Wednesday, April 21, 2010

Are insects conscious? Well, it depends...

Scientists sometimes use words in strange ways. Newspaper and magazine articles that report thrilling results like the discovery of a “gay gene,” homosexual behavior in animals, or the biological roots of dreaming can often be misleading if not read carefully. When you see a word in a scientific context, you have to ask what does the scientist mean by this? Only then can you be sure that you understand the significance of the finding.

This is one reason why scientists are often reluctant to speculate about the implications of their work. They worry about using human terms like “gay” to describe animal behavior, for example.

Recently, I have thought about this issue in relation to the question of whether insects are “conscious.” There are scientist who cite experimental evidence in support of this assertion, but in order to understand the significance of their results, we first must ask what they mean by “consciousness?”

Reducing Suffering linked to "Consciousness in a Cockroach", a Discovery Magazine article about insect consciousness. The article discusses the work of neurobiologist Nicholas Strausfeld, who has spent his career analyzing the structure of insect brains.

Strausfeld says, “Many people would pooh-pooh the notion of insects having brains that are in any way comparable to those of primates.” But, on a deep level, Strausfeld argues, insect brains are organized according to similar principles as our own.

One journal asserts that research of this kind may provide insights into “the remote roots of consciousness.”

The article goes on to quote Christof Koch, a Caltech neuroscientist: “"We have literally no idea at what level of brain complexity consciousness stops…Most people say, 'For heaven's sake, a bug isn't conscious.' But how do we know? We're not sure anymore. I don't kill bugs needlessly anymore." Koch assumes that if an insect is conscious, it has some sort of right to life, and therefore, that it is wrong to kill it needlessly.

What is the connection between “consciousness” and a “right to life?” Why do conscious things (like people and animals in this case) deserve to live while “unconscious” things (like plants?) do not?

Off the top of my head, I can think of at least two answers to this question: first, it may be that consciousness implies the capacity to feel pain. A human and an animal can feel pain, while a plant cannot. Alternatively, consciousness may imply self-consciousness. If a being can be aware of losing its life, than it is wrong to kill it. I am not sure that I buy either of these arguments as they are. Both seem to require further elaboration.

The problem is that it is not clear if science can tell us whether an insect has a capacity to feel pain or whether an insect is self-aware. Consciousness is a tricky concept to work with, and therefore, before we can draw social and political implications from a scientific result that insects are conscious, we must first ask, what do scientists mean when they say that insects are conscious? Do they mean that an insect brain looks like a human brain? That is, that there is a structural similarity between human and insect brains? Is it that insects exhibit certain types of behaviors?

In his article, “What in the world is consciousness?” published in Progressive Brain Research, Adam Zeman reviews the different scientific approaches to the study of consciousness. He draws a distinction between “easy” and “hard” questions about consciousness. The former involve “the underlying neurobiology of wakefulness and awareness, and the latter the allegedly more mysterious process by which biological processes generate experience.” The easy definition of “consciousness” equates it with “awareness.” The hard definition of “consciousness” equates is with “experience.”

The Discovery article only addresses the “easy” questions. It summarizes results about how the brain structure of insects leads them to exhibit behaviors that imply awareness. That is, if you try to swat a fly, certain neurons will fire and it will fly away, demonstrating that it is aware of your hand. However, Koch’s decision not to kill flies needlessly seems to rest on an assumed answer to the “hard” questions. That is, he seems to assume that science will someday unravel the “mysterious process by which biological processes generate experience.” Zeman assumes that there is a process that allows purely biological processes to generate experience (although it is mysterious), and Koch assumes that science will someday (although admittedly not today) unravel that process.

I agree that if a fly experiences the world like I do, I shouldn’t kill it (needlessly). However, merely demonstrating awareness does not seem necessary or sufficient for establishing experience. People who are sleeping are unconscious in that they are unaware, but they are conscious in that they, presumably, still have experiences (dreams for instance). Similarly, a plant will respond to changes in temperature and light, implying some level of awareness, but a plant (presumably) does not have experiences.

Confusing “easy” consciousness for “hard” consciousness can lead to political and social implications for human behavior. Just as I don’t believe that discoveries about the physiological correlates of dreams have implications for their meaning, I don’t necessarily believe that discoveries about the neurobiological correlates of awareness have implications for morality.

No comments:

Post a Comment