Consciousness in Nonhumans

Consciousness in Machines and in Nonhuman Mammals

When one starts thinking about the problem of consciousness, the question of whether or not a machine can be conscious begins to appear rather ridiculous. Some day this question might only be asked by people who are unfamiliar with the essential neuroscientific facts about consciousness. Consciousness has everything to do with being embodied, with awareness of one's bodily state in relation to what is going on around one. Moreover, this mechanism seems to have evolved only because bodies have needs. Consciousness is therefore deeply rooted in a set of ancient biological values. These values are what feelings are, and consciousness is feeling. It is therefore very difficult to imagine how, why, and where a disembodied machine would generate consciousness. This does not rule out the possibility of an artificial system with self-monitoring properties. But the self that it monitors would have to be a body (and preferably one with a long evolutionary history( if it is really going to generate feelings.

This argument has interesting implications, too, for the question of consciousness in other animals. It suggests that any animal with a brainstem designed roughly like our own – that is, a brainstem that modulates visceral processes and relays its output to cortex – is likely to experience consciousness. As it happens, all mammals have breainstems with nuclei that are structured and connected in roughly the same way as are those of humans – their brainstem nuclei even excrete the same chemicals (and deliver them to roughly the same places) as their human counterparts. There is therefore very good reason to believe that dogs, cats, dolphins, whales – even laboratory rats and mice – possess “core consciousness”. This implies that all mammals share our most basic (biologically rooted) values.

The same elementary things are likely to male a mouse and human being feel “good” and “bad”. We now that mice, no less than men, most probably feel pleasurable excitement when anticipating the consummation of a need, fear in the presence of an enemy, anger when prevented from having what they want, distress on being separated from loved ones, and so on. Recognizing these facts has profound ethical implications for humanity.

There are, however, “higher” levels of consciousness which involve neural structures that we do not share with other mammals. As a result, the nature of the cognitive aspects of their consciousness is likely to differ quite dramatically from our experience.

There is very good reason to believe that cats possess core consciousness. Photo by Elena.

Children of the Fleet

Children of the Fleet

By Orson Scott Card

What do you do when all your plans work out? When all your dreams come true?

In his heart, Dabeet was already gone. From the moment Graff told him he was accepted into Fleet School, Dabeet detached from his friends. None had been close – or so it seemed to Dabeet, since he never felt toward his friends the kind of relentless dependency that others seemed to feel. He noticed when he wasn't included in some event – a party, a movie, a new game – but he didn't mind much, because he had other things to do. And now that he was preparing to go to Fleet School, he declined such invitations as he received. There was no point in investing any more time and effort with people he would never see again.

His friends, if they noticed his increased distance, said nothing about it. It was the teachers who were most demanding. Dabeet had not understood until now how much his teachers valued him. They were so eager to congratulate him – not just once, but over and over. And without Dabeet telling a soul about it, news of his acceptance into Fleet School flew through Charlie Conn. But only the reachers seemed to think it mattered much.

There was only one real surprise for Dabeet – how painful it was to think of leaving Mother. For more than a year, he had bent all his efforts to get away from her preferably with many miles of empty space between him. Now that he was really leaving, he began to realize how completely she had given over her life to him, and how dependent he was on her. Perhaps one of the reasons he hadnèt minded that he didn't have close friends was that his mother cared about everything he did, praised what was praiseworthy, commiserated with his miseries, and constantly told others how gifted he was. That which had been most annoying about her – the constant brag, the promises and lies – was now the mainstay of his life, and he could not imagine living without seeing her every day.

And yet when she immediately started trying to think of ways to come with him, he resisted her almost instinctively. Yes, he would miss her, and going to this new school would be frightening because of her absence. But he also knew that it would be disastrous it, through some fluke, she were allowed to come along.

“They must need some kind of nursing staff for the children,” said Mother. “It wouldn't take me long to take a refresher course.”

“Nursing staff?” asked Dabeet.

“I was a school nurse, once upon a time,” said Mother.

It was the first Dabeet had ever heard of it. “Then why aren't you working in medicine?”

“Because I chose not to,” said Mother. “I chose to work at the same kind of job as the other women in the neighborhood.”

“The hate their jobs.”

“And so do I,” said Mother. “Why do they do their jobs even though they hate them?”

“To put food on the table for their families.”

Mother shrugged as if that answer would do for her, as well.

Children of the fleet. Photo by Elena.

Basic Neurophysiology

Basic Neurophysiology

The brain is made up of neurons, together with a range of non-nervous cells that act in support of neurons and help to maintain their survival. One of the unique properties of the living neuron is its capacity to transmit information. It does this by “firing”. This term denotes the fact that every cell periodically transmits small quantities of neurotransmitter to its neighboring neurons. All cells in the body absorb a and expel molecules. Neurons do this in a special way. Neurotransmitter molecules are expelled from the end of the axon of the neuron, into the small space separating it from the next cell, the synapse. The neurotransmitter substance is then taken up by receptors on the dendrites of neurons on the other side of the synapse. This affects the second set of neurons by increasing or decreasing the chances that they will fire. Thus, neurons are in constant communication with each other through neurotransmitters. The communication is constant. Neurons always have a base (“resting”) rate of firing; even when they are not specifically stimulated by other neurons, the fire at regular intervals. However, the action of other neurons via their neurotransmitters, modifies the base firing rate - making each neuron fire more, or less, frequently than its resting rate.

There are two general types of neurotransmitter: excitatory and inhibitory. The excitatory type (the most common) increases firing rates – or, more precisely, it increases the chances that the next neuron will fire. In increases the chances of it firing, because we are actually dealing with aggregates of large numbers of neurons firing in concert. Each neuron is influenced (via multiple neurotransmitters acting at multiple synopses) by dozens, even hundreds of thousands, of other neurons. Thus, the reception of an excitatory neurotransmitter increases the chances of the neuron firing. Similarly, an inhibitory neurotransmitter decreases the chances of that neuron firing. Because we are dealing with aggregates of neurons, it is the overall “average” outcome that will determine whether the neuron fires or not, or rather the rate at which it fires. To take a crude example, if 60% of a neuron's inputs are exciting it and 40% of them are inhibiting it, it is going to fire, but at a level not much above its base rate. If 90% are exciting it and 10% are inhibiting it, it is going to fire at a much faster rate. The complete mechanism of neurotransmission is more complex. For example, neurons are equipped with different synaptic receptors that receive, or “recognize,” different neurotransmitters – but this preliminary account conveys the essentials in sufficient detail for the purposes of this text.

So that is how neurons work. Again, it is worth noting that there is nothing mystical about these processes that “produce” the mind. They are just ordinary cellular processes. How they produce our beloved selves, with all the richness of our inner life, must involve something more than the simple facts of neurotransmission.

The Brain and the Inner World, Introduction to Basic Concepts. Mark Solms, Oliver Turnbull.

Where there is controversy, neuro-scientists can devise and execute critical experiments to test who is right and who is wrong. Typically (after some debate about whether the experiment was the correct test or not!), the losing side agrees that they were wrong. Illustration by Elena.

The Limbic System

Our Brain: The Limbic System

The term Limbic System is frequently used as though it referred to an anatomical structure, but it is really a theoretical concept about a group of structures that, many neuroscientists feel, are linked together in a functionally significant way. Because it is a theoretical concept rather than a concrete thing, different neuroscientists include different structures under the term “limbic system.” It is therefore a rather vaguely defined entity (the very usefulness of which some neuroscientists question).

However, more or less everyone includes the following structures in it. At its core is the hypothalamus. Around this core, and connected with it, the other limbic structures are arranged in a ringlike formation. Within the diencephalon, we include part of the thalamus (most theorists include the anterior and dorsomedial nuclei of the thalamus in the limbic system). Outside the diencephalon, in the temporal lobe, we include the amygdala and the hippocampus, together with a fiber pathway called the fornix, which courses under the corpus callosum as it links back to diencephalon, where it joins the hippocampus to a small nucleous but, rather, consists of a phylogenetically old kind of cortex, running along the inner surface of the temporal lobe. It is also strongly connected to the group of basal forebrain nuclei, including those embedded in the septum Several of these structures too are connected to the anterior cingulate gyrus, which is therefore also usually included in the limbic system.

This highly interconnected set of brain structures, most of which lie deep within the brain, comprises the limbic system. There are many other structures that connect with these in complicated ways, some of which are also sometimes considered “limbic.” Howere, these are not core components of the limbic system.

Limbic system is part of the basic anatomical material. The anatomical terms are mentioned time and again, and repeated exposure (especially in the context of discussion of their psychological functions) will lead to much greater familiarity with these terms and the anatomical structures to which they refer.

The Brain and the Inner World, Introduction to Basic Concepts. Mark Solms, Oliver Turnbull.

In the end, we believe, we shall be able to say with confidence: this is how the mind really works. Photo by Elena.

The Sea Gypsies

The Sea Gypsies

The Sea Gypsies are nomadic people who live in a cluster of tropical islands in the Burmese archipelago and off the west coast of Thailand. A wandering water tribe, they learn to swim before they learn to walk, and live over half their lives in boats on the open sea, where they are often born and die. They survive by harvesting clams and sea chambers. Their children dive down, often thirty feet beneath the water's surface, and pluck up their food, including small morsels of marine life, and have done so for centuries. By learning to lower their heart rate, they can stay under water twice as long as most swimmers. They do this without any diving equipment. One tribe, the Sulu, dive over seventy-five feet for pearls.

But what distinguishes these children, for our purposes, is that they can see clearly at these great depths, without goggles. Most human beings cannot see clearly under water because as sunlight passes through water, it is bent, or “refracted,” so that light doesn't land where it should on the retina.

Anna Gislén, a Swedish researcher, studied the Sea Gypsies' ability to read placard under water and found that they were more than twice as skillful as European children. The Gypsies learned to control the shape of their lenses and, more significantly, to control the size of their pupils, constricting from 22 percent. This is a remarkable finding, because human pupils reflexively get larger under water, and pupil adjustment has been thought to be a fixed, innate reflex, controlled by the brain and nervous system.

This ability of the Sea Gypsies to see under water isn't the product of a unique genetic endowment. Gislén has since taught Swedish children to constrict their pupils to see under water – one more instance of the brain and nervous system showing unexpected training effects that alter what was thought to be a hardwired, unchangeable circuit.

The Sea Gypsies have survived using a combination of their experience of the sea and holistic perception. Illustration by Elena.

Cultural activities change brain structure

The Sea Gypsies's underwater sight is just one example of how cultural activities can change brain circuits, in this case leading to a new and seemingly impossible change in perception. Though the Gypsies' brain have yet to be scanned, we do have studies that show cultural activities changing brain structure. Music makes extraordinary demands on the brain. A pianist performing the eleventh variation of the Sixth Paganini Etude by Franz Liszt must play a staggering eighteen hundred notes per minute. Studies by Taub and others of musicians who play stringed instruments have shown that the more these musicians practice, the larger the brain maps for their active left hands become, and the neurons and maps that respond string timbers increase; in trumpeters the neurons and maps that respond to “brassy” sound enlarge. Brain imaging shows that musicians have several areas of their brains – the motor cortex and the cerebellum, among others – that differ from those of nonmusicians. Imaging also shows that musicians who begin playing before the age of seven have larger brain areas connecting the two hemispheres. 

Giorgio Vasari, the art historian, tells us that when Michelangelo painted the Sistine Chapel, he built a scaffold almost to the ceiling and painted for twenty months. As Vasari writes,“The work was executed in great discomfort, as Michelangelo had to stand with his head thrown back, and he so injured his eyesight that for several months he could only read and look at designs in that posture.” This may have been a case of his brain rewiring itself, to see only in the odd position that it had adapted itself to. Vasari's idea might seem incredible, but studies show that when people wear prism inversion glasses, which turn the world upside down, they find that, after a short while, their brain changes and their perceptual centers “flip”, so that they perceive the world right side up and even read books held upside down. When they take the glasses off, they see the world as though it were upside down, until they readapt, as Michelangelo did.

It is not just :highly cultured” activities that rewire the brain. Brain scans of London taxi drivers show that the more years a cabbie spends navigating London streets, the larger the volume of his hippocampus, that part of the brain that stores spatial representations. Even leisure activities change our brain; mediators and meditation teachers have a thicker insula, a part of the cortex activated by paying close attention.

The Sea Gypsies are an entire culture of hunter-gatherers on the open sea, all of whom share underwater sight. For Sea Gypsies it is seeing under water. For those of us living in the information age, signature activities include reading, writing, computer literacy, and using electronic media.

In all cultures members tend to share certain common activities, the “signature activities of a culture.” Signature activities differ from such universal human activities as seeing, hearing, and walking, which develop with minimal prompting and are shared by all humanity, even those rare people who have been raised outside culture. Signature activities requires training and cultural experience and lead to the development of a new, specially wired brain. Human beings did not evolve to see clearly under water = we left our “aquatic eyes” behind with scales and fins, when our ancestors emerged from the sea and evolved to see on land. Underwater sight is not the gift of evolution; the gift is brain plasticity, which allows us to adapt to a vast range of environments.

(The Brain That Changes Itself by Norman Doidge, M.D., excerpt).

The implosion of the media into us, affecting our brains, is not so obvious, but we have seen many examples in our lives. Photo by Elena.