bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Cerebral Basis of Mapping Nonsymbolic Numerical Quantities onto Abstract Symbols: An fMRI Training Study
Authors: Lyons Ian M. , Ansari Daniel 
Published: September 2008

Abstract
Although significant insights into the neural basis of numerical and mathematical processing have been made, the neural processes that enable abstract symbols to become numerical remain largely unexplored in humans. In the present study, adult participants were trained to associate novel symbols with nonsymbolic numerical magnitudes (arrays of dots). Functional magnetic resonance imaging was used to examine the neural correlates of numerical comparison versus recognition of the novel symbols after each of two training stages. A left-lateralized fronto-parietal network, including the intraparietal sulcus, the precuneus, and the dorsal prefrontal cortex, was more active during numerical comparison than during perceptual recognition. In contrast, a network including bilateral temporal–occipital regions was more active during recognition than comparison. A whole-brain three-way interaction revealed that those individuals who had higher scores on a postscan numerical task (measuring their understanding of the global numerical organization of the novel symbols) exhibited increasing segregation between the two tasks in the bilateral intraparietal sulci as a function of increased training. Furthermore, whole-brain regression analysis showed that activity in the left intraparietal sulcus was systematically related to the effect of numerical distance on accuracy. These data provide converging evidence that parietal and left prefrontal cortices are involved in learning to map numerical quantities onto visual symbols. Only the parietal cortex, however, appeared systematically related to the degree to which individuals learned to associate novel symbols with their numerical referents. We conclude that the left parietal cortex, in particular, may play a central role in imbuing visual symbols with numerical meaning.
Word Semantics Is Processed Even without Attentional Effort
Authors: Relander Kristiina , Rämä Pia , Kujala Teija 
Published: September 2008

Abstract
We examined the attentional modulation of semantic priming and the N400 effect for spoken words. The aim was to find out how the semantics of spoken language is processed when attention is directed to another modality (passive task), to the phonetics of spoken words (phonological task), or to the semantics of spoken words (word task). Equally strong behavioral priming effects were obtained in the phonological and the word tasks. A significant N400 effect was found in all tasks. The effect was stronger in the word and the phonological tasks than in the passive task, but there was no difference in the magnitude of the effect between the phonological and the word tasks. The latency of the N400 effect did not differ between the tasks. Although the N400 effect had a centroparietal maximum in the phonological and the word tasks, it was largest at the parietal recording sites in the passive task. The effect was more pronounced at the left than right recording sites in the phonological task, but there was no laterality effect in the other tasks. The N400 effect in the passive task indicates that semantic priming occurs even when spoken words are not actively attended. However, stronger N400 effect in the phonological and the word tasks than in the passive task suggests that controlled processes modulate the N400 effect. The finding that there were no differences in the N400 effect between the phonological and the word tasks indicates that the semantics of attended spoken words is processed regardless of whether semantic processing is relevant for task performance.
Learning to Become an Expert: Reinforcement Learning and the Acquisition of Perceptual Expertise
Authors: Krigolson Olav E. , Pierce Lara J. , Holroyd Clay B. , Tanaka James W. 
Published: September 2008

Abstract
To elucidate the neural mechanisms underlying the development of perceptual expertise, we recorded ERPs while participants performed a categorization task. We found that as participants learned to discriminate computer generated “blob” stimuli, feedback modulated the amplitude of the error-related negativity (ERN)—an ERP component thought to reflect error evaluation within medial–frontal cortex. As participants improved at the categorization task, we also observed an increase in amplitude of an ERP component associated with object recognition (the N250). The increase in N250 amplitude preceded an increase in amplitude of an ERN component associated with internal error evaluation (the response ERN). Importantly, these electroencephalographic changes were not observed for participants who failed to improve on the categorization task. Our results suggest that the acquisition of perceptual expertise relies on interactions between the posterior perceptual system and the reinforcement learning system involving medial–frontal cortex.
Neural Systems Supporting the Control of Affective and Cognitive Conflicts
Authors: Ochsner Kevin N. , Hughes Brent , Robertson Elaine R. , Cooper Jeffrey C. , Gabrieli John D. E. 
Published: September 2008

Abstract
Although many studies have examined the neural bases of controlling cognitive responses, the neural systems for controlling conflicts between competing affective responses remain unclear. To address the neural correlates of affective conflict and their relationship to cognitive conflict, the present study collected whole-brain fMRI data during two versions of the Eriksen flanker task. For these tasks, participants indicated either the valence (affective task) or the semantic category (cognitive task) of a central target word while ignoring flanking words that mapped onto either the same (congruent) or a different (incongruent) response as the target. Overall, contrasts of incongruent &gt; congruent trials showed that bilateral dorsal ACC, posterior medial frontal cortex, and dorsolateral pFC were active during both kinds of conflict, whereas rostral medial pFC and left ventrolateral pFC were differentially active during affective or cognitive conflict, respectively. Individual difference analyses showed that separate regions of rostral cingulate/ventromedial pFC and left ventrolateral pFC were positively correlated with the magnitude of response time interference. Taken together, the findings that controlling affective and cognitive conflicts depends upon both common and distinct systems have important implications for understanding the organization of control systems in general and their potential dysfunction in clinical disorders.
Seeing Sounds and Hearing Colors: An Event-related Potential Study of Auditory–Visual Synesthesia
Authors: Goller Aviva I. , Otten Leun J. , Ward Jamie 
Published: September 2008

AbstractIn auditory–visual synesthesia, sounds automatically elicit conscious and reliable visual experiences. It is presently unknown whether this reflects early or late processes in the brain. It is also unknown whether adult audiovisual synesthesia resembles auditory-induced visual illusions that can sometimes occur in the general population or whether it resembles the electrophysiological deflection over occipital sites that has been noted in infancy and has been likened to synesthesia. Electrical brain activity was recorded from adult synesthetes and control participants who were played brief tones and required to monitor for an infrequent auditory target. The synesthetes were instructed to attend either to the auditory or to the visual (i.e., synesthetic) dimension of the tone, whereas the controls attended to the auditory dimension alone. There were clear differences between synesthetes and controls that emerged early (100 msec after tone onset). These differences tended to lie in deflections of the auditory-evoked potential (e.g., the auditory N1, P2, and N2) rather than the presence of an additional posterior deflection. The differences occurred irrespective of what the synesthetes attended to (although attention had a late effect). The results suggest that differences between synesthetes and others occur early in time, and that synesthesia is qualitatively different from similar effects found in infants and certain auditory-induced visual illusions in adults. In addition, we report two novel cases of synesthesia in which colors elicit sounds, and vice versa.
Anticipating Conflict Facilitates Controlled Stimulus-response Selection
Authors: Correa Ángel , Rao Anling , Nobre Anna C. 
Published: September 2008

Abstract
Cognitive control can be triggered in reaction to previous conflict, as suggested by the finding of sequential effects in conflict tasks. Can control also be triggered proactively by presenting cues predicting conflict (“proactive control”)? We exploited the high temporal resolution of ERPs and controlled for sequential effects to ask whether proactive control based on anticipating conflict modulates neural activity related to cognitive control, as may be predicted from the conflict-monitoring model. ERPs associated with conflict detection (N2) were measured during a cued flanker task. Symbolic cues were either informative or neutral with respect to whether the target involved conflicting or congruent responses. Sequential effects were controlled by analyzing the congruency of the previous trial. The results showed that cueing conflict facilitated conflict resolution and reduced the N2 latency. Other potentials (frontal N1 and P3) were also modulated by cueing conflict. Cueing effects were most evident after congruent than after incongruent trials. This interaction between cueing and sequential effects suggests neural overlap between the control networks triggered by proactive and reactive signals. This finding clarifies why previous neuroimaging studies, in which reactive sequential effects were not controlled, have rarely found anticipatory effects upon conflict-related activity. Finally, the high temporal resolution of ERPs was critical to reveal a temporal modulation of conflict detection by proactive control. This novel finding suggests that anticipating conflict speeds up conflict detection and resolution. Recent research suggests that this anticipatory mechanism may be mediated by preactivation of ACC during the preparatory interval.
An fMRI Investigation of Spontaneous Mental State Inference for Moral Judgment
Authors: Young Liane , Saxe Rebecca 
Published: September 2008

Abstract
Human moral judgment depends critically on “theory of mind,” the capacity to represent the mental states of agents. Recent studies suggest that the right TPJ (RTPJ) and, to lesser extent, the left TPJ (LTPJ), the precuneus (PC), and the medial pFC (MPFC) are robustly recruited when participants read explicit statements of an agent's beliefs and then judge the moral status of the agent's action. Real-world interactions, by contrast, often require social partners to infer each other's mental states. The current study uses fMRI to probe the role of these brain regions in supporting spontaneous mental state inference in the service of moral judgment. Participants read descriptions of a protagonist's action and then either (i) “moral” facts about the action's effect on another person or (ii) “nonmoral” facts about the situation. The RTPJ, PC, and MPFC were recruited selectively for moral over nonmoral facts, suggesting that processing moral stimuli elicits spontaneous mental state inference. In a second experiment, participants read the same scenarios, but explicit statements of belief preceded the facts: Protagonists believed their actions would cause harm or not. The response in the RTPJ, PC, and LTPJ was again higher for moral facts but also distinguished between neutral and negative outcomes. Together, the results illuminate two aspects of theory of mind in moral judgment: (1) spontaneous belief inference and (2) stimulus-driven belief integration.
Distinct Hippocampal and Basal Ganglia Contributions to Probabilistic Learning and Reversal
Authors: Shohamy Daphna , Myers Catherine E. , Hopkins Ramona O. , Sage Jake , Gluck Mark A. 
Published: September 2008

AbstractThe hippocampus and the basal ganglia are thought to play fundamental and distinct roles in learning and memory, supporting two dissociable memory systems. Interestingly, however, the hippocampus and the basal ganglia have each, separately, been implicated as necessary for reversal learning—the ability to adaptively change a response when previously learned stimulus–outcome contingencies are reversed. Here, we compared the contribution of the hippocampus and the basal ganglia to distinct aspects of learning and reversal. Amnesic subjects with selective hippocampal damage, Parkinson subjects with disrupted basal ganglia function, and healthy controls were tested on a novel probabilistic learning and reversal paradigm. In this task, reversal can be achieved in two ways: Subjects can reverse a previously learned response, or they can select a new cue during the reversal phase, effectively “opting out” of the reversal. We found that both patient groups were intact at initial learning, but differed in their ability to reverse. Amnesic subjects failed to reverse, and continued to use the same cue and response learned before the reversal. Parkinson subjects, by contrast, opted out of the reversal by learning a new cue–outcome association. These results suggest that both the hippocampus and the basal ganglia support reversal learning, but in different ways. The basal ganglia are necessary for learning a new response when a previously learned response is no longer rewarding. The failure of the amnesic subjects to reverse their response or to learn a new cue is consistent with a more general role for the hippocampus in configural learning, and suggests it may also support the ability to respond to changes in cue–outcome contingencies.
Target Selection by the Frontal Cortex during Coordinated Saccadic and Smooth Pursuit Eye Movements
Authors: Srihasam Krishna , Bullock Daniel , Grossberg Stephen 
Published: September 2008

AbstractOculomotor tracking of moving objects is an important component of visually based cognition and planning. Such tracking is achieved by a combination of saccades and smooth-pursuit eye movements. In particular, the saccadic and smooth-pursuit systems interact to often choose the same target, and to maximize its visibility through time. How do multiple brain regions interact, including frontal cortical areas, to decide the choice of a target among several competing moving stimuli? How is target selection information that is created by a bias (e.g., electrical stimulation) transferred from one movement system to another? These saccade–pursuit interactions are clarified by a new computational neural model, which describes interactions between motion processing areas: the middle temporal area, the middle superior temporal area, the frontal pursuit area, and the dorsal lateral pontine nucleus; saccade specification, selection, and planning areas: the lateral intraparietal area, the frontal eye fields, the substantia nigra pars reticulata, and the superior colliculus; the saccadic generator in the brain stem; and the cerebellum. Model simulations explain a broad range of neuroanatomical and neurophysiological data. These results are in contrast with the simplest parallel model with no interactions between saccades and pursuit other than common-target selection and recruitment of shared motoneurons. Actual tracking episodes in primates reveal multiple systematic deviations from predictions of the simplest parallel model, which are explained by the current model.
Global Perspective of the Quasi-Biweekly Oscillation*
Authors: Kikuchi Kazuyoshi , Wang Bin 
Published: September 2008

Abstract
The quasi-biweekly oscillation (QBW: here defined as a 12–20-day oscillation) is one of the major systems that affect tropical and subtropical weather and seasonal mean climate. However, knowledge is limited concerning its temporal and spatial structures and dynamics, particularly in a global perspective. To advance understanding of the QBW, its life cycle is documented using a tracking method and extended EOF analysis. Both methods yield consistent results. The analyses reveal a wide variety of QBW activity in terms of initiation, movement, development, and dissipation. The convective anomalies associated with the QBW are predominant in the latitude bands between 10° and 30° in both hemispheres. The QBW modes tend to occur regionally and be associated with monsoons. Three boreal summer modes are identified in the Asia–Pacific, Central America, and subtropical South Pacific regions. Five austral summer modes are identified in the Australia–southwest Pacific, South Africa–Indian Ocean, South America–Atlantic, subtropical North Pacific, and North Atlantic–North Africa regions.
The QBW modes are classified into two categories: westward- and eastward-propagating modes. The westward mode is found in the Asia–Pacific and Central America regions during boreal summer; it originates in the tropics and dissipates in the subtropics. The behavior of the westward-propagating mode can be understood in terms of equatorial Rossby waves in the presence of monsoon mean flow and convective coupling. The eastward-propagating mode, on the other hand, connects with upstream extratropical Rossby wave trains and propagates primarily eastward and equatorward. Barotropic Rossby wave trains play an essential role in controlling initiation, development, and propagation of the eastward QBW mode in the subtropics. The results therefore suggest that not only tropical but also extratropical dynamics are required for fully understanding the behavior of the QBW systems worldwide. The new conceptual picture of QBW obtained here based on long-term observation provides valuable information on the behavior of QBW systems in a global perspective, which is important for a thorough understanding of tropical variability on a time scale between day-to-day weather and the Madden–Julian oscillation.
Evolution of a Random Directional Wave and Freak Wave Occurrence
Authors: Waseda Takuji , Kinoshita Takeshi , Tamura Hitoshi 
Published: September 2008

Abstract
The evolution of a random directional wave in deep water was studied in a laboratory wave tank (50 m long, 10 m wide, 5 m deep) utilizing a directional wave generator. A number of experiments were conducted, changing the various spectral parameters (wave steepness 0.05 &lt; ɛ &lt; 0.11, with directional spreading up to 36° and frequency bandwidth 0.2 &lt; δk/k &lt; 0.6). The wave evolution was studied by an array of wave wires distributed down the tank. As the spectral parameters were altered, the wave height statistics change. Without any wave directionality, the occurrence of waves exceeding twice the significant wave height (the freak wave) increases as the frequency bandwidth narrows and steepness increases, due to quasi-resonant wave–wave interaction. However, the probability of an extreme wave rapidly reduces as the directional bandwidth broadens. The effective Benjamin–Feir index (BFIeff) is introduced, extending the BFI (the relative magnitude of nonlinearity and dispersion) to incorporate the effect of directionality, and successfully parameterizes the observed occurrence of freak waves in the tank. Analysis of the high-resolution hindcast wave field of the northwest Pacific reveals that such a directionally confined wind sea with high extreme wave probability is rare and corresponds mostly to a swell–wind sea mixed condition. Therefore, extreme wave occurrence in the sea as a result of quasi-resonant wave–wave interaction is a rare event that occurs only when the wind sea directionality is extremely narrow.
Multiclass ROC Analysis
Authors: Wandishin Matthew S. , Mullen Steven J. 
Published: September 2008

Abstract
Receiver operating characteristic (ROC) curves have become a common analysis tool for evaluating forecast discrimination: the ability of a forecast system to distinguish between events and nonevents. As is implicit in that statement, application of the ROC curve is limited to forecasts involving only two possible outcomes, such as rain and no rain. However, many forecast scenarios exist for which there are multiple possible outcomes, such as rain, snow, and freezing rain. An extension of the ROC curve to multiclass forecast problems is explored. The full extension involves high-dimensional hypersurfaces that cannot be visualized and that present other problems. Therefore, several different approximations to the full extension are introduced using both artificial and actual forecast datasets. These approximations range from sets of simple two-class ROC curves to sets of three-dimensional ROC surfaces. No single approximation is superior for all forecast problems; thus, the specific aims in evaluating the forecast must be considered.
EU agencies: what is common and what is distinctive compared with national-level public agencies
Authors: Barbieri Dario , Ongaro Edoardo 
Published: September 2008

The number and relevance of EU agencies have rapidly increased over the years: EU agencies nowadays constitute an important part of the EU institutional landscape. The article investigates the EU agencies through categories of analysis well established in studies of public management focused on the phenomenon of agencies at the country level: structural disaggregation, autonomy, and contractualization. It emerges that EU agencies are relatively homogeneous, an aspect that differentiates European agencies from the highly heterogeneous world of national-level agencies. The main features of the EU agencies are examined, the `European type' of agency is identified and defined, and the way the EU agency model differs from country-level agencies is analysed. Research agendas on the reform of the European Union might benefit from systematic investigation of EU agencies: theoretical frameworks drawn from the public management field can provide a significant contribution in this respect. Points for practitioners EU agencies are no longer `residual' organizations: they are a significant component of the functioning of the EU system and policy networks. By investigating the features of such agencies through the conceptual lenses of public management, and through comparison with the (much more investigated) national-level agencies, the article provides an outline of EU agencies in terms of structural relations with the other EU institutions, autonomy, and modalities of steering and control. Reforms of the EU through the establishment or revamping of agencies could benefit from the systematic consideration of such features.
Kazakhstan: modernizing government in the context of political inertia
Authors: Knox Colin 
Published: September 2008

Kazakhstan declared its independence from the Soviet Union in 1991 and joined the Commonwealth of Independent States. Since then it has witnessed a remarkable economic transformation under the leadership of President Nursultan Nazarbayev. Pursuing a policy of `economy first and then politics', Kazakhstan is under growing pressure to engage in political reforms which include a modernization agenda to improve public service provision. Recent constitutional reforms have received a lukewarm reaction from the international community that Kazakhstan is keen to become part of. At the same time a progressive agenda of public services reform is well under way rooted in new public management and a desire to become much more customer focussed in their orientation. This article examines the parallel themes of political reforms and public services modernization in Kazakhstan. Points for practitioners This article offers two key points for practitioners. First, it describes the detail of public sector reforms taking place in a developing country which secured its independence approximately 16 years ago, and the significant progress since then. Second, it poses questions about the political context in which administrative reform can take place. Has the existence of a highly centralized and autocratic form of presidential leadership resulted in a top-down imperative which has helped the pace of public services modernization in Kazakhstan?