Neural Compensatory Response During Complex Cognitive Function Tasks in Mild Cognitive Impairment: A Near-Infrared Spectroscopy Study

Abstract

The present pilot study was aimed at conducting a comparative analysis of the level of activation in the prefrontal cortex among a normal elderly group and amnestic and nonamnestic mild cognitive impairment (MCI) groups and investigating the presence of neural compensatory mechanisms according to types of MCI and different cognitive tasks. We performed functional near-infrared spectroscopy (fNIRS) along with cognitive tasks, including two-back test, Korean color word Stroop test, and semantic verbal fluency task (SVFT), to investigate hemodynamic response and the presence of neural compensation and neuroplasticity in the prefrontal cortex of patients with amnestic and nonamnestic MCI compared with a healthy elderly group. During the two-back test, there was no significant difference in the bilateral region-of-interest (ROI) analysis in the three groups. During the Stroop test, right-sided hyperactivation compared to the left side during the task was shown in the nonamnestic MCI and normal groups with statistical significance. Mean acc∆HbO2 on the right side was highest in the nonamnestic MCI group (0.30 μM) followed by the normal group (0.07 μM) and the amnestic MCI group (-0.10 μM). Otherwise, intergroup ROI analysis of acc∆HbO2 in these activated right sides showed no significant difference. During the VFT test, there was no significant difference in the bilateral region-of-interest analysis in the three groups. The highest mean acc∆HbO2 was shown in the normal group (0.79 μM) followed by the nonamnestic MCI group (0.52 μM) and the amnestic MCI group (0.21 μM). Otherwise, there was no significant difference between groups. The hemodynamic response during fNIRS showed different findings according to MCI types and cognitive tasks. Among the three tasks, the Stroop test showed results that were suggestive of neural compensatory mechanisms in the prefrontal cortex in nonamnestic MCI.

A Functional Near-Infrared Spectroscopy Examination of the Neural Correlates of Cognitive Shifting in Dimensional Change Card Sort Task

“…In the cognitive shifting during the DCCS task, those Perseverate children had to activate BA 10 to help BA 9 and BA 44 complete the complicated cognitive tasks. This could be explained with neural compensatory mechanisms recently found by Yoon et al ( 2019 ). In their fNIRS study of the normal elderly group and amnestic and non-amnestic mild cognitive impairment groups, significantly higher activation of the right pre-frontal cortex was found as the compensatory effect to supplant left pre-frontal function in the Stroop tests.…”

“…In their fNIRS study of the normal elderly group and amnestic and non-amnestic mild cognitive impairment groups, significantly higher activation of the right pre-frontal cortex was found as the compensatory effect to supplant left pre-frontal function in the Stroop tests. Although the neuroplasticity of the right pre-frontal cortex has been reported in other studies (Yoon et al, 2019), this is the first study to identify the neural compensatory mechanism of the right pre-frontal cortex in the cognitive shifting tasks in young children. Further studies with younger children are needed to explore the origin of this neural compensatory mechanism.…”

Prefrontal functional connectivity analysis of cognitive decline for early diagnosis of mild cognitive impairment: a functional near-infrared spectroscopy study

“…Hemodynamic responses in the prefrontal cortex as detected by fNIRS differ according to MCI type and cognitive task [16]. However, no significant differences were observed in prefrontal cortical activation between HC and MCI groups during an N-back task for WM.…”

“…Functional neuroimaging studies have demonstrated abnormal activation in the prefrontal cortices during WM tasks in MCI patients [15,16]. However, the processes related to cognitive function are not isolated to specific brain regions.…”

Detection of Mild Cognitive Impairment Using Convolutional Neural Network: Temporal-Feature Maps of Functional Near-Infrared Spectroscopy

“…Traditionally, the research studies compared the hemodynamic response of a patient with that of healthy control (HC) and determined neuroanatomical or neurofunctional differences at the group level. Most AD/MCI detection studies typically employed the HbO/ HbR (Jahani et al, 2017;Perpetuini et al, 2017;Vermeij et al, 2017;Katzorke et al, 2018;Yoon et al, 2019) and relative temporal features such as the mean value, slope value, number of active channels, peak location, skewness, and kurtosis (Yap et al, 2017;Li et al, 2018a), and they determined the significant differences for comparison. The straightforwardness and interpretability of this methodology has led to considerable advances in our comprehension of the neurological disorders.…”