Boundary effects on the illusory continuity of an interrupted glide through a notched noise

This study investigated the illusory continuity of an interrupted frequency glide through a notched-noise burst. A 2I-2AFC procedure was used to measure detection of the (target) portion of the frequency glide that overlapped in time with the noise. The portions of the glide preceding and following the noise (flankers) could be present or absent. The center frequency of the notch coincided with either the frequency end-point of the flanker that preceded the noise, or the onset frequency of the flanker that followed the noise. A control condition with a wideband noise burst (absent notch) was also included. Performance was poorest in the absent notch condition, and was significantly poorer with present than with absent flankers. This suggests that listeners perceptually restored the missing target when flankers were present. Performance was also less accurate (indicating stronger illusory continuity) when the notch was centered on the end-point of the flanker that preceded the noise. These results suggest that the masking of the onset of the flanker following the noise provides a stronger cue to the perception of continuity than the masking of the offset of the flanker that precedes the noise.