When considered together, the Diagnostic Group × Reinforcement and Baseline Cognition × Reinforcement interactions both remained robust.
In contrast, neither the Diagnostic Group × Reinforcement nor the SR × Reinforcement interactions accounted for unique variance when evaluated together.
However, the robust Diagnostic Group × Reinforcement and SR × Reinforcement interactions both became non-significant when tested simultaneously.
Attempts to explain Diagnostic Group × Reinforcement interactions in the ADHD literature have generally focused on motivational or cognitive deficits [ 17].
However, in order to examine the extent to which baseline differences contribute to Diagnostic Group × Reinforcement interactions, a true "baseline" must be obtained.
To do this, we combined data from reports showing Diagnostic Group × Reinforcement interactions on tasks of inhibitory control [ 26], working memory [ 15], and sustained attention [ 27], as these processes are considered central in ADHD.
In the diagnostic group-only model (Model 1), the tendency for children with ADHD to exhibit worse cognitive performance than control children, F 1, 69.5) = 37.0, p < .001, interacted with reinforcement, Diagnostic Group × Reinforcement interaction, F 1, 58) = 10.6, p = .002 (Table 2 provides parameter estimates and effect sizes for the interaction terms in each model).
Both tension and compression are treated as linear elastic plastic, and tension stiffening is used to model the tension post-failure behavior and reinforcement interaction.
Internal-external shear reinforcement interaction, i.e. reduction of the stirrup strain due to the presence of the composite, was observed for both FRP and FRCM strengthened beams, but the interaction was less pronounced for those with FRCM composites.
In terms of the critical interactions with reinforcement condition, both the Diagnostic Group × Reinforcement interaction, F 1, 58) = 8.0, p = .006, and the Baseline Cognition x Reinforcement interaction remained significant, F 1, 58) = 5.7, p = .02, and their effect sizes were relatively unchanged (see Table 2).
Results suggest significant overlapping variance between diagnostic group and SR, as the Diagnostic Group × Reinforcement interaction became non-significant, F 1, 58) = 3.3, p = .08, and there was no evidence of the SR × Reinforcement interaction, F 1, 58) = 1.3, p = .27; effect sizes for each interaction term were markedly attenuated in the presence of the other (see Table 2).
