bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcome Related Electrophysiological Subtypes of Cocaine Dependence
Authors: Prichep Leslie S. , Alper Kenneth R. , Sverdlov Lev , Kowalik Sharon C. , John E. R. , Merkin Henry , Tom MeeLee , Howard Bryant , Rosenthal Mitchell S.
Published: February 2012

We previously described the existence of two quantitative EEG (QEEG) subtypes of cocaine dependent males, identified at baseline, displaying differential pronenessto relapse. The current study expands the population to include females and enhances the measure set to include both QEEG and somatosensory EP (SEP) features. Fifty-seven cocaine dependent adults (16 F, 41 M) were evaluated 5–14 days after last cocaine use, while in residence at a drug-free therapeutic community. The median length of stay in treatment (continued abstinence) was 25 weeks. Using a small subset of QEEG and SEP baseline features, three subtypes (CLUS) were identified. CLUS 2 (n=25) and CLUS 3 (n=23) replicated the published subtypes, while CLUS 1 (n=9) was previously undescribed. Cluster membership was significantly associated with length of stay in treatment (χ2=13.789, P<0.001), but not with length of exposure to crack cocaine or to any demographic or clinical features. Seventy-eight percent of CLUS 1 and 65% of CLUS 3 left treatment ≤ 25 weeks, whereas 80% of CLUS 2 remained in treatment > 25 weeks. The existence of outcome related subtypes may reflect: [1] differential neurophysiological vulnerability, “traits,” predisposing individuals to cocaine addiction; or [2] differential neurosensitivity, “states,” due to the effects of chronic cocaine exposure, and associated differences in treatment outcome. Using Variable Resolution Electrical Tomographic Analysis (VARETA), the mathematically most probable neuroanatomical source of the scalp recorded EEG data was localized. Computation of VARETA on the baseline Cluster profiles suggest significant differences in the underlying pathophysiology of these subtypes.
The Use of Transcranial Magnetic Stimulation for Monitoring Descending Spinal Cord Motor Function
Authors: Aglio Linda S. , Romero Rafael , Desai Sukumar , Ramirez Marcela , Gonzalez Andres A. , Gugino Laverne D.
Published: February 2012

This report describes our initial clinical experience using transcranial magnetic stimulation for monitoring spinal cord motor function during surgical procedures. Motor evoked potentials were elicited using a cap shaped coil placed on the scalp of 27 patients while recording peripheral motor responses (compound muscle action potentials – CMAPs) from the upper (N=1) or lower limbs (N=26). Wherever possible, cortical somatosensory responses (SEPs) were also monitored by electrically stimulating the left and right posterior tibial nerve (N=25) or the median nerve (N=1). The judicious choice of anesthetic regimens resulted in successfully obtaining motor evoked responses (MEPs) in 21 of 27 patients and SEPs in 26 of 27 patients. Single pulse TMS resulted in peripheral muscle responses having large variability, whereas, the variability of SEPs was much less. Criteria based on response variability for assessing clinically significant changes in both MEPs and SEPs resulted in two false negative predictions for SEPs and none for MEPs when evaluating postoperative motor function. We recommend monitoring both sensory and motor pathways during procedures where placing the spinal cord at risk of damage.
EEG and Seizures in Autistic Children and Adolescents: Further Findings with Therapeutic Implications
Authors: Hughes John R. , Melyn Michelle
Published: February 2012

The goal of this study was to investigate the incidence of epilepsy and also the EEG findings among children with autism (A), a devastating disorder, and to compare these data to an EEG control group. EEGs were quantified as to the degree of epileptiform activity and also slow wave abnormalities. Abnormal EEGs were found in 75% of the 59 A children and 82% of their 151 EEGs; 46% had clinical seizures. Nearly all children with seizures had epileptiform activity, but almost 20% of those with spike discharges did not have clinical attacks. Slow wave abnormalities were more frequent and of a greater degree of severity in the A group, compared to controls. One new finding was that a greater variability of EEG abnormalities was found in the A group. Therapeutic implications, based on these latter findings, are discussed.
High Frequency EEG Activity during Sleep: Characteristics in Schizophrenia and Depression
Authors: Tekell Janet L. , Hoffmann Robert , Hendrickse William , Greene Robert W. , Rush A. John , Armitage Roseanne
Published: February 2012

Previous studies indicate that high frequency power (>20Hz) in the electroencephalogram (EEG) are associated with feature binding and attention. It has been hypothesized that hallucinations and perceptual abnormalities might be linked to irregularities in fast frequency activity. This study examines the power and distribution of high frequency activity (HFA) during sleep in healthy control subjects and unmedicated patients with schizophrenia and depression.

This is a post-hoc analysis of an archival database collected under identical conditions. Groups were compared using multivariate analyses of covariance (MANCOVA) using group frequency by stage analysis. A multiple regression analyzed the association between HFA power and clinical symptoms.

Schizophrenic (SZ) and major depressive disorder (MDD) patients showed significantly greater high frequency (HF) power than healthy controls (HC) in all sleep stages (p<0.0001). SZs also exhibited significantly greater HF power than MDD patients in all sleep stages except wakefulness (W) (p<0.05). In all groups, gamma (35–45Hz) power was greater in W, decreased during slow wave sleep (SWS) and decreased further during rapid eye movement (REM). Beta 2 (20–35 Hz) power was greater in W and REM than in SWS. Only positive symptoms exhibited an association with HF power.

Elevated HFA during sleep in unmedicated patients with SZ and MDD is associated with positive symptoms of illness. It is not clear how HFA would change in relation to clinical improvement, and further study is needed to clarify the association of HFA to the state/trait characteristics of SZ and MDD.
Discovery and Integrative Neuroscience
Authors: Koslow Stephen H.
Published: February 2012

Hypothesis driven research has been shown to be an excellent model for pursuing investigations in neuroscience. The Human Genome Project demonstrated the added value of discovery research, especially in areas where large amounts of data are produced. Neuroscience has become a data rich field, and one that would be enhanced by incorporating the discovery approach. Databases, as well as analytical, modeling and simulation tools, will have to be developed, and they will need to be interoperable and federated.

This paper presents an overview of the development of the field of neuroscience databases and associate tools: Neuroinformatics. The primary focus is on the impact of NIH funding of this process. The important issues of data sharing, as viewed from the perspective of the scientist and private and public funding organizations, are discussed. Neuroinformatics will provide more than just a sophisticated array of information technologies to help scientists understand and integrate nervous system data. It will make available powerful models of neural functions and facilitate discovery, hypothesis formulation and electronic collaboration.
Use of Normative Databases and Statistical Methods in Demonstrating Clinical Utility of QEEG: Importance and Cautions
Authors: Prichep Leslie S.
Published: February 2012

The clinical utility of the EEG, especially in psychiatric, learning and cognitive disorders, has been greatly enhanced by the use of quantitative analysis (QEEG) and comparisons to a normative database. Of primary importance in the use of such a reference database are the following considerations and cautions: adequate sampling across a broad age range; consideration of inclusion/exclusion criteria; adequate sample of artifact-free data to demonstrate reliability and replicability of norms; demonstration of specificity and sensitivity. A normative database meeting these criteria allows the multivariate description of patterns of QEEG abnormalities in patients as compared to age appropriate normative values, and the exploration of neurophysiological heterogeneity within populations. Demonstrations of the clinical significance of this approach exist in the scientific literature and demonstrate that QEEG provides high sensitivity and specificity to abnormalities in brain function seen in psychiatric populations.
Long Latency Evoked Potential Database for Clinical Applications: Justification and Examples
Authors: Duffy Frank H.
Published: February 2012

We summarize our experience with the clinical utility of long latency evoked potential (EP) data in clinical qEEG studies. In contrast to common wisdom, such EP data are consistent across appropriately chosen age groups. In a healthy adult population, EP data correlate consistently with independently collected psychological variables. In our pediatric referral population, EP data are of greatest and most unique value in the learning disabilities but also augment detection of abnormality in epilepsy and behavioral abnormality. Selection of subjects for a clinical database on the basis of examined medical, neurological and behavioral health, forms adequately consistent groupings for clinical utility. The use of the Z-SPM is essential for detection of EP abnormality. A minimum of three replications within a clinical study protects against chance/false positives. Also, the true data dimensionality within EP data sets is far less than the total number of variables typically collected.
Latency Differences of N20, P40/N60, P100/N140 SEP Components after Stimulation of Proximal and Distal Sites of the Median Nerve
Authors: Hada Y.
Published: February 2012

The latencies of SEP N20, P40, N60, P100, and N140 components were measured after stimulation of two different sites, and the differences in relation to conduction velocity and their central functions are discussed.

Subjects were 8 healthy right-handed males (age 22–31 years, height 164–184 cm). An electrical pulse of 200μ sec duration with an intensity of 2 times the motor threshold was delivered to the wrist and to the elbow alternately at a random rate of 0.1 to 0.3 Hz. Recording electrodes were Cz', C3′, and C4′ referenced to linked ears. Analysis time was 50 msec before and 450 msec after the stimulus. The band pass was 0.5 Hz to 2 kHz. Subjects were asked to mentally count the number of stimuli. The averaging was interrupted after every 16 to 24 stimuli and checked to determine whether the subject was attentive to the stimuli by verifying the number of stimuli counted. A total of 100 responses each from elbow and wrist stimuli were averaged.

Differences in peak latency between elbow and wrist stimuli for N20, P40, N60, P100, and N140 were 3.7 ± 0.7 msec, 5.0 ± 1.8, 4.3 ± 1.2, 8.1 ± 6.3, and 7.4 ± 2.6 msec, respectively. According to the latency differences, SEP components can be divided into 3 groups: the shortest difference for N20, medium difference for P40 and N60 and longest difference for P100 and N140.

Similar latency differences and similar potential distribution for P40 and N60, and for P100 and N140, and their differences from N20 confirmed that each of N20, P40/N60, and P100/N140 has a different function centrally. In addition, central processing time was longer with the more distal site stimulation.
Screening of EEG Referrals by Neurologists Leads to Improved Healthcare Resource Utilization
Authors: Gurbani Neepa S. , Gurbani Suresh G. , Mittal Meenu , McGuckin Jeanne S. , Tin Sue Nwe , Tehrani Keo , Chayasirisobhon Sirichai
Published: February 2012

The objective of this study was to determine if screening by a neurologist of all non-neurologist electroencephalogram (EEG) referrals prior to approval reduces the number of inappropriate requests. This retrospective survey included 600 consecutive EEG requisitions referred to the Anaheim Kaiser Permanente Neurodiagnostic Laboratory to rule out epilepsy. Patients with established epilepsy referred for a repeat EEG for management issues were excluded.

Three groups of EEG referrals were analyzed. Each group consisted of 200 EEGs (100 pediatric and 100 adult EEGs). The first group was referred directly by non-neurologists, the second group was referred by non-neurologists with scrutiny by a neurologist, and the third group was referred by a neurologist directly. In the pediatric group, the ratio of abnormal EEG vs normal EEG was 1: 3.35 in the first group, 1: 0.69 in the second group and 1: 0.33 in the third group. In the adult group, the ratio of abnormal EEGs vs normal EEGs was 1: 2.23 in the first group, 1: 0.82 in the second group and 1: 0.45 in the third group. In the combined pediatric and adult groups, the ratio of abnormal EEG vs normal EEG was 1: 2.70 in the first group, 1: 0.75 in the second group and 1: 0.39 in the third group. There was a significant difference between the results of the EEGs ordered by non-neurologists directly versus non-neurologists with scrutiny (p=.334, chi-square test).

Scrutiny by a neurologist of EEG referrals from non-neurologists led to a reduction in the number of normal EEG results. This suggests that inappropriate EEG requests for non-epileptic patients that yield normal EEG results are significantly reduced with scrutiny. This can help reduce the indiscriminate overuse of EEGs by non-neurologists thereby leading to better utilization of healthcare resources.
Quantitative EEG Analysis before and after Liver Transplantation
Authors: Reeves Roy R. , Struve Frederick A. , Burke Randy S.
Published: February 2012

Quantitative EEG has been shown to be effective for the assessment of hepatic encephalopathy. Initial quantitative EEG studies of patients who had undergone liver transplantation demonstrated improvement of frequency and the alpha-theta power ratio in the occipital area. This study involved the assessment of comprehensive quantitative EEG variables over the entire cortex following transplantation. Fourteen subjects underwent EEG recording prior to transplantation. Eight (6 without complications and 2 having problems with rejection) underwent the same recording between 3 and 6 months following transplantation.

For all subjects, EEG variables showing significant changes from pre- to post-transplantation included posterior alpha frequency (increase, p ≤ .03), central theta absolute power (decrease, p ≤ .03), theta relative power over anterior, central, and posterior regions (decrease, p ≤ .02, p ≤ .01, p ≤ .03, respectively), posterior beta absolute power (increase, p ≤ .01), and central and posterior beta relative power (increase, p ≤ .04, p ≤ .04, respectively). When the two subjects with complications were removed from the analyses, these variables and also anterior alpha absolute power (increase, p ≤ .02), alpha relative power over anterior, central, and posterior regions (increase, p ≤ .05, p ≤ .03, p ≤ .04, respectively), and anterior and central theta absolute power (decrease, p ≤ .05, p ≤ .04, respectively) showed significant pre- to post-transplant changes.

In conclusion, a combination of quantitative EEG parameters which are most affected by liver transplantation might provide an effective assessment tool for determining and quantitatively monitoring the cerebral status of post-transplant patients.
qEEG Monitoring of Alzheimer's Disease Treatment: A Preliminary Report of Three Case Studies
Authors: Sneddon Robert , Shankle William Rodman , Hara Junko , Rodriquez Anthony , Hoffman Donald , Saha Utpal
Published: February 2012

Previous research has shown that quantitative electroencephalography (qEEG) can monitor treatment of Alzheimer's Disease (AD). This study investigated the ability of a qEEG measure based on EEG variance, combined with a delayed recognition memory task, to measure treatment effects on patients with AD.

Three AD patients with very mild AD (CDR=0.5, FAST stage 3) were monitored with task specific EEG at multiple time points before and after medication treatment. Patients had their EEG recorded while performing a recognition memory task. A measure of (normalized) variance was applied to the EEG data. To the extent possible, the subjects received this treatment monitoring multiple times. These patients were monitored a total of 14 times, which yielded 11 measurements of qEEG change during the course of treatment.

The direction of change in patients' qEEG values agreed with patients' medication treatment on 10 out of 11 occasions, p < 0.006 (binomial test) and was more accurate than monitoring with the relative theta power, p < 0.05. The results of this monitoring also showed that the qEEG measure accurately reflected treatment in a dose dependent manner. These results were independent of the specific medication monitored; Galantamine, Memantine, Nicotine, and Rivastigmine. In conclusion, this qEEG method may be useful for measuring AD treatment responses.
EEG Topography and Tomography (LORETA) in the Classification and Evaluation of the Pharmacodynamics of Psychotropic Drugs
Authors: Saletu Bernd , Anderer Peter , Saletu-Zyhlarz Gerda M.
Published: February 2012

By multi-lead computer-assisted quantitative analyses of human scalp-recorded electroencephalogram (QEEG) in combination with certain statistical procedures (quantitative pharmaco-EEG) and mapping techniques (pharmaco-EEG mapping or topography), it is possible to classify psychotropic substances and objectively evaluate their bioavailability at the target organ, the human brain. Specifically, one may determine at an early stage of drug development whether a drug is effective on the central nervous system (CNS) compared with placebo, what its clinical efficacy will be like, at which dosage it acts, when it acts and the equipotent dosages of different galenic formulations. Pharmaco-EEG maps of neuroleptics, antidepressants, tranquilizers, hypnotics, psychostimulants and nootropics/cognition-enhancing drugs will be described. Methodological problems, as well as the relationships between acute and chronic drug effects, alterations in normal subjects and patients, CNS effects and therapeutic efficacy will be discussed.

Imaging of drug effects on the regional brain electrical activity of healthy subjects by means of EEG tomography such as low-resolution electromagnetic tomography (LORETA) has been used for identifying brain areas predominantly involved in psychopharmacological action. This will be shown for the representative drugs of the four main psychopharmacological classes, such as 3 mg haloperidol for neuroleptics, 20 mg citalopram for antidepressants, 2 mg lorazepam for tranquilizers and 20 mg methylphenidate for psychostimulants. LORETA demonstrates that these psychopharmacological classes affect brain structures differently.

By considering these differences between psychotropic drugs and placebo in normal subjects, as well as between mental disorder patients and normal controls, it may be possible to choose the optimum drug for a specific patient according to a key-lock principle, since the drug should normalize the deviant brain function. Thus, pharmaco-EEG topography and tomography are valuable methods in human neuropsychopharmacology, clinical psychiatry and neurology.
Event Related Potentials and fMRI in Neuropsychopharmacology
Authors: Pogarell Oliver , Mulert Christoph , Hegerl Ulrich
Published: February 2012

Event related potentials (ERP) are important clinical and research instruments in neuropsychiatry, particularly due to their strategic role for the investigation of brain function. These techniques are often underutilized in the evaluation of neurological and psychiatric disorders, but nevertheless they can be most useful and highly effective in the diagnostic workup of a wide range of neuropsychiatric disorders as well as in monitoring the course of the disorders and the prediction of treatment responses.

ERP are noninvasive instruments that directly reflect cortical neuronal activity. Cortical neuronal dysfunction plays a major role in variable neuropsychiatric disorders, and a change in cortical activity under medication might reflect treatment response and could be useful for monitoring drug effects.

ERP are the only methods with a sufficiently high time resolution for the analysis of the dynamic patterns of neuronal brain activity, e.g., synchronization and desynchronization, oscillations, coherence, gamma band activity, latency of event related activity, etc., which are crucial for a deeper understanding of functional (neurophysiological) correlates of cognitive, emotional and behavioral disturbances in neuropsychiatric patients.

Methodological advances have further improved and strengthened the position of ERP concerning research and clinical application. The usefulness and applicability of ERP in determining and monitoring clinico-pharmacological effects will be summarized mainly by focussing on the auditory evoked P300 and the N1/P2 component of auditory evoked potentials. Owing to important recent developments in the field of brain functional diagnostics the combination of neurophysiological techniques and functional magnetic resonance imaging (fMRI) will be included.
From Neuroscience to Application in Neuropharmacology: A Generation of Progress in Electrophysiology
Authors: Carozzo S. , Fornaro S. , Garbarino S. , Saturno M. , Sannita W.G.
Published: February 2012

A continuum from neuronal cellular/subcellular properties to system processes appears to exist in many instances and to allow privileged approaches in neuroscience and neuropharmacology research. Brain signals and the cholinergic and GABAergic systems, in vivo and in vitro evidence from studies on the retina, or the “gamma band” oscillations in neuron membrane potential/spiking rate and neuronal assemblies are examples in this respect. However, spontaneous and stimulus-event-related signals at any location and time point reflect brain state conditions that depend on neuromodulation, neurotransmitter interaction, hormones (e.g., glucocorticois, ACTH, estrogens) and neuroendocrine interaction at different levels of complexity, as well as on the spontaneous or experimentally-induced changes in metabolism (e.g., glucose, ammonia), blood flow, p02, pC02, acid/base balance, K activity, etc., that occur locally or systemically. Any of these factors can account for individual differences and/or changes over time that often are (or need to be) neglected in pharmaco-EEG studies or are dealt with statistically and by controlling the experimental conditions. As a result, the electrophysiological effects of neuroactive drugs are to an extent non-specific and require adequate modeling and precise correlation with independent parameters (e.g., drug kinetics, vigilance, hormonal profile or metabolic status, etc.) to avoid biased results in otherwise controlled studies.
Electroencephalography Hyperventilation and Stroke in Children with Sickle Cell Disease
Authors: Millichap J. Gordon
Published: February 2012

A recent study and report in which hyperventilation was used during electroencephalography (EEG) in 6 children with sickle cell disease (SCD) and seizures, without serious complication, prompted a cautionary response regarding the potential risks attending the practice of EEG hyperventilation in SCD patients. Earlier reports of neurological impairment and stroke precipitated by the routine use of hyperventilation in children with SCD are reviewed, the mechanism and management of vascular infarction following hyperventilation are discussed, and readers are reminded of the AEEGS guidelines and contraindications to routine hyperventilation, which include SCD and trait and cerebrovascular disorders. The frequent nonobservance of these guideline recommendations among neurologists, and the need to more widely inform practitioners of the risks of hyperventilation in SCD are discussed.
Benign Childhood Epilepsy with Centra-Temporal Spikes: Quantitative EEG and the Wechsler Intelligence Scale for Children (WISC-III)
Authors: Tedrus Gloria M. A. S. , Fonseca Lineu C. , Tonelotto Josiane M. F. , Costa Rebeca M. , Chiodi Marcelo G.
Published: February 2012

Benign childhood epilepsy with centro-temporal spikes (BECTS) is a form of focal idiopathic epilepsy, with seizure remission by the age of 18. Recent studies have suggested that some children with BECTS can suffer from deficits of memory, attention and learning ability and in auditory-verbal and performance sub-tests. On the other hand, alterations in the baseline brain electrical activity determined by using the quantitative electroencephalogram (qEEG) have been described. The objective of this study was to evaluate the absolute and relative powers in the delta, theta, alpha and beta bands of the qEEG in children with BECTS, and their relation to IQ measurements (WISC-III).

Twenty-six 8 to 11-year-old children with BECTS were studied, paired with a control group of healthy children according to age and gender. It was shown that the absolute delta and theta powers were statistically greater in the children with BECTS than in the control group, at almost all the electrodes. In the children with BECTS, a negative correlation (Pearson's correlation test) was observed at various electrodes between the absolute delta and theta powers and the performance IQ.

These data indicate a possible relationship between maturational disturbance in the brain electrical activity development and the tendency for inferior cognitive performance in children with BECTS.
Subacute Encephalopathy with Seizures in Alcoholics (SESA Syndrome): Report of an Unusual Case
Authors: Fernández-Torre José L. , Agirre Zaloa , Martínez-Martínez Marián , Rodríguez Eloy
Published: February 2012

Subacute encephalopathy with seizures in alcoholics (SESA syndrome) is a rare neurologic disorder complicating the chronic abuse of alcohol. This acute or subacute condition is characterized by transient neurologic deficits, seizures and severe lateralized abnormalities on the electroencephalogram (EEG). Our case demonstrates that in SESA syndrome, convulsive (generalized tonic-clonic) and nonconvulsive (complex partial) seizures may coexist.
The Development of Memory Trace Depending on the Number of the Standard Stimuli
Authors: Matuoka Takashi , Yabe Hirooki , Shinozaki Naoko , Sato Yasuharu , Hiruma Tomiharu , Ren Asai , Hara Etsuko , Kaneko Sunao
Published: February 2012

The mismatch negativity (MMN) component of the event-related potentials reflects the automatic detection mechanism of sound change. MMN is elicited by a neuronal mismatch process between deviant (infrequent) auditory input and the sensory memory trace of the standard (frequent) stimuli. Although many previous studies have investigated MMN to reveal the sensory memory mechanism, the development of memory representation still remains unclear, in particular, the topographical aspect of the trace-development in sensory memory has not been clarified.

We measured the frontal and the temporal MMN components, respectively when the sound trace was developed as the number of standard stimuli was changed to 1, 3, 5 or 7. In this experiment, the inter-train interval was 15 sec. The stimulus train with the different frequency of 800Hz, 900Hz, or 1000Hz was repeatedly presented. Thus, we reduced the influence of the previous train. For the first time, we found not only the enhanced amplitude but also the shortened latency for both MMN components when the number of standard stimuli was increased. These findings indicate that both frontal and temporal MMN components reflect the development of memory trace depending on the number of standard stimuli.
EEG Correlates of Startle Reflex with Reactivity to Eye Opening in Psychiatric Disorders: Preliminary Results
Authors: Arikan Kemal , Boutros Nash N. , Bozhuyuk Erol , Poyraz B. Cagri , Savrun B. Mert , Bayar Reha , Gunduz Aysegul , Karaali-Savrun Feray , Yaman Mehmet
Published: February 2012

Previous studies have shown alterations of eyeblink reflex in patients with various psychiatric disorders. It has previously been demonstrated by our group that EEG measures of the reactivity to eye opening could effectively predict patient-reported startle response in patients with acute stress reaction.

In our present study, EEG spectral power analysis and eyeblink electrical startle responses were acquired from a total of 39 patients diagnosed with various psychiatric disorders: 7 patients with schizophrenia, 10 patients with major depressive disorder (MDD), 10 patients with panic disorder, 5 patients with posttraumatic stress disorder (PTSD) and 7 patients with generalized anxiety disorder (GAD). EEG percent power data of each frequency band (delta, theta, alpha, beta) obtained from the 19 leads under open or closed eyelid conditions were used to calculate the arithmetical difference between eyes-open and eyes-closed states as representative of “EEG reactivity to eye opening.” Data was analyzed separately for each diagnostic group.

For all of the disorders, right-sided R2c (contralateral secondary component) latency was the single eyeblink startle measure that was found to be significantly correlated with EEG reactivity to eye opening. The correlation was most significant for right temporal theta frequency in schizophrenia, right temporal theta frequency in MDD, left central beta frequency in panic disorder, left parietotemporal delta frequency in PTSD and right occipital alpha frequency in GAD. Findings showed a newly identified pattern that has potential scientific and clinical value with respect to psychiatric medicine.
Electrophysiological Measures of Familiarity Memory
Authors: Mecklinger Axel
Published: February 2012

Event-related potentials are a valuable tool for the study of human memory function. This selective review provides a brief introduction in models of recognition memory and then describes how ERPs can be used to investigate familiarity memory, an acontextual form of remembering that can be distinguished from the recollection of detailed information of prior events. ERP studies on the mid-frontal old/new effect, the putative electrophysiological correlate of familiarity memory are reviewed. It will be illustrated how familiarity memory is reflected in this effect, how it can electrophysiologically be dissociated from other forms of memory and which brain systems mediate this form of remembering. Recent studies will be reviewed that illustrate that familiarity is not only restricted to single items but can also support the retrieval of associative information.
Electromagnetic Correlates of Recognition Memory Processes
Authors: Neufang M. , Heinze H.J. , Düzel E.
Published: February 2012

Recognition memory is critically dependent on a hierarchically organized network of brain areas including the visual ventral stream, medial temporal lobe structures, frontal and parietal cortices. In recent years, cognitive theories of recognition memory have been helpful to further our understanding of the functional organization of this network. A prominent, although not unchallenged, set of theories proposes that recognition memory is not a unitary phenomenon, but can be based on the recollection of contextual information about events or on familiarity in the absence of recollection. A number of hemodynamic and electromagnetic studies have been undertaken to relate recollection and familiarity to neuronal substrates both in healthy subjects as well as in patients with brain lesions. Today, it is evident that both event-related potential and event-related field (ERP/ERF) data as well as data of oscillatory brain activity (e.g., theta oscillations) are necessary to fully understand the neural dynamics of recollection and familiarity and their relationship to functional anatomy. Ultimately, such data are required from patients with isolated brain injuries to designated components of the networks (such as the hippocampus) to obtain converging evidence for functional relationships between recollection and familiarity and respective neuroanatomic substrates. The complexity of this task is highlighted by findings indicating that recognition memory can already be affected by preparatory processes prior to stimulus onset.
Electrophysiological Measures of Episodic Memory Control and Memory Retrieval
Authors: Wilding E.L. , Herron J.E.
Published: February 2012

Event-related potentials (ERPs) index processes that occur before, during and after retrieval of information from episodic memory. In this selective review we provide a loose theoretical framework within which retrieval processes operating at these different stages can be considered. We go on to describe how ERPs have been employed in order to index processes operating at each of these stages. These data have contributed to current understanding of the processes that are engaged around the time of episodic memory retrieval, and also illustrate the potential that ERPs have for understanding in detail how memory retrieval processes changes in populations with memory impairments.
Do I Know You? Insights into Memory for Faces from Brain Potentials
Authors: Boehm S.G. , Paller K.A.
Published: February 2012

The recognition of faces is central to human social interaction. Recordings of event-related potentials (ERPs) from the brain can shed light on the various processes that occur when a face is recognized and when knowledge related to a specific person is retrieved. ERP contrasts between processing familiar and processing novel faces offer a gateway into investigations of semantic memory for familiar persons. In particular, activity of face recognition units and semantic information units—memory representations of faces and person-related knowledge, respectively—can be indexed by specific ERPs. These potentials thus provide valuable tools for studying the cognitive and neurobiological architecture of person recognition. ERPs have also been found useful for investigating other types of memory for faces. Specifically, important insights have been derived from the study of a category of memory phenomena known as priming. Priming can be revealed in special tests when face recognition is facilitated based on prior experience. Describing the neural processes associated with memory for faces is an exciting focus of research, and future results from this line of inquiry promise to provide further knowledge about face recognition and the various types of memory that can be provoked by a human face.
Event-Related Potentials in Psychiatry
Authors: Pogarell Oliver , Mulert Christoph , Hegerl Ulrich
Published: February 2012

Electrophysiological assessments of psychiatric disorders have produced a number of promising, highly replicable findings and thus carry the potential of becoming clinically utilizable in the diagnostic or prognostic evaluation of psychopathological conditions. The procedures involved are rather complex technically and the interpretation of the findings require a combined neurophysiological and clinical expertise. On the other hand, electrophysiological techniques are in general non-invasive and relatively inexpensive, and neurophysiology laboratories are widely available in the clinical setting.

Among these techniques, event-related potentials (ERPs) are of major interest in psychiatry, particularly since these tools can indicate cortical neuronal dysfunctions, which play a major role in various neuropsychiatric disorders.
Visual Completion Processing in Human Face Perception
Authors: Chu Xiang-Li , Wang Yin-Hua , Wang Yu-Ping
Published: February 2012

Subjects discriminated whether two sequentially presented human face pictures (S1 and S2) were identical while event-related potentials were recorded to explore the neural basis of visual completion for occluded objects. Four kinds of stimulus trials were employed: S2 and S1 were identical (match-complete); S2 and S1 were identical, but S2 was partially occluded (match-incomplete); S2 was a different face from S1 (mismatch-complete); S2 was different from S1, and was partially occluded (mismatch-incomplete). Incomplete faces enhanced the amplitude of N1 compared with complete faces. The peak latency of N2 elicited by incomplete faces was delayed about 20 ms compared with complete faces. The enhancement of N1 is related to visual completion processing that requires additional time.
Considerations of the Ischemic Basis and Therapy of Alzheimer Disease
Authors: Niedermeyer E.
Published: February 2012

A recently presented concept of Alzheimer disease (AD) is based on a primarily ischemic (rather than degenerative) type of brain disease. Etiologically, this new concept is presumed to be related to the human upright gait along with individual predisposition.

The proposed treatment—head-down therapy (HDT)—is the centerpoint of this presentation: a simple and generally accessible type of therapy, with monitoring by neuropsychological questioning, electroencephalography, and transcranial Doppler. As a treatment of AD (limited to stage 1), HDT is expected to be helpful. It is possible, however, that its prophylactic use may be of even greater importance.
Prediction of Clinical Response to Antidepressants in Patients with Depression: Neurophysiology in Clinical Practice
Authors: Pogarell Oliver , Juckel Georg , Norra Christine , Leicht Gregor , Karch Susanne , Schaaff Nadine , Folkerts Malte , Ibrahim Ahmad , Mulert Christoph , Hegerl Ulrich
Published: February 2012

Brain monoaminergic neurotransmission is involved in the pathophysiology of various psychiatric disorders including depression. Reliable indicators of central monoaminergic activity might be helpful to specifically identify and differentiate dysfunctions in individual patients in order to selectively adjust medication and predict clinical response.

In patients with depression, predictors of treatment response to serotonergic versus non-serotonergic (e.g., noradrenergic) antidepressants could be of considerable clinical relevance by avoiding unfavorable factors such as a prolonged duration of the disorder, risk of suicidality and therapy-resistance. Consequently, these tools might help to decrease direct and indirect costs of treatment.

The loudness dependence of the N1/P2 component of auditory evoked potentials (LD) has been proposed as a noninvasive neurophysiological indicator of central serotonergic function. This review focuses on recent studies providing evidence for the validity of LD as an indirect serotonergic marker and highlights data on the clinical application in terms of prediction of treatment response in patients with depression.
Hand-Motor Dysfunction in Depression: Characteristics and Pharmacological Effects
Authors: Mergl Roland , Pogarell Oliver , Juckel Georg , Rihl Julian , Henkel Verena , Frodl Thomas , Müller-Siecheneder Florian , Karner Max , Tigges Peter , Schröter Andreas , Hegerl Ulrich
Published: February 2012

Motor retardation is a relevant aspect of depression. Kinematic analysis of movements can be applied to explore which type of motor dysfunction is associated with depression and to examine motor side effects of antidepressants. Using this tool, we aimed to investigate fine motor performance in patients suffering from depression and to compare a selective noradrenaline re-uptake inhibitor (NARI) (reboxetine) and a selective serotonin reuptake inhibitor (SSRI) (citalopram) regarding motor side effects after 4 weeks of treatment.

In the first study (I), we examined 37 depressed patients and 37 healthy subjects using a digitizing graphic tablet and kinematic analysis of handwriting and rapid drawing movements. Both groups were comparable regarding age, gender distribution, handedness (preponderance of right-handers) and educational level. In the second study (II), we examined different types of hand movements in 16 depressed patients receiving citalopram (flexible dosage) and 12 depressed patients treated with reboxetine (varying dosage) using the afore-mentioned methods. Both groups were comparable regarding age, gender, handedness and the baseline Hamilton Depression Rating Scale total score.

I: Depressed patients performed drawing with significantly less regular velocity than controls (p < 0.001), but normal velocity. Handwriting of depressed patients was abnormally slow (p = 0.04). II: Reboxetine led to a significant improvement of repetitive drawing movements in depression. In contrast, citalopram had no pronounced effects on hand movements in depressed patients.

I: Irregular patterns of velocity peaks in depressed patients point to basal ganglia dysfunction and/or deficient activity of the sensorimotor cortex and the supplementary motor area as possible substrates of hand-motor disturbances in depression. II: Computer-aided analysis of hand movements is a sensitive tool for the registration of differential pharmaceutical effects on hand-motor function in depression.
Influence of Anxiety on Electrophysiological Correlates of Response Inhibition Capacities in Alcoholism
Authors: Karch Susanne , Graz Christian , Jager Lorenz , Karamatskos Evangelos , Stammel Andreas , Flatz Wilhelm , Lutz Jürgen , Holtschmidt-Taschner Bettina , Genius Just , Leicht Gregor , Reiser Maximilian , Möller Hans-Jürgen , Hegerl Ulrich , Soyka Michael , Mulert Christoph
Published: February 2012

Anxiety disorders are highly prevalent in patients with alcohol use disorder. The purpose of the present study was to examine the neural correlates of behavioral inhibition in alcohol-dependent patients (ICD-10: F 10.2), and in healthy controls and to determine the influence of anxiety on these processes. Therefore, behavioral responses (reaction times; error rates) and event-related potentials of 16 patients with alcohol dependence syndrome and 16 age-and gender-matched healthy controls were recorded while the participants performed an auditory go/no-go task. The patient group was stratified according to their self-rated trait anxiety (STAI) with scores above and below median. We hypothesized that patients suffering from alcohol dependence would show reduced no-go P3 amplitudes involved in response inhibition compared to healthy subjects. In patients with alcoholism and high trait anxiety the decline of no-go P3 amplitudes was expected to be less distinct.

The estimation of effect size based on the reaction times of patients with high and low anxiety ratings revealed a cohen's d of 0.61 indicating a small effect. High trait anxiety ratings were also associated with slightly enhanced no-go P3 amplitudes in central brain regions (Mean no-go P3 amplitude at Cz: 10.43 μV) compared to patients with low anxiety scores (Mean 8.98 μV). The effect size (cohen's d) revealed a small effect. Using the Mann-Whitney-U-test for independent samples of the comparison of high- and low-anxious patients, however, did not reveal any significant differences concerning no-go P3 amplitudes. Patients with alcohol use disorder and healthy controls did not differ significantly with regard to reaction time, error rate and no-go P3 amplitudes.

This study suggests that no-go P3 amplitudes in patients with alcohol use disorder might be affected to some degree by habitual anxiety. The results emphasize the importance of monitoring trait anxiety in studies regarding cognitive functions in subjects with alcohol use disorder.
Induced Gamma Activity and Event-Related Coherence in Schizophrenia
Authors: Bucci P. , Mucci A. , Merlotti E. , Volpe U. , Galderisi S.
Published: February 2012

Evidence has been provided that high frequency oscillations within the gamma band reflect mechanisms of cortical integration. In the light of recently proposed pathophysiological models of schizophrenia, suggesting a disturbance of the functional connectivity within distributed neural networks, it has been hypothesized that abnormalities in the gamma band underlie perceptual and cognitive dysfunctions in patients with schizophrenia.

In the present study we investigated evoked and induced 40-Hz gamma power as well as frontoparietal and frontotem-poral event-related coherence in patients with deficit and nondeficit schizophrenia and in matched healthy controls. In patients, correlations between gamma oscillations and psychopathological dimensions were also investigated.

A reduction of both induced gamma power and event-related coherence was observed in patients with nondeficit schizophrenia, but not in those with deficit schizophrenia.

Our findings support the hypothesis that deficit and nondeficit schizophrenia represent separate disease entities, suggesting the presence of a poor integration of the neuronal activity within distributed neural network only in the subgroup of schizophrenic patients without primary and persistent negative symptoms.

Associations between an excess of gamma oscillations and psychopathological dimensions were observed, suggesting that abnormal thoughts, behaviors and perceptions might be related to the formation of inappropriate neural connections.
Recognizing a Mother's Voice in the Persistent Vegetative State
Authors: Machado C. , Korein J. , Aubert E. , Bosch J. , Alvarez M. A. , Rodríguez R. , Valdés P. , Portela L. , García M. , Pérez N. , Chinchilla M. , Machado Y. , Machado Y.
Published: February 2012

We studied an 8-year-old boy after a near-drowning left him in a vegetative state (VS) for 4 years before the study. Findings fulfilled all clinical criteria for the diagnosis of VS. The purpose of this study was to investigate whether there was significant differential activation of the brain in response to hearing his mother's voice compared with the voices of unknown women. The data were assessed using quantitative electric tomography (QEEGt), a technique that combines anatomical information of the brain by MRI with EEG patterns to estimate the sources of the EEG within the brain. We found significant differences for EEG frequencies from 14–58 Hz, with a peak at 33.2 Hz (gamma band). The 3D reconstruction showed that these statistical differences were localized in the lateral and posterior regions of the left hemisphere. No significant differences were found between unknown women vs. basal conditions. These results demonstrate recognition of the mother's voice and indicate high-level residual linguistic processing in a patient meeting clinical criteria for VS. These findings launch new ethical and practical implications for the management of VS patients.
Gender Specific Processing of Eye Contact within the Human Medial Temporal Lobe
Authors: Grunwald Thomas , Vannucci Manila , Pezer Nico , Kurthen Martin , Schramm Johannes , Elger Christian E.
Published: February 2012

Eye contact is a powerful social stimulus for human and non-human primates. However, it is unclear whether brain mechanisms that interpret eye contact are sensitive to gender. Here we show that human brain responses to eye contact are indeed gender specific. Recording event-related potentials directly from the medial temporal lobes, we found that eye contact elicited specific responses in men only when they saw female faces. Conversely, women responded specifically to eye contact only when they saw pictures of men. Thus, the human medial temporal lobes subserve specifically the processing of eye contact with persons of the opposite gender.