Large Language Models (LLMs) have shown success in predicting neural signals associated with narrative processing, but their approach to integrating context over large timescales differs fundamentally from that of the human brain. In this study, we show how the brain, unlike LLMs that process large text windows in parallel, integrates short-term and long-term contextual information through an incremental mechanism. Using fMRI data from 219 participants listening to spoken narratives, we first demonstrate that LLMs predict brain activity effectively only when using short contextual windows of up to a few dozen words.
View Article and Find Full Text PDFContextual embeddings, derived from deep language models (DLMs), provide a continuous vectorial representation of language. This embedding space differs fundamentally from the symbolic representations posited by traditional psycholinguistics. We hypothesize that language areas in the human brain, similar to DLMs, rely on a continuous embedding space to represent language.
View Article and Find Full Text PDFWord embedding representations have been shown to be effective in predicting human neural responses to lingual stimuli. While these representations are sensitive to the textual context, they lack the extratextual sources of context such as prior knowledge, thoughts, and beliefs, all of which constitute the listener's perspective. In this study, we propose conceptualizing the listeners' perspective as a source that induces changes in the embedding space.
View Article and Find Full Text PDFDeparting from traditional linguistic models, advances in deep learning have resulted in a new type of predictive (autoregressive) deep language models (DLMs). Using a self-supervised next-word prediction task, these models generate appropriate linguistic responses in a given context. In the current study, nine participants listened to a 30-min podcast while their brain responses were recorded using electrocorticography (ECoG).
View Article and Find Full Text PDFBackground: Prialt® was approved by the European Medicine Agency in February 2005. Besides morphine, it is the only analgesic approved for long-term intrathecal infusion in the treatment of chronic pain. As it does not bind to opioid receptors, its use in the treatment of chronic pain seemed to be safer and to lead to less adverse events compared with morphine.
View Article and Find Full Text PDFBackground: Chronic pain syndromes caused by degenerative and postinfectious changes in the cervical spine continue to pose significant management challenges to neurosurgeons and pain practitioners. The identification of an individualized treatment plan, astute surgical technique, comprehensive and multimodal analgesia, and adequate rehabilitation processes do not necessarily result in diminished pain.
Case Summary: We present the case of a patient with chronic pain treated surgically for degenerative cervical myelopathy secondary to cervical spinal stenosis.
Objective This prospective study evaluated the time to response and outcomes of navigated repetitive transcranial magnetic stimulation (TMS) at a frequency of 10 Hz in patients with chronic neuropathic pain. Methods This prospective study included patients with unilateral chronic neuropathic pain. All patients received motor cortex stimulation at 10 Hz over nine consecutive days using repetitive TMS.
View Article and Find Full Text PDFBackground: Subcutaneous peripheral nerve field stimulation (sPNFS) is an established procedure for the treatment of chronic localized neuropathic pain of peripheral origin. The treatment of nummular headache primarily focuses on conservative methods with limited prospects of success. The role of sPNFS in the treatment of nummular headache has not been investigated as yet.
View Article and Find Full Text PDFBackground: Poverty is an important problem in Germany. The health effects of poverty can lead to a higher risk of disease and the arising of chronic affections. On the other hand chronic illness may support the development and continuance of poverty.
View Article and Find Full Text PDFIntroduction: The correct positioning of spinal cord stimulator leads is assessed radiographically during their percutaneous implantation for trial stimulation. Usually the C-arm is repositioned several times to allow imaging in different planes, which may extend the total duration of surgery. The study aimed to evaluate whether the concurrent intraoperative use of 2 C-arms could safely reduce the duration of surgery.
View Article and Find Full Text PDFBackground: Spinal cord stimulation (SCS) is an established procedure for treatment of chronic neuropathic pain of peripheral origin. The efficacy of SCS in case of central poststroke pain (CPSP), especially thalamic pain, has not been adequately proven.
Objectives: The efficacy of SCS as an extracranial neurostimulation method for the management of central pain syndrome was investigated.
Objective: There is no established method for in vivo imaging during biopsy and surgery of the brain, which is capable to generate competitive images in terms of resolution and contrast comparable with histopathological staining.
Methods: Coherent anti-Stokes Raman scattering (CARS) and two photon excited fluorescence (TPEF) microscopy are non-invasive all optical imaging techniques that are capable of high resolution, label-free, real-time, nondestructive examination of living cells and tissues. They provide image contrast based on the molecular composition of the specimen which allows the study of large tissue areas of frozen tissue sections ex vivo.
Infrared spectroscopy enables the identification of tissue types based on their inherent vibrational fingerprint without staining in a nondestructive way. Here, Fourier transform infrared microscopic images were collected from 22 brain metastasis tissue sections of bladder carcinoma, lung carcinoma, mamma carcinoma, colon carcinoma, prostate carcinoma and renal cell carcinoma. The scope of this study was to distinguish the infrared spectra of carcinoma from normal tissue and necrosis and to use the infrared spectra of carcinoma to determine the primary tumor of brain metastasis.
View Article and Find Full Text PDFJ Neurol Surg A Cent Eur Neurosurg
December 2013
Objective: In general, glioblastomas multiforme (GBM) arise in the supratentorial region, but in less than 4% of cases they also occur in the posterior fossa, particularly in the cerebellum. Furthermore, a minority of malignant gliomas are multifocal. We report on an unusual case with infratentorial multifocal lesions, suspicious for metastases, which turned out to be a multifocal GBM of the posterior fossa.
View Article and Find Full Text PDFRaman spectroscopy is a promising tool towards biopsy under vision as it provides label-free image contrast based on intrinsic vibrational spectroscopic fingerprints of the specimen. The current study applied the spectral unmixing algorithm vertex component analysis (VCA) to probe cell density and cell nuclei in Raman images of primary brain tumor tissue sections. Six Raman images were collected at 785 nm excitation that consisted of 61 by 61 spectra at a step size of 2 micrometers.
View Article and Find Full Text PDFPurpose: Single center evaluation of the placement accuracy of thoracolumbar pedicle screws implanted either with fluoroscopy or under CT-navigation using 3D-reconstruction and intraoperative computed tomography control of the screw position. There is in fact a huge variation in the reported placement accuracy of pedicle screws, especially concerning the screw placement under conventional fluoroscopy most notably due to the lack of the definition of screw misplacement, combined with a potpourri of postinstrumentation evaluation methods.
Methods: The operation data of 1,006 patients operated on in our clinic between 1995 and 2005 is analyzed retrospectively.
Single band coherent anti-Stokes Raman scattering (CARS) microscopy is one of the fastest implementation of nonlinear vibrational imaging allowing for video-rate image acquisition of tissue. This is due to the large Raman signal in the C-H-stretching region. However, the chemical specificity of such images is conventionally assumed to be low.
View Article and Find Full Text PDFJ Neurol Surg A Cent Eur Neurosurg
March 2012
Background: Vagus nerve stimulation (VNS) has been introduced as a therapeutic option for treatment-resistant depression. The neural and chemical mechanisms responsible for the effects of VNS are largely unclear.
Methods: Bilateral removal of the olfactory bulbs (OBX) is a validated animal model in depression research.