Asymmetric influences of temporally vs. nasally presented masked visual information: Evidence for collicular contributions to nonconscious priming effects

It was tested whether the retino-collicular projection allows for the processing of nonconsciously registered visual information in healthy individuals. Masked primes were presented to different visual hemifields. Because the retino-collicular projection is stronger for temporal than for nasal hemifields, priming should be stronger by temporal than by nasal primes. This pattern was tested in two experiments (Experiments 1 and 3). Further, with less peripheral primes, only available to weaker parts of the retino-collicular projection, hemifield asymmetries of priming vanished (Experiment 2). In conclusion, the study offers first evidence for collicular contributions to nonconscious priming effects by visual information in healthy individuals.