It is not easy to answer this question. Many of the top scientists in the world continue to strive for such a measurement. Philosophers debate whether a measure of this kind is possible. While ethicists, policymakers, and others are busy examining how such a measure could inform decisions about animal welfare, abortion, and end-of-life care.
Current debates tend to revolve around the question of whether consciousness is a “all or none” phenomenon or if different degrees of awareness can exist. The goal of the first is to identify a single, measurable sign that an individual has consciousness or not.
Conceptually, most people seem to accept the notion that consciousness can be extinguished at a specific moment (either through anesthesia temporarily or permanently after death). It’s much more difficult to imagine a moment when consciousness suddenly appears.
Is it when the egg becomes fertilized in an infant? Is it the moment the baby leaves the womb or some magical time during the first months of life? In the same way, it’s hard to draw a clear line between animals who have conscious experiences and those that don’t. There is no consensus among scientists as to whether a dog, a bird, a fish, or a worm are aware.
The field is moving towards a hybrid approach in which consciousness can be increased or decreased (depending on the animal species or over a lifetime), but at a certain point, it becomes so minimal it ceases to exist.
In this model, the ethical decisions regarding animal welfare and the right to life are not based on identifying the point where consciousness is so tiny that it ceases to exist. The goal is to determine the point where it is not enough to qualify for the same status as a healthy adult human. It is true that some animals have brains that can’t generate enough pain to warrant anesthesia.
Scientists are working to determine how to measure “sufficientness”. Philosophers and ethicists will continue to debate the concept. The goal is a reliable way to quantify the level/degree of consciousness in a person or an animal. It is a complex problem that has no solution at the moment (although, as I’ve discussed in previous posts, some scientists think they are close).
My thoughts have been similarly focused until recently on the scientific, philosophical, and ethical questions associated with understanding how a brain produces a conscious experience. It was my son Joe’s birth that prompted me to re-examine this question.
As I mentioned above, many people share my belief that infants have a measurably lower level of consciousness than adults. Scientists tend to measure consciousness in a single dimension. According to this view, the intensity or quality of the experience is expected to increase with the increasing size and complexity in the brain. As a result, we assume that healthy adults are both blessed and cursed to have the most intense pleasure and pain. According to this theory, insects and fish experience pain or pleasure in a much less intense way (or even none at all).
What if the view you have is incorrect? What if, in fact, the intensity of a given experience decreases with the increase of the possible thoughts, emotions and sensations? The simplest of brains could have the highest intensity.
To illustrate, consider that consciousness is equivalent to your favorite tropical fruit cocktail. Each new neural connection that is formed in the brain (either through hardwired biological processes or through experience and learning) is like adding juice from a different type of fruit. When the glass is filled with juice from all fruits, you will experience the greatest variety and complexity in flavors. The strength and purity will be highest with the first drops of juice of the fruit. As you add more fruit juice, the flavor intensity will gradually decrease.
Could the same be said for conscious experiences? The more complex or varied the experiences our brains are capable of sustaining, the less intensely we experience them. Answer: We don’t really know.
It is fair to say, if we return to my son Joe’s recent birth, that he did not do anything but sleep, eat, and scream for the first few days. It is clear that his experience was much simpler than an adult’s. It is wrong to assume that the intensity of his pain was also reduced. If we look at crying as the most obvious sign of pain, it is hard to say that intensity increases with development.
Recently, my five-year old daughter Susie asked me why Max was allowed to cry more than she. We often get mad at Susie for crying when something doesn’t go her way. Her brother, however, is allowed to howl in anger if the cereal bowl is orange instead of green. I explained that Max was only two and it is harder for him not to cry. I told him that Joe, the baby, cries a lot and we won’t get angry with him because he’s a baby.
I used to think that adults cry less because they learn how to control their behavior. We do indeed learn to distract our attention from pain, or contextualise the pain as necessary or even desirable. Could it be that as our brains become more complex, our pain experience is reduced?
Scientists are improving their ability to “decode” brain activity. We can now use brain-imaging technologies to determine if a person is looking at faces, listening to words or receiving a prize. Scientists are unable, however, to determine if this activity results in a conscious or unconscious experience. Scientists are currently focusing their efforts on determining whether the brain is experiencing anything and, if it is, what that something is.
It could be argued, however, that when it comes to guiding ethical debates, the subjective intensity question should be equally important. We know that loud noises or bright lights will produce a greater neural response in the brain of any individual than a soft noise or dim lighting. To my knowledge, there has been no research done to date or currently being conducted that aims to identify a neural signature coding the relative intensity of experiences across individuals or species. In fact, it is possible that such a measure will never be discovered.
It is important to clarify that my statement that simple animals and infants are most likely to experience the highest levels of pain does not mean that I am alarmist. I don’t know how much pain these animals experience. The main point here is that we don’t know and that it is wrong to assume other measures of brain size or complexity can predict it.