Contralateral inhibition in a release from forward masking

The current study investigated contralateral inhibition involved in a release from forward masking. The masker and probe were 1-kHz pure tones shaped by a 20-Hz modulation. Durations of the masker and probe were 500 ms and 50 ms (single cycle) respectively. A 10-ms delay between the masker and probe was added to rule out any confusion. A contralateral component (cue), with various spectral and temporal properties, could be added during the masker. The first experiment showed that masking release occurred more often or increased with an increasing number of spectral cue components. The second experiment showed that increasing cue duration, leaving the cue and masker offsets synchronous, increased detection thresholds. In the third experiment the temporal position of a short cue relative to the masker was varied. The lowest thresholds were obtained for 0- and 150-ms delays between the cue and masker offsets. Despite large individual differences, the obtained release from forward masking provided support for a contralateral inhibition process. Contralateral inhibition seemed to be dependent on the number of spectral cue components and on the delay between the cue onset and the masker offset.