On the automaticity of pure perceptual sequence learning

We investigated the automaticity of implicit sequence learning by varying perceptual load in
a pure perceptual sequence learning paradigm. Participants responded to the randomly changing
identity of a target, while the irrelevant target location was structured. In Experiment 1, the target was
presented under low or high perceptual load during training, whereas testing occurred without load.
Unexpectedly, no sequence learning was observed. In Experiment 2, perceptual load was introduced
during the test phase to determine whether load is required to express perceptual knowledge.
Learning itself was unaffected by visuospatial demands, but more learning was expressed under high
load test conditions. In Experiment 3, we demonstrated that perceptual load is not required for the
acquisition of perceptual sequence knowledge. These findings suggest that perceptual load does not
mediate the perceptual sequence learning process itself, supporting the automaticity of implicit
learning, but is mandatory for the expression of pure perceptual sequence knowledge.