Convergence probability of preceding sequences modulates auditory responses to single syllables in a positive, linear manner, *A*, Average time varying responses (mean ± SE) and accompanying stimuli for length 3 sequences with varying convergence probability, followed by the target syllable “*c*.” *B*, Average responses to the target syllable “*c*” (mean ± SE for shaded region in *A*) when preceded by the sequences in *A*. *C*, Response waveform for syllable “*c*” when preceded by the 3 naturally occurring sequences shown in *A*. *D*, *E*, Second example illustrating increasing responses to target syllable “*b*” as a function of convergence probability for preceding length 4 sequences. *D*, Average time varying responses (mean ± SE) and accompanying stimuli for length 4 sequences with varying convergence probability, followed by the target syllable “*b*.” *E*, Average responses to the target syllable “*b*” (mean ± SE for shaded region in *D*) when preceded by the sequences in *D*. *F*, Distribution of slopes for regression of responses to target syllables against convergence probability of preceding sequences for entire dataset (****p* < 10^{−10}, one sample *t* test, *n* = 945 cases). Black diamond: mean slope (90 Hz/unit change in *C*). Inset shows histogram of slope values for experiments on single units (****p* < 10^{−3}, one-sample *t* test). Black diamond: mean = 96 Hz/unit change in probability. *G*, Response modulation as a function of convergence probability for all syllables and sequences of lengths 1–6 (mean ± SE). The slope of the regression line (dashed line) was significantly different from 0 (****p* < 10^{−3}). Inset shows results from single units, mean ± SE, and best-fit line (****p* < 10^{−4}). Number of unique instances of the sequences in *B*, *E*, and *G* are indicated at bottom of plots.

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