bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activating without Inhibiting: Left-edge Boundary Tones and Syntactic Processing
Authors: Roll Mikael , Horne Merle , Lindgren Magnus 
Published: February 2010

AbstractRight-edge boundary tones have earlier been found to restrict syntactic processing by closing a clause for further integration of incoming words. The role of left-edge intonation, however, has received little attention to date. We show that Swedish left-edge boundary tones selectively facilitate the on-line processing of main clauses, the syntactic structure they are associated with. In spoken Swedish, main clauses are produced with a left-edge boundary tone, which is absent in subordinate clauses. Main and subordinate clauses are further distinguished syntactically by word order when containing sentence adverbs. The effects of tone and word order on the processing of embedded main, subordinate, and neutral clauses (lacking sentence adverbs) were measured using ERPs. A posterior P600 in embedded main clauses and a smaller P600 in subordinate clauses indicated that embedded clauses with sentence adverbs were structurally less expected than neutral clauses and thus were reanalyzed. The tone functioned as a cue for main clause word order, selectively reducing the P600 in embedded main clauses, without affecting the processing of subordinate or neutral clauses. Its perception was reflected in a right frontal P200 effect. The left-edge boundary tone thus seems to activate a main clause structure, albeit without suppressing alternative structures. The P600 was also preceded by a short positive effect in cases where a left-edge boundary tone was absent.
Accessing Semantic Person Knowledge: Temporal Dynamics of Nonstrategic Categorical and Associative Priming
Authors: Wiese Holger , Schweinberger Stefan R. 
Published: February 2010

Abstract
Recent theories of semantic memory suggest a subdivision into several separate domains of knowledge. The present study examined the structure of semantic person knowledge by analyzing both behavioral and ERP correlates of associative priming (via co-occurrence and/or shared semantic information) versus purely categorical priming (via shared occupational information). Participants performed familiarity decisions for target faces, which were preceded by sandwich-masked prime names at either short (33 msec) or long (1033 msec) SOAs. Although masking effectively prevented explicit prime recognition, faster RTs were generally observed for both associative and categorical priming (relative to an unrelated prime-target condition). At the short SOA, both associatively and categorically primed targets similarly elicited more positive going ERPs compared with unrelated targets in the N400 time range (N400 priming effect), suggesting a common initial mechanism mediating both forms of priming. By contrast, at the long SOA, a typical N400 priming effect was observed for associative priming only, whereas the corresponding effect for categorical priming was small and restricted to a left parietal site. This hitherto unreported interaction of relatedness, and SOA in the N400 suggests an initial fast spreading of activation to a wide range of related targets, which subsequently focuses to more closely related people at longer SOAs. This ability of ERPs to trace the neural dynamics of activation for different forms of prime/target relatedness can be exploited for testing different models of semantic priming.
From Perception to Recognition Memory: Time Course and Lateralization of Neural Substrates of Word and Abstract Picture Processing
Authors: Maillard Louis , Barbeau Emmanuel J. , Baumann Cedric , Koessler Laurent , Bénar Christian , Chauvel Patrick , Liégeois-Chauvel Catherine 
Published: February 2010

Abstract
Through study of clinical cases with brain lesions as well as neuroimaging studies of cognitive processing of words and pictures, it has been established that material-specific hemispheric specialization exists. It remains however unclear whether such specialization holds true for all processes involved in complex tasks, such as recognition memory. To investigate neural signatures of transition from perception to recognition, according to type of material (words or abstract pictures), high-resolution scalp ERPs were recorded in adult humans engaged either in categorization or in memory recognition tasks within the same experimental setup. Several steps in the process from perception to recognition were identified. Source localization showed that the early stage of perception processing (N170) takes place in the fusiform gyrus and is lateralized according to the nature of stimuli (left side for words and right side for pictures). Late stages of processing (N400/P600) corresponding to recognition are material independent and involve anterior medial-temporal and ventral prefrontal structures bilaterally. A crucial transitional process between perception (N170) and recognition (N400/P600) is reflected by the N270, an often overlooked component, which occurs in anterior rhinal cortices and shows material-specific hemispheric lateralization.
Attentional Control in Anterior Cingulate Cortex Based on Probabilistic Cueing
Authors: Aarts Esther , Roelofs Ardi 
Published: February 2010

Abstract
In Stroop-like tasks, conflict effects in behavioral measures and ACC activity are smaller on trials following an incongruent trial than following a congruent one. Researchers have found no agreement on whether these sequential effects in ACC can be driven by experienced incongruency only or also by expectations about target types. In the present fMRI experiment, we specifically manipulated the expectancies by using symbolic cues predicting with 75% or 50% certainty the incongruent or congruent targets in a Stroop-like task. Both behavioral and dorsal ACC data replicated previous sequential effects, with conflict effects being smallest for targets following the cues that predicted with 75% certainty the incongruent targets. However, these effects were not driven by experienced conflict but by symbolic cues. These results demonstrate differential attentional control activity in ACC after probabilistic cueing, providing evidence for control adjustments driven by changes in expectation.
Neural Correlates of Sequence Learning with Stochastic Feedback
Authors: Averbeck Bruno B. , Kilner James , Frith Christopher D. 
Published: February 2010

AbstractAlthough much is known about decision making under uncertainty when only a single step is required in the decision process, less is known about sequential decision making. We carried out a stochastic sequence learning task in which subjects had to use noisy feedback to learn sequences of button presses. We compared flat and hierarchical behavioral models and found that although both models predicted the choices of the group of subjects equally well, only the hierarchical model correlated significantly with learning-related changes in the magneto-encephalographic response. The significant modulations in the magneto-encephalographic signal occurred 83 msec before button press and 67 msec after button press. We also localized the sources of these effects and found that the early effect localized to the insula, whereas the late effect localized to the premotor cortex.
Auditory Target Detection Is Affected by Implicit Temporal and Spatial Expectations
Authors: Rimmele Johanna , Jolsvai Hajnal , Sussman Elyse 
Published: February 2010

AbstractMechanisms of implicit spatial and temporal orienting were investigated by using a moving auditory stimulus. Expectations were set up implicitly, using the information inherent in the movement of a sound, directing attention to a specific moment in time with respect to a specific location. There were four conditions of expectation: temporal and spatial expectation; temporal expectation only; spatial expectation only; and no expectation. Event-related brain potentials were recorded while participants performed a go/no-go task, set up by anticipation of the reappearance of a target tone through a white noise band. Results showed that (1) temporal expectations alone speeded reaction time and increased response accuracy; and (2) implicit temporal expectations alone independently enhanced target detection at early processing stages, prior to motor response. This was reflected at stages of perceptual analysis, indexed by P1 and N1 components, as well as in task-related stages indexed by N2; and (3) spatial expectations had an effect at later response-related processing stages but only in combination with temporal expectations, indexed by the P3 component. Thus, the results, in addition to indicating a primary role for temporal orienting in audition, suggest that multiple mechanisms of attention interact in different phases of auditory target detection. Our results are consistent with the view from vision research that spatial and temporal attentional control is based on the activity of partly overlapping, and partly functionally specialized neural networks.
Slow Fluctuations in Attentional Control of Sensory Cortex
Authors: Kam Julia W. Y. , Dao Elizabeth , Farley James , Fitzpatrick Kevin , Smallwood Jonathan , Schooler Jonathan W. , Handy Todd C. 
Published: February 2010

Abstract
Top–down control of visual sensory cortex has long been tied to the orienting of visual spatial attention on a rapid, moment-to-moment basis. Here, we examined whether sensory responses in visual cortex are also modulated by natural and comparatively slower fluctuations in whether or not one is paying attention to the task at hand. Participants performed a simple visual discrimination task at fixation as the ERPs to task-irrelevant probes in the upper visual periphery were recorded. At random intervals, participants were stopped and asked to report on their attentional state at the time of stoppage—either “on-task” or “off-task.” ERPs to the probes immediately preceding these subjective reports were then examined as a function of whether attention was in an on-task versus off-task state. We found that sensory-evoked responses to the probes were significantly attenuated during off-task relative to on-task states, as measured by the visual P1 ERP component. In two additional experiments, we replicated this effect while (1) finding that off-task sensory attenuation extends to the auditory domain, as measured by the auditory N1 ERP component, and (2) eliminating state-dependent shifts in general arousal as a possible explanation for the effects. Collectively, our findings suggest that sensory gain control in cortex is yoked to the natural ebb and flow in how much attention we pay to the current task over time.
Time-dependent Neural Processing of Auditory Feedback during Voice Pitch Error Detection
Authors: Behroozmand Roozbeh , Liu Hanjun , Larson Charles R. 
Published: February 2010

AbstractThe neural responses to sensory consequences of a self-produced motor act are suppressed compared with those in response to a similar but externally generated stimulus. Previous studies in the somatosensory and auditory systems have shown that the motor-induced suppression of the sensory mechanisms is sensitive to delays between the motor act and the onset of the stimulus. The present study investigated time-dependent neural processing of auditory feedback in response to self-produced vocalizations. ERPs were recorded in response to normal and pitch-shifted voice auditory feedback during active vocalization and passive listening to the playback of the same vocalizations. The pitch-shifted stimulus was delivered to the subjects' auditory feedback after a randomly chosen time delay between the vocal onset and the stimulus presentation. Results showed that the neural responses to delayed feedback perturbations were significantly larger than those in response to the pitch-shifted stimulus occurring at vocal onset. Active vocalization was shown to enhance neural responsiveness to feedback alterations only for nonzero delays compared with passive listening to the playback. These findings indicated that the neural mechanisms of auditory feedback processing are sensitive to timing between the vocal motor commands and the incoming auditory feedback. Time-dependent neural processing of auditory feedback may be an important feature of the audio-vocal integration system that helps to improve the feedback-based monitoring and control of voice structure through vocal error detection and correction.
Failure to Engage Spatial Working Memory Contributes to Age-related Declines in Visuomotor Learning
Authors: Anguera Joaquin A. , Reuter-Lorenz Patricia A. , Willingham Daniel T. , Seidler Rachael D. 
Published: February 2010

Abstract
It is well documented that both cognitive and motor learning abilities decline with normative aging. Given that cognitive processes such as working memory are engaged during the early stages of motor learning [Anguera, J., Reuter-Lorenz, P., Willingham, D., & Seidler, R. Contributions of spatial working memory to visuomotor learning. Journal of Cognitive Neuroscience, 22(9), 1917–1930, 2010], age-related declines in motor learning may be due in part to reductions in cognitive ability. The present study examined whether age-related declines in spatial working memory (SWM) contribute to deficits in visuomotor adaptation. Young and older adult participants performed a visuomotor adaptation task that involved adapting manual aiming movements to a 30° rotation of the visual feedback display as well as an SWM task in an fMRI scanner. Young adults showed a steeper learning curve than older adults during the early adaptation period. The rate of early adaptation was correlated with SWM performance for the young, but not older, adults. Both groups showed similar brain activation patterns for the SWM task, including engagement of the right dorsolateral prefrontal cortex and bilateral inferior parietal lobules. However, when the SWM activation was used as a limiting mask, younger adults showed neural activation that overlapped with the early adaptation period, whereas older adults did not. A partial correlation controlling for age revealed that the rate of early adaptation correlated with the amount of activation at the right dorsolateral prefrontal cortex. These findings suggest that a failure to effectively engage SWM processes during learning contributes to age-related deficits in visuomotor adaptation.
Parametric Manipulation of the Conflict Signal and Control-state Adaptation
Authors: Forster Sarah E. , Carter Cameron S. , Cohen Jonathan D. , Cho Raymond Y. 
Published: February 2010

AbstractMechanisms by which the brain monitors and modulates performance are an important focus of recent research. The conflict-monitoring hypothesis posits that the ACC detects conflict between competing response pathways which, in turn, signals for enhanced control. The N2, an ERP component that has been localized to ACC, has been observed after high conflict stimuli. As a candidate index of the conflict signal, the N2 would be expected to be sensitive to the degree of response conflict present, a factor that depends on both the features of external stimuli and the internal control state. In the present study, we sought to explore the relationship between N2 amplitude and these variables through use of a modified Eriksen flankers task in which target–distracter compatibility was parametrically varied. We hypothesized that greater target–distracter incompatibility would result in higher levels of response conflict, as indexed by both behavior and the N2 component. Consistent with this prediction, there were parametric degradations in behavioral performance and increases in N2 amplitudes with increasing incompatibility. Further, increasingly incompatible stimuli led to the predicted parametric increases in control on subsequent incompatible trials as evidenced by enhanced performance and reduced N2 amplitudes. These findings suggest that the N2 component and associated behavioral performance are finely sensitive to the degree of response conflict present and to the control adjustments that result from modulations in conflict.
The Dynamic Response of the Hurricane Wind Field to Spiral Rainband Heating
Authors: Moon Yumin , Nolan David S. 
Published: February 2010

AbstractThe response of the hurricane wind field to spiral rainband heating is examined by using a three-dimensional, nonhydrostatic, linear model of the vortex–anelastic equations. Diabatic heat sources, which are designed in accordance with previous observations of spiral rainbands, are made to rotate with the flow around the hurricane-like wind field of a balanced, axisymmetric vortex. Common kinematic features are recovered, such as the overturning secondary circulation, descending midlevel radial inflow, and cyclonically accelerated tangential flow on the radially outward side of spiral rainbands. Comparison of the responses to the purely convective and stratiform rainbands indicates that the overturning secondary circulation is mostly due to the convective part of the rainband and is stronger in the upwind region, while midlevel radial inflow descending to the surface is due to the stratiform characteristics of the rainband and is stronger in the downwind region. The secondary horizontal wind maximum is exhibited in both convective and stratiform parts of the rainband, but it tends to be stronger in the downwind region. The results indicate that the primary effects of rainbands on the hurricane wind field are caused by the direct response to diabatic heating in convection embedded in them and that the structure of the diabatic heating is primarily responsible for their unique kinematic structures. Sensitivity tests confirm the robustness of the results. In addition, the response of the hurricane wind field to the rainband heating is, in the linear limit, the sum of the asymmetric potential vorticity and symmetric transverse circulations.
CPOL Radar-Derived Drop Size Distribution Statistics of Stratiform and Convective Rain for Two Regimes in Darwin, Australia
Authors: Thurai M. , Bringi V. N. , May P. T. 
Published: February 2010

Abstract
This note builds on prior technique development related to the classification of rain types utilizing C-band polarimetric (CPOL) radar measurements. While the prior work was preliminary and limited in scope, the authors elaborate here on the basis of the drop size distribution (DSD)-based indexing technique for rain-type classification (convective/stratiform/mixed), and place it on firmer footing by testing the methodology against texture- and disdrometer-based methods as applied to Darwin datasets. A microphysical-based methodology is attractive as it links more directly to the underlying rainfall physical processes.
Statistics of the DSD parameters, namely, histograms of log10(Nw) and D0, for convective and stratiform rain types across the premonsoon buildup and monsoon regimes were derived and further separated for over land and over ocean regions. The maximum value for mean D0 (1.64 mm) and the largest histogram standard deviation (0.32 mm) occurred for convective rain over land during the buildup regime. The largest differences in D0 and NW histograms were found to be for convective rain between the buildup and monsoon regimes (independent of land or ocean areas). Stratiform rain histograms were found to be very similar during the buildup regime with little land–ocean differences. However, somewhat larger land–ocean differences were found for the monsoon stratiform rain. The main histogram characteristics of the “mixed” or “uncertain” rain type were closer to the convective rain type than to stratiform, across both regimes and land–ocean areas. Additionally, the Nw versus D0 cluster of points (mean ±1σ) for convective rain agrees very well with the previously published range of values for maritime convective (equilibrium-like) DSDs.
A Synergy Approach to Estimate Properties of Raindrop Size Distributions Using a Doppler Lidar and Cloud Radar
Authors: Träumner Katja , Handwerker Jan , Wieser Andreas , Grenzhäuser Jens 
Published: February 2010

Abstract
Remote sensing systems like radars and lidars are frequently used in atmospheric measurement campaigns. Because of their different wavelengths, they operate in different scattering regimes. Combined use may result in new measurement options. Here, an approach to estimate raindrop size distribution using vertical velocities measured by a lidar–radar combination is introduced and tested using a 2-μm Doppler lidar and a 35.5-GHz cloud radar. The lidar spectra are evaluated to deduce air motion from the aerosol peak and the fall velocity of the raindrops from the rain peak. The latter is weighted by the area (D2) of the scatters. The fall velocity derived from radar measurements is weighted by D6 (Rayleigh approximation). Assuming a size-dependent fall velocity and an analytical description of the drop size distribution, its parameters are calculated from these data. Comparison of the raindrop size distribution from the lidar–radar combination with in situ measurements on the ground yields satisfying results.
Lidar Scanning of Momentum Flux in and above the Atmospheric Surface Layer
Authors: Mann J. , Peña A. , Bingöl F. , Wagner R. , Courtney M. S. 
Published: February 2010

Abstract
Methods to measure the vertical flux of horizontal momentum using both continuous wave and pulsed Doppler lidar profilers are evaluated. The lidar measurements are compared to momentum flux observations performed with sonic anemometers over flat terrain at Høvsøre, Denmark, and profile-derived vertical momentum flux observations at the Horns Rev wind farm in the North Sea. Generally, the momentum fluxes are reduced because of the finite measuring volume of the instruments, and the filtering is crudely accounted for theoretically. The essential parameter for the estimation of the reduction is the ratio of the turbulence scale to the size of the measuring volume. For the continuous wave lidar the reduction can largely be compensated by averaging Doppler spectra instead of radial velocities.
Intercomparison of Bulk Microphysics Schemes in Model Simulations of Polar Lows
Authors: Wu Longtao , Petty Grant W. 
Published: February 2010

Abstract
Four spiraliform polar lows, two over the Sea of Japan and two over the Nordic Seas, were simulated with the Weather Research and Forecasting (WRF) model. Five mixed-phase bulk microphysics schemes (BMS) provided with WRF were run respectively in order to compare their performance in polar low simulations. The observed cloud-top temperatures (CTTs) were compared with the model simulations. Precipitation rates estimated by the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and gauge-calibrated surface radar precipitation estimates around Japan were also used for validation. Although definitive validation is not possible with the available data, results from the WRF Single-Moment 6-class (WSM6) scheme appear to reproduce the cloud and precipitation processes most realistically. The model produced precipitation intensities comparable to validation products over the Sea of Japan. However, in the Nordic Seas cases, all five schemes produced significantly more precipitation than the AMSR-E estimates even though the latter estimates are known to average slightly high in the same region when validated against monthly totals measured at Jan Mayen Island (Norway).