Prefrontal intra-individual ERP variability and its asymmetry: exploring its biomarker potential in mild cognitive impairment.

BACKGROUND: The worldwide trend of demographic aging highlights the progress made in healthcare, albeit with health challenges like Alzheimer's Disease (AD), prevalent in individuals aged 65 and above. Its early detection at the mild cognitive impairment (MCI) stage is crucial. Event-related potentials (ERPs) obtained by averaging EEG segments responded to repeated events are vital for cognitive impairment research. Consequently, examining intra-trial ERP variability is vital for comprehending fluctuations within psychophysiological processes of interest. This study aimed to investigate cognitive deficiencies and instability in MCI using ERP variability and its asymmetry from a prefrontal two-channel EEG device. METHODS: In this study, ERP variability for both target and non-target responses was examined using the response variance curve (RVC) in a sample comprising 481 participants with MCI and 1,043 age-matched healthy individuals. The participants engaged in auditory selective attention tasks. Cognitive decline was assessed using the Seoul Neuropsychological Screening Battery (SNSB) and the Mini-Mental State Examination (MMSE). The research employed various statistical methods, including independent t-tests, and univariate and multiple logistic regression analyses. These analyses were conducted to investigate group differences and explore the relationships between neuropsychological test results, ERP variability and its asymmetry measures, and the prevalence of MCI. RESULTS: Our results showed that patients with MCI exhibited unstable cognitive processing, characterized by increased ERP variability compared to cognitively normal (CN) adults. Multiple logistic regression analyses confirmed the association between ERP variability in the target and non-target responses with MCI prevalence, independent of demographic and neuropsychological factors. DISCUSSION: The unstable cognitive processing in the MCI group compared to the CN individuals implies abnormal neurological changes and reduced and (or) unstable attentional maintenance during cognitive processing. Consequently, utilizing ERP variability measures from a portable EEG device could serve as a valuable addition to the conventional ERP measures of latency and amplitude. This approach holds significant promise for identifying mild cognitive deficits and neural alterations in individuals with MCI.

Corrigendum: Prefrontal event-related potential markers in association with mild cognitive impairment.

[This corrects the article DOI: 10.3389/fnagi.2023.1273008.].

Prefrontal event-related potential markers in association with mild cognitive impairment.

Background: Alzheimer's disease (AD) is among the leading contributors of dementia globally with approximately 60-70% of its cases. Current research is focused on the mild cognitive impairment (MCI), which is associated with cognitive decline but does not disrupt routine activities. Event-related potential (ERP) research is essential in screening patients with MCI. Low-density channel electroencephalography (EEG) is frequently used due to its convenience, portability, and affordability, making it suitable for resource-constrained environments. Despite extensive research on neural biomarkers for cognitive impairment, there is a considerable gap in understanding the effects on early stages of cognitive processes, particularly when combining physiological and cognitive markers using portable devices. The present study aimed to examine cognitive shortfalls and behavioral changes in patients with MCI using prefrontal selective attention ERP recorded from a prefrontal two-channel EEG device. Methods: We assessed cognitive decline using the Mini-Mental State Examination (MMSE) and the Seoul Neuropsychological Screening Battery (SNSB). We administered auditory selective attention tasks to 598 elderly participants, including those with MCI (160) and cognitively normal (CN) individuals (407). We conducted statistical analyses such as independent t-tests, Pearson's correlations, and univariate and multiple logistic regression analyses to assess group differences and associations between neuropsychological tests, ERP measures, behavioral measures, and MCI prevalence. Results: Our findings revealed that patients with MCI demonstrated slower information-processing abilities, and exhibited poorer task execution, characterized by reduced accuracy, increased errors, and higher variability in response time, compared to CN adults. Multiple logistic regression analyses confirmed the association between some ERP and behavioral measures with MCI prevalence, independent of demographic and neuropsychological factors. A relationship was observed between neuropsychological scores, ERP, and behavioral measures. Discussion: The slower information processing abilities, and poor task execution in the MCI group compared to the CN individuals suggests flawed neurological changes and reduced attentional maintenance during cognitive processing, respectively. Hence, the utilization of portable EEG devices to capture prefrontal selective attention ERPs, in combination with behavioral assessments, holds promise for the identification of mild cognitive deficits and neural alterations in individuals with MCI. This approach could potentially augment the traditional neuropsychological tests during clinical screening for MCI.

The Impact of Visual Art and High Affective Arousal on Heuristic Decision-Making in Consumers.

In marketing, the use of visual-art-based designs on products or packaging crucially impacts consumers' decision-making when purchasing. While visual art in product packaging should be designed to induce consumer's favorable evaluations, it should not evoke excessive affective arousal, because this may lead to the depletion of consumer's cognitive resources. Thus, consumers may use heuristic decision-making and commit an inadvertent mistake while purchasing. Most existing studies on visual arts in marketing have focused on preference (i.e., affective valence) using subjective evaluations. To address this, we applied a neuroscientific measure, electroencephalogram (EEG) to increase experimental validity. Two successive tasks were designed to examine the effects of affective arousal and affective valence, evoked by visual artwork, on the consecutive cognitive decision-making. In task 1, to evaluate the effect of visual art, EEG of two independent groups of people was measured when they viewed abstract artwork. The abstract art of neoplasticism (AbNP) group (n = 20) was showing Mondrian's artwork, while the abstract art of expressionism (AbEX) group (n = 18) viewed Kandinsky's artwork. The neoplasticism movement strove to eliminate emotion in art and expressionism to express the feelings of the artist. Building on Gallese's embodied simulation theory, AbNP and AbEX artworks were expected to induce lower and higher affect, respectively. In task 2, we investigated how the induced affect differentially influenced a succeeding cognitive Stroop task. We anticipated that the AbEX group would deplete more cognitive resources than AbNP group, based on capacity limitation theory. Significantly stronger affect was induced in the AbEX group in task 1 than in the AbNP group, especially in affective arousal. In task 2, the AbEX group showed a faster reaction time and higher error rate in the Stroop task. According to our hypotheses, the higher affective arousal state of the AbEX group might deplete more cognitive resources during task 1 and result in poorer performance in task 2 because affect impacted their cognitive resources. This is the first study using neuroscientific measures to prove that high affective arousal induced by visual arts on packaging may induce heuristic decision-making in consumers, thereby advancing our understanding of neuromarketing.

Impact of different antihypertensives on carotid arterial wall thickness.

Hypertension has been associated with atherosclerosis and cardiovascular disease. Carotid intima media thickness is increased in hypertensive patients. But, the correlation between carotid intima media thickness and antihypertensive agents is still uncertain. Therefore, we investigated carotid intima media thickness based on types of antihypertensive agents. 1809 patients were enrolled in this study and it showed that 1079 hypertensive patients had thicker carotid intima media thickness than non-hypertensive patients, with carotid intima media thicknesses of (0.72 ± 17 mm vs 0.64 ± 15 mm, P < .001), (0.31 ± 0.07 mm vs 0.30 ± 0.06 mm, P < .001), and (0.41 ± 0.13 mm vs 0.35 ± 0.12 mm, P < .001). Additionally, hypertensive patients on beta-blockers also had thicker carotid intima media thickness than the non-beta-blocker group, with carotid intima media thicknesses of (0.74 ± 0.18 mm vs 0.71 ± 0.16 mm, P = .018), (0.33 ± 0.09 mm vs 0.31 ± 0.07 mm, P = .029), and (0.43 ± 0.13 mm vs 0.40 ± 0.13 mm, P = .035). Multivariate analysis showed that carotid intima thickness was only correlated with beta-blockers (odds ratio = 2.489, confidence interval = 1.183-5.239, P = .016); however, this study showed that beta-blocker could be associated with increased carotid wall thickness as well.

The changes of individual carotid artery wall layer by aging and carotid intima-media thickness value for high risk.

AIM: It is still unclear which layer (intima or media) is mainly involved in increased carotid intima-media thickness (CIMT) by aging and also unclear regarding CIMT value suggesting high cardiovascular risk, although 75th percentile value of CIMT is known as a high risk in asymptomatic adults. We sought to find the changes of carotid intima thickness (CIT) and carotid media thickness (CMT) by aging and the 75th percentile value of CIMT in asymptomatic Korean adults. METHOD: This is an observational cohort study. Carotid ultrasound findings (n=2204 from 12 hospitals) were prospectively collected. The carotid images were sent to Korea Research Institute of Standards and Science for analysis using specialized software which can measure intima and media wall also. RESULTS: Mean age was 58.1±13.5 years old (52% of men). Pearson's correlation coefficient between age and right CIMT (r=.489, P<.001) and right CMT (r=.482, P<.001) was higher than that between age and right CIT (r=.284, P<.001). Mean right CIMT in male and female was 0.696±0.163 and 0.686±0.167 mm (P=.180), and the 75 percentile value was 0.778 and 0.771 mm, respectively. Mean right CIT was 0.311±0.069 and 0.303±0.064 mm (P=.009), and mean right CMT was 0.391±0.124 and 0.388±0.131 mm (P=.694) in male and female, respectively. Left carotid ultrasound findings showed similar to the right one. CONCLUSION: An increased CIMT by aging was mainly due to increased CMT rather than CIT in asymptomatic adults. The 75th percentile values of right CIMT were 0.778 and 0.771 mm in asymptomatic Korean male and female adults, respectively.

Chk1 and Hsp90 cooperatively regulate phosphorylation of endothelial nitric oxide synthase at serine 1179.

The effects of DNA damage on NO production have not been completely elucidated. Using ultraviolet (UV) irradiation as a DNA-damaging agent, we studied its effect on NO production in bovine aortic endothelial cells (BAEC). UV irradiation acutely increased NO production, the phosphorylation of endothelial NO synthase (eNOS) at serine 1179, and eNOS activity. No alterations in eNOS expression nor phosphorylation at eNOS Thr(497) or eNOS Ser(116) were found. SB218078, a checkpoint kinase 1 (Chk1) inhibitor, inhibited UV-irradiation-stimulated eNOS-Ser(1179) phosphorylation and NO production. Similarly, ectopic expression of small interference RNA for Chk1 or a dominant-negative Chk1 repressed the UV-irradiation stimulatory effect, whereas wild-type Chk1 increased basal eNOS-Ser(1179) phosphorylation. Purified Chk1 directly phosphorylated eNOS Ser(1179) in vitro. Confocal microscopy and coimmunoprecipitation studies revealed a colocalization of eNOS and Chk1. In basal BAEC, heat shock protein 90 (Hsp90) predominantly interacted with Chk1. This interaction, which decreased significantly in response to UV irradiation, was accompanied by increased interaction of Hsp90 with eNOS. The Hsp90 inhibitor geldanamycin attenuated UV-irradiation-stimulated eNOS-Ser(1179) phosphorylation by dissociating Hsp90 from eNOS. UV irradiation and geldanamycin did not alter the interaction between eNOS and Chk1. Overall, this is the first study demonstrating that Chk1 directly phosphorylates eNOS Ser(1179) in response to UV irradiation, which is dependent on Hsp90 interaction.

Individual measurement and significance of carotid intima, media, and intima-media thickness by B-mode ultrasonographic image processing.

OBJECTIVE: We assessed the clinical significance of intima (IT), media (MT), and intima-media (IMT) thickness of the common carotid artery using B-mode ultrasonographic image processing. METHODS AND RESULTS: One hundred seventy consecutive patients underwent common carotid artery scanning using high-resolution ultrasonography. A total of 150 patients could be analyzed off-line using ultrasonographic image processing, devised for individual measurement of IT, MT, and IMT. By univariate analysis, IT (range, 0.27 to 0.41 mm) was associated with age, whereas MT (range, 0.27 to 0.74 mm) and IMT (range, 0.49 to 1.12 mm) were associated with age, fibrinogen, and creatinine. Among atherosclerosis risk factors, hypertension was associated with thickness of all 3 layers, whereas smoking was associated with IT only. By multivariate analysis, IT was associated with age, hypertension, and smoking, whereas MT and IMT were associated with age, hypertension, and blood urea nitrogen level. CONCLUSIONS: Carotid IT is associated with smoking, whereas age and hypertension are associated with thickness of all 3 arterial layers. Our results suggest a differential response of the vasculature to systemic risk factors.

Nonlinear characteristics of heart rate time series: influence of three recumbent positions in patients with mild or severe coronary artery disease.

The aim of this study was to investigate the nonlinear characteristics of heart rate variability (HRV) for three recumbent positions: the supine, left lateral and right lateral decubitus positions. Recently, using a linear analyses method (for time and frequency domains), the effect of the right lateral decubitus position on vagal modulation has been found to increase parasympathetic activity and decrease sympathetic modulation. Little is known about the nonlinear dynamics of HRV for the three recumbent positions. Therefore, we studied the correlation dimension (CD), the largest Lyapunov exponent (LLE), the sample entropy (SampEn), the approximate entropy (ApEn) and the exponent alpha of the 1/falpha power spectrum as nonlinear characteristics of HRV. In response to the right lateral decubitus position, the CD, LLE, SampEn and ApEn increased significantly in both coronary artery disease (CAD) and control groups. In the linear analyses, the normalized high-frequency power (nHF) increased in the right lateral decubitus position. The CD, LLE, ApEn and SampEn correlated positively to the nHF. The alpha exponent did not correlate to either linear measure or CD, but correlated negatively to LLE, ApEn and SampEn. Among the three recumbent positions, it was found that the right lateral decubitus position can increase the complexity of the human physiological system and the vagal modulation of the cardiac autonomic nervous system the most.

Asymmetric activation in the prefrontal cortex by sound-induced affect.

This study is based on previous information regarding asymmetric activation in the prefrontal cortex by film-induced affects, as well as the inverse proportionality of prefrontal cortex activity to power in the alpha band of EEG. To search for a specific EEG band where the asymmetric activation in the prefrontal cortex by sound-induced affects is mainly reflected, we measured 32 college students' EEGs; 11 bands ranged from 6.5 to 35.0 Hz, at Fp1 and Fp2 sites. The power in the alpha band (8.0 to 13.0 Hz) at Fp2, especially in the alpha-2 band (9.0 to 11.0 Hz) increased while the students listened to music, during which participants reported positive affect. In contrast, the power at Fp1 increased while the students listened to noise, during which participants reported negative affect. These results imply that sound-induced positive affect increases relative left-sided activation in the prefrontal cortex, whereas induced negative affect elicits the opposite pattern of asymmetric activation.