Closed head injury-related information processing deficits: An event-related potential analysis

Comprehensive behavioral and physiologic assessment of peripheral and central auditory function in individuals with mild traumatic brain injury

Auditory complaints are frequently reported by individuals with mild traumatic brain injury (mTBI) yet remain difficult to detect in the absence of clinically significant hearing loss. This highlights a growing need to identify sensitive indices of auditory-related mTBI pathophysiology beyond pure-tone thresholds for improved hearing healthcare diagnosis and treatment. Given the heterogeneity of mTBI etiology and the diverse peripheral and central processes required for normal auditory function, the present study sought to determine the audiologic assessments sensitive to mTBI pathophysiology at the group level using a well-rounded test battery of both peripheral and central auditory system function. This test battery included pure-tone detection thresholds, word understanding in quiet, sentence understanding in noise, distortion product otoacoustic emissions (DPOAEs), middle-ear muscle reflexes (MEMRs), and auditory evoked potentials (AEPs), including auditory brainstem responses (ABRs), middle latency responses (MLRs), and late latency responses (LLRs). Each participant also received magnetic resonance imaging (MRI). Compared to the control group, we found that individuals with mTBI had reduced DPOAE amplitudes that revealed a compound effect of age, elevated MEMR thresholds for an ipsilateral broadband noise elicitor, longer ABR Wave I latencies for click and 4 kHz tone burst elicitors, longer ABR Wave III latencies for 4 kHz tone bursts, larger MLR Na and Nb amplitudes, smaller MLR Pb amplitudes, longer MLR Pa latencies, and smaller LLR N1 amplitudes for older individuals with mTBI. Further, mTBI individuals with combined hearing difficulty and noise sensitivity had a greater number of deficits on thalamic and cortical AEP measures compared to those with only one/no self-reported auditory symptoms. This finding was corroborated with MRI, which revealed significant structural differences in the auditory cortical areas of mTBI participants who reported combined hearing difficulty and noise sensitivity, including an enlargement of left transverse temporal gyrus (TTG) and bilateral planum polare (PP). These findings highlight the need for continued investigations toward identifying individualized audiologic assessments and treatments that are sensitive to mTBI pathophysiology.

Auditory attention measured by EEG in neurological populations: systematic review of literature and meta-analysis

Sensorimotor synchronization strategies have been frequently used for gait rehabilitation in different neurological populations. Despite these positive effects on gait, attentional processes required to dynamically attend to the auditory stimuli needs elaboration. Here, we investigate auditory attention in neurological populations compared to healthy controls quantified by EEG recordings. Literature was systematically searched in databases PubMed and Web of Science. Inclusion criteria were investigation of auditory attention quantified by EEG recordings in neurological populations in cross-sectional studies. In total, 35 studies were included, including participants with Parkinson's disease (PD), stroke, Traumatic Brain Injury (TBI), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS). A meta-analysis was performed on P3 amplitude and latency separately to look at the differences between neurological populations and healthy controls in terms of P3 amplitude and latency. Overall, neurological populations showed impairments in auditory processing in terms of magnitude and delay compared to healthy controls. Consideration of individual auditory processes and thereafter selecting and/or designing the auditory structure during sensorimotor synchronization paradigms in neurological physical rehabilitation is recommended.

Prefrontal cortex neural activity predicts reduction of non-suicidal self-injury in adolescents with major depressive disorder: An event related potential study

Background

Non-suicidal self-injury (NSSI) is common in adolescent MDD, which is also a risk factor for suicide. However, there is few research on biomarkers and predictors about treatment response of NSSI. The purpose of this study was to find the difference of P300 between adolescent MDD with NSSI and healthy controls, and to explore whether the baseline electrophysiological level can predict the change of NSSI after treatment.

Methods

We collected 62 first-episode drug-naïve MDD adolescents with NSSI (MDD with NSSI group) and 44 healthy controls (HC group). The demographic data, HAMD score, self-injury frequency and electrophysiological level of NSSI group and HC group were collected. The HAMD score, frequency of NSSI in was also collected after 8 weeks of antidepressant treatment.

Results

Compared to HC, the latency of the N2, P3a, and P3b components were significantly prolonged, whereas the amplitude of P3a and P3b were decreased in the MDD with NSSI group (P < 0.001). The frequency of self-injury decreased significantly after treatment (P < 0.001). Regression analysis showed that the amplitudes of P3b had a significant positive predictive effect on the rate of change of NSSI frequency after 8 weeks.

Conclusion

P3b at baseline can be used as potential predictor for the reduction of NSSI in adolescent MDD.

EEG reveals deficits in sensory gating and cognitive processing in asymptomatic adults with a history of concussion

OBJECTIVE

Individuals with a concussion history tend to perform worse on dual-tasks compared controls but the underlying neural mechanisms contributing to these deficits are not understood. This study used event-related potentials (ERPs) to investigate sensory gating and cognitive processing in athletes with and without a history of concussion while they performed a challenging dual-task.

METHODS

We recorded sensory (P50, N100) and cognitive (P300) ERPs in 30 athletes (18 no previous concussion; 12 history of concussion) while they simultaneously performed an auditory oddball task and a working memory task that progressively increased in difficulty.

RESULTS

The concussion group had reduced auditory performance as workload increased compared to the no-concussion group. Sensory gating and cognitive processing were reduced in the concussion group indicating problems with filtering relevant from irrelevant information and appropriately allocating resources. Sensory gating (N100) was positively correlated with cognitive processing (P300) at the hardest workload in the no-concussion group but negatively correlated in the concussion group.

CONCLUSION

Concussions result in long-term problems in behavioral performance, which may be due to poorer sensory gating that impacts cognitive processing.

SIGNIFICANCE

Problems effectively gating sensory information may influence the availability or allocation of attention at the cognitive stage in those with a concussion.

Auditory evoked brain potentials as markers of chronic effects of mild traumatic brain injury in mid-life

OBJECTIVE

Auditory event-related potential (ERP) correlates of pre-dementia in late-life may also be sensitive to chronic effects of mild traumatic brain injury (mTBI) in mid-life. In addition to mTBI history, other clinical factors may also influence ERP measures of brain function. This study's objective was to evaluate the relationship between mTBI history, auditory ERP metrics, and common comorbidities.

METHODS

ERPs elicited during an auditory target detection task, psychological symptoms, and hearing sensitivity were collected in 152 combat-exposed veterans and service members, as part of a prospective observational cohort study. Participants, with an average age of 43.6 years, were grouped according to positive (n = 110) or negative (n = 42) mTBI history. Positive histories were subcategorized into repetitive mTBI (3 + ) (n = 40) or non-repetitive (1-2) (n = 70).

RESULTS

Positive history of mTBI was associated with reduced N200 amplitude to targets and novel distractors. In participants with repetitive mTBI compared to non-repetitive and no mTBI, P50 was larger in response to nontargets and N100 was smaller in response to nontargets and targets. Changes in N200 were mediated by depression and anxiety symptoms and hearing loss, with no evidence of a supplementary direct mTBI pathway.

CONCLUSIONS

Auditory brain function differed between the positive and negative mTBI groups, especially for repetitive injury, which implicated more basic, early auditory processing than did any mTBI exposure. Symptoms of internalizing psychopathology (depression and anxiety) and hearing loss are implicated in mTBI's diminished brain responses to behaviorally relevant and novel stimuli.

SIGNIFICANCE

A mid-life neurologic vulnerability conferred by mTBI, particularly repetitive mTBI, may be detectable using auditory brain potentials, and so auditory ERPs are a target for study of dementia risk in this population.

Event related potentials indexing the influence of emotion on cognitive processing in veterans with comorbid post-traumatic stress disorder and traumatic brain injury

OBJECTIVE

Emotion regulation and cognitive executive control are significantly impaired in both post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI). These illnesses are increasingly common in veterans and their co-occurrence may exacerbate symptoms and recovery. The current study sought to investigate neural correlates of these impairments via event-related potentials (ERPs) and examined the association of PTSD symptom severity and impulsivity with these correlates.

METHODS

Electroencephalographic data from seventy-nine veterans with PTSD and TBI and 17 control participants were recorded during a visual emotional oddball task and analyzed for the N2 and P3b ERPs.

RESULTS

Results revealed that veterans showed a reduced P3b ERP in response to both target images and standard images. However, for standard images that followed a negative emotional distractor, the veterans showed a heightened N2 amplitude while the controls did not. In addition, impulsivity predicted modulation of the P3b across stimulus conditions, with a greater P3b amplitude associated with an increase in impulsivity.

CONCLUSIONS

These findings suggest that veterans showed hyper-responsivity to background information and reduced ERPs to task-relevant information.

SIGNIFICANCE

These findings may reflect heightened internal states that create neural noise and a reduced ability to modulate relevant responses.

Toward a global and reproducible science for brain imaging in neurotrauma: the ENIGMA adult moderate/severe traumatic brain injury working group

The global burden of mortality and morbidity caused by traumatic brain injury (TBI) is significant, and the heterogeneity of TBI patients and the relatively small sample sizes of most current neuroimaging studies is a major challenge for scientific advances and clinical translation. The ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Adult moderate/severe TBI (AMS-TBI) working group aims to be a driving force for new discoveries in AMS-TBI by providing researchers world-wide with an effective framework and platform for large-scale cross-border collaboration and data sharing. Based on the principles of transparency, rigor, reproducibility and collaboration, we will facilitate the development and dissemination of multiscale and big data analysis pipelines for harmonized analyses in AMS-TBI using structural and functional neuroimaging in combination with non-imaging biomarkers, genetics, as well as clinical and behavioral measures. Ultimately, we will offer investigators an unprecedented opportunity to test important hypotheses about recovery and morbidity in AMS-TBI by taking advantage of our robust methods for large-scale neuroimaging data analysis. In this consensus statement we outline the working group's short-term, intermediate, and long-term goals.

Selective impairment of auditory attention processing in idiopathic generalized epilepsies: Implications for their cognitive pathophysiology

The neuropsychological characteristics of Idiopathic Generalized Epilepsies (IGEs) as a wide syndrome encompassing different clinical entities have been as yet not well understood. We have studied neuropsychological performance in patients suffering Juvenile Myoclonic Epilepsy (JME) and Generalized Tonic Clonic Seizures (IGE-GTCS-only) to provide indirect-cognitive evidence on the pathophysiology of IGE-related neuropsychological dysfunction. Greater arousal-related impairments were expected for the auditory modality, by drawing on previous anatomo-clinical and neuro-evolutionary accounts. We have studied neurocognitive functioning in 26 IGE patients, suffering either JME (n = 16) or IGE-GTCS-only (n = 10), and their healthy counterparts consisted of 26 (18 females) demographically matched participants. IGE patients (JME and IGE-GTCS-only) did worse with respect to HC (healthy controls) in visual- and auditory- speed of information processing (reaction time), auditory-vigilance and -response inhibition, visuo-motor coordination, visual working memory and motor speed, delayed visual recall, immediate- and delayed verbal episodic recall, lexical access and retrieval, semantic associative processing, auditory-verbal memory span and verbal learning. Although both IGE-GTCS-only and JME patients delayed episodic recall was defective, the former did significantly worse. We believe that IGE patients' neuropsychological derailments represent indirect-secondary manifestations of a primary cortical tone deregulation inherent to IGEs' pathophysiology. In particular, IGE patients' worse-dissociated performance in auditory TOVA-also seen previously in TBI and schizophrenia-may implicate a grater vulnerability of the auditory information processing system, as well as a possibly shared cognitive pathophysiological component between IGE and the above nosologies.

Effects of Signal Type and Noise Background on Auditory Evoked Potential N1, P2, and P3 Measurements in Blast-Exposed Veterans

OBJECTIVES

Veterans who have been exposed to high-intensity blast waves frequently report persistent auditory difficulties such as problems with speech-in-noise (SIN) understanding, even when hearing sensitivity remains normal. However, these subjective reports have proven challenging to corroborate objectively. Here, we sought to determine whether use of complex stimuli and challenging signal contrasts in auditory evoked potential (AEP) paradigms rather than traditional use of simple stimuli and easy signal contrasts improved the ability of these measures to (1) distinguish between blast-exposed Veterans with auditory complaints and neurologically normal control participants, and (2) predict behavioral measures of SIN perception.

DESIGN

A total of 33 adults (aged 19-56 years) took part in this study, including 17 Veterans exposed to high-intensity blast waves within the past 10 years and 16 neurologically normal control participants matched for age and hearing status with the Veteran participants. All participants completed the following test measures: (1) a questionnaire probing perceived hearing abilities; (2) behavioral measures of SIN understanding including the BKB-SIN, the AzBio presented in 0 and +5 dB signal to noise ratios (SNRs), and a word-level consonant-vowel-consonant test presented at +5 dB SNR; and (3) electrophysiological tasks involving oddball paradigms in response to simple tones (500 Hz standard, 1000 Hz deviant) and complex speech syllables (/ba/ standard, /da/ deviant) presented in quiet and in four-talker speech babble at a SNR of +5 dB.

RESULTS

Blast-exposed Veterans reported significantly greater auditory difficulties compared to control participants. Behavioral performance on tests of SIN perception was generally, but not significantly, poorer among the groups. Latencies of P3 responses to tone signals were significantly longer among blast-exposed participants compared to control participants regardless of background condition, though responses to speech signals were similar across groups. For cortical AEPs, no significant interactions were found between group membership and either stimulus type or background. P3 amplitudes measured in response to signals in background babble accounted for 30.9% of the variance in subjective auditory reports. Behavioral SIN performance was best predicted by a combination of N1 and P2 responses to signals in quiet which accounted for 69.6% and 57.4% of the variance on the AzBio at 0 dB SNR and the BKB-SIN, respectively.

CONCLUSIONS

Although blast-exposed participants reported far more auditory difficulties compared to controls, use of complex stimuli and challenging signal contrasts in cortical and cognitive AEP measures failed to reveal larger group differences than responses to simple stimuli and easy signal contrasts. Despite this, only P3 responses to signals presented in background babble were predictive of subjective auditory complaints. In contrast, cortical N1 and P2 responses were predictive of behavioral SIN performance but not subjective auditory complaints, and use of challenging background babble generally did not improve performance predictions. These results suggest that challenging stimulus protocols are more likely to tap into perceived auditory deficits, but may not be beneficial for predicting performance on clinical measures of SIN understanding. Finally, these results should be interpreted with caution since blast-exposed participants did not perform significantly poorer on tests of SIN perception.

Auditory and Visual P300 Responses in Early Cognitive Assessment of Children and Adolescents with Epilepsy

Background:

The event-related potential P300 has been suggested to be valuable in the assessment of cognitive dysfunctions. Not a great deal of neurophysiological assessment has been performed at early stages in patients with epilepsy involving visual and auditory P300 measures.

Aims and Objectives:

This study aimed to assess the cognitive status in patients with epilepsy earlier by visual and auditory P300 and to find their correlation with various risk factors.

Materials and Methods:

P300 was recorded in 60 children with epilepsy in the age-group of 5–18 years and 60 age- and sex-matched controls by a rare-frequent (oddball) paradigm. Mean auditory and visual P300 latencies and amplitudes were compared among patients with epilepsy and controls and among patients with generalized and focal epilepsy by unpaired t-test. Pearson’s correlation coefficient test was computed for studying the correlation between risk factors and P300 responses. A value of P < 0.05 was considered statistically significant.

Results:

Statistically significant delay in P300 latencies and reduction in amplitudes (both visual and auditory) was found in patients with epilepsy as compared to controls and also among patients with generalized and focal epilepsy. In generalized epilepsy, both visual and auditory P300 revealed significant delay, whereas only auditory P300 delay was found in focal form. No significant correlation was obtained with risk factors. No significant difference was found in P300 responses among patients with and without antiepileptic treatment.

Conclusion:

Visual and auditory P300 latencies have an important role in the evaluation of early cognitive dysfunctions in children with epilepsy. P300 potentials are not influenced by antiepileptic treatment, whereas the type of epilepsy alters them

Acquired Central Auditory Processing Disorder in Service Members and Veterans

Purpose A growing body of evidence suggests that military service members and military veterans are at risk for deficits in central auditory processing. Risk factors include exposure to blast, neurotrauma, hazardous noise, and ototoxicants. We overview these risk factors and comorbidities, address implications for clinical assessment and care of central auditory processing deficits in service members and veterans, and specify knowledge gaps that warrant research. Method We reviewed the literature to identify studies of risk factors, assessment, and care of central auditory processing deficits in service members and veterans. We also assessed the current state of the science for knowledge gaps that warrant additional study. This literature review describes key findings relating to military risk factors and clinical considerations for the assessment and care of those exposed. Conclusions Central auditory processing deficits are associated with exposure to known military risk factors. Research is needed to characterize mechanisms, sources of variance, and differential diagnosis in this population. Existing best practices do not explicitly consider confounds faced by military personnel. Assessment and rehabilitation strategies that account for these challenges are needed. Finally, investment is critical to ensure that Veterans Affairs and Department of Defense clinical staff are informed, trained, and equipped to implement effective patient care.

A Review of the Role of Auditory Evoked Potentials in Mild Traumatic Brain Injury Assessment

Around 75% to 90% of people who experience a traumatic brain injury (TBI) are classified as having a mild TBI (mTBI). The term mTBI is synonymous with concussion or mild head injury (MHI) and is characterized by symptoms of headache, nausea, dizziness, and blurred vision. Problems in cognitive abilities such as deficits in memory, processing speed, executive functioning, and attention are also considered symptoms of mTBI. Since these symptoms are subtle in nature and may not appear immediately following the injury, mTBI is often undetected on conventional neuropsychological tests. Current neuroimaging techniques may not be sensitive enough in identifying the array of microscopic neuroanatomical and subtle neurophysiological changes following mTBI. To this end, electrophysiological tests, such as auditory evoked potentials (AEPs), can be used as sensitive tools in tracking physiological changes underlying physical and cognitive symptoms associated with mTBI. The purpose of this review article is to examine the body of literature describing the application of AEPs in the assessment of mTBI and to explore various parameters of AEPs which may hold diagnostic value in predicting positive rehabilitative outcomes for people with mTBI.

Executive (dys)function after traumatic brain injury: special considerations for behavioral pharmacology

Executive function is an umbrella term that includes cognitive processes such as decision-making, impulse control, attention, behavioral flexibility, and working memory. Each of these processes depends largely upon monoaminergic (dopaminergic, serotonergic, and noradrenergic) neurotransmission in the frontal cortex, striatum, and hippocampus, among other brain areas. Traumatic brain injury (TBI) induces disruptions in monoaminergic signaling along several steps in the neurotransmission process - synthesis, distribution, and breakdown - and in turn, produces long-lasting deficits in several executive function domains. Understanding how TBI alters monoamingeric neurotransmission and executive function will advance basic knowledge of the underlying principles that govern executive function and potentially further treatment of cognitive deficits following such injury. In this review, we examine the influence of TBI on the following measures of executive function - impulsivity, behavioral flexibility, and working memory. We also describe monoaminergic-systems changes following TBI. Given that TBI patients experience alterations in monoaminergic signaling following injury, they may represent a unique population with regard to pharmacotherapy. We conclude this review by discussing some considerations for pharmacotherapy in the field of TBI.

Impaired auditory processing and neural representation of speech in noise among symptomatic post-concussion adults

Background: The purpose of the study was to examine auditory event-related potential (AERP) evidence of changes in earlier and later stages of auditory processing in individuals with long-term post-concussion problems compared to healthy controls, with a secondary aim of comparing AERPs by functional auditory behavioral outcomes. Methods: P1-N1-P2 complex and P300 components recorded to speech in quiet and background noise conditions were completed in individuals with ongoing post-concussion symptoms following mTBI and healthy controls. AERPs were also examined between sub-groups with normal or impaired auditory processing by behavioral tests. Results: Group differences were present for later stages of auditory processing (P300). Earlier components did not significantly differ by group overall but were more affected by noise in the mTBI group. P2 amplitude in noise differed between mTBI sub-groups with normal or impaired auditory processing. Conclusion: AERPs revealed differences between healthy controls and those with chronic post-concussion symptoms following mTBI at a later stage of auditory processing (P300). Neural processing at the earlier stage (P1-N1-P2) was more affected by noise in the mTBI group. Preliminary evidence suggested that it may be only the proportion of individuals with functional evidence of central auditory dysfunction with changes in AERPs at earlier stages of processing.

Hearing complaints among veterans following traumatic brain injury

It has been shown that there is an increased risk for impaired auditory function following traumatic brain injury (TBI) in Veterans. Evidence is strongest in the area of self-report, but behavioural and electro-physiological data have been obtained that are consistent with these complaints. Peripheral and central dysfunction have both been observed. Historically, studies have focused on penetrating head injuries where central injury is more easily documented than in mild closed head injuries, but several recent reports have expanded the literature to include closed head injuries as well. The lack of imaging technology that can identify which closed head injuries are likely to impact auditory function is a significant barrier to accurate diagnosis and rehabilitation. Current behavioural and electrophysiological measures are effective in substantiating the auditory complaints of these patients but leave many questions unanswered. One significant limitation of current approaches is the lack of clear data regarding the potential influence of those mental health comorbidities that are very likely to be present in the Veteran population. In the area of rehabilitation, there are indications that hearing aids and other assistive listening devices may provide benefit, as can auditory training programmes, yet more research needs to be done.

History of concussion impacts electrophysiological correlates of working memory

Sports-related concussions occur in approximately 21% of college athletes with implications for long-term cognitive impairments in working memory. Working memory involves the capacity to maintain short-term information and integrate with higher-order cognitive processing for planning and behavior execution, critical skills for optimal cognitive and athletic performance. This study quantified working memory impairments in 36 American football college athletes (18-23years old) using event-related potentials (ERPs). Despite performing similarly in a standard 2-back working memory task, athletes with history of concussion exhibited larger P1 and P3 amplitudes compared to Controls. Concussion History group latencies were slower for the P1 and faster for the N2. Source estimation analyses indicated that previously concussed athletes engaged different brain regions compared to athletes with no concussion history. These findings suggest that ERPs may be a sensitive and objective measure to detect long-term cognitive consequences of concussion.

Longitudinal study of a NoGo-P3 event-related potential component following mild traumatic brain injury in adults

BACKGROUND

Event-related potentials have repeatedly revealed electrophysiological markers of cognitive dysfunction associated with Mild Traumatic Brain Injury (MTBI) and may represent a sensitive tool to guide cognitive rehabilitative interventions. We previously found patients with symptomatic MTBI characterized by smaller P300 (or P3) wave amplitudes in a NoGo-P3 subcomponent in the acute phase of the injury. The goal of this longitudinal study was to investigate whether this early NoGo-P3 subcomponent differs over time in symptomatic MTBI patients and healthy controls.

METHODS

We included adults with a diagnosis of MTBI and individually matched healthy controls tested at 1 week, 3 months, and 1 year after the MTBI. Symptoms were assessed by the Rivermead Post-Concussion Symptoms Questionnaire. NoGo-P3 was collected by using a cued Go/NoGo task and the relevant subcomponent was extracted by independent component analysis.

RESULTS

Among 53 adults with a diagnosis of MTBI and 53 controls, we included 35 with symptomatic MTBI and 35 matched healthy controls (18 females each group; mean age 34.06±13.15 and 34.26±12.98 years). Amplitudes for the early NoGo-P3 subcomponent were lower for symptomatic MTBI patients than controls (P<0.05) at 1 week post-injury. Furthermore, mixed ANOVA revealed a significant time by group interaction (P<0.05), so the effect of time differed for symptomatic MTBI patients and healthy controls. The amplitudes for MTBI patients normalized from 1 week to 3 months post-injury and were comparable to those of controls from 3 months to 1 year post-injury. However, amplitudes for 3 MTBI patients with particularly severe complaints 1 year post-injury did not normalize and were lower than those for the remaining MTBI sample (P<0.05).

CONCLUSIONS

Selected event-related potentials can be used as a sensitive and objective tool to illustrate the cognitive consequences of and recovery after MTBI.

Auditory Processing After Traumatic Brain Injury

Auditory processing involves many diverse aspects of the peripheral and central nervous system. Where “simple” transformation of information ends and “signal processing” begins is difficult to say with any certainty, and the distinction between “automatic” processing and “controlled” processing is an even more philosophical question. For these reasons, the damage that occurs in one portion of the nervous system can have serious implications for many other parts of the system. For this reason, it is essential that clinicians involved in working with patients for whom any portion of the auditory system is at risk need to be in close communication with those who specialize in understanding the other parts of this delicate and interwoven system.

The Application of the International Classification of Functioning, Disability and Health to Functional Auditory Consequences of Mild Traumatic Brain Injury

This article reviews the auditory consequences of mild traumatic brain injury (mTBI) within the context of the International Classification of Functioning, Disability and Health (ICF). Because of growing awareness of mTBI as a public health concern and the diverse and heterogeneous nature of the individual consequences, it is important to provide audiologists and other health care providers with a better understanding of potential implications in the assessment of levels of function and disability for individual interdisciplinary remediation planning. In consideration of body structures and function, the mechanisms of injury that may result in peripheral or central auditory dysfunction in mTBI are reviewed, along with a broader scope of effects of injury to the brain. The activity limitations and participation restrictions that may affect assessment and management in the context of an individual's personal factors and their environment are considered. Finally, a review of management strategies for mTBI from an audiological perspective as part of a multidisciplinary team is included.

P300 Amplitude in Alzheimer's Disease: A Meta-Analysis and Meta-Regression

Alzheimer's disease accounts for 60% of all dementia. Numerous biomarkers have been developed that can help in making an early diagnosis. The P300 is an event-related potential that may be abnormal in Alzheimer's disease. Given the possible association between P300 amplitude and Alzheimer's disease and the need for biomarkers in early Alzheimer's disease, the main purpose of this meta-analysis and meta-regression was to characterize P300 amplitude in probable Alzheimer's disease compared to healthy controls. Using online search engines, we identified peer-reviewed articles containing amplitude measures for the P300 in response to a visual or auditory oddball stimulus in subjects with Alzheimer's disease and in a healthy control group and pooled effect sizes for differences in P300 amplitude between Alzheimer's disease and control groups to obtain summary effect sizes. We also used meta-regression to determine whether age, sex, educational attainment, or dementia severity affected the association between P300 amplitude and Alzheimer's disease. Twenty articles containing a total of 646 subjects met inclusion and exclusion criteria. The overall effect size from all electrode locations was 1.079 (95% confidence interval=0.745-1.412, P<.001). The pooled effect sizes for the Cz, Fz, and Pz locations were 1.226 (P<.001), 0.724 (P=.0007), and 1.430 (P<.001), respectively. Meta-regression showed an association between amplitude and educational attainment, but no association between amplitude and age, sex, and dementia severity. In conclusion, P300 amplitude is smaller in subjects with Alzheimer's disease than in healthy controls.

Visuospatial attention after traumatic brain injury: The role of hemispheric specialization

PRIMARY OBJECTIVE

To evaluate the behavioural and neural effects of TBI on the hemispheric integrity of three components of visuospatial attention: alerting, orienting and executive control.

METHOD

Behavioural performance and high density event-related potentials (ERPs) were acquired while a sample of 12 patients with chronic moderate-to-severe TBI and 12 controls performed the Lateralized Attention Network Test (LANT). Neural indices of attention (posterior N1 amplitude to alerting and orienting cues, midline P3 amplitude during conflict resolution) were examined.

RESULTS

Patients with TBI exhibited smaller N1 amplitude to alerting cues, but comparable behavioural performance to controls. Participants with TBI also demonstrated poorer orienting performance to the left hemispace relative to the right. A corresponding reduction in right hemisphere N1 was found during left orienting to spatial cues in the TBI group. No group differences were observed on behavioural measures of executive control; however, patients with TBI exhibited reduced P3 amplitude overall.

CONCLUSIONS

TBI may have an enduring effect on the orienting system at both neural and behavioural levels. Assessment of attention in chronic TBI can be improved by the integration of hemispheric findings that suggest disproportionate vulnerability in leftward orienting. Results may enhance clinical sensitivity to detection of subtle signs of neglect.

Treating Postconcussion Syndrome with LORETA Z-Score Neurofeedback and Heart Rate Variability Biofeedback: Neuroanatomical/Neurophysiological Rationale, Methods, and Case Examples

Media attention has highlighted the critical problem of concussion injuries in sport and the challenge of treating and rehabilitating individuals with traumatic brain injury. The authors present a framework for the treatment of traumatic brain injury, using low-resolution electromagnetic tomography Z-score based neurofeedback and heart rate–variability biofeedback. The article advocates a comprehensive assessment process including the use of a 19-channel quantitative electroencephalogram, a heart rate variability baseline, and symptom severity questionnaires for attention deficit/hyperactivity disorder, depression, and anxiety. The initial medical assessment, neuropsychological assessment, and evoked potential studies also have potential for a more precise assessment of deficits in brain activation patterns, which assists the targeting of neurofeedback training.

Traumatic brain injury detection using electrophysiological methods

Measuring neuronal activity with electrophysiological methods may be useful in detecting neurological dysfunctions, such as mild traumatic brain injury (mTBI). This approach may be particularly valuable for rapid detection in at-risk populations including military service members and athletes. Electrophysiological methods, such as quantitative electroencephalography (qEEG) and recording event-related potentials (ERPs) may be promising; however, the field is nascent and significant controversy exists on the efficacy and accuracy of the approaches as diagnostic tools. For example, the specific measures derived from an electroencephalogram (EEG) that are most suitable as markers of dysfunction have not been clearly established. A study was conducted to summarize and evaluate the statistical rigor of evidence on the overall utility of qEEG as an mTBI detection tool. The analysis evaluated qEEG measures/parameters that may be most suitable as fieldable diagnostic tools, identified other types of EEG measures and analysis methods of promise, recommended specific measures and analysis methods for further development as mTBI detection tools, identified research gaps in the field, and recommended future research and development thrust areas. The qEEG study group formed the following conclusions: (1) Individual qEEG measures provide limited diagnostic utility for mTBI. However, many measures can be important features of qEEG discriminant functions, which do show significant promise as mTBI detection tools. (2) ERPs offer utility in mTBI detection. In fact, evidence indicates that ERPs can identify abnormalities in cases where EEGs alone are non-disclosing. (3) The standard mathematical procedures used in the characterization of mTBI EEGs should be expanded to incorporate newer methods of analysis including non-linear dynamical analysis, complexity measures, analysis of causal interactions, graph theory, and information dynamics. (4) Reports of high specificity in qEEG evaluations of TBI must be interpreted with care. High specificities have been reported in carefully constructed clinical studies in which healthy controls were compared against a carefully selected TBI population. The published literature indicates, however, that similar abnormalities in qEEG measures are observed in other neuropsychiatric disorders. While it may be possible to distinguish a clinical patient from a healthy control participant with this technology, these measures are unlikely to discriminate between, for example, major depressive disorder, bipolar disorder, or TBI. The specificities observed in these clinical studies may well be lost in real world clinical practice. (5) The absence of specificity does not preclude clinical utility. The possibility of use as a longitudinal measure of treatment response remains. However, efficacy as a longitudinal clinical measure does require acceptable test-retest reliability. To date, very few test-retest reliability studies have been published with qEEG data obtained from TBI patients or from healthy controls. This is a particular concern because high variability is a known characteristic of the injured central nervous system.

Cigarette smoking and p300 amplitude in adults: a systematic review

OBJECTIVE

To determine the association between chronic tobacco cigarette smoking and P300 amplitude.

DESIGN

Systematic review with meta-analysis and meta-regression.

DATA SOURCES

Medline, Cochrane Database of Systematic Reviews, PsychInfo, and Web of Science.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligible studies contained P300 amplitudes obtained from either visual or auditory stimuli and standard deviations or errors in female and male subjects older than 18 years in a group of nonabstaining chronic cigarette smokers and a nonsmoking control group.

RESULTS

The 9 eligible studies comprised 13 relevant datasets containing 1,956 current cigarette smokers and 2,194 nonsmoking controls (N = 4,150). The P300 amplitude was smaller in cigarette smokers than in nonsmoking controls (Hedges' g effect size = .365; 95% confidence interval [CI] = 0.196-0.534, p < .001). Meta-regression showed significant positive associations between the number of cigarettes smoked per day at the time of the study (slope estimate = .036, 95% CI = 0.016-0.056, p ≤ .001, length of smoking in years (slope estimate = .056, 95% CI = 0.005-0.102, p = .018), pack years (slope estimate = .018, 95% CI = 0.009-0.031 p = .009), and age (slope estimate = .068, 95% CI = 0.025-0.113, p = .002).

CONCLUSIONS

P300 amplitude was smaller in cigarette smokers than in nonsmoking controls, and a possible dose-response relationship was apparent. Findings indicate a possible association between cigarette smoking and decreased P300 amplitude.

The persistent influence of concussive injuries on cognitive control and neuroelectric function

CONTEXT

Increasing attention is being paid to the deleterious effects of sport-related concussion on cognitive and brain health.

OBJECTIVE

To evaluate the influence of concussion incurred during early life on the cognitive control and neuroelectric function of young adults.

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Forty young adults were separated into groups according to concussive history (0 or 1+). Participants incurred all injuries during sport and recreation before the age of 18 years and were an average of 7.1 ± 4.0 years from injury at the time of the study.

INTERVENTION(S)

All participants completed a 3-stimulus oddball task, a numeric switch task, and a modified flanker task during which event-related potentials and behavioral measures were collected.

MAIN OUTCOME MEASURE(S)

Reaction time, response accuracy, and electroencephalographic activity.

RESULTS

Compared with control participants, the concussion group exhibited decreased P3 amplitude during target detection within the oddball task and during the heterogeneous condition of the switch task. The concussion group also displayed increased N2 amplitude during the heterogeneous version of the switch task. Concussion history was associated with response accuracy during the flanker task.

CONCLUSIONS

People with a history of concussion may demonstrate persistent decrements in neurocognitive function, as evidenced by decreased response accuracy, deficits in the allocation of attentional resources, and increased stimulus-response conflict during tasks requiring variable amounts of cognitive control. Neuroelectric measures of cognitive control may be uniquely sensitive to the persistent and selective decrements of concussion.

Reduced N400 semantic priming effects in adult survivors of paediatric and adolescent traumatic brain injury

The immediate and long-term neural correlates of linguistic processing deficits reported following paediatric and adolescent traumatic brain injury (TBI) are poorly understood. Therefore, the current research investigated event-related potentials (ERPs) elicited during a semantic picture-word priming experiment in two groups of highly functioning individuals matched for various demographic variables and behavioural language performance. Participants in the TBI group had a recorded history of paediatric or adolescent TBI involving injury mechanisms associated with diffuse white matter pathology, while participants in the control group never sustained any insult to the brain. A comparison of N400 Mean Amplitudes elicited during three experimental conditions with varying semantic relatedness between the prime and target stimuli (congruent, semantically related, unrelated) revealed a significantly smaller N400 response in the unrelated condition in the TBI group, indicating residual linguistic processing deviations when processing demands required the quick detection of a between-category (unrelated) violation of semantic expectancy.

Multimodal Analysis: New Approaches to the Concussion Conundrum

Sports-related concussions are complex injuries with biomechanical and biochemical etiology that present with central and autonomic nervous system dysfunction. Current methods for assessing concussions and basing return-to-play decisions rely on symptom resolution, rating scales, and neuropsychological testing, all of which are indirect measures of injury severity and detect functional capabilities but do not directly measure injury location or severity. In addition, these downstream measures are susceptible to false negatives because compensatory mechanism, such as unmasking and redundancies in brain circuitry can return functional capabilities before injury resolution. The multifactorial nature of concussion necessitates rapid, inexpensive, and easily applied multimodal analysis methods that can offer greater sensitivity and specificity. This article discusses how new approaches utilizing electrophysiology (e.g., QEEG, ERP, ECG, HRV), quantified balance measures, and biochemistry are necessary to advance the science of concussion assessment, treatment, recovery projections, and return-to-play decisions. These additional assessment tools offer a more direct window into the severity and location of the injury, real-time measures of brain function, and the ability to measure the multiple body systems negatively affected by concussion.

Avaliação eletrofisiológica da audição em indivíduos após traumatismo cranioencefálico

OBJETIVO: caracterizar o potencial evocado auditivo de tronco encefálico e de longa latência em pacientes pós traumatismo cranioencefálico, comparando-os com indivíduos normais. MÉTODO: estudo clínico transversal realizado com 20 indivíduos audiologicamente normais divididos em dois grupos pareados por idade e sexo: a) 10 indivíduos que sofreram traumatismo cranioencefálico (grupo pesquisa); b) 10 indivíduos sem qualquer tipo de alteração neurológica (grupo controle). Foram submetidos à avaliação audiológica básica, ao potencial evocado auditivo de tronco encefálico e ao potencial evocado auditivo de longa latência (P300). RESULTADOS: observou-se no potencial evocado auditivo de tronco encefálico, latências absolutas das ondas I, III e V e intervalo interpico I-III mais prolongados no grupo pesquisa do que no grupo controle, sendo estatisticamente significante para as latências absolutas das ondas I e III à direita e para a onda III e intervalo interpico I-III à esquerda. A amplitude das ondas I, III e V na orelha direita e das ondas III e V na orelha esquerda foram maiores no grupo controle. Em relação ao P300, o grupo pesquisa apresentou maior latência e menor amplitude em ambas as orelhas, sem significância estatística, quando comparado ao grupo controle. CONCLUSÃO: indivíduos que sofreram traumatismo cranioencefálico apresentam alterações no potencial evocado auditivo de tronco encefálico e não apresentam diferenças significantes no potencial evocado auditivo de longa latência (P300) quando comparados a indivíduos sem lesões cerebrais.

Electrophysiological assessments of cognition and sensory processing in TBI: applications for diagnosis, prognosis and rehabilitation

Traumatic brain injuries are often associated with damage to sensory and cognitive processing pathways. Because evoked potentials (EPs) and event-related potentials (ERPs) are generated by neuronal activity, they are useful for assessing the integrity of neural processing capabilities in patients with traumatic brain injury (TBI). This review of somatosensory, auditory and visual ERPs in assessments of TBI patients is provided with the hope that it will be of interest to clinicians and researchers who conduct or interpret electrophysiological evaluations of this population. Because this article reviews ERP studies conducted in three different sensory modalities, involving patients with a wide range of TBI severity ratings and circumstances, it is difficult to provide a coherent summary of findings. However, some general trends emerge that give rise to the following observations and recommendations: 1) bilateral absence of somatosensory evoked potentials (SEPs) is often associated with poor clinical prognosis and outcome; 2) the presence of normal ERPs does not guarantee favorable outcome; 3) ERPs evoked by a variety of sensory stimuli should be used to evaluate TBI patients, especially those with severe injuries; 4) time since onset of injury should be taken into account when conducting ERP evaluations of TBI patients or interpreting results; 5) because sensory deficits (e.g., vision impairment or hearing loss) affect ERP results, tests of peripheral sensory integrity should be conducted in conjunction with ERP recordings; and 6) patients' state of consciousness, physical and cognitive abilities to respond and follow directions should be considered when conducting or interpreting ERP evaluations.

Decreased prefrontal cortex activity in mild traumatic brain injury during performance of an auditory oddball task

Up to one-third of patients with mild traumatic brain injury (TBI) demonstrate persistent cognitive deficits in the 'executive' function domain. Mild TBI patients have shown prefrontal cortex activity deficits during the performance of executive tasks requiring active information maintenance and manipulation. However, it is unclear whether these deficits are related to the executive processes themselves, or to the degree of mental effort. To determine whether prefrontal deficits also would be found during less effortful forms of executive ability, fMRI images were obtained on 31 mild TBI patients and 31 control participants during three-stimulus auditory oddball task performance. Although patients and controls had similar topographical patterns of brain activity, region-of-interest analysis revealed significantly decreased activity in right dorsolateral prefrontal cortex for mild TBI patients during target stimulus detection. Between-group analyses found evidence for potential compensatory brain activity during target detection and default-mode network dysfunction only during the detection of novel stimuli.

Prefrontal Compensatory Engagement in TBI is due to Altered Functional Engagement Of Existing Networks and not Functional Reorganization

Functional neuroimaging studies of traumatic brain injury (TBI) have demonstrated altered neural recruitment, specifically within prefrontal cortex (PFC). This is manifest typically as increased recruitment of homologous regions of PFC (e.g., right ventrolateral PFC during performance of a verbal working memory task, possibly in response to damage involving the left PFC). The behavioral correlates of these functional changes are poorly understood. We used fMRI and multivariate analytic methods to investigate changes in spatially distributed activity patterns and their behavioral correlates in a sample of TBI patients with diffuse axonal injury (DAI, but without focal injury) and matched healthy controls. Participants performed working memory tasks with varying memory load and executive demand. We identified networks within left and right PFC that uniquely and positively correlated with performance in our control and TBI samples respectively, providing evidence of compensatory functional recruitment. Next we combined brain–behavior and functional connectivity analyses to investigate whether compensatory brain changes were facilitated by functional reorganization (i.e., recruitment of brain regions not engaged by our control sample) or altered functional engagement (i.e., differential recruitment of similar brain regions between the two groups based on task demands). In other words, does altered recruitment represent the instantiation of novel neural networks to support working memory performance after injury or the unmasking of extant, but behaviorally latent, functional connectivity? Our results support an altered functional engagement hypothesis. Areas within PFC that are normally coactivated during working memory are behaviorally relevant at an earlier stage of difficulty for TBI patients as compared to controls. This altered functional engagement, also evident in the aging literature, is attributable to distributed changes owing to significant DAI.

Traumatic brain injury, major depression, and diffusion tensor imaging: making connections

It is common for depression to develop after traumatic brain injury (TBI), yet despite poorer recovery, there is a lack in our understanding of whether post-TBI brain changes involved in depression are akin to those in people with depression without TBI. Modern neuroimaging has helped recognize degrees of diffuse axonal injury (DAI) as being related to extent of TBI, but its ability to predict long-term functioning is limited and has not been considered in the context of post-TBI depression. A more recent brain imaging technique (diffusion tensor imaging; DTI) can measure the integrity of white matter by measuring the directionality or anisotropy of water molecule diffusion along the axons of nerve fibers.

AIM

To review DTI results in the TBI and depression literatures to determine whether this can elucidate the etiology of the development of depression after TBI.

METHOD

We reviewed the TBI/DTI (40 articles) and depression/DTI literatures (17 articles). No articles were found that used DTI to investigate depression post-TBI, although there were some common brain regions identified between the TBI/DTI and depression/DTI studies, including frontotemporal, corpus callosum, and structures contained within the basal ganglia. Specifically, the internal capsule was commonly reported to have significantly reduced fractional anisotropy, which agrees with deep brain stimulation studies.

CONCLUSION

It is suggested that measuring the degree of DAI by utilizing DTI in those with or without depression post-TBI, will greatly enhance prediction of functional outcome.

Cortical event-related potentials in preclinical familial Alzheimer disease

OBJECTIVE

To define changes in cortical function in persons inheriting familial Alzheimer disease (FAD) mutations before the onset of cognitive decline.

METHODS

Twenty-six subjects with a family history of FAD were divided into 2 subgroups according to genotype (FAD mutation carriers, n = 15; FAD noncarriers, n = 11). Subjects were given standardized tests of cognitive function and the Clinical Dementia Rating scale (CDR). Sensory (P50, N100, P200) and cognitive (N200, P300) event-related potentials were recorded during an auditory discrimination task. Amplitudes and latencies of cortical potentials were compared among FAD mutation carriers and noncarriers.

RESULTS

FAD mutation carriers and noncarriers did not significantly differ in age or on measures of cognitive function, but FAD carriers had a greater incidence of 0.5 CDR scores (1/10 noncarriers, 5/15 carriers). Relative to noncarriers, FAD mutation carriers had significantly longer latencies of the N100, P200, N200, and P300 components, and smaller slow wave amplitudes. Subanalyses of subjects having CDR scores of 0.0 also showed latency increases in FAD mutation carriers.

CONCLUSIONS

Auditory sensory and cognitive cortical potentials in persons with familial Alzheimer disease (FAD) mutations are abnormal approximately 10 years before dementia will be manifest. Longer event-related potential latencies suggest slowing of cortical information processing in FAD mutation carriers.

Event-related potentials in clinical research: guidelines for eliciting, recording, and quantifying mismatch negativity, P300, and N400

This paper describes recommended methods for the use of event-related brain potentials (ERPs) in clinical research and reviews applications to a variety of psychiatric and neurological disorders. Techniques are presented for eliciting, recording, and quantifying three major cognitive components with confirmed clinical utility: mismatch negativity (MMN), P300, and N400. Also highlighted are applications of each of the components as methods of investigating central nervous system pathology. The guidelines are intended to assist investigators who use ERPs in clinical research, in an effort to provide clear and concise recommendations and thereby to standardize methodology and facilitate comparability of data across laboratories.

Assessment of the attention impairment in absence epilepsy: comparison of visual and auditory P300

We report an investigation of P300 measures of information processing in patients with generalized epilepsy of the absence type and those with complex partial epilepsy. Studies have demonstrated that absence patients perform more poorly than complex partial patients on behavioral tests of sustained attention (the Continuous Performance Test, or CPT). Duncan [Duncan, C.C., 1988. Application of event-related brain potentials to the analysis of interictal attention in absence epilepsy. In: Myslobodsky, M.S., Mirsky, A.F. (Eds.), Elements of Petit Mal Epilepsy. Peter Lang, New York, pp. 341-364] reported that P300 was significantly reduced in a group of absence patients as compared with healthy controls. The present investigation was undertaken to compare the attention deficit in absence patients to that in complex partial seizure patients. Thus, ERPs were recorded while participants with absence seizure disorder, complex partial seizure disorder, and healthy controls performed auditory and visual versions of the CPT. A significant reduction in the amplitude of P300 on the visual CPT was observed in both groups of seizure patients as compared to controls. In contrast, P300 on the auditory CPT was reduced only in the group with absence seizures. These ERP data support and amplify previous behavioral findings of the impaired capacity of absence patients to mobilize and sustain attentional resources. Auditory sustained attention seems to be more affected by the pathophysiology of absence epilepsy than visual attention. Two possible factors may be involved: (a) There are separate visual and auditory attention systems in the brain, and the latter is more vulnerable than the former [Duncan, C.C., Kosmidis, M.H., Mirsky, A.F., 2005. Closed head injury-related information processing deficits: An event-related potential analysis. Int. J. Psychophysiol. 58, 133-157]; and (b) Auditory processing depends on intact mechanisms in the brainstem, which are dysfunctional in patients with absence seizures.

Characteristics of cognitive function in patients after traumatic brain injury assessed by visual and auditory event-related potentials

OBJECTIVE

Using auditory and visual stimuli including facial affective stimuli, we analyzed the P300 components of event-related potentials (ERPs) in patients after traumatic brain injury (TBI) to assess their cognitive characteristics.

DESIGN

Twenty TBI patients and 32 age-matched control subjects were recruited. Using conventional oddball paradigms, visual ERPs were recorded using images of crying and smiling babies as visual stimuli. Auditory ERPs were obtained using 2-kHz tones as stimuli without affective stimuli. The peak amplitude and latency for P300, and the latency for N200, were recorded.

RESULTS

: In visual ERPs, the P300 amplitudes were significantly smaller in patients than in controls for the crying baby, but the amplitudes were similar between groups for the smiling baby. Controls showed smaller P300 amplitudes for the smiling baby than for the crying baby, but patients showed no difference. In patients, the P300 latency for both smiling and crying babies was longer than in the controls. Patients' auditory ERPs showed smaller P300 amplitudes but similar P300 latencies compared with controls. The N200 latency in patients was significantly longer than in controls only for the crying baby.

CONCLUSIONS

Visual ERPs are a potentially useful marker for evaluating cognitive dysfunction in patients after TBI.

Pathophysiology of mental illness: A view from the fourth ventricle

The concept of mental disorders as diseases of the brain is as old as the ancient Greek philosopher-physicians. However, for thousands of years, the majority of doctors, as well as laypersons, held strongly to the belief that epilepsy and "madness" (i.e., schizophrenia)--the major disorders discussed in this paper--were caused by demonic "possession." As always, the theory of causation led to apposite therapies: Cast out the devil by whatever means necessary. Later, more enlightened views of etiology led to less punitive "cures," which, to modern sensibilities, still seem barbaric. The 20th century saw the introduction of medications that provide symptomatic relief, if not cures, for seizure disorders and schizophrenia. In this paper, we consider the etiology of absence (petit mal) epilepsy and schizophrenia based on the pathophysiology underlying the shared symptom of impaired sustained attention. We emphasize the role of abnormal functioning of brainstem structures in the region of the fourth ventricle, whether caused by genetic or environmental factors or a combination thereof. Our theorizing relies on the findings of Lindsley, Magoun, and Moruzzi, who delineated the role of the brainstem reticular activating system in sleep, wakefulness, and consciousness. It also relies on the work of Penfield, Jasper, and Gloor, who sought to illuminate the role of brainstem-thalamus-cortical dysfunction in idiopathic generalized epilepsies. We consider evidence from recent studies that emphasize the phasic attentional functions supported by brainstem structures in the region of the fourth ventricle, and possible genetic links among disorders in which impaired attention is a prominent symptom.

Neuroscientific Psychophysiology: The International Organization of Psychophysiology (I.O.P.) associated with the United Nations (New York) in the 21st Century

This Presidential Address 2004 emphasizes the pivotal role of Psychophysiology as an integrated neuroscience with a panoply of electrophysiological and neuroimaging technologies for the establishment of methodologically crucial conceptual links for the understanding and mapping of brain functions pertaining to cognitive, emotional and motivational processes. Moreover, Psychophysiology's unique neuroscientific perspective by integrating functions of central and autonomic nervous systems with behavior in health and disease is underlined. Based on these developments, the progress of rigorous neuroscientific Clinical Psychophysiology offers possibilities for diagnosis, treatment and objective evaluation of therapeutic outcome in various pathological conditions.