Time effects on event-related brain potentials and vigilance performance

Baddeley's influential model of working memory postulates a unitary central executive that allocates mental resources to several distinct short-term buffers. Subjects viewed individually presented single numerals and were required to maintain memory sets comprised of the most recently represented three stimuli. A clearly discernible visual event-related potentials (ERP) component emerged once the lengths of series of individual numbers exceeded memory set size and revision of working memory contents was required. An ERP correlate of working memory revision also emerged upon updating of auditory stimuli. This component was absent when subjects were exposed to the same series of stimuli in a standard “oddball” target detection situation. ERPs elicited when subjects were given the opportunity to rehearse without the need to update working memory contents clearly differed in latency from ERPs seen during updating. These findings provide support for previous studies suggesting a specific ERP correlate of central executive processes in working memory and are consistent with Baddeley's model.

Cortical Inhibition in Alcohol Dependence

Reliable biomarkers of memory decline are critical for the early detection of Alzheimer’s disease. Previous work has found three EEG measures, namely the event-related brain potential P600, suppression of oscillatory activity in the alpha frequency range (∼10 Hz) and cross-frequency coupling between low theta/high delta and alpha/beta activity, each of which correlates strongly with verbal learning and memory abilities in healthy elderly and patients with mild cognitive impairment or prodromal Alzheimer’s disease. In the present study, we address the question of whether event-related or oscillatory measures, or a combination thereof, best predict the decline of verbal memory in mild cognitive impairment and Alzheimer’s disease. Single-trial correlation analyses show that despite a similarity in their time courses and sensitivities to word repetition, the P600 and the alpha suppression components are minimally correlated with each other on a trial-by-trial basis (generally |rs| < 0.10). This suggests that they are unlikely to stem from the same neural mechanism. Furthermore, event-related brain potentials constructed from bandpass filtered (delta, theta, alpha, beta or gamma bands) single-trial data indicate that only delta band activity (1–4 Hz) is strongly correlated (r = 0.94, P < 0.001) with the canonical P600 repetition effect; event-related potentials in higher frequency bands are not. Importantly, stepwise multiple regression analyses reveal that the three event-related brain potential/oscillatory measures are complementary in predicting California Verbal Learning Test scores (overall R2’s in 0.45–0.63 range). The present study highlights the importance of combining EEG event-related potential and oscillatory measures to better characterize the multiple mechanisms of memory failure in individuals with mild cognitive impairment or prodromal Alzheimer’s disease.

Two experiments examined phonological priming effects on reaction times, error rates, and event-related brain potential (ERP) measures in an auditory lexical decision task. In Experiment 1 related prime-target pairs rhymed, and in Experiment 2 they alliterated (i.e., shared the consonantal onset and vowel). Event-related potentials were recorded in a delayed response task. Reaction times and error rates were obtained both for the delayed and an immediate response task. The behavioral data of Experiment 1 provided evidence for phonological facilitation of word, but not of nonword decisions. The brain potentials were more negative to unrelated than to rhyming word-word pairs between 450 and 700 rnsec after target onset. This negative enhancement was not present for word-nonword pairs. Thus, the ERP results match the behavioral data. The behavioral data of Experiment 2 provided no evidence for phonological Facilitation. However, between 250 and 450 msec after target onset, i.e., considerably earlier than in Experiment 1, brain potentials were more negative for unrelated than for alliterating Word-word and word-nonword pairs. It is argued that the ERP effects in the two experiments could be modulations of the same underlying component, possibly the N400. The difference in the timing of the effects is likely to be due to the fact that the shared segments in related stimulus pairs appeared in different word positions in the two experiments.

Event Abstract Back to Event Brain pathways underlying Response Inhibition and Response Caution Renate Thienel1*, Elise Mansfield1, Patrick S. Cooper1, Andrew Heathcote1, Birte Forstmann2, Pat Michie1, Gavin Cooper1 and Frini Karayanidis1 1 School of Psychology, University of Newcastle, Australia 2 University of Amsterdam, Netherlands Background: Our previous findings suggest that the striatum is instrumental in mediating response caution in a task switching paradigm (Mansfield et al., J. Neurosci 2011, 31:14688-92), and that structural integrity in two separate fronto-striatal networks are associated with adopting an overall more risky or more cautious response threshold. In the present study, we examine whether a similar network underlies response inhibition, as operationalized by a stop signal task. Response inhibition has been shown to be mediated by cortical and subcortical structures within the inferior frontal lobe and the subthalamic nucleus, respectively. We investigate whether structural integrity measures in these regions can explain the relationship between stop signal related event related potential (ERP) components and estimates of stop signal reaction time (SSRT). Finally the relationship between, and the differential structural pathways contributing to, response threshold adjustment (task-switching paradigm) and stop signal response time will be examined. Methods: Diffusion weighted Imaging (DWI), ERP and behavioural data has been collected in 16 healthy participants (24.5 years, 5 male). A correlational analysis was performed for the ERPs and the behavioural measures of both tasks (task switching and stop signal task). Tract based spatial statistics (TBSS) of the DWI data was performed to compare the white matter pathways associated with response thresholds adjustment (task-switching task), and response inhibition (stop-signal task) respectively. These regions were then used to explain variation in ERP data. Results/Discussion: The integrity within distinct structural pathways (DWI data) explained the relationship between (1) ERP measures and response threshold adjustment and (2) ERP measures and SSRTs. Distinct fronto-basal ganglia pathways mediated threshold setting and response suppression. Keywords: task-switching, stop signal task, DWI, fronto-striatal circuits, response inhibition Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Executive Processes Citation: Thienel R, Mansfield E, Cooper PS, Heathcote A, Forstmann B, Michie P, Cooper G and Karayanidis F (2013). Brain pathways underlying Response Inhibition and Response Caution. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00145 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Sep 2013; Published Online: 25 Nov 2013. * Correspondence: Dr. Renate Thienel, School of Psychology, University of Newcastle, Newcastle, Australia, renate.thienel@newcastle.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Renate Thienel Elise Mansfield Patrick S Cooper Andrew Heathcote Birte Forstmann Pat Michie Gavin Cooper Frini Karayanidis Google Renate Thienel Elise Mansfield Patrick S Cooper Andrew Heathcote Birte Forstmann Pat Michie Gavin Cooper Frini Karayanidis Google Scholar Renate Thienel Elise Mansfield Patrick S Cooper Andrew Heathcote Birte Forstmann Pat Michie Gavin Cooper Frini Karayanidis PubMed Renate Thienel Elise Mansfield Patrick S Cooper Andrew Heathcote Birte Forstmann Pat Michie Gavin Cooper Frini Karayanidis Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

The influence of stimulus duration on odor perception

Auditory P300 event related potentials and serotonin reuptake inhibitor treatment in patients with fibromyalgia

EnAbstract Objects Problem-tinnitus refers to tinnitus that is sufficiently severe to produce a major disruption in the patient’s life; tinnitus of such severity involves a number of regions of the auditory system and other brain systems may also play an essential role. Auditory brainstem responses (ABR) and event-related potentials (ERP) were recorded from sensorineural hearing loss (SNHL) patients with problem-tinnitus and were then compared with responses from normal hearing and hearing loss tinnitus-free patients. Aim To study whether differences exist in ABR and/or ERP parameters in SNHL patients with and without problem-tinnitus when matched as closely as possible for hearing loss, age, and sex to investigate the mechanism responsible for tinnitus. Materials and Methods Ninety participants were included in this study. They were divided into two groups: the study group included 66 participants with bilateral symmetrical SNHL that did not exceed a moderate degree. The study group was divided into two subgroups: 36 patients had problem-tinnitus and 30 patients were tinnitus-free (SNHL, age, and sex matched). Participants in each of these subgroups were compared with each other and were also compared with 24 healthy individuals in the control group (age and sex matched with the study group). All participants were subjected to a basic audiological evaluation and electrophysiological tests (ABR and ERP). Results This work had shown a higher prevalence of ABR abnormalities in tinnitus patients in comparison with either the control group or the SNHL tinnitus-free group. Statistically significant differences were found in III–V and I–V interpeak latencies and in the VI amplitude ratio in problem-tinnitus female patients compared with tinnitus-free female patients. Meanwhile, in problem tinnitus male patients when compared with tinnitus-free male patients at III–V interpeak latencies and at VI amplitude ratio. As regards the results of ERP in this work, an increase in latency and amplitude reduction were found. Statistically significant differences were observed regarding both the mean latency values of waves N1, P2, and P300 and the amplitude mean values of P2 and P300 when we compared the problem-tinnitus subgroup with either the tinnitus-free subgroup or the control group (both female and male patients. Conclusion A variety of ABR and ERP components are altered in tinnitus patients; this would indicate impairment in both the central auditory pathway and central auditory processing. Thus, it is suggested that this form of ABR, ERP testing could be considered as an objective measure to complement behavioral, audiologic, and other physiologic methods of assessing tinnitus, rather than a single definitive tinnitus measure in an attempt to supplement and thereby extend knowledge of the nature and origins of tinnitus. Furthermore, these results provide the basis for future neurofeedback-based tinnitus therapies aiming at maximizing the ability to shift attention away from the tinnitus.

BackgroundSeveral studies have suggested that migraineurs suffer from neurocognitive abnormalities, but this phenomenon and exact mechanisms remain controversial. In this study, we aimed to reevaluate visual spatial attention via event-related potential (ERP) examinations and explore further correlations between ERP data and migraine characteristics.MethodsAltogether, 25 migraine patients (9 males, 16 females; mean age 35.240 years) in the interictal period and 21 age-matched healthy controls (8 males, 13 females; mean age 35.286 years) were recruited. A modified visual oddball paradigm which contained standard, target and novel stimuli was used in the test, and amplitudes and latencies of corresponding original/difference ERP components were measured and analyzed independently.ResultsWe found that P3 amplitude was markedly reduced in migraineurs. This phenomenon was further validated in analysis of difference P3 components (target minus standard and novel minus standard). Additionally, the N1 and N2 latencies elicited by novel stimulus were both delayed in patients compared with controls. Furthermore, these deviant cognitive ERPs were correlated with frequency and duration of migraine attacks.ConclusionsThese results indicated impaired visual spatial attention in migraine patients, which could be related to frequency and duration of attacks.

Event-related brain potentials (ERPs) are altered in patients with a variety of psychiatric disorders and may represent quantitative correlates of disease liability that are more amenable to genetic analysis than disease status itself. Estimates of heritability are presented for amplitude and latency of the N1 and P3 components of the ERP measured at 19 scalp locations in response to visual and auditory stimuli for 604 individuals in 100 pedigrees ascertained as part of the Collaborative Study on the Genetics of Alcoholism. Significant heritabilities were found for visual P3 amplitude in response to all stimuli and for visual P3 latency in response to target and novel, but not non-target, stimuli. Heritability of visual N1 latencies was uniformly low, whereas heritability of visual N1 amplitude was significant for all electrodes in response to the non-target stimuli but only for posterior electrodes in the other two stimulus conditions. Heritabilities for auditory target P3 were similar to those of the visual stimuli, with auditory target P3 amplitudes and latencies both demonstrating significant heritability. For auditory P2 in response to non-target stimuli, peak amplitude was heritable, but latency was not. Auditory N1 amplitude and latency were significantly heritable for both target and non-target conditions and did not demonstrate the anterior/posterior patterning obtained for visual N1 amplitude. This study represents the first systematic assessment of heritability of these potential neurophysiological markers in families with a history of alcoholism and suggests that many of these ERP phenotypes have heritabilities strong enough to justify genomic screening for loci jointly influencing ERP abnormalities and liability to alcoholism.

A number of recent reports have emphasized neuropyschological symptoms in ALS, including frontal functions, memory and attention. We investigated visual search behaviour of ALS in two types of tasks: a simple, relatively effortless parallel search task and a more complex attention-demanding serial search task. Behavioural parameters and cognitive event-related potentials (ERP) from 19 scalp channels were obtained from 13 ALS patients and 13 matched controls during task performance. ALS patients showed the same target detection rates as controls in the parallel task but were significantly impaired in the serial task. Performance was slower in the patients than in the controls. This slowing could be attributed to cognitive rather than motor impairments, by inspection of the latency of the P3 component, which was delayed by 120 ms in the patients. In addition, the ERPs in the serial task showed a grossly reduced P3 amplitude, indicating disturbed stimulus evaluation in the patients under these conditions. Changes of an early attention-sensitive ERP component suggest an attention deficit underlying the disturbances in search behaviour.

Object categorization using single-trial electroencephalography (EEG) data measured while participants view images has been studied intensively. In previous studies, multiple event-related potential (ERP) components (e.g., P1, N1, P2, and P3) were used to improve the performance of object categorization of visual stimuli. In this study, we introduce a novel method that uses multiple-kernel support vector machine to fuse multiple ERP component features. We investigate whether fusing the potential complementary information of different ERP components (e.g., P1, N1, P2a, and P2b) can improve the performance of four-category visual object classification in single-trial EEGs. We also compare the classification accuracy of different ERP component fusion methods. Our experimental results indicate that the classification accuracy increases through multiple ERP fusion. Additional comparative analyses indicate that the multiple-kernel fusion method can achieve a mean classification accuracy higher than 72%, which is substantially better than that achieved with any single ERP component feature (55.07% for the best single ERP component, N1). We compare the classification results with those of other fusion methods and determine that the accuracy of the multiple-kernel fusion method is 5.47, 4.06, and 16.90% higher than those of feature concatenation, feature extraction, and decision fusion, respectively. Our study shows that our multiple-kernel fusion method outperforms other fusion methods and thus provides a means to improve the classification performance of single-trial ERPs in brain-computer interface research.

Sedative-hypnotic drugs not only increase sedation, but also impair memory as serum concentration increases. These drugs also produce profound changes in the auditory event-related potential (ERP). The ability of various ERP components to predict changes in sedation and memory produced by various drugs was tested. Sixty-five healthy volunteers randomly received intravenous placebo, midazolam, propofol, thiopental, fentanyl with ondansetron, or ondansetron alone at five different stable target concentrations (three increasing, two decreasing) using a computer-controlled infusion pump to produce varying degrees of sedation without loss of consciousness. ERPs were recorded while volunteer participants detected a deviant auditory stimulus and made a button-press response to a target tone (standard oddball paradigm, 80:20 ratio, to elicit a P3 response). At each target concentration, volunteers learned a list of 16 words. The predictive probabilities (Pk) of various ERP components were determined for word recognition at the end of the day (memory) and log reaction time to the deviant stimulus (sedation). The N2 latency of the ERP consistently predicted log reaction time in all groups (Pk +/- SE from 0.58 +/- 0.04 to 0.71 +/- 0.04). The N2P3 amplitude of the ERP was the best predictor of memory performance for midazolam (Pk, 0.63 +/- 0.04), propofol (Pk, 0.62 +/- 0.05), and thiopental (Pk, 0.66 +/- 0.04). There was a differential ability to predict memory performance from sedation for midazolam and propofol. Midazolam and propofol affect memory differentially from their sedative effects, and these are indexed by specific components of the auditory ERP. These components of the ERP are associated with specific, but not necessarily unique, neuroanatomic structures. Thus, these drugs act by additional mechanisms beyond general central nervous system depression to produce the effects of sedation and memory impairment.

Auditory P300 amplitude as a state marker for positive symptoms in schizophrenia: cross-sectional and retrospective longitudinal studies

Frequent observations of atypical sensory reactivity in people with autism spectrum disorders (ASD) suggest that the perceptual experience of those on the Spectrum is dissimilar to neurotypicals. Moreover, variable attention abilities in people with ASD, ranging from good control to periods of high distractibility, may be related to atypical sensory reactivity. This study used auditory event-related potential (ERP) measures to evaluate top-down and bottom-up attentional processes as a function of perceptual load, and examined these factors with respect to sensory reactivity. Twenty-five age and IQ-matched participants (ASD: 22.5 year, SD = 4.1 year; Controls: 22.8 year, SD = 5.1 year) completed the Adolescent/Adult Sensory Profile prior to performing a modified 3-stimulus (target, non-target, and distractor) auditory oddball target detection task EEG was recorded during task completion. ERP analysis assessed early sensory processing (P50, ∼50 ms latency; N100, ∼100 ms latency), cognitive control (N200, ∼200 ms latency), and attentional processing (P3a and P3b, ∼300 ms latency). Behavioral data demonstrates participants with ASD and neurotypical performed similarly on auditory target detection, but diverged on sensory profiles. Target ERP measures associated with top-down control (P3b latency) significantly increased under greater load in controls, but not in participants with ASD. Early ERP responses associated with bottom-up attention (P50 amplitude) were positively correlated to increased sensory sensitivity. Findings suggest specific neural mechanisms for increased perceptual capacity and enhanced bottom-up processing of sensory stimuli in people with autism. Results from participants with ASD are consistent with load theory and enhanced perceptual functioning. Autism Res 2016, 9: 1079-1092. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.