The magnitude of the testing effect is independent of retrieval practice performance.

Practicing retrieval is a potent learning enhancer. Theoretical accounts of the testing effect generally suggest that the magnitude of the testing effect is dependent on retrieval practice performance, such that conditions that promote better retrieval practice performance should result in a greater testing effect. Empirical evidence, however, has been mixed. Although some studies showed a positive association between retrieval practice performance and the testing effect, others have shown either no relation or the reverse. In the present study, we experimentally manipulated retrieval practice performance using a retrieval-based response deadline manipulation and an encoding-based study trial manipulation. Across six experiments, the magnitude of the testing effect was independent of retrieval practice performance. However, when we aggregated the data across the experiments, participants with superior retrieval practice performance showed a greater testing effect-an individual difference. This dissociation between experimental and correlational outcomes suggests that the positive relation between retrieval practice performance and the testing effect is not causal, and indeed, simulation data showed that the correlation between retrieval practice performance and testing effect was an artifact. We discuss the challenges these findings present to existing accounts of the testing effect. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Examining the consistency in bilingualism and white matter research: A meta-analysis.

This study aimed to systematically investigate the relationship between bilingualism, age, L2 onset age of acquisition (AoA), and white matter integrity (operationalized as fractional anisotropy, FA), addressing inconsistencies in the literature. We conducted a meta-analysis of 23 studies and used meta-regression models to assess the influence of age and L2AoA on effect sizes in studies comparing monolinguals and bilinguals. Even though the overall between-group effect size across the whole brain was unreliable, bilingualism was associated with increased white matter integrity in specific tracts and in groups with a limited range of age and L2AoA. Age had a small, negative effect on white matter integrity, with differences between monolinguals and bilinguals more pronounced in younger adults, consistent with a view of an initial increase in white matter integrity, followed by remodeling for efficiency over time. In contrast, later L2AoA was associated with greater white matter integrity in bilinguals than monolinguals, again consistent with the remodeling for efficiency model. Our findings highlight the importance of considering age and L2AoA when examining the neural basis of bilingualism on white matter in the brain and how bilingualism contributes to structural changes that stave off cognitive decline in older age.