The two situations in which effects could not be replicated were for short-duration masked priming (with prime durations of 64 ms or less), and for category learning (which was not response-time-based, and appeared to be down to motivational issues in the participants).
There was a significant main effect of Prime Identity, F 1,96) = 73.19, p<.001, η2 = .43, qualified however by a significant Prime Identity×Prime Duration interaction, F 5,96) = 14.90, p<.001, η2 = .44, which indicates that the magnitude of the priming effect increased with increasing prime duration (see Table 1).
Experiment 2 confirmed the prediction that associative priming increases and then decreases with increasing prime duration, but remains positive even with long duration primes.
In this study, a prime duration of 70 ms yielded a reliable priming effect across subjects, indicating that this is enough time to extract information that can lead to successful object identification.
This suggests that the priming effect was not modulated by object orientation at any prime duration.
On the other hand, previous studies have found that priming effect could change from positive to negative as a function of prime duration [36], [49].
The between subjects ANOVA comparing repetition suppression in the masked and unmasked priming conditions did not identify a significant interaction of LvOT repetition suppression and prime duration (P < 0.05 uncorrected).
The priming task used a (2×7)×6 design, with Prime Identity (Same vs. Different prime) and Prime Orientation (0°, 30°, 60°, 90°, 120°, 150°, 180°) as within-subject factors and Prime Duration (16 ms, 47 ms, 70 ms, 95 ms, 141 ms, 350 ms) as a between-subjects factor.
Contrary to these predictions, we did not find preferential priming for upright prime-target pairs compared to other orientations even for very short prime durations (see Fig. 2).
As such, these models would predict priming only for identically oriented (i.e., upright) prime-target pairs for short prime durations, with correspondingly smaller amounts of priming for more rotated primes, as compensation for object misorientation (whatever form that takes) could not be completed in the time available.
