Figure 1 .

Experimental design. (a) “Passive-listening experiment.” 10 stories from Moth Radio Hour were used to compile a single-speaker stimulus set. Subjects were instructed to listen to the stimulus vigilantly without any explicit task in the passive-listening experiment. (b) “Cocktail-party experiment.” A pair of stories told by individuals of different genders were selected from the single-speaker stimulus set and overlaid temporally to generate a 2-speaker stimulus set. Subjects were instructed to attend either to the male or female speaker in the cocktail-party experiment. The same 2-speaker story was presented twice in separate runs while the target speaker was varied. Attention condition was fixed within runs and it alternated across runs.