Inhibition of return in subliminal letter priming.

The present study combined exogenous spatial cueing with masked repetition priming to study attentional influences on the processing of subliminal stimuli. Participants performed an alphabetic decision task (letter versus pseudo-letter classification) with central targets and briefly presented peripherally located primes that were either cued or not cued by an abrupt onset. A relatively long delay between cue and prime was used to investigate the effect of inhibition of return (IOR) on the processing of subliminal masked primes. Primes presented to the left visual field showed standard effects of Cue Validity and no IOR (significant priming with valid cues only). Primes presented to the right visual field showed no priming from valid cues (an IOR effect), and priming with invalid cues that depended on hand of response to letter targets (right-hand in Experiment 1, left-hand in Experiment 2). The results are interpreted in terms of a differential speed of engagement and disengagement of attention to the right and left visual fields for alphabetic stimuli, coupled with a complex interaction that arises between Prime Relatedness and response-hand.