December 2008
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Not just a few animals

Article in the Scientific American Mind site by Paul Patton on intelligence in animals, One World Many Minds, talks about goldfish learning mazes with the skill that rats show.

“By performing tests on goldfish after parts of their forebrain had been destroyed, the Spanish team showed in a study published in 2006 that the spatial abilities of goldfish derive from a part of the roof, or pallium, of the forebrain that may correspond to the hippocampus in mammals. Together these new studies indicate that the common ancestor of cartilaginous fishes, bony fishes and land vertebrates may already have possessed a hippocampuslike structure and the spatial cognitive abilities it confers. The hippocampus, which is also involved in processing emotions, is the main pallial component of the limbic system; in MacLean’s triune brain scheme, it was supposed to have originated with mammals. A variety of other limbic system structures are now known to exist in nonmammals.”

Goldfish are part of the teleost fishes that first evolved 200 million years ago - and well after land vertebrates appeared. Their brain structures therefore developed independently from those of the land vertebrates from common early fish structures. The two main branches of land vertebrates have evolved separately for about 300 million years. The one branches evolved into modern mammals and the second into birds and modern reptiles. They have evolved different brain plans, again based on the plan of their common ancestors. The difference in anatomy was first interpreted mistakenly so that it was thought that birds and reptiles did not have a well developed pallium. It is now known that the dorsal ventricular ridge in birds and reptiles is a pallium structure and is similar in function to the mammalian pallium structure, the cortex. Both the cortex and the DVR are involved cognition, planning, learning, remembering, perceiving, and controlling fine movements. Similar connections with other areas of the brain and between areas within the pallium are found in the cortex and the DVR. The neuroanatomical terminology for birds was revised in 2002 to reflect this new understanding.

“Far from being “birdbrains,” our feathered friends have displayed clever behaviors. Among birds, the largest forebrains are those of parrots and corvids (a group that includes crows, jays, ravens and jackdaws). Relative to body size, the brain of a parrot is as large as that of a chimpanzee, although, in absolute terms, it is about the size of a walnut. In recent years researchers have documented stunning cognitive abilities in these two groups of birds.”

In another Scientific American Mind site item by Nicole Branan there is a report on self-awareness in magpies, Magpies Recognize their faces.

“When you look in the mirror, you know you are seeing yourself. Your dog, on the other hand, thinks its reflection is a fellow canine (if anything). So far scientists thought this lack of self-recognition was ubiquitous in the animal kingdom—with the exception of apes, elephants and dolphins. But a new study presents evidence that self-recognition has also evolved in a bird species.

Helmut Prior of Goethe University in Frankfurt, Germany, and his team tagged magpies with a brightly colored mark below their beaks, where the birds could not see it directly. When the magpies looked in the mirror, some of them tried to reach the mark with their beak or touch it with their foot, which shows that they recognized their own mirror image, the researchers say.”

If that isn’t enough, we also have the invertebrates. Some such as the octopus long known to be quite intelligent with some remarkable talents. But now there are indications that bees may have some consciousness. A Scientific American Mind site article by Christof Kock looks at the talents of bees,

Exploring Consciousness through the Study of Bees.

“And contrary to assertions made by philosophers, novelists and other literati, by and large this stream of consciousness does not relate to quiet self-reflection and introspective thoughts. No, most of it is filled with raw sensations… I suspect this feeling is not that dissimilar to the way animals consciously experience their world. Except perhaps for the great apes and a few other privileged big-brained animals, most species do not posses the highly developed sense of self, the ability to reflect on oneself, that people have. Most biologists and pet owners are willing to grant consciousness to cats, dogs and other mammals. Yet our intuitions fail us completely when we consider fish and birds, let alone invertebrates such as squid, flies or worms. Do they experience the sights and sounds, the pains and pleasures, of life? Surely they can’t be conscious—they look too different from us, too alien.

Insects, in particular, were long thought to be simple, reflexive creatures with hardwired instinctual behaviors. No more. Consider the amazing capabilities of the honeybee, Apis mellifera….”

Experiments are described using glass mazes and sugar-water rewards that show that bees can be taught to run glass mazes using the delayed matching-to-sample paradigm. For example, the bee can be shown a green patch and will remember this in the maze and will turn right if the T has a green patch and left if it has a different colour. Having mastered this skill it can quickly learn to run a maze with different colours to match and with different stripe patterns.  

“Bees live in highly stratified yet flexible social organizations with group decision-making skills that rival academic, corporate or government committees in efficiency. In spring, when bees swarm, they choose a new hive that needs to satisfy many demands within a couple of days (consider that the next time you go house hunting). They communicate information about the location and quality of food sources using the waggle dance. Bees can fly several kilometers and return to their hive, a remarkable navigational performance. Their brains seem to have incorporated a map of their environment. And a scent blown into the hive can trigger a return to the site where the bee previously encountered this odor.

…What this dilemma highlights is that there is no accepted theory of consciousness, no principled theory that would tell us which systems, organic or artificial, are conscious and why. In the absence of such a theory, we must at the very least remain agnostic about consciousness in these creatures.”

It seems to me easier to explain the intelligent actions of animals if they have some form of consciousness then if they haven’t.

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