C J Price

..In this review of studies published between January 2004 and February 2005, we discuss imaging studies of speech production and comprehension in patients with aphasia after left hemisphere stroke...

..They also highlight the different types of information that can be drawn from functional imaging and neuropsychological studies...

..We conclude that these inverted U effects in left hemisphere language areas reflect the temporal dynamics of visual word processing and we highlight the implication of these effects for the design of activation studies involving reading...

..Dynamic diaschisis reveals abnormalities of functional integration that may have profound implications for neuropsychological inference, functional anatomy and, vicariously, cognitive rehabilitation...

..Overall, functional neuroimaging demonstrates that the 19(th) Century neurological model of language is remarkably insightful...

..Progress in unravelling these and other related issues will depend on the integration of behavioural, computational and neurophysiological approaches, including neuroimaging...

..In contrast, deficits in functional integration are implied when the influence of one brain region on another is stronger or weaker in patients relative to control subjects...

..In contrast, switching the input language resulted in activation of Broca's area and the supramarginal gyri, areas associated with phonological recoding. The results are discussed in terms of the cognitive control of language processes...

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..Future studies are required to examine the connectivity between these areas during normal and abnormal reading...

..This, in turn, has important implications for understanding the mechanisms that mediate recovery and the organizational principles that underlie functional architectures in the human brain...

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..However, for negative effects of rate, fMRI did not replicate the effects seen in PET, suggesting some form of hemodynamic "rectification." The discussion focuses on differences between evoked rCBF and BOLD signals...

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..These results suggest that, within a distributed conceptual system activated by words, the more prominent neural distinction relates to type of attribute...

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..Counting activates additional left prefrontal, parietal, and bilateral premotor areas, again independently from stimulus modality. These results dissociate two neuronal systems that underlie different numerosity judgements...

..This is interpreted in terms of previous findings that associated the left pars opercularis with phonetic expertise in the native language...

..Furthermore they reconcile some of the apparent inconsistencies between lesion studies and functional neuroimaging data...

..Left AIP and LPMT did not distinguish between different types of actions such as hand actions and whole body movements, although a right STS region responded selectively to whole body movements...

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..At a neuronal level, it may reflect differences in the speed with which different areas are activated and integrate with one another...

..We conclude that changes in activity in regions distant from the patients' structural damage support the argument that their prominent anomia is due to disrupted temporal lobe connections...

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..In conclusion, this study dissociates the effects of semantic and phonological relatedness between successive items during reading and naming aloud...

..Our study therefore provides novel insights into the role of the left head of caudate in the mechanisms that suppress word interference...

..Furthermore, we show that the error variance can change with the experimental design. This highlights a problem with a priori comparison of efficiency for two or more experimental designs, which usually assumes identical error variance...

..This is the first demonstration that structural brain scans can be used to predict language lateralization on a voxel-by-voxel basis in the normal healthy brain...

..We discuss the implications of these results which may be important for understanding how reading is learnt in childhood or re-learnt following brain damage in adulthood...

..Our methods provide a framework for future studies aiming to predict the consequences of brain damage...

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..Generative models represent a far more plausible framework for understanding selective neurophysiological responses and how representations are constructed in the brain...

..Thus, we demonstrate how brain activation for audiovisual integration depends on the verbal content of the stimuli, even when stimulus and task processing differences are controlled...

..In addition, they highlight the importance of the right anterior superior temporal cortex where the response was dissociated from that in the left posterior temporal lobe...

..By demonstrating this effect in populations of German-English and Japanese-English bilinguals, we suggest that the left caudate plays a universal role in monitoring and controlling the language in use...

..Here we focus on the implications for cognitive neuroscience in the context of neuroimaging...

..e., a word). Furthermore, our lateralization results suggest left hemisphere specificity for the processing of phonological stimuli, regardless of their elemental (i.e., spectrotemporal) characteristics...

..Thus, in cognitive terms, we dissociate phonological (speech) and semantic responses and propose that word specificity arises from functional integration among shared phonological and semantic areas...

..Thus, syntactic adaptation during sentence comprehension is demonstrated in a neural area that has previously been linked to both lexical semantic and sentence processing...

..Results speak against the idea of the two processes being implemented in separable neural systems...

..These results suggest that semantic decisions on auditory-visual compound stimuli might be accomplished by two overlapping degenerate neuronal systems...

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..From a clinical perspective, our method should help to compute the total volume of lesion or to trace precisely lesion boundaries that might be pertinent for surgical or diagnostic purposes...

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..More generally, they show that studies using low statistical thresholds in single subject analyses should correct the statistical threshold for the number of comparisons made or replicate effects within subject...

..The advantage of using FCP is that it searches all voxels systematically and can identify atypical activation patterns in a quantitative and unsupervised manner...

..The method applied here will be particularly useful for modelling structure-function relationships within other complex cognitive domains...

..Task-related, directional effects can now be incorporated into models of speech comprehension...

..The outputs of this system are the longitudinal language outcomes of corresponding patients in the database. This approach will provide the patient with a range of probable recovery patterns over a variety of language measures...

..Finally, we conclude by summarising the novel contribution of these studies to date and potential directions for future research...

..We conclude that the putamen plays a special role in reading but this is likely to vary with individual reading preferences and strategies...

..On the basis of prior studies, we suggest that the locations of these gray and white matter changes in speakers of a tonal language are consistent with a role in linking the pitch of words to their meaning...

..We conclude that the processing of semantically reversible sentences places additional demands on the subarticulation component of phonological working memory...

..Anatomical and functional connectivity studies are now required to identify the processing pathways that integrate these areas to support language...

..Our results generate a new set of hypotheses that have implications for the design of future behavioral and functional imaging studies of patients with left and right parietal damage...

..We propose that these effects reflect the acquisition of vocabulary through context, when new words are learnt within the context of semantically and syntactically related words...

..Neural components of this pathway would be expected to respond to sudden, perhaps unexpected changes in speech signal that result in a change to narrative meaning...

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..We discuss the complex interhemispheric processes that might underlie this effect...

..We therefore conclude that, of the variables tested, age and reading strategy were the most prominent source of variability in activation for reading familiar words aloud...

..These findings indicate that category effects in the occipital and temporal cortex can be mediated by bottom-up mechanisms-a finding that needs to be embraced by models of category specificity...

..This relation between grey-matter density and performance may represent a general principle of brain organization...

..Subjects might therefore generate an appropriate semantic sentential context to fully explore and specify the meaning of abstract concepts. Our results also explain why abstract semantics is vulnerable to left frontotemporal lesions...

..We discuss how degenerate neuronal systems can be revealed using (1) intersubject variability, (2) multiple lesion studies and (3) an iterative approach integrating information from lesion and functional imaging studies...

..e. the left middle temporal, right hippocampus and anterior superior temporal sulcus); and (ii) recruiting right hemisphere regions (i.e. the right inferior frontal sulcus) that are not activated in control subjects...

..Together, these findings have implications for cognitive models of reading that have previously relied on input from behavioural data...

..These results therefore have implications for understanding the convergence of functional imaging and neuropsychological findings...

..We conclude that there is no evidence that visual word form representations are subtended by a single patch of neuronal cortex and it is misleading to label the left midfusiform region as the visual word form area...

..In terms of neuronal mechanisms, the category selectivity may be mediated by distinct top-down (task-dependent) and bottom-up (stimulus-dependent) mechanisms...

..In contrast, the exuberant functional connectivity between extrastriate and 'core' semantic retrieval regions might be explained by abnormal pruning processes during early neurodevelopment...

..The present investigation is the first to identify distinct neuronal mechanisms for semantic and phonological contributions to reading...

..The discussion focuses on the implications of our findings and on further applications of the multisubject network analysis...

..The coordinated variations we report are likely to be determined by both genetic and environmental factors and may be the basis for differences in individual behavior...

..In addition, we show that the advantage of the event-related over epoch model was engendered by its early onset rather than its late offset, relative to the epoch model...

..Furthermore, (iii) they suggest that inconsistencies observed in the previous literature may result from effects arising from a small number of subjects only...

..Additionally non-selective, top-down processes, originating in superior parietal areas, contribute to the generation of mental images, regardless of their content, and their maintenance in the 'mind's eye'...

..Our findings provide a framework for reporting and interpreting AG activations with greater definition...

..We conclude that there is no current evidence for cortical sites dedicated to visual or auditory word form processing...

..Precise characterization of the hemodynamic latency and its interpretation in terms of underlying neural differences remain problematic, however...

..It requires only the functional data and can thus be applied post hoc and without any additional scans...

..Together, these analyses highlight the cognitive and anatomical mechanisms that mediate an essential language skill...

..We show that the thrombocytic activity of MAOB is proportionate to the number of X-chromosomes, and hypothesize that haploinsufficiency of this enzyme in 45,X females predisposes to their deficits in social cognition...

..On the basis of our findings, we also predict that lesions to the pre-SMA and caudate nuclei may have a greater impact on phonemic than semantic fluency, particularly in L2 speakers...

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..Our investigation points to a common neurological basis for deficits in word reading and picture naming in developmental dyslexia...

..It also suggests that increased activation in the medial fusiform gyrus typically found for artefacts > animals can be explained by different semantic relevance for animal and artefact items...

..Thus, the neuroanatomical basis of a verbal/nonverbal conceptual processing dissociation is established...

..These effects, induced by simply shifting stimulus presentation by a fraction of the interscan interval, suggest that fixed sampling does indeed bias estimated responses, even in blocked designs...

..Critically, in patients with atrophy in precisely these areas, the most pronounced deficit was in the retrieval of specific semantic information...

..Activity in the anterior medial temporal cortex has previously been shown to contribute to the N400 component, a finding that links the priming results obtained with efMRI and ERP methods...

..We attribute these effects to differences in the demands on speech production and decision-making processes, respectively...

..semantic) determines its regional expression (middle temporal gyrus/STS vs. AG/intraparietal sulcus)...

..We then give an example of how comparisons of this sort may lead to advanced designs in future meta-analytic research...

..Specifically, words with high-frequency syllables may increase lexical competition in the inferior temporal lobe while facilitating articulatory planning in the left anterior insula...

..We discuss the implications of these findings, arguing that they are most consistent with a semantic system undifferentiated by category at the neural level...