Do nematodes have consciousness?
These and similar questions are asked again and again, and in extension the inanimate nature, indeed the entire universe, is included. The question is justified by the fact that the attribution of consciousness exclusively to humans is anthropocentric. But how can you ever find out what it’s like to be a bat, a nematode or a stone?
If you take a closer look, you will notice that the initial question has already been posed incorrectly. After all, the very concept of consciousness is an anthropocentric one. In its interpretation, it is tailored to the human being. This is because we assign it exclusively human characteristics. And these range from the sensation of pain to philosophical contemplation. In the next step, we then take this term and scale it down according to the species we have in mind. In the case of less complex nervous systems, we then speak of a little less pain and a little less cognition. It doesn’t get much more human-centered than that. Considering that central questions in philosophy and neuroscience, such as the so-called hard problem of consciousness, arise from such false schematizations, one may shake one’s head in astonishment. So we look at consciousness as a human phenomenon and then see how much of it other animals, plants and possibly all matter have of it. What a naïve view.
Instead, we would have to ask what consciousness is in the first place, by working out the most general aspects and principles that are really common to all living beings. Once these have been found, they can be reconstructed historically for each species, i.e. along the evolutionary process.
Consciousness is first and foremost an expression of life, and one that we can read from the brain. And yes, of course the body and environment are constitutive, but not identical with consciousness as a property of the brain, because only there can we measure it. It is a condition that we can see in other organs as well.
While the heart’s job is to pump blood throughout the body, the brain ensures that we can orient ourselves in the world. Therein lies the commonality with all other living beings. They all orient themselves in the world in their own way. The nematode does this by means of chemical and physical gradients, among other things.
This orientation function, which is inherent in every living being, ensures its survival. We do not know whether subjective experience is a selection advantage in the nematode. However, 302 neurons may not be enough to integrate a multi-layered experience theater from all sensors. The integration of all sensors is not a nice experience. Let’s imagine a network of 302 neurons. Depending on the requirements, the (information) density shifts and thus forms a reaction center (density = reaction probability), which has a controlling effect. To experience, you need a second layer that literally reflects the data from the first layer. Whether this is the case with the nematode would have to be researched by means of an adequate technology. In any case, the nematode cannot develop feelings because it lacks the necessary endocrinological area.
But experience is an essential part of consciousness. It is an important evaluation function for cognition, it contributes to the order of cognitive, logical actions for the subject. It therefore stands to reason that what triggers pain in us causes an analogous reaction in the nematode, such as a flight reaction.
If we assume only a few sensors, such as chemosensors, mechanoreceptors, photosensors, thermal sensors, osmoreceptors, gyro sensors or electrosensors, each of which makes up a few hundred, then we arrive at a necessary number of neurons that corresponds to that of 302. This means that the capacity of the nematode neurons is far from sufficient for a second (reflection) layer.
If we take three of each of the seven types of sensors working at the same time, then we have 21 and assume that all of them are linked together, then we need over 400 neurons for this. This would more than exhaust the capacity of the nematode. This is of course a very crude assumption.
For the reasons mentioned (capacity of neurons, probably no second layer, no endocrinology), it can be said with a fair degree of certainty that a nematode (C. elegans) does not and cannot have consciousness in our understood sense.
From what has been said, it logically follows that everything inanimate can also have no consciousness, because the orientation function is a property of living beings, inanimate nature does not have one.
A consciousness characterized in this way also solves the above-mentioned hard problem of consciousness, which seeks to establish a connection between first and third person perspective. Orientation by means of experience obviously represents a considerable selection advantage, since it is multidimensional and reflects this multidimensionality in an experiential manner.
However, to merge the two perspectives would be a category error, as they are two incompatible perspectives. Talking about the experience is something completely different from experiencing it yourself.
