Figure 3.
Phase space of the AL two-cell design and their output time series. Depending on the production rate of LacI (γLacI) and the production rate of LacI under cI regulation (γλ), there are four different response behaviours. (A) Non-learning situation; the system responds to the unconditioned stimulius (X) (blue region), the system is unable to respond to the conditioned signal (Y) even after the conditioning stimulus. (B) Damped learning; the learning cell has a temporal association (turquoise), the producer cells only respond to the conditioned signal for a limited time after the conditioning. (C) AL region (yellow), the learning cell change the state of the toggle switch after the simultaneous stimulation with X and Y signals, then the system has learned. (D) Learned system (orange); the system responds to the unconditioned (X) and conditioned (Y ) signals independently before the conditioning process pulses. The time series of the other variables can be seen in the electronic supplementary material, figures S3–S6. The parameters are the same as in previous figures; the phase space is performed with a 400 × 400 lattice. (Online version in colour.)