Eshel Ben-Jacob

In the early 1990s, Ben-Jacob's group discovered two pattern-forming bacteria species—the Paenibacillus dendritiformis and the Paenibacillus vortex (see also Paenibacillus). Combining microbiological experiments with physical principles of self-organization and advanced modeling, Ben-Jacob advanced the recognition that bacteria are smart cooperative organisms that employ advanced communication to lead intricate social lives in large and complex colonies. Sophisticated chemical communication allows bacteria to rapidly adapt to changes in the environment, distribute tasks, "learn from experience", make decisions and prepare for the future.¹¹ Ben-Jacob put forward the idea of bacterial social intelligence and his group devised a social IQ score of bacteria as a comparative genomic tool to assess the genome potential of bacteria to conduct successful cooperative and adaptable behaviors, or social behaviors, in complex environments.¹

Inspired by Ben-Jacob's observations of how bacteria can spontaneously order their motion during collective swarming, the groups of T. Vicsek and Ben-Jacob devised a simple model able to generate non-equilibrium states that violate the usual physics theorems for equilibrium states. This work has led to the creating of a new field of multi-agent swarming (swarming intelligence), proposed to explain a wide variety of phenomena ranging from collective navigation (swarming intelligence) of bacteria, amoeba and insects, to flocking of birds and schools of fish as well as to the design of autonomous vehicles capable of functional self-organization even in the absence of an overall omniscient controller. Using fratricide to fight bacteria: In 2000, Ben-Jacob's group discovered a fascinating phenomenon of competition between two sibling bacteria colonies of the P. dendritiformis when inoculated side by side.¹ Recent studies of the phenomenon revealed that the two colonies not only inhibited each other from growing into the territory between them but induced the death of those cells close to the border.¹ By employing molecular biology methods combined with the new genome sequencing information and bioinformatics, they discovered a new toxin (sibling lethal factor), which acts selectively only on the same bacterial strain.¹

Building upon understanding he gained from research in neuroscience (the inhibition of inhibition principle), Ben-Jacob and his collaborators discovered that the ingenious scheme is composed of a stochastic switch regulated by a timer with adaptable clock rate (that is adjusted by the cell stress) via a special decision-circuit composed of a cascade of inhibitions. The decision-circuits of the individual bacteria are coupled by exchange of chemical messages between the cells to guarantee collective decision for the group benefit.¹¹

Ben-Jacob's studies in neuroscience are guided by an effort to simplify the complexity searching for principles of information coding, memory and learning. He has many unique contributions in the field of Systems Neuroscience and Neural Networks, including the relations between network size and its synchronized activity, the discovery of hidden neuron correlations, function-form relations and mutual synchronization in engineered networks, the effect of DNA damage on network synchronization, neuro-glia communication, new modeling of intra- and inter-cell calcium dynamics, using nano technology for network engineering,¹ discovery and modeling of the dynamical motives (repertoire) of coupled neural networks, development of a novel system-level analysis of neural network activity (the functional holography analysis), mapping and assessments of epileptic foci, and more. Yet, the development of the first neuro-memory-chip with his doctoral student at the time, Itay Baruchi, is Ben-Jacob's most important contribution in systems neuroscience. While previous attempts were based on "teaching by reward" (enhancing excitatory synapses) or "teaching by punishment" (inhibition of excitatory synapses), Baruchi and Ben-Jacob's approach was "teaching by liberation", or "inhibition of inhibition" (inhibition of inhibitory synapses). Being recognized as a groundbreaking discovery in systems neuroscience, the achievement was awarded in 2007 the SciAm 50, The Scientific American Award for the 50 most important achievements in all fields of science and technology.