Understanding and interpreting how words are organized in a sentence to convey distinct meanings is a cornerstone of human communication. The neural underpinnings of this ability, known as syntactic comprehension, are far from agreed upon in current neurocognitive models of language comprehension. Traditionally, left frontal regions (e.
View Article and Find Full Text PDFIdeomotor apraxia is a cognitive disorder most often resulting from acquired brain lesions (i.e., strokes or tumors).
View Article and Find Full Text PDFMental health problems are common for persons with neurological disorders (PWNDs) and their caregivers (CGs) but often are not adequately treated. Despite this growing need, the training of clinical psychologists typically does not include coursework or practicum experience working with these populations. To address this, a team of faculty, supervisors, and doctoral students in UC Berkeley's Clinical Science program undertook a year-long process that consisted of building a training curriculum that integrated coursework and consultation with visiting experts; providing supervised practicum training with PWNDs and CGs and evaluating training and clinical outcomes.
View Article and Find Full Text PDFStroke alters blood flow to the brain resulting in damaged tissue and cell death. Moreover, the disruption of cerebral blood flow (perfusion) can be observed in areas surrounding and distal to the lesion. These structurally preserved but suboptimally perfused regions may also affect recovery.
View Article and Find Full Text PDFIntroduction: Apraxia of speech (AOS) is a motor speech disorder impairing the coordination of complex articulatory movements needed to produce speech. AOS typically co-occurs with a non-fluent aphasia, or language disorder, making it challenging to determine the specific brain structures that cause AOS. Cases of pure AOS without aphasia are rare but offer the best window into the neural correlates that support articulatory planning.
View Article and Find Full Text PDFOur brains enable us to learn language. We develop it early on in life and use it effortlessly every day. It is only when the language system breaks down that we fully realize how complicated it is to speak and understand.
View Article and Find Full Text PDFThe frontal aslant tract (FAT) is a recently described intralobar tract that connects the superior and inferior frontal gyri. The FAT has been implicated in various speech and language processes and disorders, including motor speech impairments, stuttering disorders, opercular syndrome, and verbal fluency, but the specific function(s) of the FAT have yet to be elucidated. In the current study, we aimed to address this knowledge gap by investigating the underlying role that the FAT plays in motor aspects of speech and language abilities in post-stroke aphasia.
View Article and Find Full Text PDFOne of the most challenging symptoms of aphasia is an impairment in auditory comprehension. The inability to understand others has a direct impact on a person's quality of life and ability to benefit from treatment. Despite its importance, limited research has examined the recovery pattern of auditory comprehension and instead has focused on aphasia recovery more generally.
View Article and Find Full Text PDFCurrent evidence strongly suggests that the arcuate fasciculus (AF) is critical for language, from spontaneous speech and word retrieval to repetition and comprehension abilities. However, to further pinpoint its unique and differential role in language, its anatomy needs to be explored in greater detail and its contribution to language processing beyond that of known cortical language areas must be established. We address this in a comprehensive evaluation of the specific functional role of the AF in a well-characterized cohort of individuals with chronic aphasia ( = 33) following left hemisphere stroke.
View Article and Find Full Text PDFDespite increased awareness of the lack of gender equity in academia and a growing number of initiatives to address issues of diversity, change is slow, and inequalities remain. A major source of inequity is gender bias, which has a substantial negative impact on the careers, work-life balance, and mental health of underrepresented groups in science. Here, we argue that gender bias is not a single problem but manifests as a collection of distinct issues that impact researchers' lives.
View Article and Find Full Text PDFNaming of nouns and verbs can be selectively impaired in neurological disorders, but the specificity of the neural and cognitive correlates of such dissociation remains unclear. Functional imaging and stroke research sought to identify cortical regions selectively recruited for nouns versus verbs, yet findings are inconsistent. The present study investigated this issue in neurodegenerative diseases known to selectively affect different brain networks, thus providing new critical evidence of network specificity.
View Article and Find Full Text PDFThe role of white matter pathways in cognition is a topic of active investigation that is vital to both the fields of clinical neurology and cognitive neuroscience. White matter pathways provide critical connectivity amongst numerous specialized brain regions thereby enabling higher level cognition. While the effects of dissections and lesions of the corpus callosum have been reported, it is less understood how unilateral focal white matter lesions may impact cognitive processes.
View Article and Find Full Text PDFProactive interference in working memory refers to the fact that memory of past experiences can interfere with the ability to hold new information in working memory. The left inferior frontal gyrus (LIFG) has been proposed to play an important role in resolving proactive interference in working memory. However, the role of white matter pathways and other cortical regions has been less investigated.
View Article and Find Full Text PDFAphasia classifications and specialized language batteries differ across the fields of neurodegenerative disorders and lesional brain injuries, resulting in difficult comparisons of language deficits across etiologies. In this study, we present a simplified framework, in which a widely-used aphasia battery captures clinical clusters across disease etiologies and provides a quantitative and visual method to characterize and track patients over time. The framework is used to evaluate populations representing three disease etiologies: stroke, primary progressive aphasia (PPA), and post-operative aphasia.
View Article and Find Full Text PDFLesion symptom mapping (LSM) tools are used on brain injury data to identify the neural structures critical for a given behavior or symptom. Univariate lesion symptom mapping (ULSM) methods provide statistical comparisons of behavioral test scores in patients with and without a lesion on a voxel by voxel basis. More recently, multivariate lesion symptom mapping (MLSM) methods have been developed that consider the effects of all lesioned voxels in one model simultaneously.
View Article and Find Full Text PDFIntrinsic connectivity networks (ICNs) identified through task-free fMRI (tf-fMRI) offer the opportunity to investigate human brain circuits involved in language processes without requiring participants to perform challenging cognitive tasks. In this study, we assessed the ability of tf-fMRI to isolate reproducible networks critical for specific language functions and often damaged in primary progressive aphasia (PPA). First, we performed whole-brain seed-based correlation analyses on tf-fMRI data to identify ICNs anchored in regions known for articulatory, phonological, and semantic processes in healthy male and female controls (HCs).
View Article and Find Full Text PDFBackground: Although language deficits after awake brain surgery are usually milder than post-stroke, postoperative language assessments are needed to identify these. Follow-up of brain tumor patients in certain geographical regions can be difficult when most patients are not local and come from afar. We developed a short telephone-based test for pre- and postoperative language assessments.
View Article and Find Full Text PDFVisuospatial processing deficits are typically associated with damage to the right hemisphere. However, deficits on spatial working memory have been reported among some individuals with focal left hemisphere damage (LHD). It has been suggested that the left hemisphere may play a role in such non-verbal working memory tasks due to the use of subvocal, verbally-mediated strategies.
View Article and Find Full Text PDFThe semantic variant of primary progressive aphasia (svPPA) is a clinical syndrome characterized by semantic memory deficits with relatively preserved motor speech, syntax, and phonology. There is consistent evidence linking focal neurodegeneration of the anterior temporal lobes (ATL) to the semantic deficits observed in svPPA. Less is known about large-scale functional connectivity changes in this syndrome, particularly regarding the interplay between affected and spared language networks that leads to the unique cognitive dissociations typical of svPPA.
View Article and Find Full Text PDFPrevious studies indicate that repetition is affected in primary progressive aphasia (PPA), particularly in the logopenic variant, due to limited auditory-verbal short-term memory (avSTM). We tested repetition of phrases varied by length (short, long) and meaning (meaningful, non-meaningful) in 58 participants (22 logopenic, 19 nonfluent, and 17 semantic variants) and 21 healthy controls using a modified Bayles repetition test. We evaluated the relation between cortical thickness and repetition performance and whether sub-scores could discriminate PPA variants.
View Article and Find Full Text PDFThe neural basis of reading and writing has been a source of inquiry as well as controversy in the neuroscience literature. Reading has been associated with both left posterior ventral temporal zones (termed the "visual word form area") as well as more dorsal zones, primarily in left parietal cortex. Writing has also been associated with left parietal cortex, as well as left sensorimotor cortex and prefrontal regions.
View Article and Find Full Text PDFStudies of language disorders have shaped our understanding of brain-language relationships over the last two centuries. This article provides a review of this research and how our thinking has changed over the years regarding how the brain processes language. In the 19th century, a series of famous case studies linked distinct speech and language functions to specific portions of the left hemisphere of the brain, regions that later came to be known as Broca's and Wernicke's areas.
View Article and Find Full Text PDF