The Influence of Exposure Amount on the Persistence of Short-Term, Haptically Acquired Sensorimotor Memorial Representations

This study investigates the influence that the amount of exposure has on the persistence of sensorimotor memories. Participants acquired memories of an unexpectedly heavy object in one of four groups that varied in the number lifts of the object they each performed. All participants followed this acquisition period with retention lifts immediately and after 2-second and 10-second intervals, as well as after 15 minutes and 24 hours. Grasp force profiles were evaluated for the maintenance of memory-dependent adaptations. A lack of any group effects indicates that the quantity of exposure offers the sensorimotor memory system no temporal advantage in the maintenance of short-term representations. The results are discussed in light of the possibility that, within a short time frame, only the information from the preceding lift has functional relevance to the current lift.