Comparison of speed versus complexity effects on the hemodynamic response of the trail making test in block designs

Abstract

Abstract.The use of functional near-infrared spectroscopy (fNIRS) in block designs provides measures of cortical activity in ecologically valid environments. However, in some cases, the use of block designs may be problematic when data are not corrected for performance in a time-restricted block. We sought to investigate the effects of task complexity and processing speed on hemodynamic responses in an fNIRS block design. To differentiate the effects of task complexity and processing speed, 20 subjects completed the trail making test (TMT) in two versions (TMT-A versus TMT-B) and three different speed levels (slow versus moderate versus fast). During TMT-A, subjects are asked to connect encircled numbers in numerically ascending order (1-2-3…). In the more complex TMT-B, subjects are instructed to connect encircled numbers and letters in alternating ascending order (1-A-2-B…). To illustrate the obscuring effects of processing speed on task complexity, we perform two different analyses. First, we analyze the classical measures of oxygenated blood, and second, we analyze the measures corrected for the number of processed items. Our results show large effects for processing speed within the bilateral inferior frontal gyrus, left dorsolateral prefrontal cortex, and superior parietal lobule (SPL). The TMT contrast did not show significant effects with classical measures, although trends are observed for higher activation during TMT-B. When corrected for processed items, higher activity for TMT-B in comparison to TMT-A is found within the SPL. The results are discussed in light of recent research designs, and simple to use correction methods are suggested.

Neural correlates of mindful emotion regulation in high and low ruminators

“…In their study, Hasenkamp and colleagues observed increased activity within areas of the default mode network during mindwandering, increased activity within the salience network during awareness of mindwandering and increased activity in the cognitive control network during attention shifting and sustained attention 75 . Associations of CCN activation and attentional control/shifting have also been shown in other fNIRS and fMRI studies 52 , 69 , 76 – 79 . Correspondingly, we propose that our results might reflect a naturally occurring effect that is present during mindfulness meditation when reflecting on emotions in a mindful state.…”

Processing speed dysfunction is associated with functional corticostriatal circuit alterations in childhood epilepsy with centrotemporal spikes: a PET and fMRI study

“…Therefore, the two NBS additional subnetworks may be branches of the cortical-striatal circuit in the main subnetwork. The cortical regions in the two branches, including the fusiform, pericalcarine, lateral orbitofrontal, rostral anterior cingulate, and superior parietal, were also considered to be associated with processing speed [33][34][35][36][37].…”

Effects of aging on functional connectivity in a neurodegenerative risk cohort: resting state versus task measurement using near-infrared spectroscopy

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