Gender effects on auditory P300: A systematic review

Association of GAD1 gene polymorphism rs3749034 with the information processing and cognitive event-related potentials in schizophrenia patients and healthy subjects

OBJECTIVE

Glutamic acid decarboxylase, an enzyme in GABA biosynthesis, is encoded by the GAD1 gene, the transcriptional activity of which is affected by the rs3749034 polymorphism. The aim was to investigate the effects of rs3749034 on cognitive event-related potentials (P300) in healthy subjects and schizophrenic patients.

METHODS

Determination of rs3749034 polymorphism was performed in 89 healthy volunteers and 109 schizophrenic patients (males). Two-stimulus oddball task performance and P300 auditory evoked potentials were analyzed and patient symptomatology was assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

An increased frequency of C allele carriers was disclosed in patients. In controls, superior task performance was observed in cytosine-thymine carriers, while a greater P300 amplitude and shorter latency were found in C/C carriers. Analogous effects were found in patients with a disease onset before 25 years of age. Higher N5 and lower P3 and G5 PANSS scales were revealed in C/C homozygotes.

CONCLUSIONS

The findings substantiate an involvement of GABA-ergic mechanisms in maintaining an optimal excitatory-inhibitory balance and an association of rs3749034 with early-onset disorder and negative symptoms of schizophrenia.

SIGNIFICANCE

These results are important for understanding underlying mechanisms and the development of evidence-based methods for assessing the risk of schizophrenia.

Relationship between event-related potentials and cognitive dysfunction in multiple sclerosis: A systematic review

OBJECTIVE

This systematic review aimed to evaluate if event-related potentials (ERPs) can be a relevant tool for cognitive dysfunction diagnosis in Multiple Sclerosis (MS).

METHODS

Four databases were consulted (PubMed, Embase, Scielo, and Web of Science). The included studies should include adults with clear MS diagnoses, independently of having cognitive complaints, and all should have been submitted to ERPs (P300, N400 or mismatch negativity (MMN)). The main outcomes evaluated were ERPs' amplitude and/or latency.

RESULTS

425 studies were obtained initially from all databases, with 26 studies fulfilling the eligibility criteria. P300 was the most used ERP (25 studies), showing a reduced amplitude or an increased latency in 84% of those. N400 was evaluated in one study, showing also abnormal results. MMN was addressed in two studies with inconsistent findings. Some studies further suggest that ERPs may show earlier abnormal results compared with neuropsychological tests.

CONCLUSIONS

Most MS patient groups revealed ERP abnormalities, suggesting that these neurophysiological tests may be a relevant and appropriate diagnostic aid method for cognitive impairment in MS.

SIGNIFICANCE

The use of ERPs in MS patients seems able to demonstrate cognitive impairment and its use should be considered as part of the regular patient evaluation.

An auditory brain-computer interface based on selective attention to multiple tone streams

In this study, we attempted to improve brain-computer interface (BCI) systems by means of auditory stream segregation in which alternately presented tones are perceived as sequences of various different tones (streams). A 3-class BCI using three tone sequences, which were perceived as three different tone streams, was investigated and evaluated. Each presented musical tone was generated by a software synthesizer. Eleven subjects took part in the experiment. Stimuli were presented to each user's right ear. Subjects were requested to attend to one of three streams and to count the number of target stimuli in the attended stream. In addition, 64-channel electroencephalogram (EEG) and two-channel electrooculogram (EOG) signals were recorded from participants with a sampling frequency of 1000 Hz. The measured EEG data were classified based on Riemannian geometry to detect the object of the subject's selective attention. P300 activity was elicited by the target stimuli in the segregated tone streams. In five out of eleven subjects, P300 activity was elicited only by the target stimuli included in the attended stream. In a 10-fold cross validation test, a classification accuracy over 80% for five subjects and over 75% for nine subjects was achieved. For subjects whose accuracy was lower than 75%, either the P300 was also elicited for nonattended streams or the amplitude of P300 was small. It was concluded that the number of selected BCI systems based on auditory stream segregation can be increased to three classes, and these classes can be detected by a single ear without the aid of any visual modality.

Effect of Healthy Aging and Gender on Syntactic Input Processing: A P600 Event-Related Potential Study

PURPOSE

This study aimed to investigate the effect of healthy aging and gender, as well as the interaction, thereof, on syntactic input processing during sentence comprehension. This was achieved through the recording of the P600 event-related potential.

METHOD

Sixty Flemish (native speakers of Dutch) participants (30 men and 30 women), equally distributed into three age groups (young, middle-aged, and older adults), were subjected to a visually presented word order violation task under simultaneous electro-encephalography recording. The task contained 60 sentences, of which half were grammatical and half contained a word order violation. P600 responses were analyzed for amplitude, latency, topographical distribution, and source localization.

RESULTS

Regarding the effect of healthy aging, no age-related differences were found for the amplitude, onset latency, and topographical distribution of the P600 effect (difference wave). Although aging effects on the P600 effect amplitude were absent, a reduced P600 amplitude in response to both the grammatical and ungrammatical sentences was found, next to a reduced overall degree of source activation in linguistic regions of interest. Also, a reduced behavioral accuracy in response to the word order violation was observed in the older adults group. Regarding the effect of gender, females exhibited a larger P600 effect amplitude and a reduced behavioral accuracy compared to males. No gender-related differences were found for P600 effect onset latency, topographical distribution, and source activation.

CONCLUSIONS

While this study demonstrates no effect of aging on the P600 effect, the lower behavioral response and absence of any activation shift argues against functional compensation. Moreover, although increased neural activation in women combined with their reduced behavioral accuracy may indicate the use of different cognitive strategies in men and women, source localization analysis could not objectify this hypothesis.

The Relationship between P300 and Central Auditory Processing Test Result

BACKGROUND

 Central auditory processing (CAP) refers to the perceptual processing of auditory inputs in the central nervous system and includes a series of auditory skills such as sound localization, auditory pattern recognition, and temporal sequencing which is a component of temporal processing. This skill can be assessed by frequency pattern test (FPT) and duration pattern test (DPT). Auditory attention is another skill that contributes to the CAP and can be analyzed by the P300.

PURPOSE

 This study assesses the relationship between the P300 latency and the CAP test results of individuals with normal hearing.

RESEARCH DESIGN

 An experimental study was used in which the determined tests were applied to the participants.

STUDY SAMPLE

 Thirty-four individuals with normal hearing between the ages of 20 and 40 years were included in the study.

DATA COLLECTION AND ANALYSIS

 P300, FPT, and DPT were applied to the participants. The Spearman correlation test and Mann-Whitney U test were used for analysis.

RESULTS

 There were significant moderate and strong-level negative correlations between P300 latency and the scores obtained from frequency pattern and DPT (p < 0.01). We also analyzed whether P300 latency and frequency pattern and DPT scores differed according to gender and, as a result, did not find significant relationship (p > 0.05).

CONCLUSION

 We observed that frequency pattern and DPT scores decreased as P300 latency increased. We propose that these results could contribute to the diagnosis and follow-up process of CAP disorder by allowing P300 and CAP tests to be cross-checked.

Developments in scalable strategies for detecting early markers of cognitive decline

Effective strategies for early detection of cognitive decline, if deployed on a large scale, would have individual and societal benefits. However, current detection methods are invasive or time-consuming and therefore not suitable for longitudinal monitoring of asymptomatic individuals. For example, biological markers of neuropathology associated with cognitive decline are typically collected via cerebral spinal fluid, cognitive functioning is evaluated from face-to-face assessments by experts and brain measures are obtained using expensive, non-portable equipment. Here, we describe scalable, repeatable, relatively non-invasive and comparatively inexpensive strategies for detecting the earliest markers of cognitive decline. These approaches are characterized by simple data collection protocols conducted in locations outside the laboratory: measurements are collected passively, by the participants themselves or by non-experts. The analysis of these data is, in contrast, often performed in a centralized location using sophisticated techniques. Recent developments allow neuropathology associated with potential cognitive decline to be accurately detected from peripheral blood samples. Advances in smartphone technology facilitate unobtrusive passive measurements of speech, fine motor movement and gait, that can be used to predict cognitive decline. Specific cognitive processes can be assayed using 'gamified' versions of standard laboratory cognitive tasks, which keep users engaged across multiple test sessions. High quality brain data can be regularly obtained, collected at-home by users themselves, using portable electroencephalography. Although these methods have great potential for addressing an important health challenge, there are barriers to be overcome. Technical obstacles include the need for standardization and interoperability across hardware and software. Societal challenges involve ensuring equity in access to new technologies, the cost of implementation and of any follow-up care, plus ethical issues.

Documentation of Peripheral Auditory Function in Studies of the Auditory P300 Response

Abstract. A critical review was conducted to examine whether the peripheral hearing status of participants with neurological and psychological disorders was documented in published clinical studies of the auditory P300 response. Literature searches were conducted with three databases: PubMed, PsycINFO, and Scopus. Studies of participants with seven neurological or psychological disorders were included in the study. Each disorder was coupled with the main search phrase in separate searches on each database. Of the total 102 papers which met the inclusion criteria, the majority (64%) did not describe the peripheral hearing sensitivity of participants. In this review with studies that included participants at risk for hearing impairment, particularly age-related hearing loss, only a single publication adequately described formal hearing evaluation. Peripheral hearing status is rarely defined in studies of the P300 response. The inclusion of participants with a hearing loss likely affects the validity of findings for these studies. We recommend formal hearing assessment prior to inclusion of participants in studies of the auditory P300 response. The findings of this study may increase the awareness among researchers outside the field of audiology of the effects of peripheral hearing loss on the auditory P300.

Assessment of Cognition in Hypertensives and Normotensives: A Comparative P300 Study

Background: Hypertension is an established risk factor for dementia, and the prevalence of hypertension and dementia is rising. Current tests to diagnose cognitive dysfunction at an early stage lack sensitivity and specificity. Recently event-related potentials (ERPs) have gained much attention in diagnosing cognitive dysfunction and are independent of the education status of the subject. This study was done to find any cognitive deficits in the hypertensive population with electrophysiological evidence, which might open the doors for the need to screen the population at an earlier stage so that the population can be prevented from dementia.

Methods: Some 31 middle-aged (18-65 years) hypertensives were compared with 31 age, sex, education, and handedness matched normotensives about cognition by neuropsychometric test battery including Hindi Mini-mental Status Examination (HMSE), Hindi Montreal Cognitive Assessment (MoCA), choice reaction time (CRT), and auditory event-related potentials.

Results: Hypertensives and normotensives differed significantly concerning P300 potentials’ latency (Fz and Cz P300 latencies: p-value: 0.001), and this change was correlated well with the duration of diastolic blood pressure (BP) (r-value: 0.670). The remaining tests, HMSE, Hindi MoCA, and CRT, were dependent on the education status of the patient.

Conclusions: The effect of hypertension on cognitive impairment is evident and can be proved early in its pre-clinical stage using ERPs. Early identification can help in specifying high-risk individuals. ERPs have great potential in screening and diagnosing and can also help in assessing cognition as a reliable tool to show the effect of treatments/interventions on cognitive defects.

The reliability of P300 and the influence of age, gender and education variables in a 50 years and older normative sample

OBJECTIVES

The present study aims to investigate the effects of age, gender, and level of education on P300 in a healthy population, aged 50 years and over; and determine the reliability metrics for different conditions and measurement methods.

METHOD

Auditory and visual oddball recordings of 171 healthy adults were investigated. A fully automated preprocessing was applied to elicit ERP P300. Maximum peak amplitude, latency and mean amplitudes were measured. Data were stratified by age, gender, and education to determine group-level differences by using repeat measures of ANOVA. The internal consistency of P300 was calculated by a split-half method using odd-even segments. Test-retest reliability was assessed by calculating the intraclass correlation coefficient (ICC).

RESULTS

Maximum peak P300 amplitudes were higher in the 50-64 years age group compared to the >65 years age group; and females showed increased P300 amplitudes compared to males. P300 measures showed fair to good internal consistency and poor to good test-retest reliability.

CONCLUSION

Age and gender should be taken into account when designing ERP studies with elderly individuals. P300 showed good internal consistency in general, between gender groups and age groups. Long-term test-retest reliability was lower but acceptable. These findings can be interpreted as the strength of P300 by being an objective and reliable method independent of cultural differences. Here we underline several factors that may affect P300 measures and discuss other possible factors that should be standardized for P300 to be used in clinical settings.

Behavioral and neurophysiological correlates of emotional face processing in borderline personality disorder: are there differences between men and women?

Emotional dysregulation is a core feature of borderline personality disorder (BPD); it is, for example, known to influence one's ability to read other people's facial expressions. We investigated behavioral and neurophysiological foundations of emotional face processing in individuals with BPD and in healthy controls, taking participants' sex into account. 62 individuals with BPD (25 men, 37 women) and 49 healthy controls (20 men, 29 women) completed an emotion classification task with faces depicting blends of angry and happy expressions while the electroencephalogram was recorded. The cortical activity (late positive potential, P3/LPP) was evaluated using source modeling. Compared to healthy controls, individuals with BPD responded slower to happy but not to angry faces; further, they showed more anger ratings in happy but not in angry faces, especially in those with high ambiguity. Men had lower anger ratings than women and responded slower to angry but not happy faces. The P3/LPP was larger in healthy controls than in individuals with BPD, and larger in women than in men; moreover, women but not men produced enlarged P3/LPP responses to angry vs. happy faces. Sex did not interact with behavioral or P3/LPP-related differences between healthy controls and individuals with BPD. Together, BPD-related alterations in behavioral and P3/LPP correlates of emotional face processing exist in both men and women, supposedly without sex-related interactions. Results point to a general 'negativity bias' in women. Source modeling is well suited to investigate effects of participant and stimulus characteristics on the P3/LPP generators.

Tactile P300 to unpredictable electric shocks: Association with anxiety symptoms, intolerance of uncertainty, and neuroticism

The no, predictable, and unpredictable threat (NPU-threat) task is an experimental paradigm that delineates the anticipation of predictable vs. unpredictable threat. The current literature suggests that heightened defensive motivation in anticipation of unpredictable threat is associated with anxiety disorders and increased symptoms. Few investigations have examined whether a heightened response to actual threat is also associated with anxiety-related phenomenology. The present study examined the relationship between the tactile P300 to shock delivery during the NPU-threat task and individual differences in anxiety symptoms, intolerance of uncertainty, and neuroticism. Overall, the tactile P300 was enhanced in response to unpredictable shocks relative to predictable shocks. Greater tactile P300 enhancement to unpredictable shocks was associated with greater anxiety symptoms, intolerance of uncertainty, and neuroticism. The present study suggests that temporal unpredictability enhances attentional engagement to threat, which is greater in individuals characterized by narrow and broad anxiety constructs.

Stress effects on the oddball P300 and N2 in males and females

We examined the effect of psychosocial stress on electrophysiological markers of novelty and deviance processing, the N2 and P300, as well as sex differences therein. Participants underwent the Trier Social Stress Test (TSST) or a control procedure, followed by an oddball paradigm. A physiological stress response was induced in both sexes in the TSST condition. Furthermore, a reduced target P300 amplitude was elicited in the TSST condition in fronto-central electrodes, an effect that did not differ in magnitude between both sexes. By contrast, stressor effects on N2 amplitude differed by sex: In females, N2 amplitude was decreased in the TSST condition, while in males, no stress effects were observed. Exploratory correlational analyses suggested that a stress-induced P300 amplitude reduction, at least in males, could be due to a modulation of adrenergic activity. These results are consistent with sex differences in the manner in which stress affects lower-level, stimulus-driven vs. higher-level, more controlled processing stages.

APOE genotype influences P3b amplitude and response to smoking abstinence in young adults

RATIONALE

There is strong evidence that nicotine can enhance cognitive functions and growing evidence that this effect may be larger in young healthy APOE ε4 carriers. However, the moderating effects of the APOE ε4 allele on cognitive impairments caused by nicotine deprivation in chronic smokers have not yet been studied with brain indices.

OBJECTIVE

We sought to determine whether young female carriers of the APOE ε4 allele, relative to noncarriers, would exhibit larger abstinence-induced decreases in P3b amplitude during a two-stimulus auditory oddball task.

METHODS

We compared parietal P3bs in female chronic smokers with either APOE ε3/ε3 (n = 54) or ε3/ε4 (n = 20) genotype under nicotine-sated conditions and after 12-17-h nicotine deprivation.

RESULTS

Nicotine deprivation significantly reduced P3b amplitudes in APOE ε4 carriers, but not in APOE-ε3/ε3 individuals, such that the difference seen prior to nicotine deprivation was eliminated.

CONCLUSIONS

The results suggest that subjects with the APOE ε4 allele are more sensitive to nicotine, which could influence smoking patterns, the risk for nicotine dependence, and the cognitive effects of nicotine use in these individuals.

A multicenter effectiveness trial of QEEG-informed neurofeedback in ADHD: Replication and treatment prediction

•

QEEG-informed neurofeedback resulted in remission rates of 55%.

•

In the total sample, non-remitters had higher hyperactivity scores at baseline.

•

In women, non-remitters had longer P300 latencies.

•

In boys, a low individual alpha peak frequency (iAPF) was associated with remission.

Introduction

Quantitative Electroencephalogram-(QEEG-)informed neurofeedback is a method in which standard neurofeedback protocols are assigned, based on individual EEG characteristics in order to enhance effectiveness. Thus far clinical effectiveness data have only been published in a small sample of 21 ADHD patients. Therefore, this manuscript aims to replicate this effectiveness in a new sample of 114 patients treated with QEEG-informed neurofeedback, from a large multicentric dataset and to investigate potential predictors of neurofeedback response.

Methods

A sample of 114 patients were included as a replication sample. Patients were treated with standard neurofeedback protocols (Sensori-Motor-Rhythm (SMR), Theta-Beta (TBR), or Slow Cortical Potential (SCP) neurofeedback), in combination with coaching and sleep hygiene advice. The ADHD Rating Scale (ADHD-RS) and Pittsburgh Sleep Quality Index (PSQI) were assessed at baseline, every 10th session, and at outtake. Holland Sleep Disorder Questionnaire (HSDQ) was assessed at baseline and outtake. Response was defined as ≥25% reduction (R25), ≥50% reduction (R50), and remission. Predictive analyses were focused on predicting remission status.

Results

In the current sample, response rates were 85% (R25), 70% (R50), and remission was 55% and clinical effectiveness was not significantly different from the original 2012 sample. Non-remitters exhibited significantly higher baseline hyperactivity ratings. Women who remitted had significantly shorter P300 latencies and boys who remitted had significantly lower iAPF’s.

Discussion

In the current sample, clinical effectiveness was replicated, suggesting it is possible to assign patients to a protocol based on their individual baseline QEEG to enhance signal-to-noise ratio. Furthermore, remitters had lower baseline hyperactivity scores. Likewise, female remitters had shorter P300 latencies, whereas boys who remitted have a lower iAPF. Our data suggests initial specificity in treatment allocation, yet further studies are needed to replicate the predictors of neurofeedback remission.

Altered Auditory P300 Performance in Parents with Attention Deficit Hyperactivity Disorder Offspring

Objective

Altered event-related potential (ERP) performances have been noted in attention deficit hyperactivity disorder (ADHD) patients and reflect neurocognitive dysfunction. Whether these ERP alterations and correlated dysfunctions exist in healthy parents with ADHD offspring is worth exploring.

Methods

Thirteen healthy parents with ADHD offspring and thirteen healthy controls matched for age, sex and years of education were recruited. The auditory oddball paradigm was used to evaluate the P300 wave complex of the ERP, and the Wechsler Adult Intelligence Scale-Revised, Wisconsin Card Sorting Test, and continuous performance test were used to measure neurocognitive performance.

Results

Healthy parents with ADHD offspring had significantly longer auditory P300 latency at Fz than control group. However, no significant differences were found in cognitive performance.

Conclusion

The presence of a subtle alteration in electro-neurophysiological activity without explicit neurocognitive dysfunction suggests potential candidate of biological marker for parents with ADHD offspring.

Sex differences in event-related potential (ERP) waveforms of primary psychotic disorders: A systematic review

Research aimed at understanding primary psychotic disorders such as schizophrenia, schizophreniform disorder, and schizoaffective disorder, with electrophysiological methods has flourished over recent years. However, a significant component that is often overlooked or underreported in electrophysiological research of psychosis is the factor of biological sex. Thus, the goal of this systematic review was to summarize the current understanding of EEG sex differences in primary psychotic disorders. Our study found a consistent sex difference relating to the P300 component (male amplitude < females), and that research examining sex differences of ERP waveforms, other than the P300, is very limited with ambiguous findings. This review also addressed the lack of consideration of sex as an influencing factor in electrophysiological research.

The Late Positive Potentials Evoked by Cigarette-Related and Emotional Images Show no Gender Differences in Smokers

When trying to quit, women are less likely than men to achieve long-term smoking abstinence. Identifying the neuropsychological mechanisms underlying women's higher relapse vulnerability will help clinicians to develop effective tailored smoking cessation interventions. Here we used event-related potentials (ERPs), a direct measure of brain activity, to evaluate the extent to which neurophysiological responses to cigarette-related and other emotional stimuli differ between female and male smokers. Both women and men showed similar patterns of brain reactivity across all picture categories; pleasant and unpleasant images prompted larger Late Positive Potentials (LPPs, a robust measure of motivational relevance) than neutral images in both groups, and cigarette-related images prompted lower LPPs than high arousing emotional images in both groups. Unlike previous studies, there were no differences between male and female smokers with regard to LPP responses to cigarette-related images. This suggests that the LPP may not be ideally suited to discriminate neurophysiological gender differences or that there are simply no gender differences in the neurophysiological responses to cigarette-related stimuli. We collected ERPs from 222 non-nicotine-deprived smokers (101 women) while they watched a slideshow that included high and low emotionally arousing pleasant and unpleasant pictures, cigarette-related, and neutral pictures. We used the mean amplitude of the LPP to assess the affective significance that participants attributed to these pictures.