Working memory (WM) training improves WM ability in Attention-Deficit/Hyperactivity Disorder (ADHD), but its efficacy for non-cognitive ADHD impairments ADHD has been sharply debated. The purpose of this preliminary study was to characterize WM training-related changes in ADHD brain function and see if they were linked to clinical improvement. We examined 18 adolescents diagnosed with DSM-IV Combined-subtype ADHD before and after 25 sessions of WM training using a frequently employed approach (CogmedTM) using a nonverbal Sternberg WM fMRI task, neuropsychological tests, and participant- and parent-reports of ADHD symptom severity and associated functional impairment. Whole brain SPM8 analyses identified ADHD activation deficits compared to 18 non-ADHD control participants, then tested whether impaired ADHD frontoparietal brain activation would increase following WM training. Post hoc tests examined the relationships between neural changes and neurocognitive or clinical improvements. As predicted, WM training increased WM performance, ADHD clinical functioning, and WM-related ADHD brain activity in several frontal, parietal and temporal lobe regions. Increased left inferior frontal sulcus region activity was seen in all Encoding, Maintenance, and Retrieval Sternberg task phases. ADHD symptom severity improvements were most often positively correlated with activation gains in brain regions known to be engaged for WM-related executive processing; improvement of different symptom types had different neural correlates. The responsiveness of both amodal WM frontoparietal circuits and executive process-specific WM brain regions was altered by WM training. The latter might represent a promising, relatively unexplored treatment target for researchers seeking to optimize clinical response in ongoing ADHD WM training development efforts.

There was evidence for both increased and decreased connectivity which is consistent with findings in other chronic pain disorders. Preliminary evidence was found that subcortical brain regions might contribute to neurodevelopmental abnormalities in chronic pain. The results support a model in which SCD pain sensitization involves abnormally low functional integration of brain regions that make use of nociceptive information to plan movements, and hyperconnectivity of various frontal and parietal lobe regions that direct attention to or represent higher-order abstractions within circuits involved with either nocioceptive processing or detection of abnormally salient environmental stimuli.

Previous research has implicated the prefrontal cortex (PFC) in successful associative encoding and subjective awareness of one’s memory performance. We tested the causal role of the PFC in these processes by applying transcranial direct current stimulation (tDCS) during a verbal associative encoding and judgment-of-learning task. TDCS over the PFC impaired associative encoding compared to sham and parietal tDCS, as showed fewer hits on a subsequent associative recognition test. There were no effects of tDCS on the magnitude or accuracy of judgments-of-learning. These results suggest the PFC plays a causal role in objective measures of encoding, and that objective and subjective aspects of associative encoding are separable.

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