Brain Sciences Center - News

Brain oscillatory activity during motor preparation: effect of directional uncertainty on beta, but not alpha, frequency band

In time-constraint activities, such as sports, it is advantageous to be prepared to act even before knowing precisely what action will be needed. Here, we studied the relation between neural oscillations during motor preparation and amount of uncertainty about the direction of the upcoming target. Ten right-handed volunteers participated in a cued center-out task. A brief visual cue identified the region of space in which the target would appear. Three cue sizes were used to vary the amount of information about the direction of the upcoming target. The target appeared at a random location within the region indicated by the cue, and the participants moved a joystick-controlled cursor toward it. Time-frequency analyses showed phasic increases of power in low (delta/theta: <7 Hz) and high (gamma: >30 Hz) frequency-bands in relation to the onset of visual stimuli and of the motor response. More importantly in regard to motor preparation, there was a tonic reduction of power in...
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Neural communication in posttraumatic growth

Posttraumatic growth (PTG), or positive psychological changes following exposure to traumatic events, is commonly reported among trauma survivors. In the present study, we examined neural correlates of PTG in 106 veterans with and 193 veteran controls using task-free , diagnostic interviews and measures of PTG, and traumatic event exposure. Global (SNIs) were significantly modulated downward with increasing PTG scores in controls (p = .005), but not in veterans with (p = .601). This effect was primarily characterized by negative slopes in local neural networks, was strongest in the medial prefrontal cortex, and was much stronger and more extensive in the control than the group. The present study complements previous research highlighting the role of neural adaptation in healthy functioning.

Diagnostic and Statistical Manual of Mental Disorders, Fifth EditionDiagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)The 2013 update to the American Psychiatric Association's (APA) classification and diagnostic tool. In the United States the DSM serves as a universal authority for psychiatric diagnosis. Treatment recommendations, as well as payment by health care providers, are often determined by DSM classifications, so the appearance of a new version has significant practical importance. personality traits discriminate between posttraumatic stress disorder and control groups

The relevance of personality traits to the study of psychopathology has long been recognized, particularly in terms of understanding patterns of comorbidity. In fact, a multidimensional personality trait model reflecting five higher-order personality dimensions-negative affect, detachment, antagonism, disinhibition, and psychoticism-is included in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders () and represented in the Personality Inventory for (PID-5). However, evaluation of these dimensions and underlying personality facets within clinical samples has been limited. In the present study, we utilized the PID-5 to evaluate the personality profile elevation and composition of 150 control veterans and 35 veterans diagnosed with posttraumatic stress disorder (). Results indicated that veterans with endorsed significantly more personality pathology than control veterans, with scores on detachment and psychoticism domains most clearly discriminating between the two groups. When personality domain scores were considered as parts of each subject's personality profile, a slightly...
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White Noise Test: detecting autocorrelation and nonstationarities in long time series after ARIMA modeling

Time series analysis has been a dominant technique for assessing relations within atasets collected over time and is becoming increasingly prevalent in the scientific community; for example, assessing brain networks by calculating pairwise correlations of time series generated from different areas of the brain. The assessment of these relations relies, in turn, on the proper calculation of interactions between time series, which is achieved by rendering each individual series stationary and nonautocorrelated (i.e., white noise, or to "prewhiten" the series). This ensures that the relations computed subsequently are due to the interactions between the series and do not reflect internal dependencies of the series themselves. An established method for prewhitening time series is to apply an Autoregressive (AR, p) Integrative (I, d) Moving Average (MA, q) model (ARIMA) and retain the residuals. To diagnostically check whether the model orders (p, d, q) are sufficient, both visualization and statistical tests (e.g., Ljung-Box...
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The effect of Apolipoprotein EApolipoprotein E (ApoE)a plasma lipoprotein discovered in 1973 (Shore and Shore 1973). It binds low-density lipoprotein receptors, thereby facilitating cellular lipoprotein exchange and metabolism. The human apoE polypeptide consists of 299 amino acids and comprises three polymorphisms resulting from single amino acid substitutions. Three isoforms (E4, E3, and E2) are the result of cysteine^aEUR"arginine interchanges at two sites, namely residues 112 and 158; however, other genetic variants have been described. These three isoforms, each differentially affecting protein function, result in six phenotypes: three homozygotes (E4/4, E3/3, E2/2) and three heterozygotes (E4/3, E4/2, E3/2). With respect to the number of cysteine residues per mole, E2/2 contains 4, E3/2 contains 3, E4/2 and E3/3 each contain 2, E4/3 contains 1, and E4/4 contains 0. The number of cysteine residues per mole (CysR/mole) provides a numerical, biochemical scale in lieu of the genotype-based categories.4 on SNISynchronous Neural Interactions (SNI)Zero-lag partial correlations in pairs of MEG time series and denote the strength and polarity (positive or negative) of neuronal interactions. Anomalies in SNIs as assessed by MEG differentiate psychiatric disorders from healthy brain functioning and can discriminate among various brain diseases. From this research, a highly distinctive, unique PTSD SNI signature characterized by miscommunication of temporal and parietal and/or parieto-occipital right hemispheric areas with other brain areas has emerged. These findings, in addition to the growing research applying MEG to other psychiatric disorders, highlight the utility of MEG in identifying biomarkers of disease and underscore the potential for broader clinical applications of MEG. in brain cultures

In a previous study, we assessed the in a developing neural network in brain cultures on multielectrode arrays (Christopoulos et al. in J Neural Eng 9:046008, 2012). Here, we report on the effects of 4 (4) on these neural interactions. We carried out six experiments (five using rodent brain cultures and one using neuroblastoma cultures) in which we recorded local field potentials (LFP) from 59 sites for several days in vitro under the following conditions. In one experiment, we added to the culture media triglyceride (TG)-rich lipoproteins from a human subject with the 4/4 genotype, whereas in the other experiments, we added recombinant human 4. We found that in the 4-treated cultures had higher coefficient of variation, as compared to control cultures. These findings further document the role of as a fundamental aspect of the dynamic organization of neural networks (Langheim et al....
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Posttraumatic Stress Disorder in Women Veterans

Researchers use brain imaging to identify biological indicators of in women and genetic tests to understand why some women will develop while others won't.

The Danieli Inventory of Multigenerational Legacies of Trauma, Part II: Reparative Adaptational Impacts

The impacts of the Holocaust on children of survivors have been widely investigated. However, consensus is limited, and no validated measures have been tailored with or to them. We aimed to develop and validate a scale that measures these specific impacts (Part II of the Danieli Inventory of Multigenerational Legacies of Trauma). We studied 484 adult children of survivors who participated in a cross-sectional web-based survey in English or Hebrew; of these, 191 participated in a clinical interview. Exploratory factor analyses of 58 items to reduce and refine the measure yielded a 36-item scale, Reparative Adaptational Impacts, that had excellent internal consistency (α = .91) and congruence between English and Hebrew versions (φ ≥ .95). Associations between impacts and SCID-based diagnoses of major depressive episode, posttraumatic stress disorder, and generalized anxiety disorder were moderate to strong (ds = 0.48-0.89). Strong associations also emerged between severity of offspring's reparative adaptational impacts and...
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Spatial attentional control is not impaired in schizophrenia: Dissociating specific deficits from generalized impairments

A large literature has established that people with schizophrenia are impaired on tasks that require attentional control. However, evidence is mixed as to whether these impairments are specific deficits (Oltmanns & Neale, 1975) or merely reflect a generalized impairment (Dickinson & Harvey, 2009). Recent evidence also suggests visual attentional control for encoding into working memory may be selectively spared in people with schizophrenia (Gold et al., 2006). The current study used a cued backward masking task to investigate 23 people with schizophrenia and 27 healthy controls. People with schizophrenia were hypothesized to perform better on invalidly cued trials when making a simple identification or location judgment. However, we found schizophrenia impaired performance on both valid and invalid cues to the same degree whether the cue was a stored representation (top-down) or presented at the location of the stimulus (bottom-up). In contrast to a large neuropsychological literature, these findings suggest that people...
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Client report of spirituality in recovery from serious mental illness

Concerns about the ability to understand and communicate about spiritual material have become a source of controversy regarding spiritually integrated care for individuals managing serious mental illnesses (Hathaway, 2011). In this study, 91 people receiving outpatient services for serious mental illnesses provided information on their symptoms, level of recovery, spiritual functioning, and preferences about spiritually integrated care, as well as their responses to an infrequency/inconsistency scale. Results indicated that (a) most participants were interested in spirituality and wanted to discuss this with mental health care providers, (b) as a group, most participants were able to provide reliable and valid responses to questions about spirituality.

Cognitive mechanisms underlying instructed choice exploration of small city maps

We investigated the cognitive mechanisms underlying the exploration and decision-making in realistic and novel environments. Twelve human subjects were shown small circular U.S. city maps with two locations highlighted on the circumference, as possible choices for a post office ("targets"). At the beginning of a trial, subjects fixated a spot at the center of the map and ultimately chose one of the two locations. A space syntax analysis of the map paths (from the center to each target) revealed that the chosen location was associated with the less convoluted path, as if subjects navigated mentally the paths in an "ant's way," i.e., by staying within street boundaries, and ultimately choosing the target that could be reached from the center in the shortest way, and the fewest turns and intersections. The subjects' strategy for map exploration and decision making was investigated by monitoring eye position during the task. This revealed a restricted...
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The Number of Cysteine Residues per Mole in Apolipoprotein EApolipoprotein E (ApoE)a plasma lipoprotein discovered in 1973 (Shore and Shore 1973). It binds low-density lipoprotein receptors, thereby facilitating cellular lipoprotein exchange and metabolism. The human apoE polypeptide consists of 299 amino acids and comprises three polymorphisms resulting from single amino acid substitutions. Three isoforms (E4, E3, and E2) are the result of cysteine^aEUR"arginine interchanges at two sites, namely residues 112 and 158; however, other genetic variants have been described. These three isoforms, each differentially affecting protein function, result in six phenotypes: three homozygotes (E4/4, E3/3, E2/2) and three heterozygotes (E4/3, E4/2, E3/2). With respect to the number of cysteine residues per mole, E2/2 contains 4, E3/2 contains 3, E4/2 and E3/3 each contain 2, E4/3 contains 1, and E4/4 contains 0. The number of cysteine residues per mole (CysR/mole) provides a numerical, biochemical scale in lieu of the genotype-based categories. Is Associated With the Severity of PTSDPost-traumatic Stress Disorder (PTSD)A complex psychiatric syndrome that develops in response to trauma exposure. Individuals with PTSD experience intrusive recollections or reexperiencing of the traumatic event, avoidance of trauma reminders, emotional numbing, and hyperarousal. In addition, PTSD is associated with high rates of concomitant physical and mental health problems, increased health care use, and impairment in social and occupational functioning. Almost 7% of the general population and up to 30% of veterans meet lifetime criteria for PTSD. Indeed, PTSD is one of the most common psychiatric disorders, representing a significant and costly public health concern. Re-Experiencing Symptoms

Apolipoprotien E () is involved in critical neural functions and is associated with various neuropsychiatric disorders. exists in three isoforms that differ in the number of cysteine residues per mole (CysR/mole). This study evaluated associations between this informative ordinal biochemical scale (CysR/mole) and symptom severity in veterans with posttraumatic stress disorder () or subthreshold . Results demonstrated a significant negative relationship between the CysR/mole and severity of re-experiencing symptoms, adjusted for trauma. The findings suggest a genetic influence on symptomatology and dovetail with recent advances regarding the molecular mechanisms underlying the differential effects of in the brain.

An information theory analysis of spatial decisions in cognitive development

Performance in a cognitive task can be considered as the outcome of a decision-making process operating across various knowledge domains or aspects of a single domain. Therefore, an analysis of these decisions in various tasks can shed light on the interplay and integration of these domains (or elements within a single domain) as they are associated with specific task characteristics. In this study, we applied an information theoretic approach to assess quantitatively the gain of knowledge across various elements of the cognitive domain of spatial, relational knowledge, as a function of development. Specifically, we examined changing spatial relational knowledge from ages 5 to 10 years. Our analyses consisted of a two-step process. First, we performed a hierarchical clustering analysis on the decisions made in 16 different tasks of spatial relational knowledge to determine which tasks were performed similarly at each age group as well as to discover how the tasks clustered...
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Development and application of a diagnostic algorithm for posttraumatic stress disorder

Intact cognitive functions rely on synchronous neural activity; conversely, alterations in synchrony are thought to underlie psychopathology. We recently demonstrated that anomalies in determined by magnetoencephalography represent a putative biomarker. Here we develop and apply a regression-based diagnostic algorithm to further validate as a biomarker in 432 veterans (235 controls; 138 pure ; 59 plus comorbid disorders). Correlation coefficients served as proximities in multidimensional scaling (MDS) to obtain a two-dimensional representation of the data. In addition, least absolute shrinkage and selection operator (LASSO) regression was used to derive a diagnostic algorithm for . Performance of this algorithm was assessed by the area under the receiver operating characteristic (ROC) curves, sensitivity, and specificity in 1000 randomly divided testing and validation datasets and in independent samples. MDS revealed that individuals with , regardless of comorbid psychiatric conditions, are highly distinct from controls. Similarly, application of...
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Columnar Organization of the Motor Cortex: Direction of Movement

The discovery by Vernon B. Mountcastle of the columnar organization of the cerebral cortex (Mountcastle VB, J Neurophysiol 20:408-434, 1957, Brain 120:701-722, 1997) was the single most important discovery of the twentieth century in cortical physiology. Not only did it serve as the framework for the orderly arrangement of knowledge concerning cortical organization and function (Edelman and Mountcastle, The mindful brain. MIT Press, Cambridge, MA, 1978) but also as a framework for exploring and investigating new ideas and for revisiting old ones about the organization of particular cortical areas. Here I review the history of facts and ideas about the organization of the motor cortex and discuss the evidence that the direction of movement is the principle governing motor cortical columnar organization.

Cognitive modulation of local and callosal neural interactions in decision making

Traditionally, the neurophysiological mechanisms of cognitive processing have been investigated at the single cell level. Here we show that the dynamic, millisecond-by-millisecond, interactions between neuronal events measured by local field potentials are modulated in an orderly fashion by key task variables of a space categorization task performed by monkeys. These interactions were stronger during periods of higher cognitive load and varied in sign (positive, negative). They were observed both within area 7a of the posterior parietal cortex and between symmetric 7a areas of the two hemispheres. Time lags for maximum interactions were longer for opposite- vs. same-hemisphere recordings, and lags for negative interactions were longer than for positive interactions in both recording sites. These findings underscore the involvement of dynamic neuronal interactions in cognitive processing within and across hemispheres. They also provide accurate estimates of lags in callosal interactions, very comparable to similar estimates of callosal conduction delays derived from neuroanatomical...
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Social support as a mediator in the relationship between religious comforts and strains and trauma symptoms

Recent research shows that religious and spiritual variables are related to adjustment among those who have experienced trauma (Harris et al., 2008). It is also known that social support influences posttraumatic adjustment (Frazier et al., 2011). Critics have argued that religious and spiritual variables primarily serve as a proxy for social support because individuals in spiritual communities access higher levels of social support than those with no such community (Bradley, Schwartz, & Kaslow, 2005). We sought to explore the interrelationships among these 3 domains by studying church members with histories of trauma exposure. We found that social support and religious comforts and strains are distinguishable. Social support, religious comfort, and religious fear and guilt make independent contributions to posttraumatic adjustment, whereas social support partially mediates the relationship between alienation from one's higher power, religious rifts, and trauma symptoms.

Cell directional spread determines accuracy, precision, and length of the neuronal population vector

The neuronal population vector (NPV) for movement direction is the sum of weighted neuronal directional contributions. Based on theoretical considerations, we proposed recently that the sharpness of tuning will impact the directional precision, accuracy, and length of the NPV, such that sharper tuning will yield NPV with higher precision, higher accuracy, and shorter length (Mahan and Georgopoulos in Front Neural Circuits 7:92, 2013). Furthermore, we proposed that controlling the inhibitory drive in a local network could be the mechanism by which the sharpness of directional tuning would be varied, resulting in a continuous specification and control of movement's directional precision, accuracy, and speed (Mahan and Georgopoulos in Front Neural Circuits 7:92, 2013, Fig. 5). As a first step in testing this idea, here we analyzed data from 899 cells recorded in the motor cortex during performance of a center → out task. There were two major findings. First, directional selectivity varied...
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Understanding Post-traumatic Stress DisorderPost-traumatic Stress Disorder (PTSD)A complex psychiatric syndrome that develops in response to trauma exposure. Individuals with PTSD experience intrusive recollections or reexperiencing of the traumatic event, avoidance of trauma reminders, emotional numbing, and hyperarousal. In addition, PTSD is associated with high rates of concomitant physical and mental health problems, increased health care use, and impairment in social and occupational functioning. Almost 7% of the general population and up to 30% of veterans meet lifetime criteria for PTSD. Indeed, PTSD is one of the most common psychiatric disorders, representing a significant and costly public health concern.

Doctor Brian Engdahl talks about the reality of and how those suffering from the disorder can get effective help

Risk-Taking Behaviors and Impulsivity Among Veterans With and Without Post-traumatic Stress DisorderPost-traumatic Stress Disorder (PTSD)A complex psychiatric syndrome that develops in response to trauma exposure. Individuals with PTSD experience intrusive recollections or reexperiencing of the traumatic event, avoidance of trauma reminders, emotional numbing, and hyperarousal. In addition, PTSD is associated with high rates of concomitant physical and mental health problems, increased health care use, and impairment in social and occupational functioning. Almost 7% of the general population and up to 30% of veterans meet lifetime criteria for PTSD. Indeed, PTSD is one of the most common psychiatric disorders, representing a significant and costly public health concern. and Mild TBI

Military personnel commonly experience and mild traumatic brain injury (mTBI), both of which are associated with premature mortality. The present study examined two factors that may play a role in premature mortality-impulsivity and risk-taking behaviors-in a sample of 234 veterans screening positive for , mTBI, + mTBI, and controls. Analyses of variance demonstrated that veterans with , regardless of mTBI status, reported engaging in more frequent risky behaviors and reported a greater tendency to engage in impulsive behaviors when in a negative affective state. They also reported more premilitary delinquent behaviors and more suicide-related behaviors than controls. The present study highlights associations between impulsivity, risk-taking behaviors, and , and suggests continuity across the lifespan in terms of a predisposition to engage in impulsive and/or risky behaviors. Thorough evaluation of impulsivity and potentially risky behaviors is important in clinical settings to guide interventions and reduce the mortality...
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Departure from Network Equilibrium (DNE): an efficient and scalable measure of instantaneous network dynamics, with an application to magnetoencephalography

The assessment of the dynamic status of a network is currently unavailable. It is important to know how far a network is away from its equilibrium (as an indicator of instability) at a moment, and over periods of time. Here, we introduce the Departure from Network Equilibrium (DNE), a new measure of instantaneous network dynamics. DNE is simple, fast to compute, and scalable with network size. We present the results of its application on white noise networks (as a basis) and on networks derived from magnetoencephalographic recordings from the human brain.