Figure 2
From: Learning and adaptation in speech production without a vocal tract

Audiomotor map learning with touchscreen. (a,b) Response density of all 18 participants during the first 30 trials of training (a) and the final 30 trials of the experiment (b), with yellow indicating highest response density and blue lowest response density. (c,d) Improvement on the touchscreen-based vowel production of the task over the course of 480 trials as indicated by response accuracy (c) and response consistency (d).