Late Auditory Event-related Potentials Research Articles

Cognitive impairments in patients with first episode psychosis: The relationship between neurophysiological and neuropsychological assessments

Cognitive deficits in schizophrenia have been widely reported. Neurophysiological and neuropsychological assessments have been conducted to study these impairments. Event-related potentials (ERPs) are relevant markers of cognitive deficits in schizophrenia, and reductions in specific ERP components have been found. The MATRICS Consensus Cognitive Battery (MCCB) was developed to obtain a consensus battery for the assessment of cognitive deficits in schizophrenia. Here, we aimed to study modulations of several ERP components in first episode psychosis (FEP). We also examined neuropsychological deficits using the MCCB, and correlations between ERP and MCCB impairments. Thirty-eight FEP patients were compared to thirty-eight healthy controls. The following ERP components were examined: P1, N1, MMN, P2, early-P3 and late-P3. We used an auditory three-stimulus oddball paradigm, with standard (60%), target (20%) and distractor (20%) stimuli. FEP patients showed significantly lower amplitudes of P2, early-P3 and late-P3 components. FEP patients also showed significant deficits in all the MCCB cognitive domains. Finally, correlational analyses found strong associations between amplitudes of P2, early-P3 and late-P3 components and MCCB tests for attention and speed of processing. These findings indicate that deficits in late auditory ERP components are present in FEP, whereas early components are preserved. These reductions in late ERP components were related to attentional deficits in FEP as assessed by MCCB. These findings indicate that MCCB is a valid battery for studying cognitive impairments in the initial stages of schizophrenia, and highlight the utility of converging neurophysiological and neuropsychological measures to examine attentional impairments in schizophrenia.

Validation of the Emotiv EPOC EEG system for research quality auditory event-related potentials in children.

Background. Previous work has demonstrated that a commercial gaming electroencephalography (EEG) system, Emotiv EPOC, can be adjusted to provide valid auditory event-related potentials (ERPs) in adults that are comparable to ERPs recorded by a research-grade EEG system, Neuroscan. The aim of the current study was to determine if the same was true for children.Method. An adapted Emotiv EPOC system and Neuroscan system were used to make simultaneous EEG recordings in nineteen 6- to 12-year-old children under “passive” and “active” listening conditions. In the passive condition, children were instructed to watch a silent DVD and ignore 566 standard (1,000 Hz) and 100 deviant (1,200 Hz) tones. In the active condition, they listened to the same stimuli, and were asked to count the number of ‘high’ (i.e., deviant) tones.Results. Intraclass correlations (ICCs) indicated that the ERP morphology recorded with the two systems was very similar for the P1, N1, P2, N2, and P3 ERP peaks (r = .82 to .95) in both passive and active conditions, and less so, though still strong, for mismatch negativity ERP component (MMN; r = .67 to .74). There were few differences between peak amplitude and latency estimates for the two systems.Conclusions. An adapted EPOC EEG system can be used to index children’s late auditory ERP peaks (i.e., P1, N1, P2, N2, P3) and their MMN ERP component.

Auditory acclimatization and hearing aids: late auditory evoked potentials and speech recognition following unilateral and bilateral amplification.

The aim of this study was to investigate changes in central auditory processing following unilateral and bilateral hearing aid fitting using a combination of physiological and behavioral measures: late auditory event-related potentials (ERPs) and speech recognition in noise, respectively. The hypothesis was that for fitted ears, the ERP amplitude would increase over time following hearing aid fitting in parallel with improvement in aided speech recognition. The N1 and P2 ERPs were recorded to 500 and 3000 Hz tones presented at 65, 75, and 85 dB sound pressure level to either the left or right ear. New unilateral and new bilateral hearing aid users were tested at the time of first fitting and after 12 weeks hearing aid use. A control group of long-term hearing aid users was tested over the same time frame. No significant changes in the ERP were observed for any group. There was a statistically significant 2% improvement in aided speech recognition over time for all groups, although this was consistent with a general test-retest effect. This study does not support the existence of an acclimatization effect observable in late ERPs following 12 weeks' hearing aid use.

Poster #M91 THE MATRICS CONSENSUS COGNITIVE BATTERY (MCCB): PERFORMANCE AND FUNCTIONAL CORRELATES

Cognitive deficits in schizophrenia have been widely reported. Neurophysiological and neuropsychological assessments have been conducted to study these impairments. Event-related potentials (ERPs) are relevant markers of cognitive deficits in schizophrenia, and reductions in specific ERP components have been found. The MATRICS Consensus Cognitive Battery (MCCB) was developed to obtain a consensus battery for the assessment of cognitive deficits in schizophrenia. Here, we aimed to study modulations of several ERP components in first episode psychosis (FEP). We also examined neuropsychological deficits using the MCCB, and correlations between ERP and MCCB impairments. Thirty-eight FEP patients were compared to thirty-eight healthy controls. The following ERP components were examined: P1, N1, MMN, P2, early-P3 and late-P3. We used an auditory three-stimulus oddball paradigm, with standard (60%), target (20%) and distractor (20%) stimuli. FEP patients showed significantly lower amplitudes of P2, early-P3 and late-P3 components. FEP patients also showed significant deficits in all the MCCB cognitive domains. Finally, correlational analyses found strong associations between amplitudes of P2, early-P3 and late-P3 components and MCCB tests for attention and speed of processing. These findings indicate that deficits in late auditory ERP components are present in FEP, whereas early components are preserved. These reductions in late ERP components were related to attentional deficits in FEP as assessed by MCCB. These findings indicate that MCCB is a valid battery for studying cognitive impairments in the initial stages of schizophrenia, and highlight the utility of converging neurophysiological and neuropsychological measures to examine attentional impairments in schizophrenia.

Early and late auditory event-related potentials in cognitively high functioning male adolescents with autism spectrum disorder

Event-related potentials (ERP) studies have offered diverging results in characterizing the basic nature of abnormal sensory processing and discrimination in autism spectrum disorders (ASDs). In the present study we report duration mismatch negativity (MMN) and later ERP components (P3a and P3b) derived from auditory odd-ball paradigms in a homogenous sample of cognitively high functioning male adolescents with ASD. We find significantly reduced frontal and temporal MMN amplitudes and no differences in P3a or P3b amplitudes or latencies compared to controls. These findings are in contrast to recent studies reporting enhanced ERP amplitudes to auditory stimuli, and are more in support of a weakened automatic auditory sensory processing as being central to the abnormal auditory behavioral responses commonly encountered in ASD.

Validation of the Emotiv EPOC®EEG gaming system for measuring research quality auditory ERPs

Background. Auditory event-related potentials (ERPs) have proved useful in investigating the role of auditory processing in cognitive disorders such as developmental dyslexia, specific language impairment (SLI), attention deficit hyperactivity disorder (ADHD), schizophrenia, and autism. However, laboratory recordings of auditory ERPs can be lengthy, uncomfortable, or threatening for some participants – particularly children. Recently, a commercial gaming electroencephalography (EEG) system has been developed that is portable, inexpensive, and easy to set up. In this study we tested if auditory ERPs measured using a gaming EEG system (Emotiv EPOC®, www.emotiv.com) were equivalent to those measured by a widely-used, laboratory-based, research EEG system (Neuroscan).Methods. We simultaneously recorded EEGs with the research and gaming EEG systems, whilst presenting 21 adults with 566 standard (1000 Hz) and 100 deviant (1200 Hz) tones under passive (non-attended) and active (attended) conditions. The onset of each tone was marked in the EEGs using a parallel port pulse (Neuroscan) or a stimulus-generated electrical pulse injected into the O1 and O2 channels (Emotiv EPOC®). These markers were used to calculate research and gaming EEG system late auditory ERPs (P1, N1, P2, N2, and P3 peaks) and the mismatch negativity (MMN) in active and passive listening conditions for each participant.Results. Analyses were restricted to frontal sites as these are most commonly reported in auditory ERP research. Intra-class correlations (ICCs) indicated that the morphology of the research and gaming EEG system late auditory ERP waveforms were similar across all participants, but that the research and gaming EEG system MMN waveforms were only similar for participants with non-noisy MMN waveforms (N = 11 out of 21). Peak amplitude and latency measures revealed no significant differences between the size or the timing of the auditory P1, N1, P2, N2, P3, and MMN peaks.Conclusions. Our findings suggest that the gaming EEG system may prove a valid alternative to laboratory ERP systems for recording reliable late auditory ERPs (P1, N1, P2, N2, and the P3) over the frontal cortices. In the future, the gaming EEG system may also prove useful for measuring less reliable ERPs, such as the MMN, if the reliability of such ERPs can be boosted to the same level as late auditory ERPs.

Late Auditory Event-Related Potentials in Children With Cochlear Implants: A Review

The body of event-related potential (ERP) literature focusing on children with cochlear implants is growing. By studying ERPs with late latencies (>75 msec), it is possible to (a) document the emergence and quality of higher-order auditory skills prior to when valid behavioral testing is possible, (b) determine the existence of a critical period for auditory stimulation, and (c) establish whether late latency ERPs are predictive of speech and language outcomes. These topics and future directions are addressed in this review of P1 through P600 ERP studies on children with cochlear implants.