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U Noppeney

Publications and source records attributed to U Noppeney.

15 recordsLinked to original sources
PubMed2006

Language control in the bilingual brain.

How does the bilingual brain distinguish and control which language is in use? Previous functional imaging experiments have not been able to answer this question because proficient bilinguals activate the same brain regions irrespective of the language being tested. Here, we reveal that neuronal responses within the left caudate are sensitive to changes in the language or the meaning of words. 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.

Adult↗
PubMed2005

Action selectivity in parietal and temporal cortex.

The sensory-action theory proposes that the neural substrates underlying action representations are related to a visuomotor action system encompassing the left ventral premotor cortex, the anterior intraparietal (AIP) and left posterior middle temporal gyrus (LPMT). Using fMRI, we demonstrate that semantic decisions on action, relative to non-action words, increased activation in the left AIP and LPMT irrespective of whether the words were presented in a written or spoken form. Left AIP and LPMT might thus play the role of amodal semantic regions that can be activated via auditory as well as visual input. 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.

Acoustic Stimulation↗
PubMed2005

How reading differs from object naming at the neuronal level.

This paper uses whole brain functional neuroimaging in neurologically normal participants to explore how reading aloud differs from object naming in terms of neuronal implementation. In the first experiment, we directly compared brain activation during reading aloud and object naming. This revealed greater activation for reading in bilateral premotor, left posterior superior temporal and precuneus regions. In a second experiment, we segregated the object-naming system into object recognition and speech production areas by factorially manipulating the presence or absence of objects (pictures of objects or their meaningless scrambled counterparts) with the presence or absence of speech production (vocal vs. finger press responses). This demonstrated that the areas associated with speech production (object naming and repetitively saying "OK" to meaningless scrambled pictures) corresponded exactly to the areas where responses were higher for reading aloud than object naming in Experiment 1. Collectively the results suggest that, relative to object naming, reading increases the demands on shared speech production processes. At a cognitive level, enhanced activation for reading in speech production areas may reflect the multiple and competing phonological codes that are generated from the sublexical parts of written words. At a neuronal level, it may reflect differences in the speed with which different areas are activated and integrate with one another.

Adult↗
PubMed2004

The neural areas that control the retrieval and selection of semantics.

Semantic retrieval consistently activates left inferior frontal regions, yet lesions to these areas do not typically result in semantic deficits. This discrepancy has led to the hypothesis that left prefrontal areas are primarily involved in executive processes while semantic information is retrieved from temporal cortices. We investigated semantic executive processing by changing, over trials, the semantic association to a stimulus. Using fMRI and PET, we demonstrate that changes in semantic association increased activation in temporal as well as frontal areas. The similar effects in temporal and frontal areas suggest that semantic executive processes are not confined to the left inferior frontal cortex but might be distributed throughout the semantic system.

Adult↗
PubMed2004

An FMRI study of syntactic adaptation.

It is easier to produce and comprehend a series of sentences when they have similar syntactic structures. This "syntactic priming" effect was investigated during silent sentence reading using (i) blood oxygenation level-dependent (BOLD) response as a physiological measure in an f MRI study and (ii) reading time as a behavioral measure in a complementary self paced reading paradigm. We found that reading time and left anterior temporal activation were decreased when subjects read sentences with similar relative to dissimilar syntactic forms. Thus, syntactic adaptation during sentence comprehension is demonstrated in a neural area that has previously been linked to both lexical semantic and sentence processing.

Adaptation, Physiological↗
PubMed2003

Cortical localisation of the visual and auditory word form areas: a reconsideration of the evidence.

In this paper we examine the evidence for human brain areas dedicated to visual or auditory word form processing by comparing cortical activation for auditory word repetition, reading, picture naming, and environmental sound naming. Both reading and auditory word repetition activated left lateralised regions in the frontal operculum (Broca's area), posterior superior temporal gyrus (Wernicke's area), posterior inferior temporal cortex, and a region in the mid superior temporal sulcus relative to baseline conditions that controlled for sensory input and motor output processing. In addition, auditory word repetition increased activation in a lateral region of the left mid superior temporal gyrus but critically, this area is not specific to auditory word processing, it is also activated in response to environmental sounds. There were no reading specific activations, even in the areas previously claimed as visual word form areas: activations were either common to reading and auditory word repetition or common to reading and picture naming. We conclude that there is no current evidence for cortical sites dedicated to visual or auditory word form processing.

Adult↗
PubMed2002

Anatomic constraints on cognitive theories of category specificity.

Many cognitive theories of semantic organization stem from reports of patients with selective, category-specific deficits for particular classes of objects (e.g., fruit). The anatomical assumptions underlying the competing claims can be evaluated with functional neuroimaging but the findings to date have been inconsistent and insignificant when standard statistical criteria are adopted. We hypothesized that category differences in functional brain responses might be small and task dependent. To test this hypothesis, we entered data from seven PET studies into a single multifactorial design which crossed category (living vs man-made) with a range of tasks. Reliable category-specific effects were observed but only for word retrieval and semantic decision tasks. Living things activated medial aspects of the anterior temporal poles bilaterally while tools activated a left posterior middle temporal region. These category-by-task interactions provide robust evidence for an anatomical double dissociation according to category and place strong constraints on cognitive theories of the semantic system. Furthermore they reconcile some of the apparent inconsistencies between lesion studies and functional neuroimaging data.

Adult↗
PubMed2002

A PET study of stimulus- and task-induced semantic processing.

To investigate the neural correlates of semantic processing, previous functional imaging studies have used semantic decision and generation tasks. However, in addition to activating semantic associations these tasks also involve executive functions that are not specific to semantics. The study reported in this paper aims to dissociate brain activity due to stimulus-driven semantic associations and task-induced semantic and executive processing by using repetition and semantic decision on auditorily presented words in a cognitive conjunction design. The left posterior inferior temporal, inferior frontal (BA 44/45), and medial orbital gyri were activated by both tasks, suggesting a general role in stimulus-driven semantic and phonological processing. In addition, semantic decision increased activation in (i) left ventral inferior frontal cortex (BA 47), right cerebellum, and paracingulate, which have all previously been implicated in executive functions, and (ii) a ventral region in the left anterior temporal pole which is commonly affected in patients with semantic impairments. We attribute activation in this area to the effortful linkage of semantic features. Thus, our study replicated the functional dissociation between dorsal and ventral regions of the left inferior frontal cortex. Moreover, it also dissociated the semantic functions of the left posterior inferior temporal gyrus and anterior temporal pole: The posterior region subserves stimulus-driven activation of semantic associations and the left anterior region is involved in task-induced association of semantic information.

Adult↗
PubMed2002

Retrieval of visual, auditory, and abstract semantics.

Conceptual knowledge is thought to be represented in a large distributed network, indexing a range of different semantic features (e.g., visual, auditory, functional). We investigated the anatomical organization of these features, using PET, by contrasting brain activity elicited by heard words with (i) visual (e.g., blue), (ii) auditory (e.g., noise), or (iii) abstract (e.g., truth) meaning. The activation task was either repetition or semantic decision (e.g., does the meaning of the word relate to religion?). In the baseline conditions, the sound track of the words was reversed and subjects had to say "OK" (control for repetition) or make an acoustic decision (control for semantic decision). Irrespective of task, words relative to their corresponding controls activated the left posterior inferior temporal and inferior frontal cortices. In addition, semantic decisions on words with sensory (visual and auditory) meanings enhanced activation in a ventral region of the left anterior temporal pole. These results are consistent with neuropsychological studies showing that anterior temporal lobe damage can cause deficits for items that are mainly defined by their sensory features (i.e., concrete, particularly living items). Since modality-specific activation was observed only during the semantic decision task, we discuss whether it reflects retrieval of sensory semantics per se or the degree to which semantic associations are triggered during effortful retrieval.

Adult↗
PubMed2001

Kurt Goldstein--a philosophical scientist.

Kurt Goldstein was one of the major proponents of the holistic movement which was opposed to the classical connectionist Wernicke-Lichtheim-Model in aphasiology at the beginning of the 20th century. Influenced by Kant, Husserl and Cassirer, his work goes beyond purely empirical research and approaches traditionally philosophical questions: How can we proceed from empirical data to a theory adequately reflecting reality? How can we understand man as mind and body? What is the relation between language and cognition? Goldstein's concepts of biological knowledge, self-actualization and abstract attitude seek to address these questions. His work thus becomes attractive for philosophers. It was taken up and interpreted by Cassirer, Merleau-Ponty and Gurwitsch.

Aphasia↗
PubMed2000

Differential effects of pain and spatial attention on digit representation in the human primary somatosensory cortex.

Reorganization of primary somatosensory cortex subsequent to either reduced or enhanced peripheral input is well established. Recently, plastic changes following arm amputation in humans were shown to correlate with phantom limb pain. This raised the question whether spatial attention and pain may cause cortical reorganization in the absence of deafferentation. Using non-invasive neuroelectric imaging to study the digit representation in the human primary somatosensory cortex, we report a delayed shift of the representation of digits 2-3 due to pain on the digits 4-5, which outlasted the pain by several minutes. In contrast, reorganization during spatial attention was less pronounced, was seen almost immediately and only during the condition. These data indicate that spatial attention and pain without peripheral deafferentation cause cortical reorganization by different mechanisms. The differential time course of reorganizational effects observed at the cortex may be due to modulation of the lemniscal pathways by nociceptive input from the spinal cord dorsal horn.

Adult↗
PubMed2000

Language and cognition-Kurt Goldstein's theory of semantics.

Kurt Goldstein is regarded as one of the major proponents of the holistic movement at the beginning of the 20th century. He rejected the strong localization hypothesis in the field of aphasiology and attempted to link language disturbances to an underlying general intellectual impairment. Goldstein's criticism was based on his subtle symptomatology, his organismic biology, and his philosophical reflections. In his concept of abstract attitude Goldstein searched for a general psychological function that might explain a variety of aphasic symptoms. Abstract attitude bridges the gap between cognitive and linguistic structures. According to Goldstein, it is the basis for words to have a meaning, to be employed in a categorical sense. Since amnesic aphasics are confined to a concrete attitude, their words have lost their representational function. Although Goldstein's concept of abstract attitude is no longer used in scientific discourse, it is analyzed for its heuristic value. It led Goldstein to questions about the relation between cognition and language and to fragments of a semantic theory.

Aphasia↗
PubMed1999

Spatial attention modulates the cortical somatosensory representation of the digits in humans.

The topographic organization of the primary somatosensory cortex adapts to alterations of afferent input. Here, electric source imaging was used to show that spatial attention modifies cortical somatosensory representations in humans. The cortical representation of the electrically stimulated digit 2 (resp. digits 2 and 3) of the right hand was more medial along the somatosensory area 3b in subjects who focused attention on digit 4 of the right hand, while it was more lateral when subjects attended digit 4 of the contralateral hand. This effect was very fast since the direction of attention was changed every 6 min. The results indicate that cortical somatosensory representations not only depend on afferent input but vary when spatial attention is directed towards different parts of the body.

Adult↗
PubMed1999

Sustained attention modulates the immediate effect of de-afferentation on the cortical representation of the digits: source localization of somatosensory evoked potentials in humans.

Long-term cortical reorganization of the somatotopic arrangement of the digits after alterations of the peripheral input is well established. Studies on the immediate effects of manipulating peripheral input have shown conflicting results indicating that additional factors might modulate cortical reorganization. We present a source localization study using somatosensory evoked potentials (SEP) following electric stimulation of digits one and five before and during anaesthesia of digits two, three and four in 10 normal volunteers. When attention was directed to a stimulus at the dorsal hand, the 3D-distance between digits one and five decreased during as compared to before anaesthesia. In contrast, this distance enlarged when subjects were not attending a particular stimulus. In this condition most subjects focused their attention on the clear sensation of the de-afferented hand region. These results indicate that attention modulates the effect of immediate cortical reorganization of the hand area during partial deafferentation. As an hypothesis: it may be speculated that the sensation of the de-afferentation results in increased synchronized activity of the de-afferented somatosensory cortex and, thus, to its enlarged representation. Conversely, if attention is directed to a different hand region, the representations of the neighboring digits may expand into the de-afferented cortex.

Adult↗