One might wonder, for example, whether participants with superior response inhibition performed better during retrieval practice and strengthened Rp+ items to a greater extent than individuals with inferior response inhibition. Although faster SSRTs did predict modestly better performance during retrieval practice (r = −.13, p = .34), as well as marginally ABT-888 nmr greater benefits from retrieval practice on the final test (r = −.23, p = .08), the correlation between retrieval-induced forgetting and SSRT remained significant even when controlling for variance in these benefits.

Indeed, the partial correlation observed between SSRT and RIF-Z controlling for both practice performance and practice benefits (r = −.29, p = .03) was quite similar to the non-partial correlation observed (r = −.31). Furthermore, for completeness, we repeated the regression analysis while controlling for practice performance and practice benefits, and the same pattern of results was observed.

Recall performance generally declines as a function of serial position in a test sequence. This output interference Protein Tyrosine Kinase inhibitor effect is another manifestation of retrieval-induced forgetting (Anderson et al., 1994). As such, we can also examine the relationship between SSRT and this effect of forgetting. In particular, in the category-plus-stem final test condition, we tested participants on the Rp− items before testing the Rp+ items to ensure that any impairment observed for Rp− items did not arise from the prior output of Rp+ items. Correspondingly, we tested half of

the Nrp items in the first half of the test, to use as a baseline for Rp− items, and the other half of the Nrp items in the second test half, to use as a baseline for Rp+ items. This arrangement provides Glycogen branching enzyme a controlled manipulation of output position for Nrp items that allows us to estimate retrieval-induced forgetting at test. Specifically, as a result of testing Nrp− items first, the retrieval process engaged on those test trials should cause the retrieval-induced forgetting of the as-of-yet to-be-recalled Nrp+ items. Indeed, as would be predicted, Nrp+ items were recalled significantly less well than were Nrp− items, t(59) = 5.43, p < .001, d = −.70, thus demonstrating that Nrp+ items suffered retrieval-induced forgetting as the result of the earlier testing of Nrp− items. Using these data, an additional retrieval-induced forgetting score was calculated for each participant by subtracting Nrp+ recall from Nrp− recall, and then z-normalizing the scores within each counterbalancing condition. Importantly, individual differences in SSRT correlated significantly with this independent measure of retrieval-induced forgetting, with faster SSRTs (better inhibitory control) predicting larger test-based retrieval-induced forgetting effects, r = −.44, p < .001.