We have known for as long as we spotted unicellular organisms that they can react to their ambient, getting closer to palatable food and moving away from unfavourable encounter. However, so far scientists believed that the reaction of these little critters was cabled: you prompt them with the same stimulus and they will react in the same way. This is also the case for multi-celluar beings. Break a spiderweb and the spider will repair it and you can go on and on with the spider never wondering that something weird is going on and that a new strategy is required.
Single cells have the capability of “memorising” the occurrence of a stimulus and may become insensitive to it. This goes for our cells (you feel the touch of something but after a little while the sensation goes away and you no longer feel -or pay attention- to it. In our case this may happen both at the cells where the touch is occurring and in the neurones in our brain processing the signal. In case of unicellular cells it is often the case that the response to a stimulus decreases as the stimulus persist. This is easily explained in terms of chemical reactions in the cell.
Now, however, scientist have discovered a unicellular form of life, Stentor Roeseli, that not only responds with decreasing intensity to a stimulus but can change the response strategy. This was unexpected. It looks like a single cell has some sort of mechanism for taking more complex decisions based on a variety of factors.
We know that our neurones are “evaluating” stimuli arriving from hundreds, thousands of other neurones through synaptic connections and that these stimuli are processed in a very specific discrete time frame resulting in an activation of the axon that in turns will send excitation or depression stimuli to thousands of other neurones but as far we we know today it is a either or result: activate or not activate the axon. Now the insight gained from Stentor Roeseli cast a new light and opens a new set of possibilities that need to be investigated. In the end we might discover, as someone have been feeling all along, that neurones are much more complex and our attempt of digitalising them may not provide an adequate representation. Intelligence may be rooted in much more complex physical infrastructures that we have been led to believe in these last hundred years.
Would this be a proof that intelligence doesn’t necessarily need a complex infrastructure to emerge? Not really. A cell is a very, very complex infrastructures formed by billions of molecules (a single human cell may consist of 2 trillion molecules in up to 10,000 different proteins undergoing hundred of million of chemical reactions each second!) and running thousands processes. The Human Brain project has for the first time found a correlation among the dimension/speed of neurones and IQ. The bigger and faster, the higher the IQ.