Does consolidation of visuospatial sequence knowledge depend on eye movements?

In the current study, we assessed the retention of spatial sequence knowledge that was supported by oculomotor movements in the motor condition, but not in the perceptual condition. Participants performed two sessions of a serial reaction time task in which they had to manually react to the identity of a target letter pair presented in one of four locations around a fixation cross. More specifically, when the letter pair "XO" was presented, a left response ad to be given, and when the letter pair "OX" was presented, a right response was required. In the motor condition, eye movements were necessary to perform the task since the fixation cross and the target were separated by at least 9° visual angle. In the perceptual condition, on the other hand, eye movements were avoided by keeping the distance from the fixation cross to the target below 1° visual angle and by limiting the stimulus presentation to 100 ms. Since the target identity changed randomly in both conditions, no digital motor sequence was present in the task. However, target location was structured according to a deterministic sequence in both the perceptual and motor condition. Learning of the target location sequence was determined at the end of the first session and 24 hours after initial learning. Results indicated that the sequence learning effect in the SRT task diminished over the 24 hour interval in both conditions, although perceptual and motor knowledge both remained significant. Importantly, the occurrence of eye movements had no impact on the decline of sequence knowledge . These results suggest that the retention of spatial sequence knowledge occurs alike, irrespective of whether this knowledge is perceptual in nature or supported by a motor dimension like eye movements.