Scientists have produced mini brains that mimic preterm babies’ brains, have they created consciousness too? Jade Norton investigates.
It is difficultfor us to comprehend our own consciousness, let alone try to operationallydefine it in a scientific experiment. In the last century scientificadvancement has allowed for experiments to be conducted that cross the fieldsof possibility and allow humans to play their hand at creation. However, thereare many ethical considerations that come along with this. For example, whatresponsibilities would suddenly arise if a tissue on a bench could not onlyreact to experimental procedures but had an opinion on them? On the other hand,what if the creation of consciousness in the pursuit of understanding can leadto answers that would not have been answered otherwise? This raises thequestion of whether scientists should aim to create consciousness or is itsomething that should be left to the natural world without human interference?
One recentexperiment undertaken by scientists from the University of California, SanDiego used stem cell technology to create cortical organoids or "minibrains" that are capable of producing brain signals that mimic that ofpremature babies. The brains do not look like a typical human brain and areinstead a smooth pea-sized blob that is encased in a nutrient-rich medium. Theylack the folding seen in a human brain as they do not contain grey and whitematter but are more of a mass of neural tissue. An induced pluripotent stemcell, which is a cell capable of dividing into any cell in the human body withthe right instructions, was used to create the brain cells. These cells dividedand over the course of 10 months grew from base neuronal cells toneuroepithelium-like structures which are similar to that of human braintissue. These organoids were not capableof complex thought but were created with the idea of using them to studyneurological diseases.
Throughout thedevelopment of the tissue nested oscillatory network dynamics were measured, theseare networks of repetitive electrical activity produced by the human brain inresponse to stimuli. This electrical activity can be found in all livingneurological tissue but does not necessarily show consciousness as there is yetto be an electrical ‘ping’ signalling life as we currently understand it.
The team in SanDiego measured oscillatory spikes from the minibrains weekly usingmicroelectrode arrays and found an increase in activity as the monthsprogressed. This implied that there was a neural network capable of newdevelopment contained in the tissue. The electrical activity spawned by theneural network of the cortical organoids produced in the lab was recorded andsaved. Then using an EEG (electroencephalograph) the scientists measured the neuralactivity of a premature baby. These neural patterns were compared to see ifthere was a substantial difference between the neural activity between them.The comparison used a subset of features from the EEG to offset variablefactors not found in the cortical organoid. The results of comparison using amachine-learning algorithm found that the development of each tissue had manysimilarities which were likely to have been part of a genetically programmedtimeline. However, these minibrains were unable to progress to furtherdevelopment than that of a premature baby and it is thought that this is due tothe lack of sensory input that would usually be felt through the womb by apremature baby.
The “minibrains” that were developed in this experiment did not have any evidence ofconsciousness and were almost one million times smaller than a human brain andwithout the multiple types of cerebral cells they didn't have the capability ofdeveloping the full neurological complexity that is needed to form consciousnessas we see it. The measurements of electrical activity were done withoutcomparison of physiological features which varied greatly between the twotissues and have an effect on the maturation of neurons essential fordevelopment. The reality of creating a sentient being similar to ourselves isstill resting in the world of science-fiction, but the ability to create atissue that mimics brain activity and can be used in medical research is adefinite possibility. Brains can now be grown on a petri dish, but as of yetthey haven’t voiced any complaints.
The ability togrow an organoid that has an extensive neural network that is similar to thatof a preterm baby raises the question of at what point does consciousnessarise? It depends on who you ask. The origin of consciousness has yet to have auniversal consensus and without it there are no clear ethical rules relating tothe growth and development of cerebral tissue. There is no indicator that willtell you that consciousness has been created so it is possible that there is oronce was a homegrown sentient lab tissue somewhere.
Along with theadvancements in organoid technology, ethical considerations will continue tocome into question. Without the ability to know when consciousness has dawned,how do you know if the organoid is feeling pain or is distressed? And oncesomething develops a consciousness it becomes a subject of an experiment ratherthan an object which entitles it to its own rights. Consequently, this wouldseem that it would give scientists the responsibility to uphold these rights,however, this is still a largely unexplored area.
With theknowledge of ethical responsibility in hand, the possibilities of opportunityfor advancement is huge with a literal minibrain to work with. Medical researchcan use these organoids to see the in vivo effects of certain mental illnessessuch as schizophrenia and epilepsy and see the progression of neurodegenerativediseases such as Parkinson's and Alzheimer's without the invasive problem ofviewing it in a live person. The question of when consciousness begins issomething that can fuel a philosopher’s career but for a scientist the creationof consciousness is a possibility that has never before been so accessible,with increasing advancements we may soon have our own brain in a jar.