Abnormal processing of irrelevant information in attention deficit hyperactivity disorder

Cognitive interference is associated with neuronal marker N-acetyl aspartate in the anterior cingulate cortex: an in vivo 1H-MRS study of the Stroop Color-Word task

“…Moreover, we found different connectivity patterns across four studied brain regions and two interference groups, which provide evidence of neuronal reorganization as a mechanism of interference (most likely due to genetically predetermined control of the number of neurons, dendrites and receptors, and their function). The same ACC cognitive division has been reported to be activated in PET and fMRI studies of interference using different Stroop paradigms 3,[19][20][21][22][23][24][25] indicating how consistent these results are across different imaging modalities. Based on these studies, the ACC was most consistently engaged in the Stroop interference, which is in agreement with our findings here using 1 H-MRS. Our data are also consistent with the most recent study of MacDonald et al 24 using fMRI and a task-switching version of the Stroop task, where the right ACC was active for incongruent as compared to congruent color-naming trials.…”

“…In this study we also demonstrate a single chemical (NAA)-cognitive network in the brain, specifically in ACC, as a possible neurobiological/neurochemical mechanism for development of cognitive interference. Given that the SCW interference has been found abnormal in several neuropsychiatric disorders, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] this neuroimaging/cognitive tool may be useful for documentation of interference in studying cognitive control mechanisms in general, and in diagnosis of neuropsychiatric disorders particularly where dysfunction of cingulate cortex is expected. Another valuable application of these findings might be a new drug development in the pharmaceutical industry to design new chemical compounds and drugs which would produce brain changes that would be reflected in the interference and NAA measures (eg, in attention deficit hyperactivity disorder, where dysfunction of the ACC was already revealed by fMRI and the Counting Stroop; 4 or in obsessive-compulsive disorder, where reduced levels of cingulate NAA have been found using 1 H-MRS 48 ) and as an imaging tool to study effects of these chemical compounds and drugs (eg, as a guide in pre-clinical and early clinical development of drug candidates, and as proof of the effectiveness of new drugs as well as decisions on their future development).…”

“…For example, a color word such as blue that appears in an ink color such as red may inhibit naming of the color red due to automatic perception of incompatible information (such as color word blue). Previous studies of the Stroop effect provides convincing evidence that cognitive interference is abnormal in various neuropsychiatric disorders such as attention deficit hyperactivity disorder, 3,4 schizophrenia, 5-9 depression, 10,11 anxiety disorders, [12][13][14][15] Parkinson's disease, 16 Alzheimer's disease, 17 and HIV disease. 18 New imaging technologies, including positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have determined which functional circuitry in the brain is engaged in interference.…”

“…18 New imaging technologies, including positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have determined which functional circuitry in the brain is engaged in interference. Most of these studies performed using the classic SCW task 3,[19][20][21][22][23][24] and the Counting Stroop paradigm 25 indicate involvement of the anterior cingulate cortex (ACC) (ie, cognitive midsupracallosal division, which correspond to Brodmann's areas 24Ј/32Ј; 26 as opposed to the more anterior affective pregenual division, which activated in the Emotional Counting Stroop paradigm 27 ). The ACC activity has been also observed when tasks require divided attention, 28 monitoring the occurrence of errors, 29,30 and the presence of response conflict and/or inhibition, 24,[30][31][32][33] which suggest overlapping cognitive control mechanisms that linked with this region.…”

Stroop interference and attention-deficit/hyperactivity disorder: A review and meta-analysis.

“…The present meta-analysis revealed higher effect sizes for studies that used time per card or per item as an outcome variable rather than number of items per unit of time. Moreover, computerized Stroop tests (see the relatively high effect size from Carter, Krener, Chaderjian, Northcutt, & Wolfe, 1995) may be more sensitive than standard or Golden Stroop tests. An additional argument for using computerized Stroop tests is the tightly controlled experimental situation, resulting more easily in significance because of a relative low variance of interference scores.…”