> This paper nicely settles a debate between those [researchers] willing to accept that non-neuronal organisms are also capable of processing information and acting on that information, and those that stick to the idea that only neuronal organisms are capable of complex decision making,” Madeleine Beekman ... writes ....

I don't know who Dr. Beekman has been debating with, but, at best, this has only been a debate of semantics for at least 50 years.

Here is an excerpt from a review titled Bacterial Microprocessing (Cold Spring Harb Symp Quant Biol. 1990;55:539-45. doi: 10.1101/sqb.1990.055.01.052.). The review is from 1990, but the work goes back at least to the late 1960s.

To someone trying to understand the brain, the bacterium Escherichia coli must be an awesome beast. Its talents are legion, but its size is miniscule. E. coli is a cylindrical organism less than 1 μm in diameter by 2/μm long--20 would fit end-to-end in a single rod cell of the human retina or some 3000 in that of a frog. Yet, it is adept at counting molecules of specific sugars, amino acids, or dipeptides; at integration of similar or dissimilar sensory inputs over space and time; at comparing counts taken over the recent and the not so recent past; at triggering an all-or-nothing response; at swimming in a viscous medium; and as we shall see, even at pattern formation.

At the 53rd Symposium, I presented an overview of sensory transduction in bacterial chemotaxis (Berg 1988), describing the kinds of measurements that E. coli makes on its surroundings and noting how this strategy matches the physical constraints imposed by small size in an aqueous environment (i.e., by life at low Reynolds number; see Purcell 1977). I will restate that case briefly, comment on progress made in the field during the past 2 years, and mention some of the work going on in my own laboratory.