Fig. 4: Spatial evolution of processing trajectory.

A Reconstructing time since phoneme onset from 15 equally spaced samples from 100 to 400 ms. The horizontal dashed line indicates mean of time latency (i.e. what would be reconstructed in absence of evidence to the contrary). The coloured dots represent the 21 participants at a given time sample. B Decoding model coefficients plotted as topographies (above) and trajectories (below) over time. Coefficients are shown for the decoding of three phonetic features and phoneme position. Phoneme onset is shown in the darkest purple (0 ms) and colours shift towards yellow as a function of time. Contours on the topographies highlight 90% percentile coefficient magnitude at 100 ms increments. Trajectories below represent the cosine distance between the coefficient topography and a binary posterior/anterior mask (y-axis) and a binary left/right mask (x-axis). Overall the results show that the topographies evolve over time, where phonetic features remain concentrated around auditory cortex, and phoneme position takes an anterior path from auditory to frontal cortices. Source data are provided as a Source Data file.