Figure 1. Sonograms show a relationship between phrase duration, the context of a phrase, and future choices.

Phrases consist of repetitions of elementary units—the syllables. Distinct phrase types are indicated by colored bars beneath each sonogram. On the right side of each sonogram is a “barcode” summary of all occurrences of the phrases shown in the sonograms. The phrases before (left) and after (right) the gray phrase are color-coded by syllable identity, and the length of the bars in each row indicates duration of the phrase. A square flanks each barcode to indicate the scale, with the width corresponding to 2 seconds and the height to 20 trials. A, A case where the duration of a phrase predicts the future path—the barcode is sorted by duration of the black phrase. Short black bars on the bottom of the barcode typically lead to blue, while long black bars at the top typically lead to green. B, A case where the identity of the starting phrase (red, yellow, or purple) determines which phrase type comes after the black/gray phrase (green or magenta for example.) The barcode in this panel is sorted by the phrase that comes before the black/gray phrase.