1,533 research outputs found

    Review: Do the Different Sensory Areas within the Cat Anterior Ectosylvian Sulcal Cortex Collectively Represent a Network Multisensory Hub?

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    Current theory supports that the numerous functional areas of the cerebral cortex are organized and function as a network. Using connectional databases and computational approaches, the cerebral network has been demonstrated to exhibit a hierarchical structure composed of areas, clusters and, ultimately, hubs. Hubs are highly connected, higher-order regions that also facilitate communication between different sensory modalities. One region computationally identified network hub is the visual area of the Anterior Ectosylvian Sulcal cortex (AESc) of the cat. The Anterior Ectosylvian Visual area (AEV) is but one component of the AESc that also includes the auditory (Field of the Anterior Ectosylvian Sulcus - FAES) and somatosensory (Fourth somatosensory representation - SIV). To better understand the nature of cortical network hubs, the present report reviews the biological features of the AESc. Within the AESc, each area has extensive external cortical connections as well as among one another. Each of these core representations is separated by a transition zone characterized by bimodal neurons that share sensory properties of both adjoining core areas. Finally, core and transition zones are underlain by a continuous sheet of layer 5 neurons that project to common output structures. Altogether, these shared properties suggest that the collective AESc region represents a multiple sensory/multisensory cortical network hub. Ultimately, such an interconnected, composite structure adds complexity and biological detail to the understanding of cortical network hubs and their function in cortical processing

    Altered Auditory and Multisensory Temporal Processing in Autism Spectrum Disorders

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    Autism spectrum disorders (ASD) are characterized by deficits in social reciprocity and communication, as well as by repetitive behaviors and restricted interests. Unusual responses to sensory input and disruptions in the processing of both unisensory and multisensory stimuli also have been reported frequently. However, the specific aspects of sensory processing that are disrupted in ASD have yet to be fully elucidated. Recent published work has shown that children with ASD can integrate low-level audiovisual stimuli, but do so over an extended range of time when compared with typically developing (TD) children. However, the possible contributions of altered unisensory temporal processes to the demonstrated changes in multisensory function are yet unknown. In the current study, unisensory temporal acuity was measured by determining individual thresholds on visual and auditory temporal order judgment (TOJ) tasks, and multisensory temporal function was assessed through a cross-modal version of the TOJ task. Whereas no differences in thresholds for the visual TOJ task were seen between children with ASD and TD, thresholds were higher in ASD on the auditory TOJ task, providing preliminary evidence for impairment in auditory temporal processing. On the multisensory TOJ task, children with ASD showed performance improvements over a wider range of temporal intervals than TD children, reinforcing prior work showing an extended temporal window of multisensory integration in ASD. These findings contribute to a better understanding of basic sensory processing differences, which may be critical for understanding more complex social and cognitive deficits in ASD, and ultimately may contribute to more effective diagnostic and interventional strategies

    Comparison of Post-injection Site Pain Between Technetium Sulfur Colloid and Technetium Tilmanocept in Breast Cancer Patients Undergoing Sentinel Lymph Node Biopsy.

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    BackgroundNo prior studies have examined injection pain associated with Technetium-99m Tilmanocept (TcTM).MethodsThis was a randomized, double-blinded study comparing postinjection site pain between filtered Technetium Sulfur Colloid (fTcSC) and TcTM in breast cancer lymphoscintigraphy. Pain was evaluated with a visual analogue scale (VAS) (0-100 mm) and the short-form McGill Pain Questionnaire (SF-MPQ). The primary endpoint was mean difference in VAS scores at 1-min postinjection between fTcSC and TcTM. Secondary endpoints included a comparison of SF-MPQ scores between the groups at 5 min postinjection and construction of a linear mixed effects model to evaluate the changes in pain during the 5-min postinjection period.ResultsFifty-two patients underwent injection (27-fTcSC, 25-TcTM). At 1-min postinjection, patients who received fTcSC experienced a mean change in pain of 16.8 mm (standard deviation (SD) 19.5) compared with 0.2 mm (SD 7.3) in TcTM (p = 0.0002). At 5 min postinjection, the mean total score on the SF-MPQ was 2.8 (SD 3.0) for fTcSC versus 2.1 (SD 2.5) for TcTM (p = 0.36). In the mixed effects model, injection agent (p < 0.001), time (p < 0.001) and their interaction (p < 0.001) were associated with change in pain during the 5-min postinjection period. The model found fTcSC resulted in significantly more pain of 15.2 mm (p < 0.001), 11.3 mm (p = 0.001), and 7.5 mm (p = 0.013) at 1, 2, and 3 min postinjection, respectively.ConclusionsInjection with fTcSC causes significantly more pain during the first 3 min postinjection compared with TcTM in women undergoing lymphoscintigraphy for breast cancer

    Behavioral, perceptual, and neural alterations in sensory and multisensory function in autism spectrum disorder.

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    Although sensory processing challenges have been noted since the first clinical descriptions of autism, it has taken until the release of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013 for sensory problems to be included as part of the core symptoms of autism spectrum disorder (ASD) in the diagnostic profile. Because sensory information forms the building blocks for higher-order social and cognitive functions, we argue that sensory processing is not only an additional piece of the puzzle, but rather a critical cornerstone for characterizing and understanding ASD. In this review we discuss what is currently known about sensory processing in ASD, how sensory function fits within contemporary models of ASD, and what is understood about the differences in the underlying neural processing of sensory and social communication observed between individuals with and without ASD. In addition to highlighting the sensory features associated with ASD, we also emphasize the importance of multisensory processing in building perceptual and cognitive representations, and how deficits in multisensory integration may also be a core characteristic of ASD

    Evaluation of the ALMA Prototype Antennas

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    The ALMA North American and European prototype antennas have been evaluated by a variety of measurement systems to quantify the major performance specifications. Nearfield holography was used to set the reflector surfaces to 17 microns RMS. Pointing and fast switching performance was determined with an optical telescope and by millimeter wavelength radiometry, yielding 2 arcsec absolute and 0.6 arcsec offset pointing accuracies. Path length stability was measured to be less than or approximately equal to 20 microns over 10 minute time periods using optical measurement devices. Dynamical performance was studied with a set of accelerometers, providing data on wind induced tracking errors and structural deformation. Considering all measurements made during this evaluation, both prototype antennas meet the major ALMA antenna performance specifications.Comment: 83 pages, 36 figures, AASTex format, to appear in PASP September 2006 issu

    The impact of multisensory integration deficits on speech perception in children with autism spectrum disorders.

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    Speech perception is an inherently multisensory process. When having a face-to-face conversation, a listener not only hears what a speaker is saying, but also sees the articulatory gestures that accompany those sounds. Speech signals in visual and auditory modalities provide complementary information to the listener (Kavanagh and Mattingly, 1974), and when both are perceived in unison, behavioral gains in in speech perception are observed (Sumby and Pollack, 1954). Notably, this benefit is accentuated when speech is perceived in a noisy environment (Sumby and Pollack, 1954). To achieve a behavioral gain from multisensory processing of speech, however, the auditory and visual signals must be perceptually bound into a single, unified percept. The most commonly cited effect that demonstrates perceptual binding in audiovisual speech perception is the McGurk effect (McGurk and MacDonald, 1976), where a listener hears a speaker utter the syllable ā€œba,ā€ and sees the speaker utter the syllable ā€œga.ā€ When these two speech signals are perceptually bound, the listener perceives the speaker as having said ā€œdaā€ or ā€œtha,ā€ syllables that are not contained in either of the unisensory signals, resulting in a perceptual binding, or integration, of the speech signals (Calvert and Thesen, 2004)

    Standardized Patient Encounters Periodic Versus Postencounter Evaluation of Nontechnical Clinical Performance

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    Introduction: Standardized patients are a beneficial component of modern healthcare education and training, but few studies have explored cognitive factors potentially impacting clinical skills assessment during standardized patient encounters. This study examined the impact of a periodic (vs. traditional postencounter) evaluation approach and the appearance of critical verbal and nonverbal behaviors throughout a standardized patient encounter on scoring accuracy in a video-based scenario. Methods: Forty-nine standardized patients scored either periodically or at only 1 point in time (postencounter) a healthcare provider\u27s verbal and nonverbal clinical performance during a videotaped standardized patient encounter. The healthcare provider portrayed in this study was actually a standardized patient delivering carefully scripted verbal and nonverbal behaviors in their portrayal of an actual physician. The encounter itself was subdivided into 3 distinct segments for the purpose of supporting periodic evaluation, with the expectation that both verbal and nonverbal cues occurring in the middle segment would be more challenging to accurately report for participants in the postscenario evaluation group as a result of working memory decay. Results: Periodic evaluators correctly identified a significantly greater number of critical verbal cues midscenario than postencounter evaluators (P \u3c 0.01) and correctly identified a significantly greater number of critical nonverbal cues than their postscenario counterparts across all 3 scenario segments (P \u3c 0.001). Further, postscenario evaluations exhibited a performance decrement in terms of midscenario correct identifications that periodic evaluators did not (P \u3c 0.01). Also, periodic evaluators exhibited fewer verbal cue false-positives during the first segment of the scenario than postscenario evaluators (P \u3c 0.001), but this effect did not extend to other segments regardless of the cue type (ie, verbal or nonverbal). Discussion: Pausing lengthier standardized patient encounters periodically to allow for more frequent scoring may result in better reporting accuracy for certain clinical behavioral cues. This could enable educators to provide more specific formative feedback to individual learners at the session\u27s conclusion. The most effective encounter design will ultimately depend on the specific goals and training objectives of the exercise itself

    Measurement of CP asymmetry in D 0 ā†’ K - K + and D 0 ā†’ Ļ€ - Ļ€ decays

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    Time-integrated CP asymmetries in D 0 decays to the final states K - K + and Ļ€ - Ļ€ + are measured using proton-proton collisions corresponding to 3fb-1 of integrated luminosity collected at centre-of-mass energies of 7 TeV and 8 TeV. The D 0 mesons are produced in semileptonic b-hadron decays, where the charge of the accompanying muon is used to determine the initial flavour of the charm meson. The difference in CP asymmetries between the two final states is measured to be Ī” ACP = ACP (K- K +) ACP (Ļ€- Ļ€+) = (+ 0.14 Ā± 0.16 (stat) Ā± 0.08 (syst)) %. A measurement of A CP (K - K +) is obtained assuming negligible CP violation in charm mixing and in Cabibbo-favoured D decays. It is found to be ACP (K- K+) = (- 0.06 Ā± 0.15 (stat) Ā± 0.10 (syst)) %, where the correlation coefficient between Ī”A CP and A CP (K - K +) is Ļ = 0.28. By combining these results, the CP asymmetry in the D 0 ā†’ Ļ€ - Ļ€ + channel is A CP (Ļ€ - Ļ€ +) = (-0.20 Ā± 0.19 (stat) Ā± 0.10 (syst))%

    Measurement of the Xi(-)(b) and Omega(-)(b) baryon lifetimes

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    Using a data sample of pp collisions corresponding to an integrated luminosity of 3 fbāˆ’1, the Īžāˆ’b and Ī©āˆ’b baryons are reconstructed in the Īžāˆ’b ā†’ J/ĻˆĪžāˆ’ and Ī©āˆ’b ā†’ J/ĻˆĪ©āˆ’ decay modes and their lifetimes measured to be Ļ„(Īžāˆ’b) = 1.55+0.10āˆ’0.09 (stat) Ā± 0.03 (syst) ps, Ļ„(Ī©āˆ’b) = 1.54+0.26āˆ’0.21 (stat) Ā± 0.05 (syst) ps. These are the most precise determinations to date. Both measurements are in good agreement with previous experimental results and with theoretical predictions

    Measurement of the resonant and CP components in BĀÆ 0 ā†’ J=ĻˆĻ€Ć¾Ļ€āˆ’ decays

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    The resonant structure of the reaction BĀÆ0ā†’J/ĻˆĻ€+Ļ€āˆ’ is studied using data from 3ā€‰ā€‰fbāˆ’1 of integrated luminosity collected by the LHCb experiment, one third at 7 TeV center-of-mass energy and the remainder at 8 TeV. The invariant mass of the Ļ€+Ļ€āˆ’ pair and three decay angular distributions are used to determine the fractions of the resonant and nonresonant components. Six interfering Ļ€+Ļ€āˆ’ states, Ļ(770), f0(500), f2(1270), Ļ(1450), Ļ‰(782) and Ļ(1700), are required to give a good description of invariant mass spectra and decay angular distributions. The positive and negative charge parity fractions of each of the resonant final states are determined. The f0(980) meson is not seen and the upper limit on its presence, compared with the observed f0(500) rate, is inconsistent with a model where these scalar mesons are formed from two quarks and two antiquarks (tetraquarks) at the eight standard deviation level. In the qqĀÆ model, the absolute value of the mixing angle between the f0(980) and the f0(500) scalar mesons is limited to be less than 17Ā° at 90% confidence level
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