Search results for "Functional Laterality"
showing 10 items of 274 documents
When nominal features are marked on verbs: A transcranial magnetic stimulation study
2006
It has been claimed that verb processing (as opposed to noun processing) is subserved by specific neural circuits in the left prefrontal cortex. In this study, we took advantage of the unusual grammatical characteristics of clitic pronouns in Italian (e.g., lo and la in portalo and portala 'bring it [masculine]/[feminine]', respectively)-the fact that clitics have both nominal and verbal characteristics, to explore the neural correlates of verb and clitic processing. We used repetitive transcranial magnetic stimulation (rTMS) to suppress the excitability of the left prefrontal cortex and to assess its role in producing verb+det+noun and verb+clitic phrases. Results showed an interference ef…
Bilateral cystic pulmonary glial heterotopia and palatinal teratoma causing respiratory distress in an infant
2009
We report on a male infant with extensive, bilateral cystic and solid lung lesions who presented postnatally with respiratory distress caused by bilateral cystic lung lesions. Parenchyma-sparing resections were performed. Histology revealed the presence of neuroglial cell-lined cysts and glial nodules. In addition, a neural element containing palatinal teratoma was detected and excised. Based on previously published cases, the pathogenesis and clinical features of pulmonary neuroglial heterotopia are discussed.
Habituation and laterality of orienting processes as reflected by slow negative waves
2000
The study is concerned with the question of whether the orienting wave (O-wave), a slow potential shift of the event-related brain potential, is a component of the orienting response (OR). As habituation is supposed to be the most important characteristic of the OR, we focussed particularly on any habituating aspect of the O-wave. Results suggest that its bilateral distribution over midfrontal areas might constitute such a link relating the O-wave to orienting activity. Hemispheric asymmetry linearly decreased its right-sided predominance in response to repeated presentations of an initially novel auditory stimulus. A similar, concomitant diminution of the skin conductance response (SCR) oc…
Erratum to typical asymmetry in the hemispheric activation during an fMRI verbal comprehension paradigm is related to better performance in verbal an…
2019
Chronic exposure to seizures in patients with left hemisphere (LH) epileptic focus could favor higher activation in the contralateral hemisphere during language processing, but the cognitive effects of this remain unclear. This study assesses the relationship between asymmetry in hemispheric activation during language fMRI and performance in verbal and non-verbal tasks. Whereas prior studies primarily used fMRI paradigms that favor frontal lobe activation and less prominent activation of the medial or superior temporal lobes, we used a verbal comprehension paradigm previously demonstrated to activate reliably receptive language areas. Forty-seven patients with drug-resistant epilepsy candid…
Neural substrates of the interaction of emotional stimulus processing and motor inhibitory control: an emotional linguistic go/no-go fMRI study.
2007
Neural substrates of behavioral inhibitory control have been probed in a variety of animal model, physiologic, behavioral, and imaging studies, many emphasizing the role of prefrontal circuits. Likewise, the neurocircuitry of emotion has been investigated from a variety of perspectives. Recently, neural mechanisms mediating the interaction of emotion and behavioral regulation have become the focus of intense study. To further define neurocircuitry specifically underlying the interaction between emotional processing and response inhibition, we developed an emotional linguistic go/no-go fMRI paradigm with a factorial block design which joins explicit inhibitory task demand (i.e., go or no-go)…
Maturation of near-field and far-field somatosensory evoked potentials after median nerve stimulation in children under 4 years of age
2000
Abstract Objectives : The maturation of subcortical SEPs in young children. Methods : Median nerve SEPs were recorded during sleep in 42 subjects aged 0–48 months. Active electrodes were at the ipsilateral Erb's point, the lower and upper dorsal neck, and the frontal and contralateral centroparietal scalp; reference electrodes were at the contralateral Erb's point, the ipsilateral earlobe and the frontal scalp; bandpass was 10–3000 Hz. The peaks were labelled by their latencies in adults. Results : The peak latencies of N9 (brachial plexus potential) decreased exponentially with age during the first year, but increased with height thereafter. The interpeak latencies (IPLs) N9–N11, which mea…
Quantitative investigations on the human entorhinal area: left-right asymmetry and age-related changes
1994
The total nerve cell numbers in the right and in the left human entorhinal areas have been calculated by volume estimations with the Cavalieri principle and by cell density determinations with the optical disector. Thick gallocyanin-stained serial frozen sections through the parahippocampal gyrus of 22 human subjects (10 female, 12 male) ranging from 18 to 86 years were analysed. The laminar composition of gallocyanin (Nissl)-stained sections could easily be compared with Braak's (1972, 1980) pigmentoarchitectonic study, and Braak's nomenclature of the entorhinal laminas was adopted. Cell-sparse laminae dissecantes can more clearly be distinguished in Nissl than in aldehydefuchsin preparati…
Asymmetry in dopamine D2/3 receptors of caudate nucleus is lost with age
2007
Molecular and functional imaging techniques reveal evidence for lateralization of human cerebral function. Based on animal data, we hypothesized that asymmetry in dopamine neurotransmission declines during normal aging. In order to test this hypothesis, we measured dopamine D2/3 receptor availability with [18F]desmethoxyfallypride-PET (DMFP) in putamen and caudate nucleus (NC) of 21 healthy, right-handed males (24-60 years; 35+/-10). For volumetric analysis, high-resolution T1-weighted MR-images were obtained in 18 of the PET-subjects in order to assess possible age-related decreases in NC and putamen volume. The calculated DMFP binding potentials (BP) showed a right-ward asymmetry in NC of…
Illusory contours and specific regions of human extrastriate cortex: evidence from rTMS.
2003
Functional magnetic resonance imaging studies showed that perception of illusory contours is associated with extrastriate cortex activation prevailing on the right side. 1 Hz repetitive transcranial magnetic stimulation (rTMS) is able to induce lasting inhibition of cortical activity. The objective of the study was to investigate the role of extrastriate cortex in illusory contour perception inducing 1 Hz rTMS interference in healthy subjects. Eight healthy subjects underwent 1 Hz rTMS (600 pulses) through a figure-of-eight coil over right and left occipital cortex (O1 and O2 of 10/20 EEG system); sham magnetic stimulation on the same sites and right motor cortex rTMS (in three subjects) we…
Differential impact of continuous theta-burst stimulation over left and right DLPFC on planning
2011
Most neuroimaging studies on planning report bilateral activations of the dorsolateral prefron- tal cortex (dlPFC). Recently, these concurrent activations of left and right dlPFC have been shown to dou- ble dissociate with different cognitive demands imposed by the planning task: Higher demands on the extraction of task-relevant information led to stronger activation in left dlPFC, whereas higher demands on the integration of interdependent information into a coherent action sequence entailed stronger activa- tion of right dlPFC. Here, we used continuous theta-burst stimulation (cTBS) to investigate the supposed causal structure-function mapping underlying this double dissociation. Two grou…