Fig. 1: Auditory WM stimuli and task.

a Time-frequency representations of a prototypical WM set of 6 different moving ripple sounds, modulated across time (ripple velocity, ω cycles/s) and frequency (Ω cycles/octave). b Trial design. After a visual preparatory cue, subjects heard two ripple sound stimuli (i.e., potential WM items) in a row. A brief visual retrocue then followed, to instruct which of the previous two items was to be actively memorized for a period of 15 s (“Maintaenance”). After hearing the probe, the subject was asked to press one button (“yes”) if the probe matched the relevant item, and another (“no”) if it did not. The different MVPA analyses were conducted during the Maintenance period (for details, see Methods).