Experimental stimuli. In each of the four stimulus conditions, a duration deviant tone (D) was interspersed with a repeated standard tone (S).

<p>In the SSI²⁰⁰/SDI²⁰⁰ and SSI⁵⁰⁰/SDI⁵⁰⁰-conditions, the duration of the deviant was 25 ms of the standard 75 ms. In the SSI²⁰⁰/SDI⁵⁰⁰ and SSI⁵⁰⁰/SDI²⁰⁰-conditions, each duration was assigned to each stimulus type in separate series. Otherwise, the four conditions differed in stimulus-onset-asynchrony (200 ms or 500 ms) between consecutive standards (SSI) and between deviants and their immediately preceding standards (SDI).