14 research outputs found

    Neural correlate of the construction of sentence meaning

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    The neural processes that underlie your ability to read and understand this sentence are unknown. Sentence comprehension occurs very rapidly, and can only be understood at a mechanistic level by discovering the precise sequence of underlying computational and neural events. However, we have no continuous and online neural measure of sentence processing with high spatial and temporal resolution. Here we report just such a measure: intracranial recordings from the surface of the human brain show that neural activity, indexed by γ-power, increases monotonically over the course of a sentence as people read it. This steady increase in activity is absent when people read and remember nonword-lists, despite the higher cognitive demand entailed, ruling out accounts in terms of generic attention, working memory, and cognitive load. Response increases are lower for sentence structure without meaning (“Jabberwocky” sentences) and word meaning without sentence structure (word-lists), showing that this effect is not explained by responses to syntax or word meaning alone. Instead, the full effect is found only for sentences, implicating compositional processes of sentence understanding, a striking and unique feature of human language not shared with animal communication systems. This work opens up new avenues for investigating the sequence of neural events that underlie the construction of linguistic meaning.United States. National Institutes of Health (EB00856)United States. National Institutes of Health (EB006356)United States. National Institutes of Health (EB018783)United States. Army Research Office (W911NF-08-1-0216)United States. Army Research Office (W911NF-12-1-0109)United States. Army Research Office (W911NF-14-1-0440)Eunice Kennedy Shriver National Institute of Child Health and Human Development (U.S.) (HD-057522

    Facephenes and rainbows: Causal evidence for functional and anatomical specificity of face and color processing in the human brain

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    Neuroscientists have long debated whether some regions of the human brain are exclusively engaged in a single specific mental process. Consistent with this view, fMRI has revealed cortical regions that respond selectively to certain stimulus classes such as faces. However, results from multivoxel pattern analyses (MVPA) challenge this view by demonstrating that category-selective regions often contain information about “nonpreferred” stimulus dimensions. But is this nonpreferred information causally relevant to behavior? Here we report a rare opportunity to test this question in a neurosurgical patient implanted for clinical reasons with strips of electrodes along his fusiform gyri. Broadband gamma electrocorticographic responses in multiple adjacent electrodes showed strong selectivity for faces in a region corresponding to the fusiform face area (FFA), and preferential responses to color in a nearby site, replicating earlier reports. To test the causal role of these regions in the perception of nonpreferred dimensions, we then electrically stimulated individual sites while the patient viewed various objects. When stimulated in the FFA, the patient reported seeing an illusory face (or “facephene”), independent of the object viewed. Similarly, stimulation of color-preferring sites produced illusory “rainbows.” Crucially, the patient reported no change in the object viewed, apart from the facephenes and rainbows apparently superimposed on them. The functional and anatomical specificity of these effects indicate that some cortical regions are exclusively causally engaged in a single specific mental process, and prompt caution about the widespread assumption that any information scientists can decode from the brain is causally relevant to behavior.National Institutes of Health (U.S.) (Grant DP1HD091947

    Symptoms Improve After a Yoga Program Designed for PTSD in a Randomized Controlled Trial With Veterans and Civilians

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    Objective: Although yoga shows promise as a treatment for posttraumatic stress disorder (PTSD), there are few randomized controlled trials that demonstrate significant benefits for individuals with PTSD. The present study addresses this need by comparing the effects of a holistic yoga program (HYP) to that of a wellness lifestyle program (WLP) on PTSD symptom severity with a randomized clinical trial. Method: The sample consisted of 209 participants (91.4% veterans; 66% male; 61.7% White) who met diagnostic criteria for PTSD at baseline. Participants were randomly assigned to attend one of the 2 weekly interventions for 16 weeks. The HYP consisted of yoga instruction, while the WLP consisted of didactics, discussions, and walking. PTSD severity was measured using the Clinician Administered PTSD Scale (CAPS-5) and the PTSD Checklist (PCL-5). Results: Analyses revealed that the HYP reduced PTSD severity measured by the CAPS-5 significantly more than the WLP at treatment end (mean difference = −5.4, effect size = 0.46, p < .001), but not at 7-month follow up (mean difference = −0.9, p = .603). Similarly, the HYP reduced PTSD severity measured by the PCL-5 significantly more than the WLP at treatment end (difference = −6.0, p = .001), but not at 7-month follow up (mean difference = −1.0, p = .682). Conclusion: Yoga may be an effective intervention for PTSD in addition to standard treatments. Future yoga trials should consider adding a social component to interventions or booster classes to maintain effects long term

    The Impact of Yoga on Quality of Life after Stroke

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    poster abstractAbstract Objective: Evaluate the effect of an innovative 8 week yoga-based rehabilitation intervention on 1) stroke specific quality of life (QoL) and 2) activity and participation scores in veterans with chronic stroke. Rationale/Background: Declines in Quality of Life (QoL), activity, and participation are common after stroke. Such declines are related to increased mortality, dependence, and costs. As more people live with long-term effects of stroke, it is necessary to develop innovative and evidence-based rehabilitation and occupational therapy interventions to improve QoL, activity, and participation in people with chronic stroke. Methods: • Participants- Participants included veterans with chronic stroke (>9 months) who had completed all occupational and physical therapy after stroke, reported some residual disability or functional loss after stroke; and scored >4 out of 6 on the Short Mini Mental Status Exam. • Setting- All data were collected in the Rehabilitation and Integrative Therapy lab at an urban university. • Design- This was a mixed methods pilot study of an 8 week yoga-based rehabilitation intervention. Data were collected before and after the 8 week yoga intervention. Data collection was completed by a trained research assistant. We used paired t-tests and Wilcoxon non-parametirc tests as appropriate to compare group change in scores over the 8-weeks. • Measure(s)- Measures included the Stroke Specific Quality of Life scale (SSQoL) (high score=better QoL) to measure QoL and activity and participation were measured with the ICF Measure of Participation and Activity (IMPACT) (low score=less limitations in activity and participation). Both are valid and reliable instruments. Qualitative comments were collected during focus groups after the intervention. Supportive qualitative comments regarding improved QoL and activity and participation are included. All qualitative comments were reviewed by two researchers, and exemplar quotes are included

    Cervico-Vaginal Inflammatory Cytokine and Chemokine Responses to Two Different SIV Immunogens

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    Studies have shown that vaccine vectors and route of immunization can differentially activate different arms of the immune system. However, the effects of different HIV vaccine immunogens on mucosal inflammation have not yet been studied. Because mucosal sites are the primary route of HIV infection, we evaluated the cervico-vaginal inflammatory cytokine and chemokine levels of Mauritian cynomolgus macaques following immunization and boost using two different SIV vaccine immunogens. The PCS vaccine delivers 12 20-amino acid peptides overlapping the 12 protease cleavage sites, and the Gag/Env vaccine delivers the full Gag and full Env proteins of simian immunodeficiency virus. We showed that the PCS vaccine prime and boosts induced short-lived, lower level increases of a few pro-inflammatory/chemotactic cytokines. In the PCS-vaccine group only the levels of MCP-1 were significantly increased above the baseline (P = 0.0078, Week 6; P = 0.0078, Week 17; P = 0.0234; Week 51) following multiple boosts. In contrast, immunizations with the Gag/Env vaccine persistently increased the levels of multiple cytokines/chemokines. In the Gag/Env group, higher than baseline levels were consistently observed for IL-8 (P = 0.0078, Week 16; P = 0.0078, Week 17; P = 0.0156, Week 52), IL-1b (P = 0.0234, Week 16; P = 0.0156, Week 17; P = 0.0156, Week 52), and MIP-1a (P = 0.0313, Week 16; P = 0.0156, Week 17; P = 0.0313, Week 52). Over time, repeated boosts altered the relative levels of these cytokines between the Gag/Env and PCS vaccine group. 18 weeks after final boost with a higher dosage, IP-10 levels (P = 0.0313) in the Gag/Env group remained higher than baseline. Thus, the influence of vaccine immunogens on mucosal inflammation needs to be considered when developing and evaluating candidate HIV vaccines

    Cervico-Vaginal Inflammatory Cytokine and Chemokine Responses to Two Different SIV Immunogens

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    Studies have shown that vaccine vectors and route of immunization can differentially activate different arms of the immune system. However, the effects of different HIV vaccine immunogens on mucosal inflammation have not yet been studied. Because mucosal sites are the primary route of HIV infection, we evaluated the cervico-vaginal inflammatory cytokine and chemokine levels of Mauritian cynomolgus macaques following immunization and boost using two different SIV vaccine immunogens. The PCS vaccine delivers 12 20-amino acid peptides overlapping the 12 protease cleavage sites, and the Gag/Env vaccine delivers the full Gag and full Env proteins of simian immunodeficiency virus. We showed that the PCS vaccine prime and boosts induced short-lived, lower level increases of a few pro-inflammatory/chemotactic cytokines. In the PCS-vaccine group only the levels of MCP-1 were significantly increased above the baseline (P = 0.0078, Week 6; P = 0.0078, Week 17; P = 0.0234; Week 51) following multiple boosts. In contrast, immunizations with the Gag/Env vaccine persistently increased the levels of multiple cytokines/chemokines. In the Gag/Env group, higher than baseline levels were consistently observed for IL-8 (P = 0.0078, Week 16; P = 0.0078, Week 17; P = 0.0156, Week 52), IL-1b (P = 0.0234, Week 16; P = 0.0156, Week 17; P = 0.0156, Week 52), and MIP-1a (P = 0.0313, Week 16; P = 0.0156, Week 17; P = 0.0313, Week 52). Over time, repeated boosts altered the relative levels of these cytokines between the Gag/Env and PCS vaccine group. 18 weeks after final boost with a higher dosage, IP-10 levels (P = 0.0313) in the Gag/Env group remained higher than baseline. Thus, the influence of vaccine immunogens on mucosal inflammation needs to be considered when developing and evaluating candidate HIV vaccines

    Mucosal antibody responses to vaccines targeting SIV protease cleavage sites or full-length Gag and Env proteins in Mauritian cynomolgus macaques.

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    HIV mutates rapidly and infects CD4+ T cells, especially when they are activated. A vaccine targeting conserved, essential viral elements while limiting CD4+ T cell activation could be effective. Learning from natural immunity observed in a group of highly HIV-1 exposed seronegative Kenyan female sex workers, we are testing a novel candidate HIV vaccine targeting the 12 viral protease cleavage sites (PCSs) (the PCS vaccine), in comparison with a vaccine targeting full-length Gag and Env (the Gag/Env vaccine) in a Mauritian cynomolgus macaque/SIV model. In this study we evaluated these vaccines for induction of mucosal antibodies to SIV immunogens at the female genital tract. Bio-Plex and Western blot analyses of cervicovaginal lavage samples showed that both the PCS and Gag/Env vaccines can elicit mucosal IgG antibody responses to SIV immunogens. Significantly higher increase of anti-PCS antibodies was induced by the PCS vaccine than by the Gag/Env vaccine (p<0.0001). The effect of the mucosal antibody responses in protection from repeated low dose pathogenic SIVmac251 challenges is being evaluated
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