Vaccination attitudes and intentions reported by Canadian children and their parents in the CHILD Cohort Study during the COVID-19 pandemic.

Dementia causes a gradual decline in cognitive function that can considerably interfere with daily life. It can be categorized into subtypes, such as Alzheimer’s disease (AD), vascular dementia, Lewy body dementia, frontotemporal dementia, and mixed dementia, depending on its cause. Among them, AD is the most common type, accounting for 60% of all cases. The occurrence of dementia is strongly correlated with aging, and its incidence is rapidly increasing along with the global growth of the elderly population. The global prevalence of dementia reached 55 million people in 2019, resulting in a societal cost of over US$ 1.31 trillion. The number of dementia patients is expected to rise to 152 million by 2050. Additionally, dementia is the seventh leading cause of death worldwide and has a substantial impact on our lives. However, there is no medical treatment that can completely cure dementia, making its prevention and proper management crucial. Mild cognitive impairment (MCI) is recognized as the prodromal stage of dementia. It is a condition in which an individual can perform daily activities but experiences mild cognitive deficit. Up to 15.56% of the population aged 50 and above may be affected by MCI, and over 46% of those with MCI may progress to dementia within 3 years. Therefore, MCI testing and detection in the elderly are necessary for the prevention and delay of dementia, which can contribute to public health and the reduction of medical expenses. Neuroimaging is known as an effective tool for diagnosing MCI. It uses magnetic resonance imaging (MRI) or positron emission tomography to analyze temporal lobe atrophy or cerebral blood flow and glucose hypometabolism in the brain. These methods enable objective and direct identification of neurological changes but require specialized examination equipment and expert interpretation. As a more cost-effective and convenient testing tool, various questionnaire-based methods have been developed, including the mini mental state examination (MMSE) and the Montreal cognitive assessment. This approach improves accessibility to the MCI test, making it useful as an initial screening tool. However, it may be affected by the participant’s subjective perception and psychological factors, and it has limitations in obtaining detailed information about the participant’s neurophysiological condition. Additionally, repeated assessments may lead to a learning effect, potentially influencing the reliability of the results. To complement this, physiological information such as bio-signals, voice, and eye-tracking can be utilized. Among these, studies using electroencephalography (EEG), which measures the electrical activity of the brain, have been widely conducted to assess cognitive function in subjects. One study recorded resting-state EEG with 19 channels in an eyes-closed condition from 72 normal and 150 MCI participants. Functional lagged linear connectivity was analyzed, revealing reduced alpha-band connectivity in MCI. investigated the distribution of permutation entropy to classify normal, MCI, and dementia groups, each consisting of 85 individuals. It was possible to distinguish the three groups using EEG signals recorded from the TP8 electrode with eyes closed and from the C3, C4, T8 and O2 electrodes with eyes open. The frontal beta asymmetry of resting-state EEG was extracted from the EEG data of subjects (58 normal and 41 MCI) in another study. MCI participants exhibited higher asymmetry values. When incorporated into logistic regression alongside demographic information and computerized cognitive tests, it was able to distinguish normal and MCI with an area under the receiver operating characteristic curve of 0.933. Although the effectiveness of EEG in MCI assessment has been confirmed in these studies, EEG measurements can increase patient discomfort; multiple electrodes must be attached to the head, and their contact status must be checked, often requiring the use of gel that requires cleaning afterward. To minimize the burden of EEG measurement, some studies have used dry-contact electrodes or reduced the number of channels. collected data from 40 subjects using a portable EEG system and analyzed event-related potential (ERP) elicited by a visual oddball task. The results showed that the peak amplitude of P300 was lower in the MCI group, with a statistically significant difference from the normal group. Resting-state EEG data from 496 elderly individuals were obtained using a device with two dry-contact electrodes placed in the prefrontal regions. The authors compared MMSE scores with EEG parameters, such as median frequency, peak frequency, and alpha-to-theta ratio, and confirmed a moderate correlation with a Pearson correlation coefficient (PCC) of 0.758. The same device was utilized in subsequent studies. Several useful behavioral and ERP measures were identified from the data of 407 normal and 160 MCI participants. expanded the data to include 1,754 subjec