In his blog, Pugh concludes that the Pong playing minibrains are not sentient. This is because in his view they do not possess phenomenal consciousness and thus are unable to experience pain or pleasure. To some the property of phenomenal consciousness is an essential requirement for moral status. This is because they claim that only entities that are phenomenally conscious have the kinds of interests that warrant strong forms of moral protection.
I agree with Pugh that minibrains currently are not sentient. This is because they are constituted like biological brains and do not possess pain receptors, which would be needed for them to experience pain or pleasure. In addition, they do not have a body, because they are merely brain organs that reside in a laboratory dish. As such, they are not connected up to a nervous system. Having a nervous system is normally a functional requirement for being sentient.
This would mean that these brains would have rights that agents such as stem cell scientists, would have a duty to respect. This could include the right, for example, not to be interfered with or experimented on without a compelling reason. It might also include the right not to be destroyed and the right to be sustained corporeally by the scientists who have created them.
So why might the laboratory grown brains of the future potentially possess sufficient degrees of sapience to have moral status? In terms of sufficiency, this might be the point, for example, at which the laboratory brains start to make their own decisions and set their own goals. One reason why they might meet this sufficiency condition, is as follows.
Pugh mentions that some commentators believe that laboratory grown brains are better thought of as thinking systems, rather than as systems that are sentient. If we accept that to be the case, this then provokes the following question: Could laboratory brains be created in the future that are sufficiently advanced sapience wise, that they also possess some level of moral status, even if they are completely insentient? If the answer to this question is ‘Yes’, this would be an unusual situation. This is because we often attribute moral status to other humans and animals, in part based on the degree to which they are sentient.
Current day minibrains are small and are only comprised of collections of between 800 thousand to 1 million cells. This is one thousand times smaller than a normal human adult brain, which has over 100 billion neuron cells alone. However, even though the minibrains are small, they are already exhibiting some rudimentary thinking abilities. They can adjust and improve the quality of their game play in Pong, for example, based on the electronic feedback that they are receiving whenever they try and hit the ball with their bat. Hence, if much bigger laboratory brains are created in the future, it also seems conceivable that the mental capacities of these brains will increase too.
However, laboratory grown brains might have another property which is relevant to moral status. This is the property of sapience. Sapience enables thinking states to occur, including the mental states of reasoning, conceiving, judging, and planning, amongst other things.
Although philosophers disagree on exactly which properties are needed for moral status, many do agree that the property of sapience is important. Some deontologists, for example, claim that agents should respect and provide protections to those entities who are able to make their own rational decisions, which is an example of high functioning sapience.
Written by Dominic McGuire, DPhil Student, Queen’s College Oxford
Jonathan Pugh’s interesting Practical Ethics blog of October 14th, 2022, http://blog.practicalethics.ox.ac.uk/2022/10/brain-cells-slime-mold-and-sentience-semantics/, prompted several additional thoughts. Pugh’s blog considered some of the implications from recent media reports about laboratory grown brains, also called minibrains, which can play the video game of Pong. Pong is a simple representation of the game of table tennis.
Hence, if you believe first that entities with moral status ought to be given consideration for their own sake and second that certain types of sapience are important for moral status, such as the capacity for making your own rational decisions, then potentially the laboratory brains of the future might have some moral status.
Also, given that the adult human brain is constrained by the dimensions of the skull, it is also appears conceivable that laboratory grown brains could be created that vastly exceed the size of the human brain, because they will not be physically constrained in this way. This might even enable laboratory created brains to achieve higher degrees of sapience in certain domains, than is shown by existing biological species. Although, clearly, there would also be other medical and ethical issues that would need to be considered before these larger brains could be created.