Information transfer in collective computation by ants and slime molds
Abstract: Living systems have extraordinary abilities to gather, store and transform information. Even simple unicellular organisms lacking a brain, such as the slime mold Physarum polycephalum, have the ability to solve complex computational problems in nearly optimal ways. However, how living systems harness the power of information to solve complex problems is still poorly understood. Shedding light on this has the potential to open new perspectives on alternative computing approaches and shape the design of artificial systems. In this talk, I will discuss two recent studies of information transfer during collective computation. In the first study, we look at the tandem running behavior of Temnothorax rugatulus ants. When recruiting colony members to a potential new home, pairs of T. rugatulus ants use tandem runs in which an informed ant that has found a candidate site leads a naive follower there. This behavior involves frequent pauses that superficially appear to be caused by accidental loss of contact of the follower from the leader. Using information-theoretic tools we show that these pauses implement instead a regulation of information flow similar to acknowledgement-based flow control governing communication in distributed networks such as Internet. To our knowledge, this is the first non-human example of signals whose strategic value is to regulate other signals. In a second study we looked at binary food choices by the slime mold P. polycephalum and investigated the transfer of information along single tubules. We analyzed the direction and magnitude of information transfer and found that these differ as a function of the relative quality of the food sources. Unexpectedly, when a difference in food quality exists, information is transferred from the region of the slime mold in contact with the lower quality food towards that in contact with the higher quality food pointing future research efforts to investigate more closely the mechanisms in place in this region.
Those unable to attend can stream the lecture from our YouTube channel.