have domain generality and form simple concepts. Third, these animals are aware of their position, both within themselves and in larger space, including having a working memory of foraging areas in the recent past. Thus if using a ‘global workspace’ which evaluates memory input and focuses attention is the criterion, cephalopods appear to have primary consciousness.

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March 27, 2008

Who’s bad? Chimps figure it out by observation

thinkchimp.jpgChimpanzees make judgments about the actions and dispositions of strangers by observing others’ behavior and interactions in different situations. Specifically, chimpanzees show an ability to recognize certain behavioral traits and make assumptions about the presence or absence of these traits in strangers in similar situations thereafter. These findings, by Dr. Francys Subiaul – from the George Washington University in Washington DC – and his team, have just been published online in Animal Cognition, a Springer journal.

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December 11, 2007

The trivial function of sleep

Rest in poikilothermic animals is an adaptation of the organism to adjust to the geophysical cycles, a doubtless valuable function for all animals. In this review, we argue that the function of sleep could be trivial for mammals and birds because sleep does not provide additional advantages over simple rest. This conclusion can be reached by using the null hypothesis and parsimony arguments.

First, we develop some theoretical and empirical considerations supporting the absence of specific effects after sleep deprivation. Then, we question the adaptive value of sleep traits by using non-coding DNA as a metaphor that shows that the complexity in the design is not a definitive proof of adaptation.

We then propose that few, if any, phenotypic selectable traits do exist in sleep. Instead, the selection of efficient waking has been the major determinant of the most significant aspects in sleep structure. In addition, we suggest that the regulation of sleep is only a mechanism to enforce rest, a state that was challenged after the development of homeothermy.

As a general conclusion, there is no direct answer to the problem of why we sleep; only an explanation of why such a complex set of mechanisms is used to perform what seems to be a simple function. This explanation should be reached by following the evolution of wakefulness rather than that of sleep. Sleep could have additional functions secondarily added to the trivial one, although, in this case, the necessity and sufficiency of these sleep functions should be demonstrated.

The trivial function of sleep. R.V. Rial, Maria C. Nicolau, Antoni Gamundi, Mourad Akaarir, Sara Aparicio, Celia Garau, Silvia Tejada, Catalina Roca, Lluis Gene, David Moranta, Susana Esteban, 2007. Sleep Medicine Reviews 11(4):311-325.

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September 12, 2007

Gorillas heads race to extinction

animal minds,comparative studies — thomasr @ 2:07 pm

According to the Red List of Threatened Species for 2007, gorillas, orangutans, and corals are among the plants and animals which are sliding closer to extinction. You can read more about this at BBC.

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September 8, 2007

Forgetting the fear

animal minds,emotions — thomasr @ 4:00 pm

shark-fear.jpgThere are some memories one would rather forget. This is especially true for people who suffer from phobias or from post-traumatic stress disorder. Some memories can decrease and even disappear through a process called extinction, but the mechanisms that are involved are not known. Tsai and colleagues now show that a molecular pathway in the hippocampus that involves cyclin-dependent kinase 5 (Cdk5) regulates the extinction of contextual fear in mice.

When mice are exposed to an aversive stimulus in a neutral context, they develop fear for that context — this is called conditioned fear. In a subsequent ‘extinction procedure’ that consists of daily 3-minute long re-exposures to the context alone, the animals gradually become less afraid of the environment, as evidenced by reduced freezing.

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September 6, 2007

Higher social skills are uniquely human

chimp1.jpgA new study published today in Science reports that humans have distinctive social skills. Esther Herrmann, lead author of the study, answers Scitizen’s questions.

Apes bite and try to break a tube to retrieve the food inside while children follow the experimenter’s example to get inside the tube to retrieve the prize, showing that even before preschool, toddlers are more sophisticated in their social learning skills than their closest primate relatives, according to a report published in the 7 September issue of the journal Science.

This innate proficiency allows them to excel in both physical and social skills as they begin school and progress through life.

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August 26, 2007

Chimps hold out

animal minds,executive functions — thomasr @ 9:20 am

thinkingchimp.jpgResearchers have found that chimps know how to distract themselves with play in order to ward off temptation.

Most children practice this mental trick: When asked to wait patiently for a promised treat–say, an hour of television–they occupy themselves with a toy or a book. Researchers have now shown that chimpanzees engage in similar self-distraction, a finding that further blurs the cognitive and behavioral boundary between humans and other primates. The discovery comes from a study conducted at Georgia State University in Atlanta. Psychologists Theodore Evans and Michael Beran put each of four chimps in front of a container connected to a candy dispenser. The chimps could reach over and pick up the container to eat the accumulated candies at any time, but doing so stopped the dispenser from delivering any more. That allowed the chimps to delay the reward as long as they wanted–so that they could get more of it.

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May 22, 2007

Resting states in unconscious monkeys

Nature has an interesting report from Marc Raichle‘s laboratory that studies the resting states in monkeys. This study not only demonstrates that resting states occur in non-human primates, but that it is possible to find such activity during unconscious states.

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May 21, 2007

Smarter, sentient whales

animal minds,evolution,theory of mind — thomasr @ 4:13 am

whale.jpgRecent studies have shown that the brains of sperm whales is second in size only to human (relative to body size). It is about 60% larger in absolute mass than that of an elephant. How this brain evolution has occurred is the topic of a most interesting article in PLoS Biology, authored by Lori Marino et al. In this article the authors also forcefully argue that the increased brain size is paralleled by a comparable increase in cognitive complexity. As the authors write:

We believe that the time is ripe to present an integrated view of cetacean brains, behavior, and evolution based on the wealth of accumulated and recent data on these topics. Our conclusions support the more generally accepted view that the large brain of cetaceans evolved to support complex cognitive abilities.

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March 5, 2007

Scrub-jays plan for the future

animal minds,future thinking — alice @ 11:19 pm

A recent paper in Nature, which came out of Nicky Clayton’s lab at the University of Cambridge, reports on the ability of western scrub-jays to plan for the future. The findings of this paper, by Raby et al., suggest that scrub-jays can (and do!) plan for the following day without reference to their current motivational state, challenging the idea that the ability to think about the future is unique to humans. It will be interesting to see what kind evidence will follow on this topic.

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January 17, 2007

Jane Goodall Podcast

goodall_461.jpgABC Radio National in Australia has an excellent podcast on a talk by Jane Goodall , an English primatologist, ethologist and anthropologist, who is well known for conducting a forty-five year study of chimpanzee social and family life.

In her talk, Goodall addresses the issue of animal personality and animal minds. It is a powerful reminder of how much this issue has been a scientific taboo for not too long ago.

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January 13, 2007

Memory for what, where, when and who in nonhuman animals

animal minds,memory — alice @ 5:13 pm

Can birds remember who watched them do what, as well as when and where?

Scrub jays have already been demonstrated to encode the “what-where-when” (what happened, where it happened and when it happened) of specific caching episodes (Clayton, N.S. & Dickenson, A., 1998). It has even been shown that scrub jays, when observed caching food, re-cache food only if they have stolen the food of another bird in the past (Emery & Clayton, 2001). This finding suggests that jays who have stolen food in the past can also anticipate their own food being stolen in the future, and, therefore, take precautionary measures to reduce this possibility.

Now, the results of a recent study by Dally et al. (2006) suggest that scrub jays also remember who was present during earlier caching events. In this study, jays were more likely to re-cache food if a more dominant bird observed them caching than if a less dominant bird did so. As Dally et al. note, since scrub-jays can only defend their caches against subordinates, it seems very likely that the observed re-caching behaviour is advantageous in situations where the jays are caching in view of dominant birds, as it is thought to reduce the likelihood of future pilfering.

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October 21, 2006

The chemical sense of retaining detailed memories

animal minds,cognitive science,memory — thomasr @ 7:50 pm

acethyl.jpgThe levels of a chemical released by the brain determine how detailed a memory will later be, according to researchers at UC Irvine.

The neurotransmitter acetylcholine, a brain chemical already established as being crucial for learning and memory, appears to be the key to adding details to a memory. In a study with rats, Norman Weinberger, research professor of neurobiology and behavior, and colleagues determined that a higher level of acetylcholine during a learning task correlated with more details of the experience being remembered. The results are the first to tie levels of acetylcholine to memory specificity and could have implications in the study and treatment of memory-related disorders.

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December 27, 2005

Detecting a touch

animal minds — thomasr @ 7:59 pm

What happens in the brain when a stimulus is detected? How does the brain activity look when there is no such detection? This question has been addressed by study by de Lafuente et al. in a study of monkeys. Using somatosensory stimuli, the results indicated that the primary sensory cortices are not part of the neural correlates of conscious detection. On the other hand, conscious detection led to increased activity in the frontal lobes. This study corresponds nicely with theories suggesting that consciousness involves a spread network of brain areas instead of sensory-specific areas. Furthermore, this study is interesting due to its use of somatosensory stimuli, while the majority of studies on NCC is about visual perception.

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September 7, 2005

Chimps to People: Apes show contrasts in genetic makeup

animal minds — thomasr @ 11:43 am

Despite sharing much of their genetic identity with people, chimpanzees exhibit previously unappreciated DNA distinctions, according to the first rigorous comparisons of the two species’ complete genetic sequences.

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September 3, 2005

Fishing For Birds

animal minds — thomasr @ 5:47 am

A crafty killer whale has devised a new way to catch a tasty bite. The orca spits regurgitated fish onto the surface of the water – and then waits. When a passing gull dives for the bait, the whale lunges at the feathery treat with open jaws. What’s more, the trick was picked up by other family members.

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April 7, 2003

Does the duck-billed platypus dream?

SCR Feature,animal minds — thomasr @ 7:53 pm

You can see a dog dreaming: it twitches and whines, and its eyes move in “rapid eye movement” (REM) sleep. In fact, dreaming in dogs and cats is quite similar to human dreaming. But a recent study of dream patterns in the duck-billed platypus, the odd-looking Australian marsupial, reveals an interesting surprise.

In humans, dreaming has all the earmarks of a conscious state. Our brains look like they are awake: They shows massive amounts of “gamma activity,” the high-frequency, low-intensity and irregular electrical waves that can be seen simply by placing electrodes on our scalps. People also give vivid dream reports (if they are awakened immediately after REM rather than waiting until the next day). In humans, dreaming has all the earmarks of a conscious state That is, they SAY they were conscious of something in their own minds. We can’t ask dogs and cats to report their dreams, but the same brain pattern occurs in a very wide range of mammals. Their eyes move (REM), their EEG goes into gamma, their bodies become limp, and they block incoming stimuli. Physiologically it looks like dogs and cats, and perhaps a very wide range of mammals, are conscious during REM dreams.

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