Figure 2.

Response amplitudes. (A) The response to speech with clear auditory component (Clear A, combination of AV and AVn stimulus conditions) and noisy auditory component (Noisy A, combination of AnV and AnVn conditions) collapsed across electrodes (error bars show SEM). The response amplitude is the mean percent change in high-gamma power (70–110 Hz) in the 0–500 msec time window relative to prestimulus baseline (−500 to − 100 msec). (B) The response to Clear A versus Noisy A speech for each individual electrode, with each anterior electrode shown as a green circle and each posterior electrode shown as a purple circle. The black dashed line represents the line of equality. Electrodes shown in C and D are labeled. (C) High-gamma response to Clear A speech (blue trace) and Noisy A speech (orange trace) for a single anterior electrode (labeled “C” in inset brain). Shaded regions indicate the SEM across trials. Black vertical dashed lines indicate visual and auditory stimulus onsets, respectively. (D) High-gamma response to Clear A and Noisy A speech in a single posterior electrode (labeled “D” in inset brain). (E) Coordinate system for STG measurements. y Axis indicates distance from medial/superior border of STG (black dashed line); x axis shows distance from the A–P boundary (white dashed line). (F) The response amplitude to Clear A speech minus the response amplitude to Noisy A speech as a function of distance from the medial/ superior border, one symbol per electrode (anterior electrodes in green, posterior electrodes in purple). (G) The response amplitude to Clear A minus Noisy A speech as a function of distance from the A–P boundary. (H) Discrete model: Constant values were fit separately to the anterior and posterior electrode data in G (y = a and y = b), and the correlation with the data was calculated. (I) Continuous model: A linear model with two parameters was fit to both anterior and posterior electrodes (y = mx + b).