Figure 1. Stimulus sequences used to test the effect of acoustic context on ASR.

Startle stimuli of different intensities (blue blocks) are presented as bursts separated by different time intervals (red double-headed arrows). In the first context (A), silence is maintained during the inter-stimulus interval (black lines) throughout the test battery. In the second context (B), a background noise, with or without an intervening gap of silence, fills some of the inter-stimulus intervals, but the startle stimulus only condition is identical to that in context 1. In either context, numbered solid blue block are those used to determine the ASR. Red diamond: time interval during which the background noise is interrupted by a gap.