Contextual Interference Effect Is Independent of Retroactive Inhibition but Variable Practice Is Not Always Beneficial

Abstract

Positive effects of variable practice conditions on subsequent motor memory consolidation and generalization are widely accepted and described as the contextual interference effect (CIE). However, the general benefits of CIE are low and these benefits might even depend on decreased retest performances in the blocked-practicing control group, caused by retroactive inhibition. The aim of this study was to investigate if CIE represents a true learning phenomenon or possibly reflects confounding effects of retroactive inhibition. We tested 48 healthy human participants adapting their reaching movements to three different force field magnitudes. Subjects practiced the force fields in either a Blocked (B), Random (R), or Constant (C) schedule. In addition, subjects of the Blocked group performed either a retest schedule that did (Blocked-Matched; BM) or did not (Blocked-Unmatched; BU) control for retroactive inhibition. Results showed that retroactive inhibition did not affect the results of the BU group much and that the Random group showed a better consolidation performance compared to both Blocked groups. However, compared to the Constant group, the Random group showed only slight benefits in its memory consolidation of the mean performance across all force field magnitudes and no benefits in absolute performance values. This indicates that CIE reflects a true motor learning phenomenon, which is independent of retroactive inhibition. However, random practice is not always beneficial over constant practice.

Random Practice Enhances Retention and Spatial Transfer in Force Field Adaptation

“…Former studies on the CIE in our lab are inconsistent in this regard. The finding in this study concurs well with Thürer et al (2017 , 2019) but differs to Thürer et al (2018) . In the latter, a difference was only found for the enclosed area parameter (kinematic error) but not for the FFCF.…”

“…The retroactive inhibition hypothesis explains the CIE such that learning a similar task in a repetitive manner inhibits recalling a memory of a preceding, different task. However, this hypothesis is probably not valid for the CIE in motor adaptation tasks ( Thürer et al, 2018 , 2019 ). The forgetting-and-reconstruction hypothesis proposes that the action plan for a task is forgotten over time and vanishes from short-term memory.…”

“…Originally formulated by Battig (1972) for verbal learning, a large body of research has supported the CIE in motor skill learning, especially for simple laboratory tasks but also in more complex sport tasks (for an overview; see Schmidt et al, 2019 ). However, compared to skill learning, the CIE has not been widely studied in the context of motor adaptation ( Thürer et al, 2019 ). Accordingly, this study focuses on the analysis of the CIE in a motor adaptation task.…”

No Difference in the Acute Effects of Randomization vs. Blocking of Units of Lower-Extremity Proprioceptive Training on Balance and Postural Control in Young Healthy Male Adults

“…According to the forgetting-reconstruction hypothesis, the learner forgets after each task in order to focus on and reconstruct the action plan for the next task, resulting in stronger memory representation of the practiced task ( Lee and Magill, 1985 ). The retroactive inhibition hypothesis suggests that contextual interference is related to disadvantages of blocked practice rather than the advantages of random practice ( Thürer et al, 2019 ) ( Shewokis et al, 1998 ).…”

Mini-Review: practice organization beyond memory processes

“…While variable practices result in more effective motor learning than constant practice, 4 random and serial variable practices are more effective than the blocked variable practice. 5,6 A point of convergence in all proposed behavioral hypotheses is that more variable practices demand more from mnemonic processes than more repetitive practices, being this feature responsible for the better learning observed in random and serial practices when compared with constant and blocked practices.…”