Figure 2.

Effect of the strength of the reinforcing stimulus on learning rate in Anopheles gambiae females. The mean proportion (± 95%CIs) of females probing and feeding on the preferred feeder associated with the positive reinforcement is shown for two sets of experiments. In the first experiment (white circles) the positive and negative reinforcing stimuli were the preferred sausage-skin membrane or the disliked Parafilm membrane; in the second (black circles), unpalatable salted blood and non-salted blood was used (see text and Table 1, 2 for details).