Publications

Abstract

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.

Abstract

Sensorimotor areas activate to action- and object-related words, but their role in abstract meaning processing is still debated. Abstract emotion words denoting body internal states are a critical test case because they lack referential links to objects. If actions expressing emotion are crucial for learning correspondences between word forms and emotions, emotion word–evoked activity should emerge in motor brain systems controlling the face and arms, which typically express emotions. To test this hypothesis, we recruited 18 native speakers and used event-related functional magnetic resonance imaging to compare brain activation evoked by abstract emotion words to that by face- and arm-related action words. In addition to limbic regions, emotion words indeed sparked precentral cortex, including body-part–specific areas activated somatotopically by face words or arm words. Control items, including hash mark strings and animal words, failed to activate precentral areas. We conclude that, similar to their role in action word processing, activation of frontocentral motor systems in the dorsal stream reflects the semantic binding of sign and meaning of abstract words denoting emotions and possibly other body internal states.

Abstract

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.

Abstract

When we talk we communicate our intentions. Although the origin of intentional action is debated in cognitive neuroscience, the question of how the brain generates the intention in speech remains still open. Using magnetoencephalography, we investigated the cortical dynamics engaged when healthy subjects attended to either their intention to speak or their actual speech. We found that activity in the right and left parietal cortex increased before subjects became aware of intending to speak. Within the time window of parietal activation, we also observed a transient left frontal activity in Broca's area, a crucial region for inner speech. During attention to speech, neural activity was detected in left prefrontal and temporal areas and in the temporoparietal junction. In agreement with previous results, our findings suggest that the parietal cortex plays a multimodal role in monitoring intentional mechanisms in both action and language. The coactivation of parietal regions and Broca's area may constitute the cortical circuit specific for controlling intentional processes during speech.

Abstract

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.