Post-training stimulation of the right dorsolateral prefrontal cortex impairs working memory training performance.

Research investigating transcranial direct current stimulation (tDCS) to enhance cognitive training augments both our understanding of its long-term effects on cognitive plasticity as well as potential applications to strengthen cognitive interventions. Previous work has demonstrated enhancement of working memory training while applying concurrent tDCS to the dorsolateral prefrontal cortex (DLPFC). However, the optimal stimulation parameters are still unknown. For example, the timing of tDCS delivery has been shown to be an influential variable that can interact with task learning. In the present study, we used tDCS to target the right DLPFC while participants trained on a visuospatial working memory task. We sought to compare the relative efficacy of online stimulation delivered during training to offline stimulation delivered either immediately before or afterwards. We were unable to replicate previously demonstrated benefits of online stimulation; however, we did find evidence that offline stimulation delivered after training can actually be detrimental to training performance relative to sham. We interpret our results in light of evidence suggesting a role of the right DLPFC in promoting memory interference, and conclude that while tDCS may be a promising tool to influence the results of cognitive training, more research and an abundance of caution are needed before fully endorsing its use for cognitive enhancement. This work suggests that effects can vary substantially in magnitude and direction between studies, and may be heavily dependent on a variety of intervention protocol parameters such as the timing and location of stimulation delivery, about which our understanding is still nascent.

Correction to: Living "in the zone": hyperfocus in adult ADHD.

Authors have noted one error in the online published article, which they wish to clarify. The version of the Hobby Hyperfocus (HF) subscale that we administered to participants was unintentionally missing one answer option ("once a week").

Living "in the zone": hyperfocus in adult ADHD.

Adults with ADHD often report episodes of long-lasting, highly focused attention, a surprising report given their tendency to be distracted by irrelevant information. This has been colloquially termed "hyperfocus" (HF). Here, we introduce a novel assessment tool, the "Adult Hyperfocus Questionnaire" and test the preregistered a priori hypothesis that HF is more prevalent in individuals with high levels of ADHD symptomology. We assess (1) a pilot sample (n = 251) and (2) a replication sample (n = 372) of adults with or without ADHD. Participants completed highly validated scales, including the Conners' Adult ADHD Rating Scale, to index ADHD symptomology. Those with higher ADHD symptomology reported higher total and dispositional HF and more frequent HF across each of the three settings (school, hobbies, and screen time) as well as on a fourth subscale describing real-world HF scenarios. These findings are both clinically and scientifically significant, as this is the first study to comprehensively assess HF in adults with high ADHD symptomology and to present a means for assessing HF. Moreover, the sizable prevalence of HF in adults with high levels of ADHD symptomology leads to a need to study it as a potentially separable feature of the ADHD syndrome.