Neurocognitive Responses Research Articles

Machine learning prediction of mental health strategy selection in school aged children using neurocognitive data

This study investigates the use of neurocognitive data collected via functional near infrared spectroscopy (fNIRS) for the development of predictive algorithms related to client Dialectical Behavior Therapy (DBT) skill use in Digital Counseling Environments (DCEs). Specifically, the aim of this study is to examine the utility of using neurocognitive data in combination with a machine learning algorithm to predict client selection of strategies in a virtual environment. Participants were recruited from a rural school located in the United States (n = 50). Student participants engaged in one of three DBT skill development conditions: time-delay-control, face-to-face, and virtual reality-based. Neurocognitive responses in the form of ratios of oxygenated and deoxygenated blood in neural tissue (hemodynamic response) were collected during the learning phase within each condition. The data was then used to train and develop a model to predict the success of client selection of DBT strategies when presented with the opportunity in an assessment phase. The average predictive accuracy of the resultant algorithm was ∼83%. Results also illustrated the potential to capture changes in cognition via hemodynamic response as they occur during DBT skill development in near real-time (∼300 ms). Findings from this study illustrate that the use of neurocognitive data in DCEs may be used to successfully predict client outcomes and increase the quality and reliability of counselor assessments of client progress, aid in the development of artificially intelligent counselors, and improve counselors use of client-based analytics in face-to-face and digital counseling environments.

Neurocognitive responses to spatial design behaviors and tools among interior architecture students: a pilot study

The impact of emotions on human behavior is substantial, and the ability to recognize people's feelings has a wide range of practical applications including education. Here, the methods and tools of education are being calibrated according to the data gained over electroencephalogram (EEG) signals. The issue of which design tools would be ideal in the future of interior architecture education, is an uncertain field. It is important to measure the students’ emotional states while using manual and digital design tools to determine the different impacts. Brain-computer interfaces have made it possible to monitor emotional states in a way that is both convenient and economical. In the research of emotion recognition, EEG signals have been employed, and the resulting literature explains basic emotions as well as complicated scenarios that are created from the combination of numerous basic emotions. The objective of this study is to investigate the emotional states and degrees of attachment experienced by interior architecture students while engaging in their design processes. This includes examining the use of 2D or 3D tools, whether manual or digital, and identifying any changes in design tool usage and behaviors that may be influenced by different teaching techniques. Accordingly, the hierarchical clustering which is a technique used in data analysis to group objects into a hierarchical structure of clusters based on their similarities has been conducted.

What makes a Tweet so sweet: The neurocognitive effects of hedonic information consumption

Hedonic information consumption (HIC) refers to the consumption of information for non-task-oriented purposes such as entertainment or pleasure. With the explosive growth of information availability through online channels such as social media, HIC has become a common and growing phenomenon; however, most information systems research to date has focused on factors surrounding information consumption for utilitarian rather than hedonic purposes. In this paper, we take an initial step to inform theory in this area by applying a NeuroIS lens to explore HIC behavior. We postulate that information is more likely to be hedonically consumed when it is appraised as interesting, and that certain characteristics of the information involved in HIC, namely its novelty and valence, play a role in determining its interestingness. Moreover, we hypothesize that HIC is driven by the neurobiological reactions that take place in response to information novelty and valence. We report the results of a behavioral and an fMRI experiment designed to measure the relationship between these information dimensions and neurocognitive responses in the context of a popular social media platform. Our results provide preliminary evidence for differential processing patterns related to novelty and valence that can inform ongoing theory building surrounding HIC behaviors.

Differences in engineers’ brain activity when CAD modelling from isometric and orthographic projections

A way of presenting information in visual representations of technical systems influences the progress and the outcome of the engineering design process. Consequently, improving the means by and through which information is utilised during the process is one suggested approach to advancing engineering design. Engineers’ interaction with visual representations of technical systems is mainly visual and virtual. Although such interactions are cognitively complex, little is known about cognition (mental information processing) underlying the utilisation of design information during engineering design. To narrow the research gap, this study explores how visual representations of technical systems affect engineers’ brain activity while generating computer-aided design (CAD) models based on them. More precisely, the brain activity of 20 engineers is captured and analysed using electroencephalography (EEG) during the visuospatially-intensive design tasks of CAD modelling in two conditions; when technical systems are presented with orthographic and isometric projections in technical drawings. The results imply the sensitivity of engineers’ brain activity in CAD modelling to the visual representation from which a technical system is interpreted. In particular, significant differences are found in theta, alpha, and beta task-related power (TRP) over the cortex when interpreting the technical drawings and CAD modelling from them. Furthermore, the results reveal significant differences in theta and alpha TRP when considering the individual electrodes, the cortical hemispheres, and the cortical areas. In particular, theta TRP over the right hemisphere and the frontal area seems essential in distinguishing neurocognitive responses to the orthographic and isometric projections. As such, the conducted exploratory study sets the foundations for exploring engineers’ brain activity while performing visuospatially-intensive design tasks, whose segments are relatable to the aspects of visuospatial thinking. Future work will explore brain activity in other design activities that are highly visuospatial, with a larger sample size and an EEG device of a higher spatial resolution.

Effects of Low-Intensity Aerobic Exercise on Neurophysiological and Behavioral Correlates of Cognitive Function.

Acute aerobic exercise exerts a small beneficial effect on cognition. Previous research primarily examines cognitive changes following a bout of exercise, while little is currently known about changes in cognitive performance during exercise. The primary purpose of this study was to examine the effects of low-intensity cycling on cognitive function indexed by behavioral (response accuracy; reaction time) and neurocognitive (P3 mean amplitude; P3 centroid latency) responses. Twenty-seven (Mage = 22.9 ± 3.0 years old) individuals were counterbalanced into low-intensity exercise (EX) and seated control (SC) conditions spread across two testing sessions. During each condition, participants completed a 10 min resting baseline period, 20 min of either sustained cycling or seated rest, and a 20 min recovery period. Primary outcomes were assessed at 10 min intervals (five blocks total) throughout each condition via a modified visual oddball task while electroencephalography (EEG) responses were measured. Across time blocks, both conditions exhibited faster reaction times on frequent trials but reduced accuracy to rare trials, suggesting a speed-accuracy tradeoff. There were no differences between conditions in P3 centroid latency, whereas a significant reduction in P3 amplitude was observed during the 20 min exercise period compared to the control condition. Taken together, results suggest that exercise at lower doses may have minimal influence on behavioral outcomes of cognitive performance but may impact more basic measures of brain function. Information gathered from this study may aid in the development of appropriate exercise prescriptions for populations looking to specifically target cognitive function deficits.

Trait Energy and Fatigue Influence Inter-Individual Mood and Neurocognitive Responses during Work Done While Sitting, Standing, and Intermittent Walking: A Randomized-Controlled Crossover Design

College students can be sedentary for a majority of the day, which may exacerbate mental health issues or lead to declines in cognitive task performance; however, interventions to address sedentary behaviors may not positively influence everyone. Therefore, the present study sought to identify inter-individual cognitive performance and mood changes of college students during the performance of a cognitive task battery, while seated, standing and with intermittent bouts of walking. Participants (n = 31, age = 25.80 ± 3.61 yrs, 7 male) completed a series of baseline questionnaires including the Trait Mental and Physical Energy and Fatigue survey. Using a randomized controlled cross-over design, participants completed 3 separate testing sessions. At each session, they performed a series of three rounds of cognitive tasks for 27 min and self-reporting mood states for 1 min in the seated position. Each round of cognitive testing was followed by a 2 min break. Each testing day had participants spend the 2 min break in a different condition: sitting, standing, or walking. A series of mixed ANOVAs were used for the primary analysis and a combination of machine learning regressors and classifiers were used for the secondary analysis. Our results suggest that there are unique inter-individual responses to each of the interventions used during the 2 min break. Participants who were low-trait mental and low-trait physical energy benefited the most from the standing desk intervention, while also reporting significant benefits of intermittent walking. However, participants who were low-trait mental fatigue had significant negative consequences of using both standing desks and walking intermittently, while those who were high-trait mental fatigue saw no change in cognitive responses or moods in those conditions. Post hoc machine learning analyses had modest accuracy rates (MAEs < 0.7 for regressors and accuracy rates >60% for classifiers), suggesting that trait mental and physical energy and fatigue may predict inter-individual responses to these interventions. Incorporating standing desks into college classroom settings may result in some students receiving cognitive benefits when inter-individual variability in mood and cognitive responses are accounted for.

Exploration of fMRI brain responses to oral sucrose after Roux-en-Y gastric bypass in obese yucatan minipigs in relationship with microbiota and metabolomics profiles

In most cases, Roux-en-Y gastric bypass (RYGBP) is an efficient intervention to lose weight, change eating behavior and improve metabolic outcomes in obese patients. We hypothesized that weight loss induced by RYGBP in obese Yucatan minipigs would induce specific modifications of the gut-brain axis and neurocognitive responses to oral sucrose stimulation in relationship with food intake control. An integrative study was performed after SHAM (n=8) or RYGBP (n=8) surgery to disentangle the physiological, metabolic and neurocognitive mechanisms of RYGBP. BOLD fMRI responses to sucrose stimulations at different concentrations, brain mRNA expression, cecal microbiota, and plasma metabolomics were explored 4 months after surgery and integrated with WGCNA analysis. We showed that weight loss induced by RYGBP or SHAM modulated differently the frontostriatal responses to oral sucrose stimulation, suggesting a different hedonic treatment and inhibitory control related to palatable food after RYGBP. The expression of brain genes involved in the serotoninergic and cannabinoid systems were impacted by RYGBP. Cecal microbiota was deeply modified and many metabolite features were differentially increased in RYGBP. Data integration with WGCNA identified interactions between key drivers of OTUs and metabolites features linked to RYGBP. This longitudinal study in the obese minipig model illustrates with a systemic and integrative analysis the mid-term consequences of RYGBP on brain mRNA expression, cecal microbiota and plasma metabolites. We confirmed the impact of RYGBP on functional brain responses related to food reward, hedonic evaluation and inhibitory control, which are key factors for the success of anti-obesity therapy and weight loss maintenance.

Ensuring the level of creativity in neuromarketing tests between human-made objects and artificial intelligence

In the current era of increasing influence of artificial intelligence on content creation, it is essential to investigate how the origin of the creator influences the neurocognitive responses of consumers in neuromarketing experiments. This theoretical paper aims to delve into the issue of ensuring the same creative level of the objects used in these experiments in order to explore how these objects, created by both humans and artificial intelligence, shape the perception and response of the brain. With an introduction to the increasing complexity of content creation, we emphasize the importance of understanding the impact of creativity on neurocognitive processes and the importance of equal creative level for adequate comparisons in neuromarketing research. In more detail, we define creativity as a multidimensional phenomenon that relates to visual aesthetics and content originality. In the field of neuromarketing and creative testing, exploring how neurocognitive responses differ between human-created and artificial intelligence-created test objects is still a novelty. In the final discussion, we interpret the results in the context of existing research in neuromarketing. We evaluate practical applications of the proposed method and suggest future directions for research on the relationship between creativity, artificial intelligence, and neurocognitive responses of consumers in the field of neuromarketing.

Listen to my feelings! How prosody and accent drive the empathic relevance of complaining speech

Interpersonal communication often involves sharing our feelings with others; complaining, for example, aims to elicit empathy in listeners by vocally expressing a speaker's suffering. Despite the growing neuroscientific interest in the phenomenon of empathy, few have investigated how it is elicited in real time by vocal signals (prosody), and how this might be affected by interpersonal factors, such as a speaker's cultural background (based on their accent). To investigate the neural processes at play when hearing spoken complaints, twenty-six French participants listened to complaining and neutral utterances produced by in-group French and out-group Québécois (i.e., French-Canadian) speakers. Participants rated how hurt the speaker felt while their cerebral activity was monitored with electroencephalography (EEG). Principal Component Analysis of Event-Related Potentials (ERPs) taken at utterance onset showed culture-dependent time courses of emotive prosody processing. The high motivational relevance of ingroup complaints increased the P200 response compared to all other utterance types; in contrast, outgroup complaints selectively elicited an early posterior negativity in the same time window, followed by an increased N400 (due to ongoing effort to derive affective meaning from outgroup voices). Ingroup neutral utterances evoked a late negativity which may reflect re-analysis of emotively less salient, but culturally relevant ingroup speech. Results highlight the time-course of neurocognitive responses that contribute to emotive speech processing for complaints, establishing the critical role of prosody as well as social-relational factors (i.e., cultural identity) on how listeners are likely to “empathize” with a speaker.

The Neural Responses of Visual Complexity in the Oddball Paradigm: An ERP Study

This research measured human neural responses to images of different visual complexity levels using the oddball paradigm to explore the neurocognitive responses of complexity perception in visual processing. In the task, 24 participants (12 females) were required to react to images with high complexity for all stimuli. We hypothesized that high-complexity stimuli would induce early visual and attentional processing effects and may elicit the visual mismatch negativity responses and the emergence of error-related negativity. Our results showed that the amplitude of P1 and N1 were unaffected by complexity in the early visual processing. Under the target stimuli, both N2 and P3b components were reported, suggesting that the N2 component was sensitive to the complexity deviation, and the attentional processing related to complexity may be derived from the occipital zone according to the feature of the P3b component. In addition, compared with the low-complexity stimulus, the high-complexity stimulus aroused a larger amplitude of the visual mismatch negativity. The detected error negativity (Ne) component reflected the error detection of the participants’ mismatch between visual complexity and psychological expectations.

Vocabulary Repetition Following Multisensory Instruction Is Ineffective on L2 Sentence Comprehension: Evidence From the N400.

Putting the principles of multisensory teaching into practice, this study investigated the effect of audio-visual vocabulary repetition on L2 sentence comprehension. Forty participants were randomly assigned to experimental and control groups. A sensory-based model of instruction (i.e., emotioncy) was used to teach a list of unfamiliar vocabularies to the two groups. Following the instruction, the experimental group repeated the instructed words twice, while the control group received no vocabulary repetition. Afterward, their electrophysiological neural activities were recorded through electroencephalography while doing a sentence acceptability judgment task with 216 sentences under acceptable (correct) and unacceptable (pragmatically violated) conditions. A one-way analysis of variance (ANOVA), a multivariate analysis of variance (MANOVA), and a Bayesian repeated-measures ANOVA were used to compare the behavioral and neurocognitive responses [N400 as the main language-related event-related brain potential (ERP) effect] of the two groups. The results showed no significant N400 amplitude difference in favor of any of the groups. The findings corroborated the ineffectiveness of two repetitions preceded by multisensory instruction on L2 sentence comprehension.

Real-time prediction of science student learning outcomes using machine learning classification of hemodynamics during virtual reality and online learning sessions

Current data sources used for the prediction of student outcomes average about 55% accuracy and require a significant amount of input data and time for researchers and educators to produce predictive models of student outcomes. The aim of this study is to examine how neurocognitive data collected via functional near infrared spectroscopy (fNIRS) may be used to create predictive models of student outcomes with greater speed and accuracy when using a synthetic adaptive learning environment (SALEs). Specifically, this study examines the utility of using neurocognitive data to develop student response prediction on a science content test. Participants were recruited from schools located in the United States ( n = 40). Participants in the study engaged in three conditions: no content, video and virtual reality. The lesson video and virtual reality lesson provides an explanation of deoxyribonucleic acid replication. Observed neurocognitive responses were collected during each condition and used to predict the success of student responses on an assessment. On average the predicative accuracy of this approach is 85% and occur within 300 ms. Predictive error rates are less than 15%. Results of this study provides evidence to support the use of neurocognitive data for adaption of digitally presented content and how machine learning approaches and artificial intelligence may be used to classify student data in real-time as students engage with content. Results also illustrate good accuracy and capture of moment-to- moment fluctuations of cognition in real-time. These findings may help the development of artificially intelligent tutors and improve student-based learning analytics. • Classification of neurocognitive data lends itself to prediction of student outcomes. • Describes neurocognitive data sources for development of predictive learning platforms. • Hemodynamic response can help to understand levels of student attention and engagement.

Processing of infant emotion in mothers with mood disorders and implications for infant development.

Atypical neurocognitive responses to emotional stimuli are core features of unipolar depression (UD) and bipolar disorder (BD). For mothers with these mood disorders, this may influence interactions with their infants and consequently infant development. The study aimed to investigate psychophysiological and cognitive responses to infant emotional stimuli, and their relation to mother-infant interaction and infant development, in mothers with BD or UD in full or partial remission. Four months after birth, mothers' cognitive responses to emotional infant stimuli were assessed with computerized tasks, while their facial expressions, galvanic skin responses (GSR), gazes, and fixations were recorded. Infant development and mother-infant interactions were also assessed. We included 76 mothers: 27 with BD, 13 with UD, and 36 without known psychiatric disorders, and their infants. Mothers with BD and UD were in full or partial remission and showed blunted GSR and spent less time looking at infant stimuli (unadjusted p values < 0.03). Mothers with BD showed subtle positive neurocognitive biases (unadjusted p values<0.04) and mothers with UD showed negative biases (unadjusted p values < 0.02). Across all mothers, some measures of atypical infant emotion processing correlated with some measures of delays in infant development and suboptimal mother-infant interaction (unadjusted p values<0.04). Mothers with mood disorders in full or partial remission showed atypical cognitive and psychophysiological response to emotional infant stimuli, which could be associated with mother-infant interactions and infant development. The study is explorative, hypothesis generating, and should be replicated in a larger sample. Investigation of the long-term implications of reduced maternal sensitivity is warranted.

Modulation of Amygdala Response by Cognitive Conflict in Adolescents with Conduct Problems and Varying Levels of CU Traits

Adolescents with conduct problems and low callous-unemotional traits are characterised by high levels of reactive aggression. Prior studies suggest that they can have exaggerated neural and behavioural responses to negative emotional stimuli, accompanied by compromised affect regulation and atypical engagement of prefrontal areas during cognitive control. This pattern may in part explain their symptoms. Clarifying how neurocognitive responses to negative emotional stimuli can be modulated in this group has potential translational relevance. We present fMRI data from a cognitive conflict task in which the requirement to visually scan emotional (vs. calm) faces was held constant across low and high levels of cognitive conflict. Participants were 17 adolescent males with conduct problems and low levels of callous-unemotional traits (CP/LCU); 17 adolescents with conduct problems and high levels of callous-unemotional traits (CP/HCU, who typically show blunted reactivity to fear), and 18 typically developing controls (age range 10–16). Control participants showed typical attenuation of amygdala response to fear relative to calm faces under high (relative to low) conflict, replicating previous findings in a healthy adult sample. In contrast, children with CP/LCU showed a reduced (left amygdala) or reversed (right amygdala) attenuation effect under high cognitive conflict conditions. Children with CP/HCU did not differ from controls. Findings suggest atypical modulation of amygdala response as a function of task demands, and raise the possibility that those with CP/LCU are unable to implement typical regulation of amygdala response when cognitive task demands are high.

Randomized Controlled Trial of an Alcohol-related Sexual Risk Reduction Intervention with Adolescents: The Role of Neurocognitive Activation During Risky Decision-Making

Justice-involved youth are at a higher risk of negative outcomes from sexual activity and alcohol use relative to their non-justice involved peers. In the current study, we tested the extent to which variability in neurocognitive response (i.e., activation in the right superior parietal lobule; rSPL) during a risky decision-making task moderated the success of a sexual risk reduction intervention. In a cluster randomized trial blocked by gender, justice-involved adolescents (N = 269) first completed a risky decision-making task during a magnetic resonance imaging (MRI) session, then were assigned to an information-only control (GINFO) or sexual risk reduction intervention incorporating alcohol risk reduction content (GPI + GMET) and then re-contacted every three months for one year. Youth in the GPI + GMET intervention reported less sexual risk behavior 12months after intervention than those in the control. Although neurocognitive activation was associated with sexual risk behavior, it did not moderate intervention outcomes. This risk-reduction intervention appears to work equally well across a range of neurocognitive responses.

Effects of Chewing Gum on Nitric Oxide Metabolism, Markers of Cardiovascular Health and Neurocognitive Performance after a Nitrate-Rich Meal

Objectives Cardiovascular and neurocognitive responses to chewing gum have been reported, but the mechanisms are not well understood. Chewing gum after a nitrate-rich meal may upregulate the reduction of oral nitrate to nitrite and increase nitric oxide (NO), a molecule important to cardiovascular and neurocognitive health. We aimed to explore effects of chewing gum after a nitrate-rich meal on nitrate metabolism (through the enterosalivary nitrate-nitrite-NO pathway), endothelial function, blood pressure (BP), neurocognitive performance, mood and anxiety. Methods Twenty healthy men (n = 6) and women (n = 14) with a mean age of 48 years (range: 23–69) were recruited to a randomized controlled cross-over trial. After consumption of a nitrate-rich meal (180 mg of nitrate), we assessed the acute effects of chewing gum, compared to no gum chewing, on (i) salivary nitrate, nitrite and the nitrate reductase ratio (100 x [nitrite]/([nitrate] + [nitrite]); (ii) plasma nitrite, S-nitrosothiols and other nitroso species (RXNO); (iii) endothelial function (measured by flow mediated dilatation); (iv) BP; (v) neurocognitive performance; (vi) mood; and (vii) anxiety. Results Consumption of the nitrate-rich meal resulted in a significant increase in markers of nitrate metabolism. A significantly higher peak flow mediated dilatation was observed with chewing compared to no chewing (baseline adjusted mean difference: 1.10%, 95% CI: 0.06, 2.14; p = 0.038) after the nitrate-rich meal. A significant small increase in systolic BP, diastolic BP and heart rate were observed with chewing compared to no chewing after the nitrate-rich meal. The study did not observe increased oral reduction of nitrate to nitrite and NO, or improvements in neurocognitive performance, mood or anxiety with chewing compared to no chewing. Conclusion Chewing gum after a nitrate-rich meal resulted in an acute improvement in endothelial function and a small increase in BP but did not result in acute effects on neurocognitive function, mood or anxiety.

Neurocognitive processing of infant stimuli in mothers and non-mothers: psychophysiological, cognitive and neuroimaging evidence.

Emerging evidence indicates that mothers and non-mothers show different neurocognitive responses to infant stimuli. This study investigated mothers’ psychophysiological, cognitive and neuronal responses to emotional infant stimuli. A total of 35 mothers with 4-month-old infants and 18 control women without young children underwent computerized tests assessing neurocognitive processing of infant stimuli. Their eye gazes and eye fixations, galvanic skin responses (GSRs) and facial expressions towards infant emotional stimuli were recorded during the tasks. Participants underwent functional magnetic resonance imaging during which they viewed pictures of an unknown infant and, for mothers, their own infants. Mothers gazed more and had increased GSR towards infant stimuli and displayed more positive facial expressions to infant laughter, and self-reported more positive ratings of infant vocalizations than control women. At a neural level, mothers showed greater neural response in insula, dorsolateral prefrontal cortex and occipital brain regions within a predefined ‘maternal neural network’ while watching images of their own vs unknown infants. This specific neural response to own infants correlated with less negative ratings of own vs unknown infants’ signals of distress. Differences between mothers and control women without young children could be interpreted as neurocognitive adaptation to motherhood in the mothers.

Two-year neurocognitive responses to first occupational lead exposure.

Objectives:Lead exposure causes neurocognitive dysfunction in children, but its association with neurocognition in adults at current occupational exposure levels is uncertain mainly due to the lack of longitudinal studies. In the Study for Promotion of Health in Recycling Lead (NCT02243904), we assessed the two-year responses of neurocognitive function among workers without previous known occupational exposure newly hired at lead recycling plants.Methods:Workers completed the digit-symbol test (DST) and Stroop test (ST) at baseline and annual follow-up visits. Blood lead (BL) was measured by inductively coupled plasma mass spectrometry (detection limit 0.5 µg/dL). Statistical methods included multivariable-adjusted mixed models with participants modelled as random effect.Results:DST was administered to 260 participants (11.9% women; 46.9%/45.0% whites/Hispanics; mean age 29.4 years) and ST to 168 participants. Geometric means were 3.97 and 4.13 µg/dL for baseline BL, and 3.30 and 3.44 for the last-follow-up-to-baseline BL ratio in DST and ST cohorts, respectively. In partially adjusted models, a doubling of the BL ratio was associated with a 0.66% [95% confidence interval (CI) 0.03–1.30%; P=0.040] increase in latency time (DST) and a 0.35% (95% CI -1.63–1.63%; P=0.59) decrease in the inference effect (ST). In fully adjusted models, none of the associations of the changes in the DST and ST test results with the blood lead changes reached statistical significance (P≥0.12).Conclusions:An over 3-fold increase in blood lead over two years of occupational exposure was not associated with a relevant decline in cognitive performance.

Stevia Beverage Consumption prior to Lunch Reduces Appetite and Total Energy Intake without Affecting Glycemia or Attentional Bias to Food Cues: A Double-Blind Randomized Controlled Trial in Healthy Adults

Stevia is a zero-calorie alternative to caloric sugars. Substituting caloric sweeteners with noncaloric sweeteners reduces available energy, but their effects on appetite, subsequent food intake, and neurocognitive responses are still unclear. The aim was to examine whether sweetness with or without calories influences food intake, appetite, blood glucose concentrations, and attentional bias (AB) to food cues. This was a randomized, controlled, double-blind crossover study. Healthy participants [n=20; aged 27±5y, 55% female; BMI (kg/m2): 21.8±1.5]completed 5 visits, consuming 5 study beverages: 330 mLwater (control, no sweet taste, no calories) and either 330 mLwater containing 40g glucose or sucrose (sweet taste; calories, both 160kcal), maltodextrin (no sweet taste; calories, 160kcal), or 240ppm stevia (sweet taste, no calories). Glucose and stevia beverages were matched for sweetness. Subjective appetite ratings and blood glucose were measured at baseline and at 15, 30, and 60min postprandially. At 15min participants performed a visual-dot probe task to assess AB to food cues; at 30min, participants were offered an ad libitum lunch; food intake was measured. Subjective appetite ratings showed that preload sweetness and calorie content both affected appetite. The total AUC for glycemia was significantly higher after the caloric beverages (mean±SD: maltodextrin, 441±57.6; glucose, 462±68.1; sucrose, 425±53.6mmol × min × L-1 ) compared with both stevia (320±34.2 mmol × min × L-1)and water (304±32.0 mmol × min × L-1)(all P<0.001). Total energy intake (beverage and meal) was significantly lower after the stevia beverage (727±239kcal)compared with water (832±198 kcal, P=0.013), with no significant difference between the water and caloric beverages (P=1.00 for water vs. maltodextrin, glucose, and sucrose). However, food-related AB did not differ across conditions (P=0.140). This study found a beneficial and specific effect of a stevia beverage consumed prior to a meal on appetite and energy intake in healthy adults. This trial is registered at clinicaltrials.gov as NCT03711084.

Development of a Polymer-Based MEG-Compatible Vibrotactile Stimulator for Studying Neuromagnetic Somatosensory Responses

Vibrotactile technology has been gaining increasing interest for effective human-computer communication in various applications. In addition to psychophysical approaches commonly used to study tactile vibrations, neurocognitive responses to vibrotactile stimuli can provide new insights into mechanisms underlying human vibrotactile perception. In this study, we developed a magnetoencephalography (MEG)-compatible vibrotactile stimulation device based on a polyvinyl chloride (PVC) gel actuator to study neuromagnetic somatosensory responses. A symmetric, double-layered PVC gel structure was applied to minimize the magnetic noise from the actuator. The device was used to generate sinusoidal stimuli at high frequencies to activate mechanoreceptors responsible for high-frequency vibrations greater than 50 Hz, and this device showed very little variability in stimulation onset time from the displacement measurements. We successfully observed vibrotactile-evoked magnetic fields by analyzing whole-head MEG data recorded during the high-frequency vibrotactile stimulation of the fingertips. Prominent peak responses were observed at approximately 56 ms (M50) in the contralateral hemisphere and at approximately 100 ms (M100) in both hemispheres. We identified the activation of contralateral primary somatosensory areas as a source of the vibrotactile M50 response. These results demonstrate the feasibility of using our new device to study vibrotactile perception with neuromagnetic imaging methods.