N400 Component Of Event-related Potential Research Articles

Specificity of visual event-related potentials to subthreshold presentation of erotic pictures in pedophilia

To study visual event-related potentials (ERPs) associated with presentation of erotic pictures in backward masking condition in order to investigate perception, attention and information processing underlying the initiation and maintenance of abnormal sexual behavior in pedophilia. Participants (58 males committed sexual offenses against children) were divided into the pedophilia group (n=38) and the control group without disorders of sexual preference (n=20). Three types of stimuli were used: neutral pictures of nature (S1), adult heterosexual erotic pictures (S2) and erotic pictures with children (S3). Posterior N1 (N140) and anterior N1 (N120) and P3 (P320) ERP components were included in analysis. In both groups, the perception of erotic stimuli was accompanied by a significant increase in the amplitude and prolongation of the latency of the N140 and P320 components (p<0.001). N140 changes were characterized by right-hemispheric bias in both groups, however, asymmetry was observed for amplitude in the control group, and for latency - in the pedophilia group; besides, reactivity to S3 stimuli was weaker than to S2 ones in the pedophilia group. N120 amplitude was elevated significantly in response to S2 stimuli in the control group, and no changes were found in the pedophilia group. Between-group differences were revealed for early negative components N140 and N120, which parameters were entered as predictors into classification model based on discriminant analysis. The obtained accuracy of model was 87.23%. The specificity of neurophysiological reactions to erotic pictures in pedophilic patients corroborates the concept of disease as general neurodevelopmental disorder.

ERP indicators of situational empathy pain

This study aimed to validate a recent conceptualization proposed by Coll and colleagues (2017a) that defines empathic response as a situational, cognitively complex process requiring emotion identification and affective sharing. Sixty right-handed women university students (18–29 years) voluntarily participated in the study. We measured ratings for empathy pain to assess the individual differences in empathy. At the same time, we collected peak amplitudes of the event-related potentials (ERPs) components to empathic stimulations of painful faces or hand stimuli and neutral images. Electrophysiological results proved that the P2, N170, N2, and P3 ERP components were associated with the modulation of empathic responses. Participants with low empathic responses (p < 0.05) disclosed a larger frontal central N2 for the painful hands than for painful faces (p < .05) and a reduced temporoparietal N170 for painful hands compared to neutral ones. Furthermore, our results highlighted higher frontal central P3a and P3b to painful stimuli than controls (p ≤ 0.01). We explained these findings assuming that in identifying the emotional value of a stimulus, the emotional content can modulate the reorientation of attention and the in-memory updating process associated with the empathic response. Results are in line with Coll and colleagues' conceptualization of the empathic response that includes two cognitive processes, the identification of emotions, and affective sharing, related to the recognition of the emotional state of the other in the self.

Aging-Related Dissociation of Spatial and Temporal N400 in Sentence-Level Semantic Processing: Evidence From Source Analyses.

Age-related differences in sentence-level lexical-semantic processes have been extensively studied, based on the N400 component of event-related potential (ERP). However, there is still a lack of understanding in this regard at the brain-region level. This study explores aging effects on sentence-level semantic processing by comparing the characteristics of the N400 ERP component and brain engagement patterns within individual N400 time windows for two age groups (16 younger adults aged 24.38 ± 3.88 years and 15 older adults aged 67.00 ± 5.04 years) during sentence processing with different plausibility conditions. Our results demonstrated that the N400 effect according to the plausibility condition occurred in different temporal windows in the two age groups, with a delay in the older group. Moreover, it was identified that there was a distinct difference between the groups in terms of the source location of the condition-dependent N400 effect even though no significant difference was derived in its magnitude itself at the sensor-level. Interestingly, the source analysis results indicated that the two groups involved different functional networks to resolve the same semantic violations: the younger group activated the regions corresponding to the typical lexical-semantic network more, whereas the older group recruited the regions belonging to the multiple-demand network more. The findings of this study could be used as a basis for understanding the aging brain in a linguistic context.

Spatial selectivity of the visual duration aftereffect in the sub-second range: An event-related potentials study

Prolonged adaptation to one duration biases the perception of subsequent durations in a phenomenon known as duration adaptation. There is controversy regarding the neural substrates of the visual duration aftereffect: some researchers have argued that duration adaptation occurs in early visual cortical areas, whereas others have argued for high-level visual areas. Investigation of spatial selectivity of the duration aftereffect could help reveal the neural mechanisms underlying duration adaptation. In the present study, we used event-related potentials (ERPs) to demonstrate spatial selectivity of the visual duration aftereffect in the sub-second range. We measured the duration aftereffect at a 20° adapt-test distance that spanned 10° on either side of fixation. Our results revealed that duration adaptation first affected the N1 ERP component and then influenced the contingent negative variation (CNV) component. Moreover, the CNV component showed position effects in the temporal encoding stage, and the post-stimulus positive component was subject to a duration effect but not a position effect. These findings indicate that sub-second duration coding is closely linked to the early processing of the visual cortex. Moreover, the adaptation not only affects the earlier temporal coding stage, but also the later temporal processing stage.

Identifying Age Based Maturation in the ERP Response to Faces in Children With Autism: Implications for Developing Biomarkers for Use in Clinical Trials.

Recent proposals have suggested the potential for neural biomarkers to improve clinical trial processes in neurodevelopmental conditions; however, few efforts have identified whether chronological age-based adjustments will be necessary (as used in standardized behavioral assessments). Event-related potentials (ERPs) demonstrate early differences in the processing of faces vs. objects in the visual processing system by 4 years of age and age-based improvement (decreases in latency) through adolescence. Additionally, face processing has been proposed to be related to social skills as well as autistic social-communication traits. While previous reports suggest delayed latency in individuals with autism spectrum disorder (ASD), extensive individual and age based heterogeneity exists. In this report, we utilize a sample of 252 children with ASD and 118 children with typical development (TD), to assess the N170 and P100 ERP component latencies (N170L and P100L, respectively), to upright faces, the face specificity effect (difference between face and object processing), and the inversion effect (difference between face upright and inverted processing) in relation to age. First, linear mixed models (LMMs) were fitted with fixed effect of age at testing and random effect of participant, using all available data points to characterize general age-based development in the TD and ASD groups. Second, LMM models using only the TD group were used to calculate age-based residuals in both groups. The purpose of residualization was to assess how much variation in ASD participants could be accounted for by chronological age-related changes. Our data demonstrate that the N170L and P100L responses to upright faces appeared to follow a roughly linear relationship with age. In the ASD group, the distribution of the age-adjusted residual values suggest that ASD participants were more likely to demonstrate slower latencies than would be expected for a TD child of the same age, similar to what has been identified using unadjusted values. Lastly, using age-adjusted values for stratification, we found that children who demonstrated slowed age-adjusted N170L had lower verbal and non-verbal IQ and worse face memory. These data suggest that age must be considered in assessing the N170L and P100L response to upright faces as well, and these adjusted values may be used to stratify children within the autism spectrum.

Event-Related Potentials to Speech Relate to Speech Sound Production and Language in Young Children

ABSTRACT This research was funded through the American Speech and Hearing Foundation’s 2012 StudentResearch Grant in Early Childhood Language Development awarded to Vanessa Harwood as well as an anonymous generous donation to Haskins Laboratories. Electrophysiological measures of language within early childhood provide important information about neurolinguistic development. We investigated associations between amplitude and latency of the P1 and N2 event-related potential components in response to spoken pseudowords, and clinical measures of language performance within a sample of 58 typically developing children between 24 and 48 months. N2 amplitude differences between repeated and new tokens were correlated with measures of expressive and receptive language and speech sound production. Phonemic sensitivity measured by the N2 component may reflect the integrity of neural networks that are important for speech perception and production in young children.

Neural mechanisms of inhibitory control deficits in obesity revealed by P3 but not N2 event-related potential component

The lack of inhibitory control toward foods may cause unhealthy eating behavior and lead to obesity. However, previous research failed to reach consensus on the alterations in event-related potential (ERP) markers of inhibitory control, i.e., N2 and P3. We hypothesized that the ERP effects of inhibitory control reported in previous food-based Go/NoGo studies might be obscured by non-inhibitory processes associated with stimulus probability. We designed two food-based Go/NoGo tasks composed of stimuli with the same type and frequency of occurrence (60% non-foods, 20% high-calorie foods, 20% low-calorie foods), one with response inhibition toward high- and the other toward low-calorie foods. Such an experimental design allowed us to isolate neural activity associated with inhibitory control from that associated with non-inhibitory processes by constructing ERP difference waves between NoGo and Go trials with the same frequency of occurrence. Electroencephalography data were collected from 32 obese participants and 29 normal-weight controls. Obese participants showed significantly lower accuracy in NoGo trials than normal-weight controls in both tasks. ERP data suggested inhibition-related effects for P3 (P3d) but not N2 in the difference waves, and obese participants showed significantly decreased P3d amplitudes than normal-weight controls in both tasks. In addition, we found that across both groups, individuals with larger waist-to-hip ratios showed smaller P3d amplitudes in both tasks, while such correlations between body mass index and P3d amplitude were only observed in the high-calorie task. Our findings suggest that the decreased effect of P3, not N2, might reflect the neural substrate of inhibitory control deficits in obese people. Thus, P3 could serve as an important neural marker in the future development of new therapeutic strategy that aims to improve inhibitory control in obesity.

The impact of aging on interhemispheric transfer time and respective sex differences.

Age-related cognitive decline has been attributed to degeneration of the corpus callosum (CC), which allows for interhemispheric integration and information processing [22,69]. Along with decreased structural integrity, altered functional properties of the CC may cause impaired cognitive performance in older adults, yet this aspect of age-related decline remains insufficiently researched [59]. In this context, potential sex-related differences have been proposed [31,58]. A promising parameter, which has been suggested to estimate functional properties of the CC is the interhemispheric transfer time (IHTT), which is ideally obtained from event-related potentials (ERP) evoked by lateralized stimuli [45]. To examine the possible functional consequences of aging with regards to the CC, the present study investigated the IHTT of 107 older (67.69 ± 5.18y) as well as of 23 younger participants (25.09 ± 2.59y). IHTT was obtained using an established letter matching task and targeting early N170 ERP components at posterior electrode sites. The results revealed significantly elongated IHTT in older compared to younger participants, but no significant sex differences. Furthermore, there was a significant positive correlation between IHTT and age, predominantly driven by the female participants. The present findings add support to the notion, that IHTT is subject to age-related elongation reflecting impaired interhemispheric transmission. Age-related decline in women appears to occur at a different age range compared to men.

Changes of attention-related brain activity over 6 months after acute organophosphate pesticide poisoning: a prospective follow-up study

Context Ingestion of organophosphate (OP) pesticides is a common method of self-harm in developing countries. Apart from acute cholinergic effects, limited evidence implicates OP poisoning in long-term neurocognitive deficits. However, prospective neurophysiological evidence of long-term deficits is scarce in humans. We aimed to determine long-term cognitive changes of acute OP pesticide self-poisoning in a prospective follow-up study, using event-related potentials (ERPs), an electroencephalographic index of cognitive functioning. Methods We recruited 203 patients (147 men) hospitalised with OP pesticide ingestion (OP group; all had significant erythrocyte cholinesterase inhibition) and 50 patients (23 men) with paracetamol overdose (control group) as a means of self-harm. We recorded their ERPs and behavioural performance in a selective attention task at three post-exposure time points: on discharge from hospital (around 14 days post-ingestion), 6 weeks and 6 months post-ingestion. We compared the reaction time and ERP components of the two groups at each time point, adjusting for sex, age, education and comorbid depression in multiple regression models. Results OP group had significantly slower reaction times than the control group on discharge and at 6 weeks, but not at 6 months. On discharge, the OP group also showed significantly prolonged latency of the parietal P3b component, signifying delayed attentional processing. P3b amplitudes were also significantly smaller in the OP group on discharge and at 6 months. Within the OP group, greater clinical severity of poisoning was associated with smaller P3b amplitudes. Early pre-attentive cortical processing (as indexed by N1 ERP component) showed no significant intergroup differences. Conclusions Acute OP pesticide poisoning was associated with impaired behavioural and neurophysiological indices of selective attention. These deficits outlast the cholinergic phase of intoxication. The neurobehavioral impairment disappears over months, but neurophysiological deficits seem to last even after 6 months. This impairment could potentially compromise the performance and safety of patients for months following clinical recovery.

Nx4 Reduced Susceptibility to Distraction in an Attention Modulation Task.

Background: Stress adversely affects the attentional focus, the active concentration on stimuli, and increases susceptibility to distraction. To experimentally explore the susceptibility to distraction, the Attention Modulation by Salience Task (AMST) is a validated paradigm measuring reaction times (RT) for processing auditory information while presenting task-irrelevant visual distractors of high or low salience. We extended the AMST by an emotional dimension of distractors and an EEG-based evaluation. We then investigated the effect of the stress-relieving medication Neurexan (Nx4) on the participants' susceptibility to distraction.Methods: Data from a randomized, placebo-controlled, crossover trial (NEURIM study; ClinicalTrials.gov: NCT02602275) were exploratively reanalyzed post-hoc. In this trial, 39 participants received a single dose of placebo or Nx4 immediately before the AMST. Participants had to discriminate two different tone modulations (ascending or descending) while simultaneously perceiving task-irrelevant pictures of different salience (high or low) or valence (negative or positive) as distractors. Using EEG recordings, RT and the event-related potential (ERP) components N1, N2, and N3 were analyzed as markers for susceptibility to distraction.Results: In the placebo condition, we could replicate the previously reported task effects of salient distractors with longer RT for high salient distractors on the behavioral level. On the electrophysiological level, we observed significantly increased amplitudes of the N2 and N3 ERP components for positive emotional pictures. In terms of drug effect, we found evidence that Nx4 reduced distractibility by emotional distractors. The effect was shown by significantly reduced amplitudes of N2 and N3 ERP components and reduced RT for the positive valence domain under Nx4 compared to placebo. The Nx4 effects on RT and ERP components also showed a significant correlation.Conclusion: Emotional distractors in addition to the previously used salience distractors and the EEG based evaluation of ERPs valuably complement the AMST. Salient distractors were affecting attentional processes earlier, while valent distractors show modulatory effects later. Our results suggest that Nx4 has beneficial effects on attention by inhibiting the effect of task-irrelevant information and reducing susceptibility to emotionally distracting stimuli. The observation of a beneficial impact of Nx4 on attention regulation is supportive of Nx4's claim as a stress-relieving medication.

Reward magnitude enhances early attentional processing of auditory stimuli.

Reward associations are known to shape the brain's processing of visual stimuli, but relatively less is known about how reward associations impact the processing of auditory stimuli. We leveraged the high-temporal resolution of electroencephalography (EEG) and event-related potentials (ERPs) to investigate the influence of low- and high-magnitude stimulus-reward associations in an auditory oddball task. We associated fast, correct detection of certain auditory target stimuli with larger monetary rewards, and other auditory targets with smaller rewards. We found enhanced attentional processing of the more highly rewarded target stimuli, as evidenced by faster behavioral detection of those stimuli compared with lower-rewarded stimuli. Neurally, higher-reward associations enhanced the early sensory processing of auditory targets. Targets associated with higher-magnitude rewards had higher amplitude N1 and mismatch negativity (MMN) ERP components than targets associated with lower-magnitude rewards. Reward did not impact the latency of these early components. Higher-reward magnitude also decreased the latency and increased the amplitude of the longer-latency P3 component, suggesting that reward also can enhance the final processing stages of auditory target stimuli. These results provide insight into how the sensory and attentional neural processing of auditory stimuli is modulated by stimulus-reward associations and the magnitude of those associations, with higher-magnitude reward associations yielding enhanced auditory processingat both early and late stages compared with lower-magnitude reward associations.

Event-Related Potentials Elicited by Phonetic Errors Differentiate Children With Speech Sound Disorder and Typically Developing Peers.

A growing body of research suggests that a deficit in speech perception abilities contributes to the development of speech sound disorder (SSD). However, little work has been done to characterize the neurophysiological processes indexing speech perception deficits in this population. The primary aim of this study was to compare the neural activity underlying speech perception in young children with SSD and with typical development (TD). Twenty-eight children ages 4;1-6;0 (years;months) participated in this study. Event-related potentials (ERPs) were recorded while children completed a speech perception task that included phonetic (speech sound) and lexical (meaning) matches and mismatches. Groups were compared on their judgment accuracy for matches and mismatches as well as the mean amplitude of the phonological mapping negativity (PMN) and N400 ERP components. Children with SSD demonstrated lower judgment accuracy across the phonetic and lexical conditions compared to peers with TD. The ERPs elicited by lexical matches and mismatches did not distinguish the groups. However, in the phonetic condition, the SSD group exhibited a more consistent left-lateralized PMN effect and a delayed N400 effect over frontal sites compared to the TD group. These findings provide some of the first evidence of a delay in the neurophysiological processing of phonological information for young children with SSD compared to their peers with TD. This delay was not present for the processing of lexical information, indicating a unique difference between children with SSD and with TD related to speech perception of phonetic errors. Supplemental Material https://doi.org/10.23641/asha.16915579.

Semantic feedback processing mechanism of the enactment effect: Evidence from event-related potentials.

The enactment effect refers to a phenomenon in which the memory performance for action phrases is enhanced by performing the described action (e.g., sharpen a pencil) compared with simply reading the action phrase. This produced effect can result in improved motor processing. This study investigated the contribution of semantic integration to the enactment effect by contrasting well-integrated phrases, such as "blow up the balloon," with poorly integrated phrases, such as "sew the toothpick," and analysing the N400 component of event-related potentials (ERPs). The subjects encoded action phrases with different degrees of semantic integration by either pretending to perform or reading action phrases. They then completed a phrase recognition test, while electroencephalographic signals were simultaneously recorded. The behavioural results showed that semantic integration improved memory performance under the motor encoding condition but not under the verbal encoding condition. The ERP results revealed that, regardless of whether it was an old (memorised) or new (distractor) phrase, a larger N400 component was elicited under the motor encoding condition than under the verbal encoding condition. In the motor encoding condition, poorly integrated phrases elicited a larger N400 component than well-integrated phrases; in the verbal encoding condition, this effect was not observed. The N400 effect associated with semantic processing was enhanced by semantic integration under the motor encoding condition rather than the verbal encoding condition. These results supported a deep semantic processing mechanism under the motor encoding condition, and a semantic feedback processing mechanism for the enactment effect was partially supported.

N2 event-related potential component is associated with cardiac autonomic tone regulation during mental fatigue

Mental fatigue alters cognitive performance and autonomic regulation. The neurovisceral model proposes that forebrain structures associated to cognitive control abilities influences heart rate variability. Parasympathetic mediated heart rate variability indices reduction during mental fatigue experience is well-described in previous studies, but the contribution of heart-brain axis to cardiac autonomic adaptation remains unknown. This study investigates the association between root mean square of successive differences between RR intervals (rMSSD) and N2 event-related potential component during visual prolonged odd/ball task (≅ 60min.). The comparison between task blocks shows that rMSSD (p = 0.004) and N2 (p = 0.04) decreased with time on task. Pearson correlation shows that ΔrMSSD is associated with ΔN2 (p = 0.007). Our results support the neurovisceral integration model showing that cognitive control contributes to cardiac autonomic tone adaptation during mental fatigue experience.

Efficacy of a Single-Task ERP Measure to Evaluate Cognitive Workload During a Novel Exergame.

This study aimed to validate the efficacy of single-task event-related potential (ERP) measures of cognitive workload to be implemented in exergame-based rehabilitation. Twenty-four healthy participants took part in a novel gamified balance task where task-irrelevant auditory tones were presented in the background to generate ERPs in the participants’ electroencephalogram (EEG) as a measure of cognitive workload. For the balance task, a computer-based tilt-ball game was combined with a balance board. Participants played the game by shifting their weight to tilt the balance board, which moved a virtual ball to score goals. The game was manipulated by adjusting the size of the goalposts to set three predefined levels of game difficulty (easy, medium, and hard). The participant’s experience of game difficulty was evaluated based on the number of goals scored and their subjective reporting of perceived difficulty. Participants experienced a significant difference in the three levels of task difficulty based on the number of goals scored and perceived difficulty (p < 0.001). Post hoc analysis revealed the lowest performance for the hardest level. The mean amplitude of the N1 ERP component was used to measure the cognitive workload associated with the three difficulty levels. The N1 component’s amplitude decreased significantly (p < 0.001), with an increase in the task difficulty. Moreover, the amplitude of the N1 component for the hard level was significantly smaller compared to medium (p = 0.0003) and easy (p < 0.001) levels. These results support the efficacy of the N1 ERP component to measure cognitive workload in dynamic and real-life scenarios such as exergames and other rehabilitation exercises.

Charged With a Crime: The Neuronal Signature of Processing Negatively Evaluated Faces Under Different Attentional Conditions

Our brains rapidly respond to human faces and can differentiate between many identities, retrieving rich semantic emotional-knowledge information. Studies provide a mixed picture of how such information affects event-related potentials (ERPs). We systematically examined the effect of feature-based attention on ERP modulations to briefly presented faces of individuals associated with a crime. The tasks required participants (N = 40 adults) to discriminate the orientation of lines overlaid onto the face, the age of the face, or emotional information associated with the face. Negative faces amplified the N170 ERP component during all tasks, whereas the early posterior negativity (EPN) and late positive potential (LPP) components were increased only when the emotional information was attended to. These findings suggest that during early configural analyses (N170), evaluative information potentiates face processing regardless of feature-based attention. During intermediate, only partially resource-dependent, processing stages (EPN) and late stages of elaborate stimulus processing (LPP), attention to the acquired emotional information is necessary for amplified processing of negatively evaluated faces.

EEG signatures of cognitive and social development of preschool children-a systematic review.

BackgroundEarly identification of preschool children who are at risk of faltering in their development is essential to ensuring that all children attain their full potential. Electroencephalography (EEG) has been used to measure neural correlates of cognitive and social development in children for decades. Effective portable and low-cost EEG devices increase the potential of its use to assess neurodevelopment in children at scale and particularly in low-resource settings. We conducted a systematic review aimed to synthesise EEG measures of cognitive and social development in 2-5-year old children. Our secondary aim was to identify how these measures differ across a) the course of development within this age range, b) gender and c) socioeconomic status (SES).Methods and findingsA systematic literature search identified 51 studies for inclusion in this review. Data relevant to the primary and secondary aims was extracted from these studies and an assessment for risk of bias was done, which highlighted the need for harmonisation of EEG data collection and analysis methods across research groups and more detailed reporting of participant characteristics. Studies reported on the domains of executive function (n = 22 papers), selective auditory attention (n = 9), learning and memory (n = 5), processing of faces (n = 7) and emotional stimuli (n = 8). For papers investigating executive function and selective auditory attention, the most commonly reported measures were alpha power and the amplitude and latency of positive (P1, P2, P3) and negative (N1, N2) deflections of event related potential (ERPs) components. The N170 and P1 ERP components were the most commonly reported neural responses to face and emotional faces stimuli. A mid-latency negative component and positive slow wave were used to index learning and memory, and late positive potential in response to emotional non-face stimuli. While almost half the studies described changes in EEG measures across age, only eight studies disaggregated results based on gender, and six included children from low income households to assess the impact of SES on neurodevelopment. No studies were conducted in low- and middle-income countries.ConclusionThis review has identified power across the EEG spectrum and ERP components to be the measures most commonly reported in studies in which preschool children engage in tasks indexing cognitive and social development. It has also highlighted the need for additional research into their changes across age and based on gender and SES.

Differences in event-related potential (ERP) responses to small tie, non-tie and 1-problems in addition and multiplication

Using ERP, we investigated the cause of the tie advantage according to which problems with repeated operands are solved faster and more accurately than non-tie problems. We found no differences in early or N400 ERP components between problems, suggesting that tie problems are not encoded faster or suffer from less interference than non-tie problems. However, a lesser negative amplitude of the N2 component was found for tie than non-tie problems. This suggests more working-memory and attentional resource requirements for non-tie problems and therefore more frequent use of retrieval for tie than non-tie problems. The possible peculiarity of problems involving a 1 was also investigated. We showed less negative N2 amplitudes for these problems than for other non-tie problems, suggesting less working-memory resources for 1-problems than other non-tie problems. This could be explained either by higher reliance on memory retrieval for 1-problems than non-1 problems or by the application of non-arithmetical rules for 1-problems.

Altering sensorimotor simulation impacts early stages of facial expression processing depending on individual differences in alexithymic traits

Simulation models of facial expressions suggest that posterior visual areas and brain areas underpinning sensorimotor simulations might interact to improve facial expression processing. According to these models, facial mimicry, a manifestation of sensorimotor simulation, may contribute to the visual processing of facial expressions by influencing early stages. The aim of this study was to assess whether and how sensorimotor simulation influences early stages of face processing, also investigating its relationship with alexithymic traits given that previous studies have suggested that individuals with high levels of alexithymic traits (vs. individuals with low levels of alexithymic traits) tend to use sensorimotor simulation to a lesser extent. We monitored P1 and N170 ERP components of the event-related potentials (ERP) in participants performing a fine discrimination task of facial expressions and animals, as a control condition. In half of the experiment, participants could freely use their facial mimicry whereas in the other half they had their facial mimicry blocked by a gel. Our results revealed that only individuals with lower compared to high alexithymic traits showed a larger modulation of the P1 amplitude as a function of the mimicry manipulation selectively for facial expressions (but not for animals), while we did not observe any modulation of the N170. Given the null results at the behavioural level, we interpreted the P1 modulation as compensative visual processing in individuals with low levels of alexithymia under conditions of interference on the sensorimotor processing, providing a preliminary evidence in favor of sensorimotor simulation models.

Dietary lutein plus zeaxanthin and choline intake is interactively associated with cognitive flexibility in middle-adulthood in adults with overweight and obesity

ABSTRACT Background The xanthophyll carotenoids lutein+zeaxanthin and the dietary component choline have been linked to benefits in cognition. However, knowledge on the interactive influence of these dietary components on cognitive function is sparse. Design 80 middle-aged adults with overweight and obesity (Body Mass Index: (BMI) ≥25.0 kg/m²), completed 7-day diet records, venous blood draws, heterochromatic flicker photometry, assessment of intelligence quotient (IQ), and a cognitive flexibility task while undergoing electroencephalographic recording for event-related potential (ERP) extraction. Multiplicative interaction terms and hierarchical linear regressions, controlling for age, BMI, sex, annual household income, and IQ were utilized to assess independent and interactive contributions of dietary and biomarker data on Switch task outcomes. Results Higher intake of lutein+zeaxanthin and choline was associated interactively, but not independently, with faster reaction time (RT), after controlling for pertinent covariates. Dietary intake of lutein+zeaxanthin and choline was associated with serum lutein concentrations, but not with plasma choline metabolites nor macular pigmentation. Plasma phosphatidylcholine (PC) concentrations were associated with higher accuracy in Switch trials, while no other biomarkers were associated with cognitive outcomes. Dietary intake and biomarker data were not related to the N2 nor P3 ERP component. Conclusions Among a sample of adults with overweight and obesity, greater intake of choline and lutein+zeaxanthin was associated with faster performance on a cognitive flexibility task. Future work examining methods of increasing consumption of both of these dietary components as a possible means of improving or maintaining cognitive flexibility among adults with overweight and obesity is therefore warranted.