bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased Response-time Variability is Associated with Reduced Inferior Parietal Activation during Episodic Recognition in Aging
Authors: MacDonald Stuart W. S. , Nyberg Lars , Sandblom Johan , Fischer Håkan , Bäckman Lars 
Published: January 2008

Abstract
Intraindividual variability (IIV) in cognitive performance shares systematic associations with aging-related processes, brain injury, and neurodegenerative pathology. However, little research has examined the neural underpinnings of IIV, with no studies investigating brain correlates of IIV in relation to retrieval success. Using functional magnetic resonance imaging, we examined links between IIV, recognition memory performance, and blood oxygenation level dependent activations. Nineteen older adults (70–79 years) were presented with 80 words at encoding, with brain scans and response latencies obtained during subsequent recognition. An index of IIV, the intraindividual standard deviation (ISD), was computed across successful latency trials. Decreasing ISDs were systematically associated with better recognition, faster latencies, and increased activation in the inferior parietal cortex (BA 40). Demonstrated links between less behavioral variability and parietal activations are consistent with the known importance of the parietal cortex for retrieval success. In support of extant findings and theory from neuroscience, neuropsychology, and cognitive aging, the present results suggest that behavioral IIV represents a proxy for neural integrity.
Differential Modulation of Word Recognition by Semantic and Spatial Orienting of Attention
Authors: Cristescu Tamara C. , Nobre Anna Christina 
Published: January 2008

Abstract
In the present study, we investigated the ability to orient attention to abstract associative features of complex stimuli, more specifically, to the semantic categories of visual word stimuli. We compared the behavioral and electrophysiological effects of semantic orienting with those elicited by spatial orienting to word stimuli. Two parallel, cued lexical-decision tasks, with semantic- or spatial-orienting cues, were used. Results showed that both semantic and spatial orienting facilitated behavioral performance. The event-related potential analysis revealed different and non-overlapping patterns of modulation of word processing by semantic and spatial orienting. Modulation by semantic orienting started later, affecting only the potentials linked to conceptual or semantic processing (N300 and N400). The pattern of N300/N400 modulation in the semantic-orienting condition was similar to that observed in semantic-priming tasks, and was compatible with the operation of controlled semantic processes. Spatial orienting significantly enhanced the amplitude of the early visual potential P1 as well as the language-related N400 potential. These findings showed that the similar end-result of behavioral facilitation by semantic and spatial orienting is achieved through largely distinct mechanisms acting upon separate levels of stimulus analysis.
Learning through Hand- or Typewriting Influences Visual Recognition of New Graphic Shapes: Behavioral and Functional Imaging Evidence
Authors: Longcamp Marieke , Boucard Céline , Gilhodes Jean-Claude , Anton Jean-Luc , Roth Muriel , Nazarian Bruno , Velay Jean-Luc 
Published: January 2008

Abstract
Fast and accurate visual recognition of single characters is crucial for efficient reading. We explored the possible contribution of writing memory to character recognition processes. We evaluated the ability of adults to discriminate new characters from their mirror images after being taught how to produce the characters either by traditional pen-and-paper writing or with a computer keyboard. After training, we found stronger and longer lasting (several weeks) facilitation in recognizing the orientation of characters that had been written by hand compared to those typed. Functional magnetic resonance imaging recordings indicated that the response mode during learning is associated with distinct pathways during recognition of graphic shapes. Greater activity related to handwriting learning and normal letter identification was observed in several brain regions known to be involved in the execution, imagery, and observation of actions, in particular, the left Broca's area and bilateral inferior parietal lobules. Taken together, these results provide strong arguments in favor of the view that the specific movements memorized when learning how to write participate in the visual recognition of graphic shapes and letters.
Evidence for Anticipatory Motor Control within a Cerebello-Diencephalic-Parietal Network
Authors: Pollok Bettina , Gross Joachim , Kamp Daniel , Schnitzler Alfons 
Published: January 2008

Abstract
The posterior parietal cortex and the cerebellum are assumed to contribute to anticipatory motor control. Thus, it is reasonable that these areas act as a functional unit. To identify a neural signature of anticipatory motor control, 11 healthy volunteers performed a bimanual finger-tapping task with respect to isochronous (i.e., regular) and randomized (i.e., irregular) auditory pacing. Neuromagnetic activity was recorded using a 122-channel whole-head neuromagnetometer. Functional interaction between spatially distributed brain areas was determined by measures of tap-related phase synchronization. Assuming that (i) the cerebellum predicts sensory events by an internal model and (ii) the PPC maintains this prediction, we hypothesized that functional interaction between both structures varies depending on the predictability of the pacing signal. During isochronous pacing, functional connectivity within a cerebello-diencephalic-parietal network before tap onset was evident, suggesting anticipatory motor control. During randomized pacing, however, functional connectivity after tap onset was increased within a parietal-cerebellar loop, suggesting mismatch detection and update of the internal model. Data of the present study imply that anticipatory motor control is implemented in a network-like manner. Our data agree well with the hypothesis that functional connectivity in a cerebello-diencephalic-parietal loop might be crucial for anticipatory motor control, whereas parietal-cerebellar interaction might be critical for feedback processing.
Refreshing One of Several Active Representations: Behavioral and Functional Magnetic Resonance Imaging Differences between Young and Older Adults
Authors: Raye Carol L. , Mitchell Karen J. , Reeder John A. , Greene Erich J. , Johnson Marcia K. 
Published: January 2008

AbstractWe explored age-related differences in executive function during selection of a target from among active representations. Refreshing (thinking briefly of a just-activated representation) is an executive process that foregrounds a target relative to other active representations. In a behavioral study, participants saw one or three words, then saw a cue to refresh one of the words, saw one word again and read it, or read a new word. Increasing the number of active representations increased response times (RTs) only in the refresh condition for young adults but increased RTs equally in all conditions for older adults, suggesting that they experienced interference from activated irrelevant information during perception and reflection. Consistent with this interpretation, in a functional magnetic resonance imaging study, young adults showed two areas of the left dorsolateral frontal cortex and a medial area of frontal cortex, including anterior cingulate, that were relatively more sensitive to number of active representations during refresh than read trials; for older adults these areas were equally sensitive to number of active items for refresh and read trials. Young and older adults showed activity associated with refreshing on trials requiring selection in left mid-ventral frontal cortex (an area associated with selection from active representations); older adults also showed activity in left anterior ventral frontal cortex (an area associated with controlled semantic activation). Our results support the hypothesis of an age-related decrease in ability to gate out activated but currently irrelevant information, and are consistent with a dissociation of function between eft mid-ventral and left anterior ventral frontal cortex.
Brain Responses to Biological Relevance
Authors: Tipper Christine M. , Handy Todd C. , Giesbrecht Barry , Kingstone Alan 
Published: January 2008

Abstract
This study examines whether orienting attention to biologically based social cues engages neural mechanisms distinct from those engaged by orienting to nonbiologically based nonsocial cues. Participants viewed a perceptually ambiguous stimulus presented centrally while performing a target detection task. By having participants alternate between viewing this stimulus as an eye in profile or an arrowhead, we were able to directly compare the neural mechanisms of attentional orienting to social and nonsocial cues while holding the physical stimulus constant. The functional magnetic resonance imaging results indicated that attentional orienting to both eye gaze and arrow cues engaged extensive dorsal and ventral fronto-parietal networks. Eye gaze cues, however, more vigorously engaged two regions in the ventral frontal cortex associated with attentional reorienting to salient or meaningful stimuli, as well as lateral occipital regions. An event-related potential study demonstrated that this enhanced occipital response was attributable to a higher-amplitude sensory gain effect for targets appearing at locations cued by eye gaze than for those cued by an arrowhead. These results endorse the hypothesis that differences in attention to social and nonsocial cues are quantitative rather than qualitative, running counter to current models that assume enhanced processing for social stimuli reflects the involvement of a unique network of brain regions. An intriguing implication of the present study is the possibility that our ability to orient volitionally and reflexively to socially irrelevant stimuli, including arrowheads, may have arisen as a useful by-product of a system that developed first, and foremost, to promote social orienting to stimuli that are biologically relevant.
The Role of Pause Cues in Language Learning: The Emergence of Event-related Potentials Related to Sequence Processing
Authors: Mueller Jutta L. , Bahlmann Joerg , Friederici Angela D. 
Published: January 2008

Abstract
Humans can derive sequential dependencies from unfamiliar artificial speech within several of minutes of exposure. However, there is an ongoing debate about the nature of the underlying learning processes. In a widely discussed study Peña et al. [Peña, M., Bonatti, L. L., Nespor, M., & Mehler, J. Signal-driven computations in speech processing. Science, 298, 604–607, 2002] argued for the importance of subtle acoustic cues in the signal, such as pauses, in order to switch between two computational mechanisms, which are conceptualized as rule-based versus statistical. The present study was aimed to approach this problem by recording event-related potentials in response to correct and incorrect phrases consisting of bisyllabics after short exposure to either rule-based or random artificial speech streams. Rule-based streams contained dependencies of the form AXC, whereby A elements reliably predicted the C elements and X elements were variable. Participants were exposed to four input and test phases. Two of the input streams were rule-based and contained either only probabilistic information related to the distribution of the AXC stimuli or an additional acoustic cue indicating the boundaries of relevant units. The other two streams were random variations of the rule-based streams. During the test phase in the condition with pause cues, an early negativity and a later positivity emerged for correct and incorrect items in comparison to their acoustically identical counterparts, which were presented after the random control condition. In the noncued condition, only negativities were seen. The timing and the scalp distribution of the negativities were different for correct and incorrect sequences in both the cued and the noncued conditions. The results are interpreted in support of a view of grammatical learning in which both distributional and acoustic cues may contribute to different aspects of syntactic learning.
Brain Error–monitoring Activity is Affected by Semantic Relatedness: An Event-related Brain Potentials Study
Authors: Ganushchak Lesya Y. , Schiller Niels O. 
Published: January 2008

Abstract
Speakers continuously monitor what they say. Sometimes, self-monitoring malfunctions and errors pass undetected and uncorrected. In the field of action monitoring, an event-related brain potential, the error-related negativity (ERN), is associated with error processing. The present study relates the ERN to verbal self-monitoring and investigates how the ERN is affected by auditory distractors during verbal monitoring. We found that the ERN was largest following errors that occurred after semantically related distractors had been presented, as compared to semantically unrelated ones. This result demonstrates that the ERN is sensitive not only to response conflict resulting from the incompatibility of motor responses but also to more abstract lexical retrieval conflict resulting from activation of multiple lexical entries. This, in turn, suggests that the functioning of the verbal self-monitoring system during speaking is comparable to other performance monitoring, such as action monitoring.
Moving Toward Dialogical Collaboration: A Critical Examination of a University— School—Community Partnership
Authors: Miller Peter M. , Hafner Madeline M. 
Published: January 2008

Purpose: This study sought to deepen current understandings of collaboration and leadership in the context of partnerships between diverse universities, schools, and communities. Using a critical epistemological perspective, the project specifically attempted to learn more about the processes employed by one particular partnership in the Western United States. To inform this process evaluation, the study's conceptual framework was rooted in tenets of Paulo Freire's (1970) concept of dialogue. Specifically, the study sought to reveal the extent to which the Freirean dialogical tenets of humility, faith, hope, and critical thinking were embodied in this collaborative process. Research Methods: Qualitative case study. Data Collection and Analysis: Data were collected through semistructured interviews with 17 participants, 25 observations, and analysis of relevant documents and archival data. After a process of open and axial coding, the findings were deductively analyzed using tenets of Freire's (1970) dialogue. Findings: The findings suggested that although the partnership's participants appeared to have intentions that were closely aligned with the tenets of dialogue, various factors inhibited the actual process from evolving as one that was comprehensively dialogical. Conclusions: It is asserted that in educational partnerships between diverse individuals and organizations, the onus is on those who occupy traditional leadership positions to ensure that equal participative opportunities are afforded to all interested parties. Several recommendations are offered to facilitate the creation of such collaborative structures.
Long-Term Follow-up of Arthroscopic Treatment of Lateral Epicondylitis
Authors: Baker Champ L. , Baker Champ L. 
Published: January 2008

Background In a previously published report of the authors’ arthroscopic technique of operative management of recalcitrant lateral epicondylitis, they demonstrated short-term success with the procedure in their patients. Hypothesis Arthroscopic management of patients with lateral epicondylitis can produce clinical improvement and have successful long-term outcomes. Study Design Case series; Level of evidence, 4. Methods Forty patients (42 elbows) with lateral epicondylitis who had not responded to nonoperative management were treated with arthroscopic resection of pathologic tissue. Thirty of these patients (30 elbows) were located for extended follow-up. At a mean follow-up of 130 months (range, 106–173 months), patients were asked to use a numeric scale to rate their elbow pain from 0 (no pain) to 10 (severe pain). Patients were also asked to rate their elbows according to the functional portion of the Mayo Clinic Elbow Performance Index. Results The mean pain score at rest was 0; with activities of daily living, 1.0; and with work or sports, 1.9. The mean functional score was 11.7 out of a possible 12 points. No patient required further surgery or repeat injections after surgery. One patient continued to wear a counterforce brace with heavy activities. Twenty-three patients (77%) stated they were “much better,” 6 patients (20%) stated they were “better,” and 1 patient (3%) stated he was the same. Twenty-six patients (87%) were satisfied, and 28 patients (93%) stated they would have the surgery again if needed. Conclusion Arthroscopic removal of pathologic tendinosis tissue is a reliable treatment for recalcitrant lateral epicondylitis. The early high rate of success in patients was maintained at long-term follow-up.
Exercise-Induced Scalenus Syndrome
Authors: Baltopoulos Panagiotis , Tsintzos Charalampos , Prionas George , Tsironi Maria 
Published: January 2008

BackgroundThoracic outlet syndrome is described as a group of distinct disorders producing signs and symptoms attributed to compression of nerves and blood vessels in the thoracic outlet region.PurposeTo describe the exercise-induced scalenus anticus syndrome attributed to the anterior scalenus hypertrophy as a thoracic outlet syndrome underlying mechanism and to give recommendations for a safe and effective surgical treatment.Study DesignCase series; Level of evidence, 4.MethodsTwelve young professional athletes admitted for thoracic outlet syndrome (8 cases of neurologic thoracic outlet syndrome, 4 cases of mixed neurologic and vascular thoracic outlet syndrome) who reported numbness, tingling, early fatigue, muscle weakness, and pain were enrolled in the study. Scalenus hypertrophy was suspected to be the causative factor. Scalenectomy was performed in all cases.ResultsAll patients had moderate to severe hypertrophy of the anterior scalenus muscle. Scalenectomy was performed, and there were no intraoperative or postoperative complications. Full activity was quickly achieved, and no recurrence of symptoms was documented.ConclusionSurgical intervention for scalenus anticus syndrome can allow an athlete to return to full activity and improve quality of life. Surgical intervention seems to be the treatment of choice in terms of restoring quality of life and physical activity.
Basal and angiopoietin-1–mediated endothelial permeability is regulated by sphingosine kinase-1
Authors: Li Xiaochun , Stankovic Milena , Bonder Claudine S. , Hahn Christopher N. , Parsons Michelle , Pitson Stuart M. , Xia Pu , Proia Richard L. , Vadas Mathew A. , Gamble Jennifer R. 
Published: January 2008

Abstract
Endothelial cells (ECs) regulate the barrier function of blood vessels. Here we show that basal and angiopoietin-1 (Ang-1)–regulated control of EC permeability is mediated by 2 different functional states of sphingosine kinase-1 (SK-1). Mice depleted of SK-1 have increased vascular leakiness, whereas mice transgenic for SK-1 in ECs show attenuation of leakiness. Furthermore, Ang-1 rapidly and transiently stimulates SK-1 activity and phosphorylation, and induces an increase in intracellular sphingosine-1-phosphate (S1P) concentration. Overexpression of SK-1 resulted in inhibition of permeability similar to that seen for Ang-1, whereas knockdown of SK-1 by small interfering RNA blocked Ang-1-mediated inhibition of permeability. Transfection with SKS225A, a nonphosphorylatable mutant of SK-1, inhibited basal leakiness, and both SKS225A and a dominant-negative SK-1 mutant removed the capacity of Ang-1 to inhibit permeability. These effects were independent of extracellular S1P as knockdown or inhibition of S1P1, S1P2, or S1P3, did not affect the Ang-1 response. Thus, SK-1 levels in ECs powerfully regulate basal permeability in vitro and in vivo. In addition, the Ang-1–induced inhibition of leakiness is mediated through activation of SK-1, defining a new signaling pathway in the Ang-1 regulation of permeability.
The TNF (−308A) polymorphism is associated with microchimerism in transfused trauma patients
Authors: Gill Ryan M. , Lee Tzong-Hae , Utter Garth H. , Reed William F. , Wen Li , Chafets Dan , Busch Michael P. 
Published: January 2008

Abstract
Microchimerism (MC), defined as the persistence of allogeneic cells at low concentrations, is well documented in transfused trauma patients. We hypothesized that genetic polymorphisms linked to cytokine production could contribute to trauma-induced immune modulation and development of microchimerism after transfusion of trauma patients. We used high-throughput SYBR-green-based genotyping of single nucleotide polymorphisms (SNPs) to characterize 59 transfused trauma patients, with MC (n = 30) and without MC (n = 29), for 4 functionally significant SNPs: TNF (−308), IL 10 (−1082), IFNG (+874), and TGFB1 (+915). We then compared likelihood for development of MC and the magnitude of immune suppression among subjects with and without these selected immune response SNPs. We identified a significant association between TNF (−308A) SNP and both development of MC and diminished immune responsiveness. Hence predisposing genetic factors may explain, in part, why only a subset of trauma patients develops transfusion-associated microchimerism.
Systematic identification of stem-loop containing sequence families in bacterial genomes
Authors: Cozzuto Luca , Petrillo Mauro , Silvestro Giustina , Di Nocera Pier Paolo , Paolella Giovanni 
Published: January 2008

Abstract

Background
Analysis of non-coding sequences in several bacterial genomes brought to the identification of families of repeated sequences, able to fold as secondary structures. These sequences have often been claimed to be transcribed and fulfill a functional role. A previous systematic analysis of a representative set of 40 bacterial genomes produced a large collection of sequences, potentially able to fold as stem-loop structures (SLS). Computational analysis of these sequences was carried out by searching for families of repetitive nucleic acid elements sharing a common secondary structure.

Results
The initial clustering procedure identified clusters of similar sequences in 29 genomes, corresponding to about 1% of the whole population. Sequences selected in this way have a substantially higher aptitude to fold into a stable secondary structure than the initial set. Removal of redundancies and regrouping of the selected sequences resulted in a final set of 92 families, defined by HMM analysis. 25 of them include all well-known SLS containing repeats and others reported in literature, but not analyzed in detail. The remaining 67 families have not been previously described. Two thirds of the families share a common predicted secondary structure and are located within intergenic regions.

Conclusion
Systematic analysis of 40 bacterial genomes revealed a large number of repeated sequence families, including known and novel ones. Their predicted structure and genomic location suggest that, even in compact bacterial genomes, a relatively large fraction of the genome consists of non-protein-coding sequences, possibly functioning at the RNA level.