Verbal fluency is a classic neuropsychological measure of language production. Phonological verbal fluency involves the generation of words beginning with a specified letter, and its functional neuroanatomy is comprised of a distributed network of regions which is modulated by cognitive load. In order to investigate the functional relationship of these regions, the effective connectivity was analyzed with covariance structural equation modeling under conditions of varying cognitive load. Significant path coefficients were evident between the anterior cingulate, left middle frontal gyrus, and precuneus. The left middle frontal gyrus showed a facilitory projection to the precuneus which had a suppressive influence on anterior cingulate activation. With increasing cognitive demand, the left middle frontal projection to the precuneus became suppressive, and the path coefficient from the precuneus to the anterior cingulate showed a marked diminution in strength. The path analysis suggests that the lead-in process for letter verbal fluency may primarily involve an orthographic visual strategy. The marked changes in path coefficients with the increased cognitive load may reflect the greater demands placed on executive function. The significant changes in path coefficient values with increased cognitive demand indicate the importance of accounting for task difficulty not only in the interpretation of brain activation maps but also for effective connectivity measurements.
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http://dx.doi.org/10.1016/j.neuroimage.2005.09.035 | DOI Listing |
J Prev Alzheimers Dis
February 2025
Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA.
Background: Recent disease-modifying treatments for Alzheimer's disease show promise to slow cognitive decline, but show no efficacy towards reducing symptoms already manifested.
Objectives: To investigate the efficacy of a novel noninvasive brain stimulation technique in modulating cognitive functioning in Alzheimer's dementia (AD).
Design: Pilot, randomized, double-blind, parallel, sham-controlled study SETTING: Clinical research site at UT Southwestern Medical Center PARTICIPANTS: Twenty-five participants with clinical diagnoses of AD were enrolled from cognition specialty clinics.
Brain Lang
January 2025
Key Laboratory of Brain Functional Genomics (MOE & STCSM), Affiliated Mental Health Center (ECNU), Institute of Brain and Education Innovation, School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China; Shanghai Changning Mental Health Center, Shanghai 200335, China; Shanghai Center for Brain Science and Brain-Inspired Technology, East China Normal University, China; NYU-ECNU Institute of Brain and Cognitive Science, New York University, Shanghai, China. Electronic address:
Hemispheric specialization of different functions is proposed to confer evolutionary benefits, yet the behavioral impacts of lateralization and its cognitive and neural mechanisms remain unclear. This study investigated the effect of lateralization pattern between language and spatial attention on dual-task performance and its association with callosal connectivity. Functional lateralization was assessed using fMRI verbal fluency and landmark tasks, and interhemispheric connections were evaluated through diffusion-weighted imaging.
View Article and Find Full Text PDFAnn Clin Transl Neurol
January 2025
NEUROFARBA Department, Neurosciences Section, University of Florence, Florence, Italy.
Objectives: We aim to investigate cognitive phenotype distribution and MRI correlates across pediatric-, elderly-, and adult-onset MS patients as a function of disease duration.
Methods: In this cross-sectional study, we enrolled 1262 MS patients and 238 healthy controls, with neurological and cognitive assessments. A subset of 222 MS patients and 92 controls underwent 3T-MRI scan for brain atrophy and lesion analysis.
There remains a scarcity of studies to evaluate the treatment effect of electroconvulsive therapy (ECT). Functional near-infrared spectroscopy (fNIRS) offers a cost-effective method to measure cerebral hemodynamics. This study used fNIRS to evaluate the effect of ECT in patients suffering from schizophrenia or bipolar disorder (manic phase).
View Article and Find Full Text PDFBrain Sci
January 2025
Department of Exercise Science and Pre-Health Professions, Creighton University, Omaha, NE 68178, USA.
Background/objectives: We examined the effects of cardiovascular exercise on verbal fluency using a between-groups design.
Methods: Within our experimental (i.e.
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