Magnetoencephalography-derived oscillatory microstate patterns across lifespan: the Cambridge centre for ageing and neuroscience cohort.

The aging brain represents the primary risk factor for many neurodegenerative disorders. Whole-brain oscillations may contribute novel early biomarkers of aging. Here, we investigated the dynamic oscillatory neural activities across lifespan (from 18 to 88 years) using resting Magnetoencephalography (MEG) in a large cohort of 624 individuals. Our aim was to examine the patterns of oscillation microstates during the aging process. By using a machine-learning algorithm, we identify four typical clusters of microstate patterns across different age groups and different frequency bands: left-to-right topographic MS1, right-to-left topographic MS2, anterior-posterior MS3 and fronto-central MS4. We observed a decreased alpha duration and an increased alpha occurrence for sensory-related microstate patterns (MS1 & MS2). Accordingly, theta and beta changes from MS1 & MS2 may be related to motor decline that increased with age. Furthermore, voluntary 'top-down' saliency/attention networks may be reflected by the increased MS3 & MS4 alpha occurrence and complementary beta activities. The findings of this study advance our knowledge of how the aging brain shows dysfunctions in neural state transitions. By leveraging the identified microstate patterns, this study provides new insights into predicting healthy aging and the potential neuropsychiatric cognitive decline.

Dread of uncertain pain: An event-related potential study.

Humans experience more stress about uncertain situations than certain situations. However, the neural mechanism underlying the uncertainty of a negative stimulus has not been determined. In the present study, event-related potential was recorded to examine neural responses during the dread of unpredictable pain. We used a cueing paradigm in which predictable cues were always followed by electric shocks, unpredictable cues by electric shocks at a 50/50 ratio and safe cues by no electric shock. Visual analogue scales following electric shocks were presented to quantify subjective anxiety levels. The behavioral results showed that unpredictable cues evoked high-level anxiety compared with predictable cues in both painful and unpainful stimulation conditions. More importantly, the ERPs results revealed that unpredictable cues elicited a larger P200 at parietal sites than predictable cues. In addition, unpredictable cues evoked larger P200 compared with safe cues at frontal electrodes and compared with predictable cues at parietal electrodes. In addition, larger P3b and LPP were observed during perception of safe cues compared with predictable cues at frontal and central electrodes. The similar P3b effect was also revealed in the left sites. The present study underlined that the uncertain dread of pain was associated with threat appraisal process in pain system. These findings on early event-related potentials were significant for a neural marker and development of therapeutic interventions.

Interictal ripples nested in epileptiform discharge help to identify the epileptogenic zone in neocortical epilepsy.

OBJECTIVE: This study aimed to identify the subtype of interictal ripples that help delineate the epileptogenic zone in neocortical epilepsy. METHODS: Totally 25 patients with focal neocortical epilepsy who had invasive electroencephalography (EEG) evaluation and subsequent surgery were included. They were followed up for at least 2years. Interictal ripples (80-250Hz) and fast ripples (250-500Hz) during slow-wave sleep were identified. Neocortical ripples were defined as type I ripples when they were superimposed on epileptiform discharges, and as type II ripples when they occurred independently. Resection ratio was calculated to present the extent to which the cortical area showing an interictal event or the seizure onset zone (SOZ) was completely removed. RESULTS: Fast ripples and types I and II ripples were found in 8, 19, and 21 patients, respectively. Only the higher resection ratio of interictal fast or type I ripples was correlated to the Engel 1a surgical outcome. CONCLUSIONS: Type I ripples could assist in localizing the epileptogenic zone in neocortical epilepsy. SIGNIFICANCE: Type I and fast ripples both may be pathological high-frequency oscillations.

Logo Effects on Brand Extension Evaluations from the Electrophysiological Perspective.

Brand extension typically has two strategies: brand name extension (BN) and brand logo extension (BL). The current study explored which strategy (BN or BL) better enhanced the success of dissimilar brand extension and product promotion in enterprises. Event-related potentials (ERPs) were used to investigate electrophysiological processes when subjects evaluated their acceptance of the brand extension using a combined picture of S1 and S2. S1 was a famous brand presented by two identity signs (brand name and brand logo). S2 was a picture of an extension product that belonged to a dissimilar product category than S1. The behavior data showed that BL was more acceptable than BN in the dissimilar brand extension. The neurophysiology process was reflected by a less negative N2 component and a larger P300 component in the BL than in the BN. We suggested that N2 reflected a whole conflict between the brand-product combination and the long-term memory and that P300 could be regarded as the reflection of the categorization process in the working memory.

Beauty premium: Event-related potentials evidence of how physical attractiveness matters in online peer-to-peer lending.

Although it is well known that attractiveness-based impressions affect the labor market, election outcomes and many other social activities, little is known about the role physical attractiveness plays in financial transactions. With the development of online finance, peer-to-peer lending has become one of the most important ways in which businesses or individuals raise capital. However, because of information asymmetry, the lender must decide whether or not to lend money to a stranger based on limited information, resulting in their decision being influenced by many other factors. In the current study, we investigated how potential borrowers' facial attractiveness influenced lenders' attitudes toward borrowers' repayment behavior at the brain level by using event-related potentials. At the priming stage, photos of attractive borrowers induced smaller N200 amplitude than photos of unattractive borrowers. Meanwhile, at the feedback stage, compared with the condition of repaying on time, breach of repayment from unattractive borrowers induced larger feedback-related negativity (FRN) amplitude, which was a frontal-central negative deflection and would be enhanced by the unexpected outcome. Furthermore, smaller P300 amplitude was also elicited by the condition of not repaying on time. These differences in the FRN and P300 amplitudes were not observed between negative and positive feedback from attractive borrowers. Therefore, our findings suggest that the beauty premium phenomenon is present in online peer-to-peer lending and that lenders were more tolerant toward attractive borrowers' dishonest behavior.

The neural and psychological basis of herding in purchasing books online: an event-related potential study.

In this study, event-related brain potentials (ERPs) were used to investigate the neural and psychological bases of consumer herding decision in purchasing books online. Sixteen participants were asked to decide as quickly as possible whether to buy a book on the basis of its title keywords and the numbers of positive and negative reviews in stimulus. The given title keywords were very similar, and participants did not have special preference for any particular one. Hence, they were forced to adopt the strategy of herding decision: choosing to buy the book when there were consistent positive reviews, choosing not to buy when there were consistent negative reviews, randomly choosing to buy or not to buy when there were no consistent reviews. The herding decision triggers a categorical processing of the consistency level of customer reviews. Remarkable late positive potential (LPP), a component of ERP sensitive to categorization processes, was elicited. The LPP amplitudes varied as a function of review consistency. The LPP amplitudes for three categories of review consistency were significantly different, and their order is such that absolute consistent review was greater than relative consistent review, which was greater than inconsistent review. In addition, behavioral data revealed that the higher the consistency of the customer reviews, the higher the herd rate. It is possible that customer reviews with higher consistency let participants make herding decisions more resolutely. The present results suggest that the LPP may be regarded as an endogenous neural signal of the herding mechanism in a sense and that the LPP amplitude is potentially a measure of consumers' herd tendency in purchase decisions.

Error-related negativity varies with the activation of gender stereotypes.

The error-related negativity (ERN) was suggested to reflect the response-performance monitoring process. The purpose of this study is to investigate how the activation of gender stereotypes influences the ERN. Twenty-eight male participants were asked to complete a tool or kitchenware identification task. The prime stimulus is a picture of a male or female face and the target stimulus is either a kitchen utensil or a hand tool. The ERN amplitude on male-kitchenware trials is significantly larger than that on female-kitchenware trials, which reveals the low-level, automatic activation of gender stereotypes. The ERN that was elicited in this task has two sources--operation errors and the conflict between the gender stereotype activation and the non-prejudice beliefs. And the gender stereotype activation may be the key factor leading to this difference of ERN. In other words, the stereotype activation in this experimental paradigm may be indexed by the ERN.

P300 and categorization in brand extension.

Brand extension is the behavior of applying an established brand to enter new product categories. Its success depends on the perception of attribute similarity between the original brand and the extension product. In this study, 16 participants were required to decide the suitability of extending the brand in stimulus 1 to the product category in stimulus 2 during a S1-S2 paradigm. S1 consists of 15 well-known beverage brands. S2 consists of products in two categories: beverage and non-beverage. P300 - an important component of ERP - was elicited in all probes. The P300 amplitude was larger and distributed over almost all parietal and occipital regions when S2 is a beverage product. The P300 amplitude, however, was smaller and presented predominantly over the right regions when S2 is a non-beverage product. We speculate that the participants' decision process is a categorization process: they tried to classify the product in S2 into brand category in S1. In this process, the brand name in prime evoked the memory of specific products, and the neurons in corresponding cortex areas were activated. The higher similarity and coherence between the brand name in prime and the product name in probe produced an overlap of the similar stimuli in prime and probe, which resulted in larger P300. Otherwise, there is no overlap, resulting in smaller P300. Hence, the P300 may potentially be used in marketing research as an endogenous neural indicator of measuring consumers' attitude towards an intended brand extension.

Event-related potential N270 correlates of brand extension.

The aim of this study is to investigate the neural mechanism of extending a brand in a specific product category to other product categories. Facing two sequential stimuli in pairs consisting of beverage brand names (stimulus 1) and product names (stimulus 2) in other categories, 16 participants were asked to indicate the suitability of extending the brand in stimulus 1 to the product category in stimulus 2. These stimulus pairs were divided into four conditions depending on the product category in stimulus 2: beverage, snack, clothing, and household appliance. A negative component, N270, was recorded for each condition on the participants' scalps,whereas the maximum amplitude was observed at the frontal area. Greater N270 amplitude was observed when participants were presented with stronger conflict between the brand product category (stimulus 1) and the extension category (stimulus 2). It suggests that N270 can be evoked not only by a conflict of physical attributes (different shapes of words of brand and product names) but also by that of lexical content. From the marketing perspective, N270 can be potentially used as a reference measure in brand-extension attempts.