Structural network differences in chronic muskuloskeletal pain: Beyond fractional anisotropy.

Chronic musculoskeletal pain is a condition that influences central nervous system structure. In this study, we combined novel structural neuroimaging techniques, using well-validated software packages including FSL, Mrtrix3, and DSI Studio, to characterize brain grey (GM) and white matter (WM) differences in chronic musculoskeletal pain participants (n = 74), compared to age-matched pain-free controls (n = 31). In participants with chronic pain, we identified significantly higher volume in subcortical GM structures using voxel-based morphometry (FSLVBM).

Cognitive Improvement after Mild Traumatic Brain Injury Measured with Functional Neuroimaging during the Acute Period.

Functional neuroimaging studies in mild traumatic brain injury (mTBI) have been largely limited to patients with persistent post-concussive symptoms, utilizing images obtained months to years after the actual head trauma. We sought to distinguish acute and delayed effects of mild traumatic brain injury on working memory functional brain activation patterns < 72 hours after mild traumatic brain injury (mTBI) and again one-week later. We hypothesized that clinical and fMRI measures of working memory would be abnormal in symptomatic mTBI patients assessed < 72 hours after injury, with most patients showing clinical recovery (i.

White matter involvement in chronic musculoskeletal pain.

Unlabelled: There is emerging evidence that chronic musculoskeletal pain is associated with anatomic and functional abnormalities in gray matter. However, little research has investigated the relationship between chronic musculoskeletal pain and white matter. In this study, we used whole-brain tract-based spatial statistics and region-of-interest analyses of diffusion tensor imaging data to demonstrate that patients with chronic musculoskeletal pain exhibit several abnormal metrics of white matter integrity compared with healthy controls.

You can't always get what you want: the influence of unexpected task constraint on voluntary task switching.

The current study assessed the effect that unexpected task constraint, following self-generated task choice, has on task switching performance. Participants performed a modified double-registration voluntary task switching procedure in which participants specified the task they wanted to perform, were presented with a cue that, on the majority of trials, confirmed the choice, and then performed the cued task. On a small portion of trials, participants were cued to perform a task that did not match their choice.

Unlearning chronic pain: A randomized controlled trial to investigate changes in intrinsic brain connectivity following Cognitive Behavioral Therapy.

Chronic pain is a complex physiological and psychological phenomenon. Implicit learning mechanisms contribute to the development of chronic pain and to persistent changes in the central nervous system. We hypothesized that these central abnormalities can be remedied with Cognitive Behavioral Therapy (CBT).

Cognitive-behavioral therapy increases prefrontal cortex gray matter in patients with chronic pain.

Unlabelled: Several studies have reported reduced cerebral gray matter (GM) volume or density in chronic pain conditions, but there is limited research on the plasticity of the human cortex in response to psychological interventions. We investigated GM changes after cognitive-behavioral therapy (CBT) in patients with chronic pain. We used voxel-based morphometry to compare anatomic magnetic resonance imaging scans of 13 patients with mixed chronic pain types before and after an 11-week CBT treatment and to 13 healthy control participants.

Disambiguating the roles of area V1 and the lateral occipital complex (LOC) in contour integration.

Contour integration, the linking of collinear but disconnected visual elements across space, is an essential facet of object and scene perception. Here, we set out to arbitrate between two previously advanced mechanisms of contour integration: serial facilitative interactions between collinear cells in the primary visual cortex (V1) versus pooling of inputs in higher-order visual areas. To this end, we used high-density electrophysiological recordings to assess the spatio-temporal dynamics of brain activity in response to Gabor contours embedded in Gabor noise (so-called "pathfinder displays") versus control stimuli.

The neurobiology of cognitive control in successful cocaine abstinence.

Introduction: Extensive evidence demonstrates that current cocaine abusers show hypoactivity in anterior cingulate and dorsolateral prefrontal cortex and respond poorly relative to drug-naïve controls on tests of executive function. Relatively little is known about the cognitive sequelae of long-term abstinence in cocaine addicts.

Methods: Here, we use a GO-NOGO task in which successful performance necessitated withholding a prepotent response to assay cognitive control in short- and long-term abstinent cocaine users (1-5 weeks and 40-102 weeks, respectively).

Early processing in the human lateral occipital complex is highly responsive to illusory contours but not to salient regions.

Human electrophysiological studies support a model whereby sensitivity to so-called illusory contour stimuli is first seen within the lateral occipital complex. A challenge to this model posits that the lateral occipital complex is a general site for crude region-based segmentation, based on findings of equivalent hemodynamic activations in the lateral occipital complex to illusory contour and so-called salient region stimuli, a stimulus class that lacks the classic bounding contours of illusory contours. Using high-density electrical mapping of visual evoked potentials, we show that early lateral occipital cortex activity is substantially stronger to illusory contour than to salient region stimuli, whereas later lateral occipital complex activity is stronger to salient region than to illusory contour stimuli.

Mismatch negativity to tonal contours suggests preattentive perception of prosodic content.

Modulation of speech conveys information that is decoded within audio-sensory structures. For example, the termination of an utterance with a rise in pitch distinguishes statements and questions. This study evaluated the sensitivity of early auditory structures to such linguistic prosodic distinctions using mismatch negativity (MMN).

Executive function and error detection: The effect of motivation on cingulate and ventral striatum activity.

Reacting appropriately to errors during task performance is fundamental to successful negotiation of our environment. This is especially true when errors will result in a significant penalty for the person performing a given task, be they financial or otherwise. Error responses and monitoring states were manipulated in a GO/NOGO task by introducing a financial punishment for errors.

Right Hemispheric Contributions to Fine Auditory Temporal Discriminations: High-Density Electrical Mapping of the Duration Mismatch Negativity (MMN).

That language processing is primarily a function of the left hemisphere has led to the supposition that auditory temporal discrimination is particularly well-tuned in the left hemisphere, since speech discrimination is thought to rely heavily on the registration of temporal transitions. However, physiological data have not consistently supported this view. Rather, functional imaging studies often show equally strong, if not stronger, contributions from the right hemisphere during temporal processing tasks, suggesting a more complex underlying neural substrate.

Hemispheric asymmetry and callosal integration of visuospatial attention in schizophrenia: a tachistoscopic line bisection study.

Background: A hallmark of visuospatial neglect syndrome is that patients with lesions to right parietal cortex misbisect horizontal lines far rightward of veridical center. Neurologically normal subjects misbisect lines with a systematic leftward bias (pseudoneglect). Both phenomena, as well as neuroimaging studies, disclose a predominant right-hemisphere control of spatial attention.

Auditory processing in schizophrenia during the middle latency period (10-50 ms): high-density electrical mapping and source analysis reveal subcortical antecedents to early cortical deficits.

Introduction: Auditory sensory processing dysfunction is a core component of schizophrenia, with deficits occurring at 50 ms post-stimulus firmly established in the literature. Given that the initial afference of primary auditory cortex occurs at least 35 ms earlier, however, an essential question remains: how early in sensory processing do such deficits arise, and do they occur during initial cortical afference or earlier, which would implicate subcortical auditory dysfunction.

Objective: To establish the onset of the earliest deficits in auditory processing, we examined the time window demarcating the transition from subcortical to cortical processing: 10 ms to 50 ms during the so-called middle latency responses (MLRs).

Object-based attention is multisensory: co-activation of an object's representations in ignored sensory modalities.

Within the visual modality, it has been shown that attention to a single visual feature of an object such as speed of motion, results in an automatic transfer of attention to other task-irrelevant features (e.g. colour).

The deployment of intersensory selective attention: a high-density electrical mapping study of the effects of theanine.

Objective: : Ingestion of the nonproteinic amino acid theanine (5-N-ethylglutamine) has been shown to increase oscillatory brain activity in the so-called alpha band (8-14 Hz) during resting electroencephalographic recordings in humans. Independently, alpha band activity has been shown to be a key component in selective attentional processes. Here, we set out to assess whether theanine would cause modulation of anticipatory alpha activity during selective attentional deployments to stimuli in different sensory modalities, a paradigm in which robust alpha attention effects have previously been established.

Subcortical visual dysfunction in schizophrenia drives secondary cortical impairments.

Visual processing deficits are an integral component of schizophrenia and are sensitive predictors of schizophrenic decompensation in healthy adults. The primate visual system consists of discrete subcortical magnocellular and parvocellular pathways, which project preferentially to dorsal and ventral cortical streams. Subcortical systems show differential stimulus sensitivity, while cortical systems, in turn, can be differentiated using surface potential analysis.

Audio-visual multisensory integration in superior parietal lobule revealed by human intracranial recordings.

Intracranial recordings from three human subjects provide the first direct electrophysiological evidence for audio-visual multisensory processing in the human superior parietal lobule (SPL). Auditory and visual sensory inputs project to the same highly localized region of the parietal cortex with auditory inputs arriving considerably earlier (30 ms) than visual inputs (75 ms). Multisensory integration processes in this region were assessed by comparing the response to simultaneous audio-visual stimulation with the algebraic sum of responses to the constituent auditory and visual unisensory stimulus conditions.

Flexible cognitive control: effects of individual differences and brief practice on a complex cognitive task.

Brain activations underlying cognitive processes are subject to modulation as a result of increasing cognitive demands, individual differences, and practice. The present study investigated these modulatory effects in a cognitive control task which required inhibition of prepotent responses based on the contents of working memory (WM) and which enabled a novel dissociation of item-specific and task-skill effects resulting from brief practice. Distinct responses in areas underlying WM and inhibitory control in the absence of behavioral changes reflected different effects of item repetition and general task practice on tonic working memory and phasic inhibitory processes.

Neural mechanisms involved in error processing: a comparison of errors made with and without awareness.

The ability to detect an error in one's own performance and then to improve ongoing performance based on this error processing is critical for effective behaviour. In our event-related fMRI experiment, we show that explicit awareness of a response inhibition commission error and subsequent post-error behaviour were associated with bilateral prefrontal and parietal brain activation. Activity in the anterior cingulate region, typically associated with error detection, was equivalent for both errors subjects were aware of and those they were not aware of making.