From left to right in inhibition of return of congenitally deaf people depending on task type

Inhibition of return (IOR) refers to a slowed response to a target appearing at a previously attended location. Previous research has shown a left-to-right bias in the IOR effect. We investigated whether left-to-right bias in IOR of deaf participants in detection and discrimination tasks was changed after auditory deprivation and examined the experience played in this bias. The results showed that the trend of the general IOR effect was approximately the opposite in the two tasks. IOR magnitude was significant when direction of cue presentation was right to left in detection task (experiment 1), but IOR was significant when direction of cue presentation was left to right in discrimination task (experiment 2). In experiment 2, the results indicated an earlier disengagement of attention in hearing participants than in deaf participants when direction of cue presentation was left to right, and also an earlier disengagement of attention in deaf participants than in hearing participants when direction of cue presentation was right to left. Thus, the regularity of shifting attention in a particular way seems to be the cause of the bias observed. Those results indicate that the spatial attention is changed after auditory deprivation and the experience plays an important role in IOR.