Description
Practice effects represent a psychometric phenomenon observed when individuals demonstrate improved performance on cognitive tests after repeated exposure to the same or similar test materials, distinct from a true change in a patient’s ability. These improvements can occur naturally, reflecting the learning and adaptation through repeated testing, and may serve as indicators of cognitive plasticity and predictors of motor learning. Despite their potential significance, these effects remain underexplored in individuals with Parkinson’s Disease (PD), a population characterized by cognitive and motor impairments. This study quantified practice effects in PD and investigated their relationship with outcomes of reactive balance training to identify predictors of rehabilitation responsiveness. Thirty-five individuals with idiopathic PD at risk for falls participated in an 18-week protocol. Cognitive assessments, including verbal episodic memory (California Verbal Learning Test; CVLT-II) and processing speed (Symbol Digit Modality Test; SDMT), were conducted at two baseline visits separated by two weeks (B1 and B2) to evaluate practice effects. Reactive stepping metrics—such as anterior-posterior margin of stability (AP MOS), step length, and latency—were assessed during the same baseline visits (B1 and B2), immediately after a two-week reactive balance training program (P1), and two months post-training for retention (P2). The two-week training program, conducted between B2 and P1, involved repeated support-surface perturbations designed to improve reactive balance. Two-week cognitive practice effects were quantified as the change in CVLT-II and SDMT scores between B1 and B2. Relationships between cognitive practice effects and improvements in reactive stepping were analyzed for immediate (B2-P1) and retained (B2-P2) outcomes. Significant practice effects were observed for CVLT-II delayed recall (mean improvement: 2.54, p < 0.001, d = 0.74) and total recall (mean improvement: 9.68, p < 0.001, d = 0.72), but not for SDMT (p = 0.21). Greater practice effects in CVLT-II delayed recall correlated strongly with immediate improvements in AP MOS (r = 0.64, p < 0.001) and moderately with step length (r = 0.39, p = 0.04) following training. No significant associations were noted between cognitive practice effects and retained improvements at P2. Practice effects in verbal episodic memory may be robust predictors of short-term responsiveness to reactive balance training in individuals with PD. These findings highlight the importance of incorporating cognitive assessments into motor rehabilitation programs to optimize outcomes and effectively target interventions. Future work should explore mechanisms linking practice effects, cognitive plasticity and motor learning in PD.| Period | 01 Jul 2025 |
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| Event title | The International Society of Posture and Gait Research World Congress: ISPGR World Congress |
| Event type | Conference |
| Location | Maastricht, NetherlandsShow on map |
| Degree of Recognition | International |