Fig. 4.

Illustration of outcome competition. In situations with less cues than outcomes (as in a), not all outcomes can be fully predicted. In that case, the updating of absent outcomes as in case 3 of Eq. 4, leads to the learning of conditional probabilities of outcome given a cue. Here, food is twice more likely to occur after the light than water (b). Without this mechanism (for illustration purposes), the single weights will both increase to the activation limit of 1 (c), a result which theoretically violates the aim of maximizing certainty of outcome predictions