Non-right-handedness, male sex, and regional, network-specific, ventral occipito-temporal anomalous lateralization in adults with a history of reading disability.

Based on historic observations that children with reading disabilities were disproportionately both male and non-right-handed, and that early life insults of the left hemisphere were more frequent in boys and non-right-handed children, it was proposed that early focal neuronal injury disrupts typical patterns of motor hand and language dominance and in the process produces developmental dyslexia. To date, these theories remain controversial. We revisited these earliest theories in a contemporary manner, investigating demographics associated with reading disability, and in a subgroup with and without reading disability, compared structural imaging as well as patterns of activity during tasks of verb generation and non-word repetition using magnetoencephalography source imaging.

Cross-Linguistic Analysis of Speech Markers: Insights from English, Chinese, and Italian Speakers.

Cross-linguistic studies with healthy individuals are vital, as they can reveal typologically common and different patterns while providing tailored benchmarks for patient studies. Nevertheless, cross-linguistic differences in narrative speech production, particularly among speakers of languages belonging to distinct language families, have been inadequately investigated. Using a picture description task, we analyze cross-linguistic variations in connected speech production across three linguistically diverse groups of cognitively normal participants-English, Chinese (Mandarin and Cantonese), and Italian speakers.

Anatomical and behavioural correlates of auditory perception in developmental dyslexia.

Developmental dyslexia is typically associated with difficulties in basic auditory processing and in manipulating speech sounds. However, the neuroanatomical correlates of auditory difficulties in developmental dyslexia (DD) and their contribution to individual clinical phenotypes are still unknown. Recent intracranial electrocorticography findings associated processing of sound amplitude rises and speech sounds with posterior and middle superior temporal gyrus (STG), respectively.

Boundary-based registration improves sensitivity for detecting hypoperfusion in sporadic frontotemporal lobar degeneration.

Introduction: Frontotemporal lobar degeneration (FTLD) is associated with FTLD due to tau (FTLD-tau) or TDP (FTLD-TDP) inclusions found at autopsy. Arterial Spin Labeling (ASL) MRI is often acquired in the same session as a structural T1-weighted image (T1w), enabling detection of regional changes in cerebral blood flow (CBF). We hypothesize that ASL-T1w registration with more degrees of freedom using boundary-based registration (BBR) will better align ASL and T1w images and show increased sensitivity to regional hypoperfusion differences compared to manual registration in patient participants.

Comorbid neuropathology and atypical presentation of Alzheimer's disease.

Introduction: Alzheimer's disease (AD) neuropathological changes present with amnestic and nonamnestic (atypical) syndromes. The contribution of comorbid neuropathology as a substratum of atypical expression of AD remains under investigated.

Methods: We examined whether atypical AD exhibited increased comorbid neuropathology compared to typical AD and if such neuropathologies contributed to the accelerated clinical decline in atypical AD.

Deciphering Distinct Genetic Risk Factors for FTLD-TDP Pathological Subtypes via Whole-Genome Sequencing.

Frontotemporal lobar degeneration with neuronal inclusions of the TAR DNA-binding protein 43 (FTLD-TDP) is a fatal neurodegenerative disorder with only a limited number of risk loci identified. We report our comprehensive genome-wide association study as part of the International FTLD-TDP Whole-Genome Sequencing Consortium, including 985 cases and 3,153 controls, and meta-analysis with the Dementia-seq cohort, compiled from 26 institutions/brain banks in the United States, Europe and Australia. We confirm as the strongest overall FTLD-TDP risk factor and identify as a novel FTLD-TDP risk factor.

Head-to-Head Comparison of Tau and Amyloid Positron Emission Tomography Visual Reads for Differential Diagnosis of Neurodegenerative Disorders: An International, Multicenter Study.

Objective: We compared the accuracy of amyloid and [F]Flortaucipir (FTP) tau positron emission tomography (PET) visual reads for distinguishing patients with mild cognitive impairment (MCI) or dementia with fluid biomarker support of Alzheimer's disease (AD).

Methods: Participants with FTP-PET, amyloid-PET, and diagnosis of dementia-AD (n = 102), MCI-AD (n = 41), non-AD diseases (n = 76), and controls (n = 20) were included. AD status was determined independent of PET by cerebrospinal fluid or plasma biomarkers.

Symptomatic progression of frontotemporal dementia with the I383V variant.

We present a longitudinal description of a man with the I383V variant of frontotemporal dementia (FTD). His progressive changes in behavior and language resulted in a diagnosis of the right temporal variant of FTD, also called the semantic behavioral variant (sbvFTD). We also present data from a small series of patients with the I383V variant who were enrolled in a nationwide FTD research collaboration (ALLFTD).

Development and validation of a nonverbal consensus-based semantic memory paradigm in patients with epilepsy.

Objective: Brain areas implicated in semantic memory can be damaged in patients with epilepsy (PWE). However, it is challenging to delineate semantic processing deficits from acoustic, linguistic, and other verbal aspects in current neuropsychological assessments. We developed a new Visual-based Semantic Association Task (ViSAT) to evaluate nonverbal semantic processing in PWE.

Parallel Encoding of Speech in Human Frontal and Temporal Lobes.

Models of speech perception are centered around a hierarchy in which auditory representations in the thalamus propagate to primary auditory cortex, then to the lateral temporal cortex, and finally through dorsal and ventral pathways to sites in the frontal lobe. However, evidence for short latency speech responses and low-level spectrotemporal representations in frontal cortex raises the question of whether speech-evoked activity in frontal cortex strictly reflects downstream processing from lateral temporal cortex or whether there are direct parallel pathways from the thalamus or primary auditory cortex to the frontal lobe that supplement the traditional hierarchical architecture. Here, we used high-density direct cortical recordings, high-resolution diffusion tractography, and hemodynamic functional connectivity to evaluate for evidence of direct parallel inputs to frontal cortex from low-level areas.

Linking Type and Extent of Head Trauma to Cavum Septum Pellucidum in Older Adults With and Without Alzheimer Disease and Related Dementias.

Background And Objectives: Cavum septum pellucidum (CSP) is a common but nonspecific MRI finding in individuals with prior head trauma. The type and extent of head trauma related to CSP, CSP features specific to head trauma, and the impact of brain atrophy on CSP are unknown. We evaluated CSP cross-sectionally and longitudinally in healthy and clinically impaired older adults who underwent detailed lifetime head trauma characterization.

Discriminating nonfluent/agrammatic and logopenic PPA variants with automatically extracted morphosyntactic measures from connected speech.

Morphosyntactic assessments are important for characterizing individuals with nonfluent/agrammatic variant primary progressive aphasia (nfvPPA). Yet, standard tests are subject to examiner bias and often fail to differentiate between nfvPPA and logopenic variant PPA (lvPPA). Moreover, relevant neural signatures remain underexplored.

Towards a dynamic, comprehensive conceptualization of dyslexia.

Here we build from the central strength of the existing definition of dyslexia-its emphasis on neurobiological origins-and proffer a set of seven core principles for a new, more comprehensive conceptualization of dyslexia. These principles derive from two major research directions: (1) the still evolving history of attempts to explain dyslexia, including in varied writing systems; and (2) the study of the reading brain circuit, its development, and its genetic and environmental influences. What emerges from connecting these two directions is a dynamic conceptualization of dyslexia that incorporates the extensive research on the heterogeneity of dyslexia and the interdependent contributions of multiple biological and socio-cultural risk and preventive factors.