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Silcox JW, Bennett K, Copeland A, Ferguson SH, Payne BR. The Costs (and Benefits?) of Effortful Listening for Older Adults: Insights from Simultaneous Electrophysiology, Pupillometry, and Memory. J Cogn Neurosci 2024; 36:997-1020. [PMID: 38579256 DOI: 10.1162/jocn_a_02161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Although the impact of acoustic challenge on speech processing and memory increases as a person ages, older adults may engage in strategies that help them compensate for these demands. In the current preregistered study, older adults (n = 48) listened to sentences-presented in quiet or in noise-that were high constraint with either expected or unexpected endings or were low constraint with unexpected endings. Pupillometry and EEG were simultaneously recorded, and subsequent sentence recognition and word recall were measured. Like young adults in prior work, we found that noise led to increases in pupil size, delayed and reduced ERP responses, and decreased recall for unexpected words. However, in contrast to prior work in young adults where a larger pupillary response predicted a recovery of the N400 at the cost of poorer memory performance in noise, older adults did not show an associated recovery of the N400 despite decreased memory performance. Instead, we found that in quiet, increases in pupil size were associated with delays in N400 onset latencies and increased recognition memory performance. In conclusion, we found that transient variation in pupil-linked arousal predicted trade-offs between real-time lexical processing and memory that emerged at lower levels of task demand in aging. Moreover, with increased acoustic challenge, older adults still exhibited costs associated with transient increases in arousal without the corresponding benefits.
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2
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Caffarra S, Kanopka K, Kruper J, Richie-Halford A, Roy E, Rokem A, Yeatman JD. Development of the Alpha Rhythm Is Linked to Visual White Matter Pathways and Visual Detection Performance. J Neurosci 2024; 44:e0684232023. [PMID: 38124006 PMCID: PMC11059423 DOI: 10.1523/jneurosci.0684-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 11/21/2023] [Accepted: 11/29/2023] [Indexed: 12/23/2023] Open
Abstract
Alpha is the strongest electrophysiological rhythm in awake humans at rest. Despite its predominance in the EEG signal, large variations can be observed in alpha properties during development, with an increase in alpha frequency over childhood and adulthood. Here, we tested the hypothesis that these changes in alpha rhythm are related to the maturation of visual white matter pathways. We capitalized on a large diffusion MRI (dMRI)-EEG dataset (dMRI n = 2,747, EEG n = 2,561) of children and adolescents of either sex (age range, 5-21 years old) and showed that maturation of the optic radiation specifically accounts for developmental changes of alpha frequency. Behavioral analyses also confirmed that variations of alpha frequency are related to maturational changes in visual perception. The present findings demonstrate the close link between developmental variations in white matter tissue properties, electrophysiological responses, and behavior.
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Affiliation(s)
- Sendy Caffarra
- Division of Developmental-Behavioral Pediatrics, Stanford University School of Medicine, Stanford 94305, California
- Stanford University Graduate School of Education, Stanford 94305, California
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Klint Kanopka
- Stanford University Graduate School of Education, Stanford 94305, California
| | - John Kruper
- Department of Psychology, University of Washington, Seattle 91905, Washington
- eScience Institute, University of Washington, Seattle 98195-1570, Washington
| | - Adam Richie-Halford
- Division of Developmental-Behavioral Pediatrics, Stanford University School of Medicine, Stanford 94305, California
- Stanford University Graduate School of Education, Stanford 94305, California
| | - Ethan Roy
- Stanford University Graduate School of Education, Stanford 94305, California
| | - Ariel Rokem
- Department of Psychology, University of Washington, Seattle 91905, Washington
- eScience Institute, University of Washington, Seattle 98195-1570, Washington
| | - Jason D Yeatman
- Division of Developmental-Behavioral Pediatrics, Stanford University School of Medicine, Stanford 94305, California
- Stanford University Graduate School of Education, Stanford 94305, California
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3
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An S, Oh SJ, Jun SB, Sung JE. Aging-Related Dissociation of Spatial and Temporal N400 in Sentence-Level Semantic Processing: Evidence From Source Analyses. Front Aging Neurosci 2022; 14:877235. [PMID: 35754967 PMCID: PMC9226558 DOI: 10.3389/fnagi.2022.877235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Age-related differences in sentence-level lexical-semantic processes have been extensively studied, based on the N400 component of event-related potential (ERP). However, there is still a lack of understanding in this regard at the brain-region level. This study explores aging effects on sentence-level semantic processing by comparing the characteristics of the N400 ERP component and brain engagement patterns within individual N400 time windows for two age groups (16 younger adults aged 24.38 ± 3.88 years and 15 older adults aged 67.00 ± 5.04 years) during sentence processing with different plausibility conditions. Our results demonstrated that the N400 effect according to the plausibility condition occurred in different temporal windows in the two age groups, with a delay in the older group. Moreover, it was identified that there was a distinct difference between the groups in terms of the source location of the condition-dependent N400 effect even though no significant difference was derived in its magnitude itself at the sensor-level. Interestingly, the source analysis results indicated that the two groups involved different functional networks to resolve the same semantic violations: the younger group activated the regions corresponding to the typical lexical-semantic network more, whereas the older group recruited the regions belonging to the multiple-demand network more. The findings of this study could be used as a basis for understanding the aging brain in a linguistic context.
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Affiliation(s)
- Sora An
- Department of Communication Disorders, Ewha Womans University, Seoul, South Korea
| | - Se Jin Oh
- Department of Communication Disorders, Ewha Womans University, Seoul, South Korea
| | - Sang Beom Jun
- Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul, South Korea.,Graduate Program in Smart Factory, Ewha Womans University, Seoul, South Korea.,Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul, South Korea
| | - Jee Eun Sung
- Department of Communication Disorders, Ewha Womans University, Seoul, South Korea
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4
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López Zunini RA, Baart M, Samuel AG, Armstrong BC. Lexico-semantic access and audiovisual integration in the aging brain: Insights from mixed-effects regression analyses of event-related potentials. Neuropsychologia 2021; 165:108107. [PMID: 34921819 DOI: 10.1016/j.neuropsychologia.2021.108107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/17/2021] [Accepted: 11/29/2021] [Indexed: 10/19/2022]
Abstract
We investigated how aging modulates lexico-semantic processes in the visual (seeing written items), auditory (hearing spoken items) and audiovisual (seeing written items while hearing congruent spoken items) modalities. Participants were young and older adults who performed a delayed lexical decision task (LDT) presented in blocks of visual, auditory, and audiovisual stimuli. Event-related potentials (ERPs) revealed differences between young and older adults despite older adults' ability to identify words and pseudowords as accurately as young adults. The observed differences included more focalized lexico-semantic access in the N400 time window in older relative to young adults, stronger re-instantiation and/or more widespread activity of the lexicality effect at the time of responding, and stronger multimodal integration for older relative to young adults. Our results offer new insights into how functional neural differences in older adults can result in efficient access to lexico-semantic representations across the lifespan.
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Affiliation(s)
| | - Martijn Baart
- BCBL, Basque Center on Cognition, Brain and Language, San Sebastian, Spain; Tilburg University, Dept. of Cognitive Neuropsychology, Tilburg, the Netherlands
| | - Arthur G Samuel
- BCBL, Basque Center on Cognition, Brain and Language, San Sebastian, Spain; IKERBASQUE, Basque Foundation for Science, Spain; Stony Brook University, Dept. of Psychology, Stony Brook, NY, United States
| | - Blair C Armstrong
- BCBL, Basque Center on Cognition, Brain and Language, San Sebastian, Spain; University of Toronto, Dept. of Psychology and Department of Language Studies, Toronto, ON, Canada
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5
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Caffarra S, Joo SJ, Bloom D, Kruper J, Rokem A, Yeatman JD. Development of the visual white matter pathways mediates development of electrophysiological responses in visual cortex. Hum Brain Mapp 2021; 42:5785-5797. [PMID: 34487405 PMCID: PMC8559498 DOI: 10.1002/hbm.25654] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 12/24/2022] Open
Abstract
The latency of neural responses in the visual cortex changes systematically across the lifespan. Here, we test the hypothesis that development of visual white matter pathways mediates maturational changes in the latency of visual signals. Thirty-eight children participated in a cross-sectional study including diffusion magnetic resonance imaging (MRI) and magnetoencephalography (MEG) sessions. During the MEG acquisition, participants performed a lexical decision and a fixation task on words presented at varying levels of contrast and noise. For all stimuli and tasks, early evoked fields were observed around 100 ms after stimulus onset (M100), with slower and lower amplitude responses for low as compared to high contrast stimuli. The optic radiations and optic tracts were identified in each individual's brain based on diffusion MRI tractography. The diffusion properties of the optic radiations predicted M100 responses, especially for high contrast stimuli. Higher optic radiation fractional anisotropy (FA) values were associated with faster and larger M100 responses. Over this developmental window, the M100 responses to high contrast stimuli became faster with age and the optic radiation FA mediated this effect. These findings suggest that the maturation of the optic radiations over childhood accounts for individual variations observed in the developmental trajectory of visual cortex responses.
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Affiliation(s)
- Sendy Caffarra
- Division of Developmental‐Behavioral PediatricsStanford University School of MedicineStanfordCalifornia
- Stanford University Graduate School of EducationStanfordCalifornia
- Basque Center on Cognition Brain and LanguageSan SebastianSpain
- Department of Biomedical, Metabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModenaItaly
| | - Sung Jun Joo
- Department of PsychologyPusan National UniversityPusanRepublic of Korea
| | - David Bloom
- Department of PsychologyUniversity of WashingtonSeattleWashington
- eScience InstituteUniversity of WashingtonSeattleWashington
| | - John Kruper
- Department of PsychologyUniversity of WashingtonSeattleWashington
- eScience InstituteUniversity of WashingtonSeattleWashington
| | - Ariel Rokem
- Department of PsychologyUniversity of WashingtonSeattleWashington
- eScience InstituteUniversity of WashingtonSeattleWashington
| | - Jason D. Yeatman
- Division of Developmental‐Behavioral PediatricsStanford University School of MedicineStanfordCalifornia
- Stanford University Graduate School of EducationStanfordCalifornia
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Yeske B, Hou J, Adluru N, Nair VA, Prabhakaran V. Differences in Diffusion Tensor Imaging White Matter Integrity Related to Verbal Fluency Between Young and Old Adults. Front Aging Neurosci 2021; 13:750621. [PMID: 34880746 PMCID: PMC8647802 DOI: 10.3389/fnagi.2021.750621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/14/2021] [Indexed: 12/14/2022] Open
Abstract
Throughout adulthood, the brain undergoes an array of structural and functional changes during the typical aging process. These changes involve decreased brain volume, reduced synaptic density, and alterations in white matter (WM). Although there have been some previous neuroimaging studies that have measured the ability of adult language production and its correlations to brain function, structural gray matter volume, and functional differences between young and old adults, the structural role of WM in adult language production in individuals across the life span remains to be thoroughly elucidated. This study selected 38 young adults and 35 old adults for diffusion tensor imaging (DTI) and performed the Controlled Oral Word Association Test to assess verbal fluency (VF). Tract-Based Spatial Statistics were employed to evaluate the voxel-based group differences of diffusion metrics for the values of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and local diffusion homogeneity (LDH) in 12 WM regions of interest associated with language production. To investigate group differences on each DTI metric, an analysis of covariance (ANCOVA) controlling for sex and education level was performed, and the statistical threshold was considered at p < 0.00083 (0.05/60 labels) after Bonferroni correction for multiple comparisons. Significant differences in DTI metrics identified in the ANCOVA were used to perform correlation analyses with VF scores. Compared to the old adults, the young adults had significantly (1) increased FA values on the bilateral anterior corona radiata (ACR); (2) decreased MD values on the right ACR, but increased MD on the left uncinate fasciculus (UF); and (3) decreased RD on the bilateral ACR. There were no significant differences between the groups for AD or LDH. Moreover, the old adults had only a significant correlation between the VF score and the MD on the left UF. There were no significant correlations between VF score and DTI metrics in the young adults. This study adds to the growing body of research that WM areas involved in language production are sensitive to aging.
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Affiliation(s)
- Benjamin Yeske
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, United States
| | - Jiancheng Hou
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, United States
- Center for Cross-Strait Cultural Development, Fujian Normal University, Fuzhou, China
| | - Nagesh Adluru
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, United States
- Waisman Center, University of Wisconsin–Madison, Madison, WI, United States
| | - Veena A. Nair
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, United States
| | - Vivek Prabhakaran
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI, United States
- Department of Psychology, Department of Psychiatry, University of Wisconsin–Madison, Madison, WI, United States
- Neuroscience Training Program, University of Wisconsin–Madison, Madison, WI, United States
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7
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Neudorf J, Kress S, Gould L, Gibb K, Mickleborough M, Borowsky R. Language lateralization differences between left and right temporal lobe epilepsy as measured by overt word reading fMRI activation and DTI structural connectivity. Epilepsy Behav 2020; 112:107467. [PMID: 33181912 DOI: 10.1016/j.yebeh.2020.107467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/18/2020] [Accepted: 08/31/2020] [Indexed: 11/19/2022]
Abstract
In cases of brain disease such as temporal lobe epilepsy (TLE), damage may lead to functional reorganization and a shift in language dominance to homolog regions in the other hemisphere. If the effects of TLE on language dominance are hemisphere-focused, then brain regions and connections involved in word reading should be less left-lateralized in left temporal lobe epilepsy (lTLE) than right temporal lobe epilepsy (rTLE) or healthy controls, and the opposite effect should be observed in patients with rTLE. In our study, functional magnetic resonance imaging (fMRI) showed that patients with rTLE had more strongly lateralized left hemisphere (LH) activation than patients with lTLE and healthy controls in language-related brain regions (pars opercularis and fusiform gyrus (FuG)). Corresponding with this difference, diffusion tensor imaging (DTI) found differences in connectivity indicative of patients with lTLE having greater tract integrity than patients with rTLE in the right hemisphere (RH) uncinate fasciculus (UF), inferior longitudinal fasciculus (ILF), and inferior fronto-occipital fasciculus (IFOF) using the network-based statistic analysis method. The UF, ILF, and IFOF tract integrity have previously been associated with lexical (whole-word) processing abilities. Multivariate distance matrix regression provided converging evidence for regions of the IFOF having different connectivity patterns between groups with lTLE and rTLE. This research demonstrates language lateralization differences between patient groups with lTLE and rTLE, and corresponding differences in the connectivity strength of the ILF, IFOF, and UF. This research provides a novel approach to measuring lateralization of language in general, and the fMRI and DTI findings were integral for guiding the neurosurgeons performing the TLE resections. This approach should inform future studies of language lateralization and language reorganization in patients such as those with TLE.
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Affiliation(s)
- Josh Neudorf
- Department of Psychology, 9 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A5, Canada
| | - Shaylyn Kress
- Department of Psychology, 9 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A5, Canada
| | - Layla Gould
- Division of Neurosurgery, Royal University Hospital, 103 Hospital Drive, Saskatoon, SK S7N 0W8, Canada
| | - Katherine Gibb
- Department of Psychology, 9 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A5, Canada
| | - Marla Mickleborough
- Department of Psychology, 9 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A5, Canada
| | - Ron Borowsky
- Department of Psychology, 9 Campus Drive, University of Saskatchewan, Saskatoon, SK S7N 5A5, Canada.
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Age-related cognitive decline in baboons: modeling the prodromal phase of Alzheimer's disease and related dementias. Aging (Albany NY) 2020; 12:10099-10116. [PMID: 32427127 PMCID: PMC7346018 DOI: 10.18632/aging.103272] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/01/2020] [Indexed: 12/12/2022]
Abstract
The aging of brain cells and synaptic loss are the major underlying pathophysiological processes contributing to the progressive decline in cognitive functions and Alzheimer’s disease. The difference in cognitive performances observed between adult and aged subjects across species highlights the decline of brain systems with age. The inflection point in age-related cognitive decline is important for our understanding of the pathophysiology of neurodegenerative diseases and for timing therapeutic interventions. Humans and nonhuman primates share many similarities including age-dependent changes in gene expression and decline in neural and immune functions. Given these evolutionary conserved organ systems, complex human-like behavioral and age-dependent changes may be modeled and monitored longitudinally in nonhuman primates. We integrated three clinically relevant outcome measures to investigate the effect of age on cognition, motor function and diurnal activity in aged baboons. We provide evidence of a naturally-occurring age-dependent precipitous decline in movement planning, in learning novel tasks, in simple discrimination and in motivation. These results suggest that baboons aged ~20 years (equivalent to ~60 year old humans) may offer a relevant model for the prodromal phase of Alzheimer’s disease and related dementias to investigate mechanisms involved in the precipitous decline in cognitive functions and to develop early therapeutic interventions
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Morrison C, Rabipour S, Taler V, Sheppard C, Knoefel F. Visual Event-Related Potentials in Mild Cognitive Impairment and Alzheimer's Disease: A Literature Review. Curr Alzheimer Res 2020; 16:67-89. [PMID: 30345915 DOI: 10.2174/1567205015666181022101036] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/26/2018] [Accepted: 10/15/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND Cognitive deficits are correlated with increasing age and become more pronounced for people with mild cognitive impairment (MCI) and dementia caused by Alzheimer's disease (AD). Conventional methods to diagnose cognitive decline (i.e., neuropsychological testing and clinical judgment) can lead to false positives. Tools such as electroencephalography (EEG) offer more refined, objective measures that index electrophysiological changes associated with healthy aging, MCI, and AD. OBJECTIVE We sought to review the EEG literature to determine whether visual event-related potentials (ERPs) can distinguish between healthy aging, MCI, and AD. METHOD We searched Medline and PyscInfo for articles published between January 2005 and April 2018. Articles were considered for review if they included participants aged 60+ who were healthy older adults or people with MCI and AD, and examined at least one visually elicited ERP component. RESULTS Our search revealed 880 records, of which 34 satisfied the inclusion criteria. All studies compared cognitive function between at least two of the three groups (healthy older adults, MCI, and AD). The most consistent findings related to the P100 and the P3b; while the P100 showed no differences between groups, the P3b showed declines in amplitude in MCI and AD. CONCLUSION Visually elicited ERPs can offer insight into the cognitive processes that decline in MCI and AD. The P3b may be useful in identifying older adults who may develop MCI and AD, and more research should examine the sensitivity and specificity of this component when diagnosing MCI and AD.
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Affiliation(s)
- Cassandra Morrison
- School of Psychology, University of Ottawa, Canada, & Bruyère Research Institute, Ottawa, Canada
| | - Sheida Rabipour
- School of Psychology, University of Ottawa, Canada, & Bruyère Research Institute, Ottawa, Canada
| | - Vanessa Taler
- School of Psychology, University of Ottawa, Canada, & Bruyère Research Institute, Ottawa, Canada
| | - Christine Sheppard
- Bruyere Research Institute, Ottawa, Canada & School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada
| | - Frank Knoefel
- Faculty of Medicine, University of Ottawa, Canada, Bruyère Research Institute, & Carleton University, Ottawa, Canada
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Xu N, Chen S, Yang Y, Zhu Z. Increased world knowledge in older adults does not prevent decline in world knowledge comprehension: An ERP study. Brain Cogn 2020; 140:105534. [PMID: 32014755 DOI: 10.1016/j.bandc.2020.105534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 12/24/2019] [Accepted: 01/25/2020] [Indexed: 11/24/2022]
Abstract
A meaningful sentence might not be sensible according to world knowledge. In aging, world knowledge continues to increase, but semantic processing declines. An intriguing question is whether increased world knowledge aids world knowledge comprehension, even in the face of declining semantic processing. The present study collected EEG data from 43 older and 43 younger adults as they read correct sentences, sentences with a semantic violation, and sentences with a world knowledge violation. Compared to younger adults, older adults had a significantly greater reduction in amplitude and delayed peak/onset latency of N400 for both semantic and world knowledge integration. A significant Group by Condition by Region interaction revealed that, although the N400 amplitude under the semantic violation condition was comparable to that under the world knowledge violation condition in younger adults, the N400 amplitude in the posterior brain region was significantly smaller under the world knowledge violation condition than under the semantic violation condition in older adults. The N400 difference between world knowledge and semantic violation conditions was negatively correlated only with vocabulary scores. In conclusion, age-related increases in world knowledge do not help older adults to comprehend world knowledge more effectively.
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Affiliation(s)
- Nannan Xu
- School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221009, China
| | - Shiyi Chen
- School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221009, China
| | - Yiming Yang
- School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221009, China; Collaborative Innovation Center for Language Competence, Xuzhou 221009, China; Jiangsu Key Laboratory of Language and Cognitive Neuroscience, Xuzhou 221009, China; Institute of Linguistic Sciences, Jiangsu Normal University, Xuzhou 221009, China.
| | - Zude Zhu
- School of Linguistic Sciences and Arts, Jiangsu Normal University, Xuzhou 221009, China; Collaborative Innovation Center for Language Competence, Xuzhou 221009, China; Jiangsu Key Laboratory of Language and Cognitive Neuroscience, Xuzhou 221009, China; Institute of Linguistic Sciences, Jiangsu Normal University, Xuzhou 221009, China.
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11
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Houston J, Allendorfer J, Nenert R, Goodman AM, Szaflarski JP. White Matter Language Pathways and Language Performance in Healthy Adults Across Ages. Front Neurosci 2019; 13:1185. [PMID: 31736704 PMCID: PMC6838008 DOI: 10.3389/fnins.2019.01185] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 10/21/2019] [Indexed: 12/14/2022] Open
Abstract
The goal of this study was to determine the relationship between age-related white matter changes, with a specific focus on previously identified language pathways, and language functioning in healthy aging. 228 healthy participants (126 female; 146 right-handed), ages 18 to 76, underwent 3.0 Tesla MR diffusion weighted imaging (DWI) and a battery of language assessments including the Boston Naming Test (BNT), the Peabody Picture Vocabulary Test (PPVT), the Controlled Oral Word Association Test (COWAT), Semantic Fluency Test (SFT), and a subset of the Boston Diagnostic Aphasia Examination (CI-BDAE). Using tract based spatial statistics (TBSS), we investigated measurements of fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD). TBSS was used to create a white matter skeleton that was then used to analyze white matter changes (indexed by FA, AD, RD, and MD) with age and language performance. Results focused primarily on significant relationships (p < 0.05, cluster-wise FDR corrected for multiple comparisons) in the canonical language white matter pathways. We found a diffuse linear decrease with age in global white matter FA and a significant focal increase in FA with age within the bilateral superior cerebellar peduncles (SCPs). We observed that increased BNT scores were associated with increased FA within the left SLF, and within the posterior and antero-lateral portions of the right inferior frontal-occipital fasciculus (IFOF). Increased SFT and PPVT scores were associated with increased FA within the posterior portion of the right IFOF and increased FA within the left body of the corpus callosum was associated with lower COWAT scores. We found no association between FA and BDAE. MD, RD, and AD, were found to be inversely proportional to FA within the IFOF, with AD showing a negative correlation with SFT, and RD and MD showing a negative correlation with BNT. There was no association between CI-BDAE and any of the white matter measures. Significant differences between sexes included more pronounced FA decrease with age within the right SLF in males vs. females; there were no differences in language performance scores between sexes. We also found that there was no decline in language testing scores with increasing age in our cohort. Taken together, our findings of varying relationships between DTI metrics and language function within multiple regions of the non-dominant IFOF suggest that more robust language networks with bilateral structural connectivity may contribute to better overall language functioning, regardless of age.
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Affiliation(s)
- James Houston
- Department of Neurology, UAB Epilepsy Center, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jane Allendorfer
- Department of Neurology, UAB Epilepsy Center, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Rodolph Nenert
- Department of Neurology, UAB Epilepsy Center, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Adam M. Goodman
- Department of Neurology, UAB Epilepsy Center, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jerzy P. Szaflarski
- Department of Neurology, UAB Epilepsy Center, The University of Alabama at Birmingham, Birmingham, AL, United States
- Departments of Neurosurgery and Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, United States
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12
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Payne BR, Silcox JW. Aging, context processing, and comprehension. PSYCHOLOGY OF LEARNING AND MOTIVATION 2019. [DOI: 10.1016/bs.plm.2019.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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13
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Zhu Z, Yang F, Li D, Zhou L, Liu Y, Zhang Y, Chen X. Age-related reduction of adaptive brain response during semantic integration is associated with gray matter reduction. PLoS One 2017; 12:e0189462. [PMID: 29236772 PMCID: PMC5728512 DOI: 10.1371/journal.pone.0189462] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/28/2017] [Indexed: 11/18/2022] Open
Abstract
While aging is associated with increased knowledge, it is also associated with decreased semantic integration. To investigate brain activation changes during semantic integration, a sample of forty-eight 25–75 year-old adults read sentences with high cloze (HC) and low cloze (LC) probability while functional magnetic resonance imaging was conducted. Significant age-related reduction of cloze effect (LC vs. HC) was found in several regions, especially the left middle frontal gyrus (MFG) and right inferior frontal gyrus (IFG), which play an important role in semantic integration. Moreover, when accounting for global gray matter volume reduction, the age-cloze correlation in the left MFG and right IFG was absent. The results suggest that brain structural atrophy may disrupt brain response in aging brains, which then show less brain engagement in semantic integration.
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Affiliation(s)
- Zude Zhu
- School of Linguistics Sciences and Arts, and Collaborative Innovation Center for Language Competence, Jiangsu Normal University, Xuzhou, China
- * E-mail: (ZZ); (XC)
| | | | | | | | - Ying Liu
- Ningcheng Central Hospital, Chifeng, China
| | - Ying Zhang
- Sucheng People’s Hospital, Suqian, China
| | - Xuezhi Chen
- Ningcheng Central Hospital, Chifeng, China
- * E-mail: (ZZ); (XC)
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14
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Zhu Y, Wang L, Xi Y, Dai T, Fei N, Liu L, Xu Z, Yang X, Fu C, Sun J, Xu J, Shi D, Tian J, Yin H, Qin W. White Matter Microstructural Properties are Related to Inter-Individual Differences in Cognitive Instability after Sleep Deprivation. Neuroscience 2017; 365:206-216. [DOI: 10.1016/j.neuroscience.2017.09.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Revised: 09/22/2017] [Accepted: 09/25/2017] [Indexed: 12/24/2022]
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15
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Kielar A, Deschamps T, Jokel R, Meltzer JA. Functional reorganization of language networks for semantics and syntax in chronic stroke: Evidence from MEG. Hum Brain Mapp 2016; 37:2869-93. [PMID: 27091757 DOI: 10.1002/hbm.23212] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/29/2016] [Accepted: 04/04/2016] [Indexed: 11/09/2022] Open
Abstract
Using magnetoencephalography, we investigated the potential of perilesional and contralesional activity to support language recovery in patients with poststroke aphasia. In healthy young controls, left-lateralized ventral frontotemporal regions responded to semantic anomalies during sentence comprehension and bilateral dorsal frontoparietal regions responded to syntactic anomalies. Older adults showed more extensive bilateral responses to the syntactic anomalies and less lateralized responses to the semantic anomalies, with decreased activation in the left occipital and parietal regions for both semantic and syntactic anomalies. In aphasic participants, we observed compensatory recruitment in the right hemisphere (RH), which varied depending on the type of linguistic information that was processed. For semantic anomalies, aphasic patients activated some preserved left hemisphere regions adjacent to the lesion, as well as homologous parietal and temporal RH areas. Patients also recruited right inferior and dorsolateral frontal cortex that was not activated in the healthy participants. Responses for syntactic anomalies did not reach significance in patients. Correlation analyses indicated that recruitment of homologous temporoparietal RH areas is associated with better semantic performance, whereas higher accuracy on the syntactic task was related to bilateral superior temporoparietal and right frontal activity. The results suggest that better recovery of semantic processing is associated with a shift to ventral brain regions in the RH. In contrast, preservation of syntactic processing is mediated by dorsal areas, bilaterally, although recovery of syntactic processing tends to be poorer than semantic. Hum Brain Mapp 37:2869-2893, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Aneta Kielar
- Rotman Research Institute, Baycrest Health Sciences Toronto, Toronto, Ontario, Canada.,Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada
| | - Tiffany Deschamps
- Rotman Research Institute, Baycrest Health Sciences Toronto, Toronto, Ontario, Canada
| | - Regina Jokel
- Rotman Research Institute, Baycrest Health Sciences Toronto, Toronto, Ontario, Canada.,Department of Speech-Language Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Jed A Meltzer
- Rotman Research Institute, Baycrest Health Sciences Toronto, Toronto, Ontario, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada.,Department of Speech-Language Pathology, University of Toronto, Toronto, Ontario, Canada.,Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada
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16
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Karunamuni R, Bartsch H, White NS, Moiseenko V, Carmona R, Marshall DC, Seibert TM, McDonald CR, Farid N, Krishnan A, Kuperman J, Mell L, Brewer JB, Dale AM, Hattangadi-Gluth JA. Dose-Dependent Cortical Thinning After Partial Brain Irradiation in High-Grade Glioma. Int J Radiat Oncol Biol Phys 2016; 94:297-304. [PMID: 26853338 PMCID: PMC4747044 DOI: 10.1016/j.ijrobp.2015.10.026] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/28/2015] [Accepted: 10/13/2015] [Indexed: 11/21/2022]
Abstract
PURPOSE Radiation-induced cognitive deficits may be mediated by tissue damage to cortical regions. Volumetric changes in cortex can be reliably measured using high-resolution magnetic resonance imaging (MRI). We used these methods to study the association between radiation therapy (RT) dose and change in cortical thickness in high-grade glioma (HGG) patients. METHODS AND MATERIALS We performed a voxel-wise analysis of MRI from 15 HGG patients who underwent fractionated partial brain RT. Three-dimensional MRI was acquired pre- and 1 year post RT. Cortex was parceled with well-validated segmentation software. Surgical cavities were censored. Each cortical voxel was assigned a change in cortical thickness between time points, RT dose value, and neuroanatomic label by lobe. Effects of dose, neuroanatomic location, age, and chemotherapy on cortical thickness were tested using linear mixed effects (LME) modeling. RESULTS Cortical atrophy was seen after 1 year post RT with greater effects at higher doses. Estimates from LME modeling showed that cortical thickness decreased by -0.0033 mm (P<.001) for every 1-Gy increase in RT dose. Temporal and limbic cortex exhibited the largest changes in cortical thickness per Gy compared to that in other regions (P<.001). Age and chemotherapy were not significantly associated with change in cortical thickness. CONCLUSIONS We found dose-dependent thinning of the cerebral cortex, with varying neuroanatomical regional sensitivity, 1 year after fractionated partial brain RT. The magnitude of thinning parallels 1-year atrophy rates seen in neurodegenerative diseases and may contribute to cognitive decline following high-dose RT.
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Affiliation(s)
- Roshan Karunamuni
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California
| | - Hauke Bartsch
- Department of Radiology, University of California San Diego, La Jolla, California
| | - Nathan S White
- Department of Radiology, University of California San Diego, La Jolla, California
| | - Vitali Moiseenko
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California
| | - Ruben Carmona
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California
| | - Deborah C Marshall
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California
| | - Tyler M Seibert
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California
| | - Carrie R McDonald
- Department of Psychiatry, University of California San Diego, La Jolla, California
| | - Nikdokht Farid
- Department of Radiology, University of California San Diego, La Jolla, California
| | - Anithapriya Krishnan
- Department of Radiology, University of California San Diego, La Jolla, California
| | - Joshua Kuperman
- Department of Radiology, University of California San Diego, La Jolla, California
| | - Loren Mell
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California
| | - James B Brewer
- Department of Radiology, University of California San Diego, La Jolla, California
| | - Anders M Dale
- Department of Radiology, University of California San Diego, La Jolla, California
| | - Jona A Hattangadi-Gluth
- Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
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17
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Lacombe J, Jolicoeur P, Grimault S, Pineault J, Joubert S. Neural changes associated with semantic processing in healthy aging despite intact behavioral performance. BRAIN AND LANGUAGE 2015; 149:118-127. [PMID: 26282079 DOI: 10.1016/j.bandl.2015.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/29/2015] [Accepted: 07/06/2015] [Indexed: 06/04/2023]
Abstract
Semantic memory recruits an extensive neural network including the left inferior prefrontal cortex (IPC) and the left temporoparietal region, which are involved in semantic control processes, as well as the anterior temporal lobe region (ATL) which is considered to be involved in processing semantic information at a central level. However, little is known about the underlying neuronal integrity of the semantic network in normal aging. Young and older healthy adults carried out a semantic judgment task while their cortical activity was recorded using magnetoencephalography (MEG). Despite equivalent behavioral performance, young adults activated the left IPC to a greater extent than older adults, while the latter group recruited the temporoparietal region bilaterally and the left ATL to a greater extent than younger adults. Results indicate that significant neuronal changes occur in normal aging, mainly in regions underlying semantic control processes, despite an apparent stability in performance at the behavioral level.
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Affiliation(s)
- Jacinthe Lacombe
- Département de psychologie, Université de Montréal, Pavillon Marie-Victorin, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; CERNEC, Université de Montréal, Pavillon Marie-Victorin, Département de psychologie, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), 4565 Chemin Queen-Mary, Montréal, Québec H3W 1W5, Canada.
| | - Pierre Jolicoeur
- Département de psychologie, Université de Montréal, Pavillon Marie-Victorin, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; CERNEC, Université de Montréal, Pavillon Marie-Victorin, Département de psychologie, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), 4565 Chemin Queen-Mary, Montréal, Québec H3W 1W5, Canada; International Laboratory for Brain, Music and Sound Research (BRAMS), Pavillon 1420 Mont-Royal, FAS - Département de psychologie, C.P. 6128, succ Centre-ville, Montréal, Québec H3C 3J7, Canada
| | - Stephan Grimault
- Département de psychologie, Université de Montréal, Pavillon Marie-Victorin, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; CERNEC, Université de Montréal, Pavillon Marie-Victorin, Département de psychologie, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; Centre national de la recherche scientifique (CNRS), 3 rue Michel-Ange 75794, Paris cedex 16, France
| | - Jessica Pineault
- Département de psychologie, Université de Montréal, Pavillon Marie-Victorin, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; CERNEC, Université de Montréal, Pavillon Marie-Victorin, Département de psychologie, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), 4565 Chemin Queen-Mary, Montréal, Québec H3W 1W5, Canada
| | - Sven Joubert
- Département de psychologie, Université de Montréal, Pavillon Marie-Victorin, C.P. 6128, succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada; Centre de recherche de l'Institut universitaire de gériatrie de Montréal (CRIUGM), 4565 Chemin Queen-Mary, Montréal, Québec H3W 1W5, Canada.
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18
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Braverman ER, Blum K, Hussman KL, Han D, Dushaj K, Li M, Marin G, Badgaiyan RD, Smayda R, Gold MS. Evoked Potentials and Memory/Cognition Tests Validate Brain Atrophy as Measured by 3T MRI (NeuroQuant) in Cognitively Impaired Patients. PLoS One 2015; 10:e0133609. [PMID: 26244349 PMCID: PMC4526533 DOI: 10.1371/journal.pone.0133609] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 06/29/2015] [Indexed: 11/30/2022] Open
Abstract
To our knowledge, this is the largest study evaluating relationships between 3T Magnetic Resonance Imaging (MRI) and P300 and memory/cognitive tests in the literature. The 3T MRI using NeuroQuant has an increased resolution 15 times that of 1.5T MRI. Utilizing NeuroQuant 3T MRI as a diagnostic tool in primary care, subjects (N=169; 19–90 years) displayed increased areas of anatomical atrophy: 34.62% hippocampal atrophy (N=54), 57.14% central atrophy (N=88), and 44.52% temporal atrophy (N=69). A majority of these patients exhibited overlap in measured areas of atrophy and were cognitively impaired. These results positively correlated with decreased P300 values and WMS-III (WMS-III) scores differentially across various brain loci. Delayed latency (p=0.0740) was marginally associated with temporal atrophy; reduced fractional anisotropy (FA) in frontal lobes correlated with aging, delayed P300 latency, and decreased visual and working memory (p=0.0115). Aging and delayed P300 latency correlated with lower FA. The correlation between working memory and reduced FA in frontal lobes is marginally significant (p=0.0787). In the centrum semiovale (CS), reduced FA correlated with visual memory (p=0.0622). Lower demyelination correlated with higher P300 amplitude (p=0.0002). Compared to males, females have higher demyelination (p=0.0064). Along these lines, the higher the P300 amplitude, the lower the bilateral atrophy (p=0.0165). Hippocampal atrophy correlated with increased auditory memory and gender, especially in males (p=0.0087). In considering temporal lobe atrophy correlations: delayed P300 latency and high temporal atrophy (p=0.0740); high auditory memory and low temporal atrophy (p=0.0417); and high working memory and low temporal atrophy (p=0.0166). Central atrophy correlated with aging and immediate memory (p=0.0294): the higher the immediate memory, the lower the central atrophy. Generally, the validation of brain atrophy by P300 and WMS-III could lead to cost-effective methods utilizable in primary care medicine following further confirmation.
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Affiliation(s)
- Eric R. Braverman
- Department of Psychiatry, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida, United States of America
- Department of Clinical Neurology, PATH Foundation NY, New York, New York, United States of America
- * E-mail:
| | - Kenneth Blum
- Department of Psychiatry, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida, United States of America
- Department of Clinical Neurology, PATH Foundation NY, New York, New York, United States of America
- Human Integrated Services, University of Vermont, Center for Clinical and Translational Science, College of Medicine, Burlington, Vermont, United States of America
- Department of Addiction Services, Dominion Diagnostics, LLC., North Kingstown, Rhode Island, United States of America
| | - Karl L. Hussman
- Alpha 3T MRI & Diagnostic Imaging, New York, New York, United States of America
| | - David Han
- Department of Management Science and Statistics, University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Kristina Dushaj
- Department of Clinical Neurology, PATH Foundation NY, New York, New York, United States of America
| | - Mona Li
- Department of Clinical Neurology, PATH Foundation NY, New York, New York, United States of America
| | - Gabriela Marin
- Department of Clinical Neurology, PATH Foundation NY, New York, New York, United States of America
| | - Rajendra D. Badgaiyan
- Department of Psychiatry, Neuroimaging Center, University Of Minnesota School of Medicine, Minneapolis, Minnesota, United States of America
| | - Richard Smayda
- Department of Clinical Neurology, PATH Foundation NY, New York, New York, United States of America
| | - Mark S. Gold
- Department of Psychiatry, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida, United States of America
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Tsolaki A, Kosmidou V, Hadjileontiadis L, Kompatsiaris I(Y, Tsolaki M. Brain source localization of MMN, P300 and N400: Aging and gender differences. Brain Res 2015; 1603:32-49. [DOI: 10.1016/j.brainres.2014.10.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 09/28/2014] [Accepted: 10/01/2014] [Indexed: 12/29/2022]
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20
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Goubran M, Hammond RR, de Ribaupierre S, Burneo JG, Mirsattari S, Steven DA, Parrent AG, Peters TM, Khan AR. Magnetic resonance imaging and histology correlation in the neocortex in temporal lobe epilepsy. Ann Neurol 2014; 77:237-50. [PMID: 25424188 DOI: 10.1002/ana.24318] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 11/17/2014] [Accepted: 11/18/2014] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To investigate the histopathological correlates of quantitative relaxometry and diffusion tensor imaging (DTI) and to determine their efficacy in epileptogenic lesion detection for preoperative evaluation of focal epilepsy. METHODS We correlated quantitative relaxometry and DTI with histological features of neuronal density and morphology in 55 regions of the temporal lobe neocortex, selected from 13 patients who underwent epilepsy surgery. We made use of a validated nonrigid image registration protocol to obtain accurate correspondences between in vivo magnetic resonance imaging and histology images. RESULTS We found T1 to be a predictor of neuronal density in the neocortical gray matter (GM) using linear mixed effects models with random effects for subjects. Fractional anisotropy (FA) was a predictor of neuronal density of large-caliber neurons only (pyramidal cells, layers 3 and 5). Comparing multivariate to univariate mixed effects models with nested variables demonstrated that employing T1 and FA together provided a significantly better fit than T1 or FA alone in predicting density of large-caliber neurons. Correlations with clinical variables revealed significant positive correlations between neuronal density and age (rs = 0.726, pfwe = 0.021). This study is the first to relate in vivo T1 and FA values to the proportion of neurons in GM. INTERPRETATION Our results suggest that quantitative T1 mapping and DTI may have a role in preoperative evaluation of focal epilepsy and can be extended to identify GM pathology in a variety of neurological disorders.
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Affiliation(s)
- Maged Goubran
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; Biomedical Engineering Graduate Program, London, Ontario, Canada
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