Encefalus

Is he self-aware?

Today we’re dealing with some revolutionary research concerning the subject of self-awareness in birds.

Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self-Recognition Prior H, Schwarz A, Güntürkün O PLoS Biology Vol. 6, No. 8, e202 doi:10.1371/journal.pbio.0060202

The above research was published a few days ago in PLoS Biology. It is the research that I believe will be considered the most important in the field of psychology for 2008. It proves that birds, who don’t belong to mammals, have a completely different evolutionary history and don’t have a neo-cortex, show signs of self-awarenes.

For those of you who have never dealt with the subject of consciousness before, you can read a previous post of mine, Split Brains, Consciousness and Michael Gazzaniga, where I explain some of the fundamentals of this field. One point I have to remention in this article is the notion of self-awareness. Consciousness can be considered to have two "levels", the first one is the primary consciousness which simply differentiates living from non-living things and it is the ability to feel. Secondary consciousness, on the other hand, is the ability to recognize one’s self, to know that you exist. 

Until know, we knew that, besides humans, only the four great apes, bottlenose dolphins, killer whales and Asian elephants had self-awareness. The test used in these experiments is called the Gallup test, and was used by Gordon Gallup in 1970 to search for evidence of self-awareness in chimpanzees. The procedure of the test is very simply. You simply put a small mark on the body of the animal and you have it sit in front of a mirror. If the animal is self-aware, it will understand what he sees in the mirror as its own self and so, it will remove the mark. Wikipedia has an entry on this one: Mirror test

Those of you who have dogs can try to do this experiment with your dog. Just have it sit in front of a mirror. All dogs initially approach carefully the mirror and stop at a certain distance. Then they pause and start barking. That is because they don’t recognize their own selves. Instead they see another dog that is approaching them. Then they see that this dog has no reactions. Feeling a possible threat they start to bark and this dog barks back at them. Finally, once they see that this dog makes no further moves, then they leave the mirror as it holds no interest for them.

Here is a little puppy giving a battle with herself Isn’t it just cute?

Link: www.youtube.com

Anyway, this time researchers used a higly controlled environment to study possible incidence of self-awareness in Magpies. They included  "sham" marks in the study, which is, marks that can’t be seen. These marks were colored black and were put on the black plume of the birds, so, they were used as a control condition. The magpies passed the test and the results (including the control condition) were found to be statistically significant.

(A) Attempt to reach the mark with the beak; (B) touching the mark area with the foot; (C) touching the breast region outside the marked area; (D) touching other parts of the body. Behaviors (A) and (B) entered the analysis as mark-directed behavior; behaviors (C) and (D) and similar actions towards other parts of the body were considered self-directed, but not related to the mark.

This study isn’t simply important because it shows evidence for self-awareness in magpies. It is important for two more reasons.

1) It shows evidence of a self-awareness in a non-mammalian species. Considering the fact that birds don’t even have a neocortex this proves pretty interesting, since we always considered the neocortex the center of all higher experiences. Of course, birds have a certain brain structure called nidopallium caudolaterale, which corresponds to the mammalian prefrontal cortex, both functionally and neurochemically, since it uses the same neurotransmitters. This is a clear evidence of convergent evolution (convergent evolution on wikipedia), two seperate species developing the same qualities. To cite the original paper on this one:

Using the mark test, we obtained evidence for mirror self-recognition in the European Magpie, Pica pica. This finding shows that elaborate cognitive skills arose independently in corvids and primates, taxonomic groups with an evolutionary history that diverged about 300 million years ago. It further proves that the neocortex is not a prerequisite for self-recognition.

Another strange case of evolution

2) It makes for the first time clear a possible connection between mirror neurons, social interaction and self-awareness.

Findings suggestive of self-recognition in mammals other than apes have been reported for dolphins [9] and elephants [10]. In monkeys, nonprimate mammals, and in a number of bird species, exploration of the mirror and social displays were observed, but no hints at mirror-induced self-directed behavior have been obtained [5]. Does this mean a cognitive Rubicon with apes and a few other species with complex social behavior on one side and the rest of the animal kingdom on the other side? This might imply that animal self-recognition is restricted to mammals with large brains and highly evolved social cognition but absent from animals without a neocortex. (emphasis mine)

So it seems, that social interaction might indeed, not only be a prerequisite for self-awareness, but the very cause of it. Another paper I found on PLoS, The Thief in the Mirror, makes the connection I mentioned above. As we know, magpies are thief-birds, stealing food from nests and humans. To succeed in this task, they have to predict the reactions of their enemies, and so they have to evolve self-recognition in order to put themselves in their opponent’s shoes. We have much evidence connecting empathy and theory of mind (the ability to attribute mental states—beliefs, intents, desires, pretending, knowledge, etc.—to oneself and others and to understand that others have beliefs, desires and intentions that are different from one’s own – Wikipedia on theory of mind).

MIrrors and perception of one’s self

So, the connection between these three is clear. This article mentions: 

. The higher levels of empathy require individuals to grasp the situation in which another finds itself, hence looking at the situation from another’s perspective. The same capacity may be reflected in MSR. This is known as the “co-emergence hypothesis,” according to which the capacities for MSR and perspective-taking appear in tandem during both evolution and development…….. 

With regards to human development, this hypothesis is well-supported. Children begin to show perspective-taking abilities at around the same time that they first pass the mirror mark test, even after age has been controlled for [16,17]. In the future, researchers may be able to address this issue more directly through neural investigation. In humans, for example, the right inferior parietal cortex, at the temporoparietal junction, underpins advanced empathy by helping distinguish between self- and other-produced actions…….

Perhaps perspective taking is critically important for a species that plunders the nests of others and steals from humans. But more likely, this capacity may serve relations among conspecifics. Magpies occasionally cache food and may raid each others’ caches, the way their close relatives, the jays, do. For scrub jays, there is evidence that “it takes a thief to know a thief,” suggesting that these birds extrapolate from their own pilfering experiences to the intentions of others [19]. Even if their perspective-taking is not used to assist others, but rather to outwit them, the same grasp of another’s situation may be needed as in advanced empathy, perhaps requiring the same parsing of self from other. 

Link: www.youtube.com

Another puppy video just because I find them cute

So, there we have it. Cognitive scientists, evolutionary biologists and philosophers have always been baffled about the evolutionary explanation of consciousness. As it seems, this might be the answer. Species start to become sociable due to evolutionary pressure. Then, they develop a social structure highly competitive. This develops further pressure in order to develop a theory of mind, so the could give an advantage over the other conspecifics. This requires mirror neurons and self-awareness. Of course, this is just the beginning, since there is very little work done on the subject of the neural correlates (wikipedia on neural correlates) of these procedures. Papers such as these, however, should keep researchers occupied .

Before, we close, we should mention one more research. Take a look at this research: The monkey in the mirror: Hardly a stranger. It describes how cappuchins have a "level of self–other distinction intermediate between seeing their mirror image as other and recognizing it as self." Is this perhaps the middle stage between human’s secondary awareness and the animal’s lack of it? Surely, further investigation is required to shed some light on what has been deemed by many the most important scientific problem of all time.

This entry was posted on Wednesday, August 27th, 2008 at 7:26 pm and is filed under Cognitive, Consciousness. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.