Forward Modeling Mediates Motor Awareness

This chapter focuses on the issue of motor awareness. It addresses three main questions: What exactly are we aware of when making a movement? What is the contribution of afferent and efferent signals to motor awareness? What are the neural bases of motor awareness? It reviews evidence that the motor system is mainly aware of its intention. As long as the goal is achieved, nothing reaches awareness about the kinematic details of the ongoing movements, even when substantial corrections have to be implemented to attain the intended state. The chapter also shows that motor awareness relies mainly on the central predictive computations carried out within the posterior parietal cortex. The outcome of these computations is contrasted with the peripheral reafferent input to build a veridical motor awareness. Some evidence exists that this process involves the premotor areas

Present and future of one of the largest Grid infrastructures in Europe

This summary paper illustrates the Italian production Grid infrastructure, its mission and its evolution strategy

The time course of language production as revealed by pattern classification of MEG sensor data

Language production involves a complex set of computations, from conceptualization to articulation, which are thought to engage cascading neural events in the language network. However, recent neuromagnetic evidence suggests simultaneous meaning-to-speech mapping in picture naming tasks, as indexed by early parallel activation of frontotemporal regions to lexical semantic, phonological, and articulatory information. Here we investigate the time course of word production, asking to what extent such “earliness” is a distinctive property of the associated spatiotemporal dynamics. Using MEG, we recorded the neural signals of 34 human subjects (26 males) overtly naming 134 images from four semantic object categories (animals, foods, tools, clothes). Within each category, we covaried word length, as quantified by the number of syllables contained in a word, and phonological neighborhood density to target lexical and post-lexical phonological/phonetic processes. Multivariate pattern analyses searchlights in sensor space distinguished the stimulus-locked spatiotemporal responses to object categories early on, from 150 to 250 ms after picture onset, whereas word length was decoded in left frontotemporal sensors at 250-350 ms, followed by the latency of phonological neighborhood density (350-450 ms). Our results suggest a progression of neural activity from posterior to anterior language regions for the semantic and phonological/phonetic computations preparing overt speech, thus supporting serial cascading models of word productio

The AMS-02 Time of Flight System. Final Design

The AMS-02 detector is a superconducting magnetic spectrometer that will operate on the International Space Station. The time of flight (TOF) system of AMS-02 is composed by four scintillator planes with 8, 8, 10, 8 counters each, read at both ends by a total of 144 phototubes. This paper describes the new design, the expected performances, and shows preliminary results of the ion beam test carried on at CERN on October 2002.Comment: 4 pages, 6 EPS figures. Proc. of the 28th ICRC (2003

The AMS-02 Time of Flight System

The Time-of-Flight (TOF) system of the AMS detector gives the fast trigger to the read out electronics and measures velocity, direction and charge of the crossing particles. The first version of the detector (called AMS-01) has flown in 1998 aboard of the shuttle Discovery for a 10 days test mission, and collected about $10^8$ events. The new version (called AMS-02) will be installed on the International Space Station and will operate for at least three years, collecting roughly $10^{10}$ Cosmic Ray (CR) particles. The TOF system of AMS-01 successfully operated during the test mission, obtaining a time resolution of 120 ps for protons and better for other CR ions. The TOF system of AMS-02 will be different due to the strong fringing magnetic field and weight constraintsComment: 6 pages, 7 figures. Talk given at the ``First International Conference on Particle and Fundamental Physics in Space'', La Biodola, Isola d'Elba (Italy), 14 -- 19 May 2002. To be published by Nuclear Physics B - Proceedings Supplement. Sep. 13, 2002: added "Conclusion" sectio

Body-part-specific Representations of Semantic Noun Categories.

Word meaning processing in the brain involves ventrolateral temporal cortex, but a semantic contribution of the dorsal stream, especially frontocentral sensorimotor areas, has been controversial. We here examine brain activation during passive reading of object-related nouns from different semantic categories, notably animal, food, and tool words, matched for a range of psycholinguistic features. Results show ventral stream activation in temporal cortex along with category-specific activation patterns in both ventral and dorsal streams, including sensorimotor systems and adjacent pFC. Precentral activation reflected action-related semantic features of the word categories. Cortical regions implicated in mouth and face movements were sparked by food words, and hand area activation was seen for tool words, consistent with the actions implicated by the objects the words are used to speak about. Furthermore, tool words specifically activated the right cerebellum, and food words activated the left orbito-frontal and fusiform areas. We discuss our results in the context of category-specific semantic deficits in the processing of words and concepts, along with previous neuroimaging research, and conclude that specific dorsal and ventral areas in frontocentral and temporal cortex index visual and affective–emotional semantic attributes of object-related nouns and action-related affordances of their referent objects

Derivational morphology of Italian: Principles for formalization

The present paper investigates the major derivational strategies underlying the formation of suffixed words in Italian, with the purpose of tackling the issue of their formalization. After having specified the theoretical cognitive premises that orient the work, the interacting component modules of the suffixation process, i.e. morphonology, morphotactics and affixal semantics, are explored empirically, by drawing ample naturally occurring data on a Corpus of written Italian. A special attention is paid to the semantic mechanisms that are involved into suffixation. Some semantic nuclei are identified for the major suffixed word types of Italian, which are due to word formation rules active at the synchronic level, and a semantic configuration of productive suffixes is suggested. A general framework is then sketched, which combines classical finite-state methods with a feature unification-based word grammar. More specifically, the semantic information specified for the affixal material is internalised into the structures of the Lexical Functional Grammar (LFG). The formal model allows us to integrate the various modules of suffixation. In particular, it treats, on the one hand, the interface between morphonology/morphotactics and semantics and, on the other hand, the interface between suffixation and inflection. Furthermore, since LFG exploits a hierarchically organised lexicon in order to structure the information regarding the affixal material, affixal co-selectional restrictions are advatageously constrained, avoiding potential multiple spurious analysis/generations

Collaborative use of contrastive markers Contextual and co-textual implications

The study presented in this paper examines the context-dependence and dialogue functions of the contrastive markers of Italian ma (but), invece (instead), mentre (while) and per (nevertheless) within task-oriented dialogues. Corpus data evidence their sensitivity to a acognitive interpersonal context, conceived as a common ground. Such a cognitive state - shared by co-participants through the coordinative process of grounding - interacts with the global dialogue structure, which is cognitively shaped by ``meta-negotiating{''} and grounding the dialogue topic. Locally, the relation between the current dialogue structural units and the global dialogue topic is said to be specified by information structure, in particular intra-utterance themes. It is argued that contrastive markers re-orient the co-participants' cognitive states towards grounding ungrounded topical aspects to be meta-negotiated. They offer a collaborative context-updating strategy, tracking the status of common ground during dialogue topic management

Neural Bases of Sequence Processing in Action and Language

Real-time estimation of what we will do next is a crucial prerequisite of purposive behavior. During the planning of goal-oriented actions, for instance, the temporal and causal organization of upcoming subsequent moves needs to be predicted based on our knowledge of events. A forward computation of sequential structure is also essential for planning contiguous discourse segments and syntactic patterns in language. The neural encoding of sequential event knowledge and its domain dependency is a central issue in cognitive neuroscience. Converging evidence shows the involvement of a dedicated neural substrate, including the prefrontal cortex and Broca's area, in the representation and the processing of sequential event structure. After reviewing major representational models of sequential mechanisms in action and language, we discuss relevant neuropsychological and neuroimaging findings on the temporal organization of sequencing and sequence processing in both domains, suggesting that sequential event knowledge may be modularly organized through prefrontal and frontal subregions