The purpose of this study was to compare working memory (WM), executive function, academic ability and problem classroom behaviors in children aged 8 to 11 years who were either identified via routine screening as having low WM, or had been diagnosed with ADHD. Standardised assessments of WM, executive function and reading and mathematics were administered to 83 children with ADHD, 50 children with low WM and 50 typically developing children. Teachers rated problem behaviors on checklists measuring attention, hyperactivity/impulsivity, oppositional behavior, (...) and difficulties associated with executive function in the classroom. The ADHD and low WM groups had highly similar WM and executive function profiles, but were distinguished in two key respects: children with ADHD had higher levels of rated and observed impulsive behavior, and children low WM had slower response times. Possible mechanisms for these common and distinct deficits are discussed. (shrink)

Individuals frequently make use of the body and environment when engaged in a cognitive task. For example, individuals will often spontaneously physically rotate when faced with rotated objects, such as an array of words, to putatively offload the performance costs associated with stimulus rotation. We looked to further examine this idea by independently manipulating the costs associated with both word rotation and array frame rotation. Surprisingly, we found that individuals’ patterns of spontaneous physical rotations did not follow patterns of performance (...) costs or benefits associated with being physically rotated, findings difficult to reconcile with existing theories of strategy selection involving external resources. Individuals’ subjective ratings of perceived benefits, rather, provided an excellent match to the patterns of physical rotations, suggesting that the critical variable when deciding on-the-fly whether to incorporate an external resource is the participant's metacognitive beliefs regarding expected performance or the effort required for each approach. Implications for metacognition's future in theories of cognitive offloading are discussed. (shrink)