| Autor: |
Friedman LM; Department of Psychology, Arizona State University, Tempe, AZ, USA., Eckrich SJ; Department of Psychology, University of Central Florida, Orlando, FL, USA.; Department of Neuropsychology, Kennedy Krieger/Johns Hopkins University School of Medicine, Baltimore, MD, USA., Rapport MD; Department of Psychology, University of Central Florida, Orlando, FL, USA., Bohil CJ; Department of Psychology, University of Central Florida, Orlando, FL, USA., Calub C; Department of Psychiatry, University of California, Sacramento, CA, USA. |
| Abstrakt: |
Working memory impairments are an oft-reported deficit among children with ADHD, and complementary neuroimaging studies implicate reductions in prefrontal cortex (PFC) structure and function as a neurobiological explanation. Most imaging studies, however, rely on costly, movement-intolerant, and/or invasive methods to examine cortical differences. This is the first study to use a newer neuroimaging tool that overcomes these limitations, functional Near Infrared Spectroscopy (fNIRS), to investigate hypothesized prefrontal differences. Children (aged 8-12) with ADHD ( N = 22) and typically developing ( N = 18) children completed phonological working memory (PHWM) and short-term memory (PHSTM) tasks. Children with ADHD evinced poorer performance on both tasks, with greater differences observed in PHWM (Hedges' g = 0.67) relative to PHSTM (g = 0.39). fNIRS revealed reduced hemodynamic response among children with ADHD in the dorsolateral PFC while completing the PHWM task, but not within the anterior or posterior PFC. No between-group fNIRS differences were observed during the PHSTM task. Findings suggest that children with ADHD exhibit an inadequate hemodynamic response in a region of the brain that underlies PHWM abilities. The study also highlights the use of fNIRS as a cost-effective, noninvasive neuroimaging technique to localize/quantify neural activation patterns associated with executive functions. |
