CiteULike: briordan's fmri

The Neurocognition of Referential Ambiguity in Language Comprehension

Mante Nieuwland — 2008-06-24T11:08:34-00:00

Language and Linguistics Compass, Vol. 0, No. 0. (0), pp. ???-???.

Abstract Referential ambiguity arises whenever readers or listeners are unable to select a unique referent for a linguistic expression out of multiple candidates. In the current article, we review a series of neurocognitive experiments from our laboratory that examine the neural correlates of referential ambiguity, and that employ the brain signature of referential ambiguity to derive functional properties of the language comprehension system. The results of our experiments converge to show that referential ambiguity resolution involves making an inference to evaluate the referential candidates. These inferences only take place when both referential candidates are, at least initially, equally plausible antecedents. Whether comprehenders make these anaphoric inferences is strongly context dependent and co-determined by characteristics of the reader. In addition, readers appear to disregard referential ambiguity when the competing candidates are each semantically incoherent, suggesting that, under certain circumstances, semantic analysis can proceed even when referential analysis has not yielded a unique antecedent. Finally, results from a functional neuroimaging study suggest that whereas the neural systems that deal with referential ambiguity partially overlap with those that deal with referential failure, they show an inverse coupling with the neural systems associated with semantic processing, possibly reflecting the relative contributions of semantic and episodic processing to re-establish semantic and referential coherence, respectively.

Neuroimaging: I see what you mean

Leonie Welberg — 2008-06-21T04:49:56-00:00

Nature Reviews Neuroscience, Vol. 9, No. 7., pp. 497-479.

Neural Substrates of Language Acquisition

Patricia Kuhl — 2008-06-18T12:15:57-00:00

Annual Review of Neuroscience, Vol. 31, No. 1. (2008), pp. 511-534.

Infants learn language(s) with apparent ease, and the tools of modern neuroscience are providing valuable information about the mechanisms that underlie this capacity. Noninvasive, safe brain technologies have now been proven feasible for use with children starting at birth. The past decade has produced an explosion in neuroscience research examining young children's processing of language at the phonetic, word, and sentence levels. At all levels of language, the neural signatures of learning can be documented at remarkably early points in development. Individual continuity in linguistic development from infants' earliest responses to phonemes is reflected in infants' language abilities in the second and third year of life, a finding with theoretical and clinical implications. Developmental neuroscience studies using language are beginning to answer questions about the origins of humans' language faculty.

Familiarity and Conceptual Priming Engage Distinct Cortical Networks

Joel Voss — 2007-12-04T14:44:07-00:00

Cereb. Cortex (1 December 2007), bhm200.

Familiarity refers to an explicit recognition experience without any necessary retrieval of specific detail related to the episode during which initial learning transpired. Prior experience can also implicitly influence subsequent processing through a memory phenomenon termed conceptual priming, which occurs without explicit awareness of recognition. Resolving current theoretical controversy on relationships between familiarity and conceptual priming requires a clarification of their neural substrates. Accordingly, we obtained functional magnetic resonance images in a novel paradigm for separately assessing neural correlates of familiarity and conceptual priming using famous and nonfamous faces. Conceptual priming, as shown by more accurate behavioral responses to strongly conceptually primed than to weakly conceptually primed faces, was associated with activity reductions in left prefrontal cortex, whereas familiarity was associated with activity enhancements in right parietal cortex for more-familiar compared with less-familiar faces. This neuroimaging evidence implicates separate neurocognitive processes operative in explicit stimulus recognition versus implicit conceptual priming. 10.1093/cercor/bhm200

Language Control and Lexical Competition in Bilinguals: An Event-Related fMRI Study

Jubin Abutalebi — 2008-06-17T12:05:10-00:00

Cereb. Cortex, Vol. 18, No. 7. (1 July 2008), pp. 1496-1505.

Language selection (or control) refers to the cognitive mechanism that controls which language to use at a given moment and context. It allows bilinguals to selectively communicate in one target language while minimizing the interferences from the nontarget language. Previous studies have suggested the participation in language control of different brain areas. However, the question remains whether the selection of one language among others relies on a language-specific neural module or general executive regions that also allow switching between different competing behavioral responses including the switching between various linguistic registers. In this functional magnetic resonance imaging study, we investigated the neural correlates of language selection processes in German-French bilingual subjects during picture naming in different monolingual and bilingual selection contexts. We show that naming in the first language in the bilingual context (compared with monolingual contexts) increased activation in the left caudate and anterior cingulate cortex. Furthermore, the activation of these areas is even more extended when the subjects are using a second weaker language. These findings show that language control processes engaged in contexts during which both languages must remain active recruit the left caudate and the anterior cingulate cortex (ACC) in a manner that can be distinguished from areas engaged in intralanguage task switching. 10.1093/cercor/bhm182

NEUROIMAGING: Growing Pains for fMRI

Greg Miller — 2008-06-15T02:00:28-00:00

Science, Vol. 320, No. 5882. (13 June 2008), pp. 1412-1414.

10.1126/science.320.5882.1412

What we can do and what we cannot do with fMRI

Nikos Logothetis — 2008-06-11T21:05:36-00:00

Nature, Vol. 453, No. 7197. (12 June 2008), pp. 869-878.

Temporal dynamics of perisylvian activation during language processing in children and adults

Jens Brauer — 2008-06-13T01:42:05-00:00

NeuroImage, Vol. 41, No. 4. (15 July 2008), pp. 1484-1492.

The perisylvian region of the human cortex is known to play a major role in language processing. Especially the superior temporal cortex (STC) and the inferior frontal cortex (IFC) have been investigated with respect to their particular involvement in language comprehension. In the present research, the timing of recruitment of these language-related brain areas in both hemispheres was examined as a function of age using functional imaging data of 6-year-old children and adults with a special focus on blood oxygenation level dependent (BOLD) response time courses. The results show that children's activation time courses differ from that of adults. First, children show an overall later peak of BOLD responses. Second, children's IFC responds much later than their STC, while in adults the difference between both regions is less pronounced. Within the STC, both groups show similar regionally U-shaped activation patterns with fastest peaks in voxels at the STC's mid-portion around Heschl's gyrus and longer latencies in anterior and posterior directions, suggesting a coarsely similar information flow in adults and children in the temporal region. Finally, children in contrast to adults, display a temporal primacy of right over left hemispheric activation. The observed overall latency differences between children and adults are in line with the assumption of ongoing maturation in perisylvian brain regions and the connections between them. A functional perspective on BOLD timing argues for a developmental change from higher processing costs in children compared to adults due to slower and less automatic language processes, in particular those located in the IFC. The observed hemispheric differences are discussed in the context of developmental models assuming a high reliance on right-hemisphere-based suprasegmental information processing during language comprehension in childhood.

Predicting Human Brain Activity Associated with the Meanings of Nouns

Tom Mitchell — 2008-05-29T22:12:26-00:00

Science, Vol. 320, No. 5880. (30 May 2008), pp. 1191-1195.

The question of how the human brain represents conceptual knowledge has been debated in many scientific fields. Brain imaging studies have shown that different spatial patterns of neural activation are associated with thinking about different semantic categories of pictures and words (for example, tools, buildings, and animals). We present a computational model that predicts the functional magnetic resonance imaging (fMRI) neural activation associated with words for which fMRI data are not yet available. This model is trained with a combination of data from a trillion-word text corpus and observed fMRI data associated with viewing several dozen concrete nouns. Once trained, the model predicts fMRI activation for thousands of other concrete nouns in the text corpus, with highly significant accuracies over the 60 nouns for which we currently have fMRI data. 10.1126/science.1152876

Neuroanatomical distribution of five semantic components of verbs: Evidence from fMRI

David Kemmerer — 2008-05-29T15:10:21-00:00

Brain and Language, Vol. In Press, Corrected Proof

The Simulation Framework, also known as the Embodied Cognition Framework, maintains that conceptual knowledge is grounded in sensorimotor systems. To test several predictions that this theory makes about the neural substrates of verb meanings, we used functional magnetic resonance imaging (fMRI) to scan subjects' brains while they made semantic judgments involving five classes of verbs--specifically, Running verbs (e.g., run, jog, walk), Speaking verbs (e.g., shout, mumble, whisper), Hitting verbs (e.g., hit, poke, jab), Cutting verbs (e.g., cut, slice, hack), and Change of State verbs (e.g., shatter, smash, crack). These classes were selected because they vary with respect to the presence or absence of five distinct semantic components--specifically, ACTION, MOTION, CONTACT, CHANGE OF STATE, and TOOL USE. Based on the Simulation Framework, we hypothesized that the ACTION component depends on the primary motor and premotor cortices, that the MOTION component depends on the posterolateral temporal cortex, that the CONTACT component depends on the intraparietal sulcus and inferior parietal lobule, that the CHANGE OF STATE component depends on the ventral temporal cortex, and that the TOOL USE component depends on a distributed network of temporal, parietal, and frontal regions. Virtually all of the predictions were confirmed. Taken together, these findings support the Simulation Framework and extend our understanding of the neuroanatomical distribution of different aspects of verb meaning.

Cognitive and Neural Contributions to Understanding the Conceptual System

Barsalou — 2008-04-12T17:32:23-00:00

Current Directions in Psychological Science, Vol. 17, No. 2. (April 2008), pp. 91-95.

Should Psychology Ignore the Language of the Brain?

Hagoort — 2008-04-12T17:32:23-00:00

Current Directions in Psychological Science, Vol. 17, No. 2. (April 2008), pp. 96-101.

Bayesian brain source imaging based on combined MEG/EEG and fMRI using MCMC

Sung Jun — 2008-04-15T23:06:14-00:00

NeuroImage, Vol. 40, No. 4. (1 May 2008), pp. 1581-1594.

A number of brain imaging techniques have been developed in order to investigate brain function and to develop diagnostic tools for various brain disorders. Each modality has strengths as well as weaknesses compared to the others. Recent work has explored how multiple modalities can be integrated effectively so that they complement one another while maintaining their individual strengths. Bayesian inference employing Markov Chain Monte Carlo (MCMC) techniques provides a straightforward way to combine disparate forms of information while dealing with the uncertainty in each. In this paper we introduce methods of Bayesian inference as a way to integrate different forms of brain imaging data in a probabilistic framework. We formulate Bayesian integration of magnetoencephalography (MEG) data and functional magnetic resonance imaging (fMRI) data by incorporating fMRI data into a spatial prior. The usefulness and feasibility of the method are verified through testing with both simulated and empirical data.

Predicting judged similarity of natural categories from their neural representation

Matt Weber — 2008-04-05T19:59:00-00:00

(2008)

Language and simulation in conceptual processing

Lawrence Barsalou — 2008-04-03T15:06:56-00:00

A selective representation of the meaning of actions in the auditory mirror system

Gaspare Galati — 2008-03-23T00:42:46-00:00

NeuroImage, Vol. 40, No. 3. (15 April 2008), pp. 1274-1286.

Mirror neurons in the monkey's premotor cortex respond during both execution and observation of actions and are thought to be critical for understanding others' actions. Human studies have shown premotor cortex activation while viewing actions, hearing their sounds, listening to or reading action-related sentences, and have compared execution and observation of similar actions. However, we still lack direct evidence in humans of the most striking and theoretically relevant feature of mirror neurons, i.e., that they map seen/heard actions onto motor representations of the same actions at an abstract level. Here we combine fast event-related functional magnetic resonance imaging with an unconscious semantic priming paradigm and show that the human auditory mirror system also holds an abstract representation of the meaning of heard actions. We analyzed the effect on brain activity of trial-by-trial semantic congruency between a target sound denoting a hand or mouth action (or an environmental event) and a briefly flashed written word acting as an unconscious cross-modal prime. Left inferior frontal and posterior temporal regions selectively responded to action sounds in a non-somatotopic fashion and were modulated by semantic congruency only in action sound trials. We also observed regions selective for either hand or mouth actions, which however did not show a corresponding effector-specific effect of semantic congruency. These results provide evidence that the human mirror system represents the meaning of actions (but not of other events) (a) at an abstract, semantic level, (b) independently of the effector, and (c) independently of conscious awareness.

Recruitment of anterior and posterior structures in lexical-semantic processing: An fMRI study comparing implicit and explicit tasks

Ilana Ruff — 2008-03-23T00:34:39-00:00

Brain and Language, Vol. 105, No. 1. (April 2008), pp. 41-49.

Previous studies examining explicit semantic processing have consistently shown activation of the left inferior frontal gyrus (IFG). In contrast, implicit semantic processing tasks have shown activation in posterior areas including the superior temporal gyrus (STG) and the middle temporal gyrus (MTG) with less consistent activation in the IFG. These results raise the question whether the functional role of the IFG is related to those processes needed to make a semantic decision or to processes involved in the extraction and analysis of meaning. This study examined neural activation patterns during a semantic judgment task requiring overt semantic analysis, and then compared these activation patterns to previously obtained results using the same semantically related and unrelated word pairs in a lexical decision task which required only implicit semantic processing (Rissman, J., Eliassen, J. C., & Blumstein, S. E. (2003). An event-related fMRI investigation of implicit semantic priming. Journal of Cognitive Neuroscience, 15, 1160-1175). The behavioral results demonstrated that the tasks were equivalent in difficulty. fMRI results indicated that the IFG and STG bilaterally showed greater activation for semantically unrelated than related word pairs across the two tasks. Comparison of the two task types across conditions revealed greater activation for the semantic judgment task only in the STG bilaterally and not in the IFG. These results suggest that the pre-frontal cortex is recruited similarly in the service of both the lexical decision and semantic judgment tasks. The increased activation in the STG in the semantic judgment task reflects the greater depth of semantic processing required in this task and indicates that the STG is not simply a passive store of lexical-semantic information but is involved in the active retrieval of this information.

The Different Neural Correlates of Action and Functional Knowledge in Semantic Memory: An fMRI Study

Nicola Canessa — 2008-03-12T00:47:20-00:00

Cereb. Cortex, Vol. 18, No. 4. (1 April 2008), pp. 740-751.

Previous reports suggest that the internal organization of semantic memory is in terms of different "types of knowledge," including "sensory" (information about perceptual features), "action" (motor-based knowledge of object utilization), and "functional" (abstract properties, as function and context of use). Consistent with this view, a specific loss of action knowledge, with preserved functional knowledge, has been recently observed in patients with left frontoparietal lesions. The opposite pattern (impaired functional knowledge with preserved action knowledge) was reported in association with anterior inferotemporal lesions. In the present study, the cerebral representation of action and functional knowledge was investigated using event-related analysis of functional magnetic resonance imaging data. Fifteen subjects were presented with pictures showing pairs of manipulable objects and asked whether the objects within each pair were used with the same manipulation pattern ("action knowledge" condition) or in the same context ("functional knowledge" condition). Direct comparisons showed action knowledge, relative to functional knowledge, to activate a left frontoparietal network, comprising the intraparietal sulcus, the inferior parietal lobule, and the dorsal premotor cortex. The reverse comparison yielded activations in the retrosplenial and the lateral anterior inferotemporal cortex. These results confirm and extend previous neuropsychological data and support the hypothesis of the existence of different types of information processing in the internal organization of semantic memory. 10.1093/cercor/bhm110

Neuroanatomical distinctions within the semantic system during sentence comprehension: Evidence from functional magnetic resonance imaging

Gina Kuperberg — 2008-02-10T01:18:42-00:00

NeuroImage, Vol. 40, No. 1. (1 March 2008), pp. 367-388.

To make sense of a sentence, we must compute morphosyntactic and semantic-thematic relationships between its verbs and arguments and evaluate the resulting propositional meaning against any preceding context and our real-world knowledge. Recent electrophysiological studies suggest that, in comparison with non-violated verbs (e.g. "...at breakfast the boys would eat..."), animacy semantic-thematically violated verbs (e.g. "...at breakfast the eggs would eat...") and morphosyntactically violated verbs (e.g. "...at breakfast the boys would eats...") evoke a similar neural response. This response is distinct from that evoked by verbs that only violate real-world knowledge (e.g. "...at breakfast the boys would plant..."). Here we used fMRI to examine the neuroanatomical regions engaged in response to these three violations. Real-world violations, relative to other sentence types, led to increased activity within the left anterior inferior frontal cortex, reflecting participants' increased and prolonged efforts to retrieve semantic knowledge about the likelihood of events occurring in the real world. In contrast, animacy semantic-thematic violations of the actions depicted by the central verbs engaged a frontal/inferior parietal/basal ganglia network known to mediate the execution and comprehension of goal-directed action. We suggest that the recruitment of this network reflected a semantic-thematic combinatorial process that involved an attempt to determine whether the actions described by the verbs could be executed by their NP Agents. Intriguingly, this network was also activated to morphosyntactic violations between the verbs and their subject NP arguments. Our findings support the pattern of electrophysiological findings in suggesting (a) that a clear division within the semantic system plays out during sentence comprehension, and (b) that semantic-thematic and syntactic violations of verbs within simple active sentences are treated similarly by the brain.

Combining structural and functional neuroimaging data for studying brain connectivity: A review

Rykhlevskaia — 2008-02-05T00:34:57-00:00

Psychophysiology, Vol. 45, No. 2. (March 2008), pp. 173-187.

Interpreting fMRI data: maps, modules and dimensions

Op — 2008-01-21T16:12:08-00:00

Nat Rev Neurosci, Vol. 9, No. 2. (February 2008), pp. 123-135.

Bloodless fMRI.

Alan Jasanoff — 2007-10-20T06:47:45-00:00

Trends Neurosci (10 October 2007)

Conventional functional magnetic resonance imaging (fMRI) is a blunt tool for studying the nervous system because it measures neural activity only indirectly, by way of hemodynamics and neurovascular coupling. Several alternative, nonhemodynamic functional imaging methods are now being explored. The methods are designed to offer better resolution and neuronal specificity than hemodynamic imaging and, in some cases, might report signals from specific molecules or cell populations. Much progress has concentrated in three areas: diffusion-weighted functional imaging; detection of neuronal electromagnetic fields; and molecular imaging of neural metabolites and signaling species. Here, we review recent developments in these areas. We consider unique advantages and disadvantages of 'bloodless fMRI' approaches, as well as their future prospects as experimental tools in cognitive and systems neuroscience.

Combining electrophysiology and functional imaging - different methods for different questions

Christoph Bledowski — 2007-12-04T12:29:09-00:00

Trends in Cognitive Sciences, Vol. 11, No. 12. (December 2007), pp. 500-502.

The Neural Substrate of Naming Events: Effects of Processing Demands but not of Grammatical Class

Simona Siri — 2007-12-16T01:39:36-00:00

Cereb. Cortex, Vol. 18, No. 1. (1 January 2008), pp. 171-177.

Grammatical class is a fundamental property of language, and all natural languages distinguish between nouns and verbs. Brain activation studies have provided conflicting evidence concerning the neural substrates of noun and verb processing. A major limitation of many previous imaging studies is that they did not disentangle the impact of grammatical class from the differences in semantic correlates. In order to tease apart the role of semantic and grammatical factors, we performed a functional magnetic resonance imaging study presenting Italian speakers with pictures of events and asked them to name them as 1) Infinitive Verb (e.g., mangiare [to eat]); 2) Inflected Verb (e.g., mangia [she/he eats]); and 3) Action Noun (e.g., mangiata [the eating]). We did not find any verb-specific activation. However, reliable left inferior frontal gyrus (IFG) activations were found when contrasting the Action Noun with the Infinitive Verb condition. A second-level analysis indicated then that activation in left IFG was greatest for Action Nouns, intermediate for Inflected Verbs, and least for Infinitive Verbs. We conclude that, when all other factors are controlled, nouns and verbs are processed by a common neural system. In the present case, differences in left IFG activation emerge as a consequence of increasing linguistic and/or general processing demands. 10.1093/cercor/bhm043

The Neural Cost of the Auditory Perception of Language Switches: An Event-Related Functional Magnetic Resonance Imaging Study in Bilinguals

Jubin Abutalebi — 2007-12-13T01:27:40-00:00

J. Neurosci., Vol. 27, No. 50. (12 December 2007), pp. 13762-13769.

One of the most remarkable abilities of bilinguals is to produce and/or to perceive a switch from one language to the other without any apparent difficulty. However, several psycholinguistic studies indicate that producing, recognizing, and integrating a linguistic code different from the one in current use may entail a processing cost for the speaker/listener. Up to now, the underlying neural substrates of perceiving language switches are unknown. In the present study, we investigated the neural mechanisms of language switching during auditory perception in bilinguals. Event-related functional magnetic resonance imaging was performed in 12 early, highly proficient Italian/French bilinguals, who were more exposed to their second language. Subjects had to listen to narratives containing "switched passages" that could either respect (i.e., regular switches) or violate (i.e., irregular switches) the constituents of sentence structure. The results indicate that switching engages an extensive neural network, including bilateral prefrontal and temporal associative regions. Moreover, a clear dissociation is observed for the types of switches. Regular switches entail a pattern of brain activity closely related to lexical processing, whereas irregular switches engage brain structures involved in syntactic and phonological aspects of language processing. Noteworthy, when switching into the less-exposed language, we observed the selective engagement of subcortical structures and of the anterior cingulate cortex, putatively involved in cognitive and executive control. This suggests that switching into a less-exposed language requires controlled processing resources. This pattern of brain activity may constitute an important neural signature of language dominance in bilinguals. 10.1523/JNEUROSCI.3294-07.2007

Symmetries in human brain language pathways correlate with verbal recall

Marco Catani — 2007-10-24T17:13:20-00:00

Proceedings of the National Academy of Sciences, Vol. 104, No. 43. (23 October 2007), pp. 17163-17168.

Lateralization of language to the left hemisphere is considered a key aspect of human brain organization. We used diffusion tensor MRI to perform in vivo virtual dissection of language pathways to assess the relationship between brain asymmetry and cognitive performance in the normal population. Our findings suggest interhemispheric differences in direct connections between Broca's and Wernicke's territories, with extreme leftward lateralization in more than half of the subjects and bilateral symmetrical distribution in only 17.5% of the subjects. Importantly, individuals with more symmetric patterns of connections are better overall at remembering words using semantic association. Moreover, preliminary analysis suggests females are more likely to have a symmetrical pattern of connections. These findings suggest that the degree of lateralization of perisylvian pathways is heterogeneous in the normal population and, paradoxically, bilateral representation, not extreme lateralization, might ultimately be advantageous for specific cognitive functions. 10.1073/pnas.0702116104

Brain areas underlying retrieval of nouns and verbs: Grammatical class and task demand effects

Manuela Berlingeri — 2007-09-28T03:06:48-00:00

Brain and Language, Vol. 103, No. 1-2. ( 2007), pp. 156-157.