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McMurdo Dry Valley lake edge ‘moats’: the ecological intersection between terrestrial and aquatic polar desert habitats
- Michael S. Stone, Shawn P. Devlin, Ian Hawes, Kathleen A. Welch, Michael N. Gooseff, Cristina Takacs-Vesbach, Rachael Morgan-Kiss, Byron J. Adams, J.E. Barrett, John C. Priscu, Peter T. Doran
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- Antarctic Science , First View
- Published online by Cambridge University Press:
- 19 April 2024, pp. 1-17
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Aquatic ecosystems - lakes, ponds and streams - are hotspots of biodiversity in the cold and arid environment of Continental Antarctica. Environmental change is expected to increasingly alter Antarctic aquatic ecosystems and modify the physical characteristics and interactions within the habitats that they support. Here, we describe physical and biological features of the peripheral ‘moat’ of a closed-basin Antarctic lake. These moats mediate connectivity amongst streams, lake and soils. We highlight the cyclical moat transition from a frozen winter state to an active open-water summer system, through refreeze as winter returns. Summer melting begins at the lakebed, initially creating an ice-constrained lens of liquid water in November, which swiftly progresses upwards, creating open water in December. Conversely, freezing progresses slowly from the water surface downwards, with water at 1 m bottom depth remaining liquid until May. Moats support productive, diverse benthic communities that are taxonomically distinct from those under the adjacent permanent lake ice. We show how ion ratios suggest that summer exchange occurs amongst moats, streams, soils and sub-ice lake water, perhaps facilitated by within-moat density-driven convection. Moats occupy a small but dynamic area of lake habitat, are disproportionately affected by recent lake-level rises and may thus be particularly vulnerable to hydrological change.
A comprehensive hierarchical comparison of structural connectomes in Major Depressive Disorder cases v. controls in two large population samples
- Gladi Thng, Xueyi Shen, Aleks Stolicyn, Mark J. Adams, Hon Wah Yeung, Venia Batziou, Eleanor L. S. Conole, Colin R. Buchanan, Stephen M. Lawrie, Mark E. Bastin, Andrew M. McIntosh, Ian J. Deary, Elliot M. Tucker-Drob, Simon R. Cox, Keith M. Smith, Liana Romaniuk, Heather C. Whalley
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- Psychological Medicine , First View
- Published online by Cambridge University Press:
- 18 March 2024, pp. 1-12
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Background
The brain can be represented as a network, with nodes as brain regions and edges as region-to-region connections. Nodes with the most connections (hubs) are central to efficient brain function. Current findings on structural differences in Major Depressive Disorder (MDD) identified using network approaches remain inconsistent, potentially due to small sample sizes. It is still uncertain at what level of the connectome hierarchy differences may exist, and whether they are concentrated in hubs, disrupting fundamental brain connectivity.
MethodsWe utilized two large cohorts, UK Biobank (UKB, N = 5104) and Generation Scotland (GS, N = 725), to investigate MDD case–control differences in brain network properties. Network analysis was done across four hierarchical levels: (1) global, (2) tier (nodes grouped into four tiers based on degree) and rich club (between-hub connections), (3) nodal, and (4) connection.
ResultsIn UKB, reductions in network efficiency were observed in MDD cases globally (d = −0.076, pFDR = 0.033), across all tiers (d = −0.069 to −0.079, pFDR = 0.020), and in hubs (d = −0.080 to −0.113, pFDR = 0.013–0.035). No differences in rich club organization and region-to-region connections were identified. The effect sizes and direction for these associations were generally consistent in GS, albeit not significant in our lower-N replication sample.
ConclusionOur results suggest that the brain's fundamental rich club structure is similar in MDD cases and controls, but subtle topological differences exist across the brain. Consistent with recent large-scale neuroimaging findings, our findings offer a connectomic perspective on a similar scale and support the idea that minimal differences exist between MDD cases and controls.
Summary of Recommendations of Nomenclature Committees Relevant to Clay Mineralogy: Report of the Association Internationale Pour l’Etude Des Argiles (AIPEA) Nomenclature Committee for 2006
- S. Guggenheim, J. M. Adams, D. C. Bain, F. Bergaya, M. F. Brigatti, V. A. Drits, M. L. L. Formoso, E. Galán, T. Kogure, H. Stanjek
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- Clays and Clay Minerals / Volume 54 / Issue 6 / December 2006
- Published online by Cambridge University Press:
- 01 January 2024, pp. 761-772
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Helium as a Surrogate for Deuterium in LPI Studies
- Matthias Geissel, Adam J. Harvey-Thompson, Matthew R. Weis, Jeffrey R. Fein, David Ampleford, David E. Bliss, Aaron M. Hansen, Christopher Jennings, Mark W. Kimmel, Patrick Rambo, Jonathon E. Shores, Ian C. Smith, C. Shane Speas, John L. Porter, Fabrizio Consoli
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- Laser and Particle Beams / Volume 2023 / 2023
- Published online by Cambridge University Press:
- 01 January 2024, e2
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Helium or neopentane can be used as surrogate gas fill for deuterium (D2) or deuterium-tritium (DT) in laser-plasma interaction studies. Surrogates are convenient to avoid flammability hazards or the integration of cryogenics in an experiment. To test the degree of equivalency between deuterium and helium, experiments were conducted in the Pecos target chamber at Sandia National Laboratories. Observables such as laser propagation and signatures of laser-plasma instabilities (LPI) were recorded for multiple laser and target configurations. It was found that some observables can differ significantly despite the apparent similarity of the gases with respect to molecular charge and weight. While a qualitative behaviour of the interaction may very well be studied by finding a suitable compromise of laser absorption, electron density, and LPI cross sections, a quantitative investigation of expected values for deuterium fills at high laser intensities is not likely to succeed with surrogate gases.
Erratum to: Summary of recommendations of nomenclature committees relevant to Clay mineralogy: Report of the Association Internationale pour l’etude des argiles (AIPEA) Nomenclature Committee for 2006
- S. Guggenheim, J. M. Adams, D. C. Bain, F. Bergaya, M. F. Brigatti, V. A. Drits, M. L. L. Formoso, E. Galán, T. Kogure, H. Stanjek
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- Clays and Clay Minerals / Volume 55 / Issue 6 / December 2007
- Published online by Cambridge University Press:
- 01 January 2024, pp. 646-647
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Increasing the equitability of data citation in paleontology: capacity building for the big data future
- Jansen A. Smith, Nussaïbah B. Raja, Thomas Clements, Danijela Dimitrijević, Elizabeth M. Dowding, Emma M. Dunne, Bryan M. Gee, Pedro L. Godoy, Elizabeth M. Lombardi, Laura P. A. Mulvey, Paulina S. Nätscher, Carl J. Reddin, Bryan Shirley, Rachel C. M. Warnock, Ádám T. Kocsis
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- Paleobiology , First View
- Published online by Cambridge University Press:
- 28 December 2023, pp. 1-12
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Data compilations expand the scope of research; however, data citation practice lags behind advances in data use. It remains uncommon for data users to credit data producers in professionally meaningful ways. In paleontology, databases like the Paleobiology Database (PBDB) enable assessment of patterns and processes spanning millions of years, up to global scale. The status quo for data citation creates an imbalance wherein publications drawing data from the PBDB receive significantly more citations (median: 4.3 ± 3.5 citations/year) than the publications producing the data (1.4 ± 1.3 citations/year). By accounting for data reuse where citations were neglected, the projected citation rate for data-provisioning publications approached parity (4.2 ± 2.2 citations/year) and the impact factor of paleontological journals (n = 55) increased by an average of 13.4% (maximum increase = 57.8%) in 2019. Without rebalancing the distribution of scientific credit, emerging “big data” research in paleontology—and science in general—is at risk of undercutting itself through a systematic devaluation of the work that is foundational to the discipline.
3 Two Dominant Post-COVID Subtypes in Patients Seeking Treatment for “Brain Fog” Through a Post-COVID Treatment Clinic
- Kristine Lokken, Jamie Hansel Robinson, Richard Kennedy, David E Vance, Ronald M Lazar, Roy C Martin, Melissa J Greenfield, Pariya F Wheeler, Adam Gerstenecker
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 876-877
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Objective:
To examine patterns of cognitive function among a clinical sample of patients seeking treatment for Post-Acute Sequelae of COVID-19 (PASC).
Participants and Methods:One hundred nineteen patients each completed a baseline neuropsychological evaluation, including clinical diagnostic interview, cognitive assessments, and a comprehensive battery of self-report questionnaires. Patients had a mean age of 50 years (range:18 to 74, SD=10.1) and a mean of 15.5 years (SD=2.54) of formal education. Patients were primarily female (74%) and of White/Caucasian race (75%). Hierarchical agglomerative clustering was used to partition the data into groups based on cognitive performance. Euclidean distance was used as the similarity measure for the continuous variables and within-cluster variance was minimized using Ward’s method. The optimal number of clusters was determined empirically by fitting models with 1 to 15 clusters, with the best number of clusters selected using the silhouette index. All analyses were conducted using the NbClust package, an R package for determining the relevant number of clusters in a data set.
Results:Clustering yielded two distinct clusters of cognitive performance. Group 1 (n=57) performed worse than Group 2 (n=62) on most cognitive variables (including a brief cognitive screener and tests of attention/working memory, executive function, processing speed, learning and delayed recall). Of note, there were no significant differences between groups on an infection severity scale, hospitalizations/ICU admissions, initial or current COVID-19 symptoms, or prior comorbidities. Groups did not differ in age or gender, but Group 1 had a lower education level than Group 2 (M=14.7, SD=2.45 vs. M=16.2, SD=2.42; p=.001). Group 1 also had significantly more minorities than Group 2 (40% vs. 8%; p<.001). No other demographic differences (income, living arrangement, or marital status) were observed. In comparison to Group 2 patients, Group 1 patients self-reported significantly higher levels of anxiety and depression and functional impairment (Functional Activities Questionnaire: M=11.3, SD=8.33 vs. M=7.65, SD=7.97), perceived stress (Perceived Stress Scale: M=24.7, SD=7.90 vs. M=20.3, SD=7.89), insomnia (Insomnia Severity Index: M=16.0, SD=6.50 vs. M=13.1, SD=6.76), and subjective cognitive functioning (Cognitive Failures Questionnaire: M=58.8, SD=16.9 vs. M=50.3, SD=18.6; p’s<.05).
Conclusions:Findings indicate two predominant subtypes of patients seeking treatment for PASC, with one group presenting as more cognitively impaired and reporting greater levels of anxiety, depression, insomnia, perceived stress, functional limitations, and subjective cognitive impairment. Future directions include follow-up assessments with these patients to determine cognitive trajectories over time and tailoring treatment adjuncts to address mood symptoms, insomnia, functional ability, and lifestyle variables. Understanding mechanisms of differences in cognitive and affective symptoms is needed in future work. Limitations to the study were that patients were referred for evaluation based on the complaint of “brain fog” and the sample was a homogenous, highly educated, younger group of individuals who experienced generally mild COVID-19 course.
6 Remote Smartphone Cognitive and Motor Testing in Frontotemporal Dementia Research: Feasibility, Reliability, and Validity
- Adam M Staffaroni, Jack Carson Taylor, Annie L Clark, Hilary W Heuer, Amy B Wise, Masood Manoochehri, Leah Forsberg, Carly T Mester, Meghana Roa, Danielle Brushaber, Julio C Rojas, Joel H Kramer, Bradley F Boeve, Howard J Rosen, Adam L Boxer
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- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 604-605
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Objective:
Therapeutics targeting frontotemporal dementia (FTD) are entering clinical trials. There are challenges to conducting these studies, including the relative rarity of the disease. Remote assessment tools could increase access to clinical research and pave the way for decentralized clinical trials. We developed the ALLFTD Mobile App, a smartphone application that includes assessments of cognition, speech/language, and motor functioning. The objectives were to determine the feasibility and acceptability of collecting remote smartphone data in a multicenter FTD research study and evaluate the reliability and validity of the smartphone cognitive and motor measures.
Participants and Methods:A diagnostically mixed sample of 207 participants with FTD or from familial FTD kindreds (CDR®+NACC-FTLD=0 [n=91]; CDR®+NACC-FTLD=0.5 [n=39]; CDR®+NACC-FTLD>1 [n=39]; unknown [n=38]) were asked to remotely complete a battery of tests on their smartphones three times over two weeks. Measures included five executive functioning (EF) tests, an adaptive memory test, and participant experience surveys. A subset completed smartphone tests of balance at home (n=31) and a finger tapping test (FTT) in the clinic (n=11). We analyzed adherence (percentage of available measures that were completed) and user experience. We evaluated Spearman-Brown split-half reliability (100 iterations) using the first available assessment for each participant. We assessed test-retest reliability across all available assessments by estimating intraclass correlation coefficients (ICC). To investigate construct validity, we fit regression models testing the association of the smartphone measures with gold-standard neuropsychological outcomes (UDS3-EF composite [Staffaroni et al., 2021], CVLT3-Brief Form [CVLT3-BF] Immediate Recall, mechanical FTT), measures of disease severity (CDR®+NACC-FTLD Box Score & Progressive Supranuclear Palsy Rating Scale [PSPRS]), and regional gray matter volumes (cognitive tests only).
Results:Participants completed 70% of tasks. Most reported that the instructions were understandable (93%), considered the time commitment acceptable (97%), and were willing to complete additional assessments (98%). Split-half reliability was excellent for the executive functioning (r’s=0.93-0.99) and good for the memory test (r=0.78). Test-retest reliabilities ranged from acceptable to excellent for cognitive tasks (ICC: 0.70-0.96) and were excellent for the balance (ICC=0.97) and good for FTT (ICC=0.89). Smartphone EF measures were strongly associated with the UDS3-EF composite (ß's=0.6-0.8, all p<.001), and the memory test was strongly correlated with total immediate recall on the CVLT3-BF (ß=0.7, p<.001). Smartphone FTT was associated with mechanical FTT (ß=0.9, p=.02), and greater acceleration on the balance test was associated with more motor features (ß=0.6, p=0.02). Worse performance on all cognitive tests was associated with greater disease severity (ß's=0.5-0.7, all p<.001). Poorer performance on the smartphone EF tasks was associated with smaller frontoparietal/subcortical volume (ß's=0.4-0.6, all p<.015) and worse memory scores with smaller hippocampal volume (ß=0.5, p<.001).
Conclusions:These results suggest remote digital data collection of cognitive and motor functioning in FTD research is feasible and acceptable. These findings also support the reliability and validity of unsupervised ALLFTD Mobile App cognitive tests and provide preliminary support for the motor measures, although further study in larger samples is required.
61 Network Segregation Predicts Processing Speed in the Cognitively Healthy Oldest-old
- Sara A Nolin, Mary E Faulkner, Paul Stewart, Leland Fleming, Stacy Merritt, Roxanne F Rezaei, Pradyumna K Bharadwaj, Mary Kathryn Franchetti, Daniel A Raichlen, Courtney J Jessup, Lloyd Edwards, G Alex Hishaw, Emily J Van Etten, Theodore P Trouard, David S Geldmacher, Virginia G Wadley, Noam Alperin, Eric C Porges, Adam J Woods, Ronald A Cohen, Bonnie E Levin, Tatjana Rundek, Gene E Alexander, Kristina M Visscher
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 367-368
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Objective:
Understanding the factors contributing to optimal cognitive function throughout the aging process is essential to better understand successful cognitive aging. Processing speed is an age sensitive cognitive domain that usually declines early in the aging process; however, this cognitive skill is essential for other cognitive tasks and everyday functioning. Evaluating brain network interactions in cognitively healthy older adults can help us understand how brain characteristics variations affect cognitive functioning. Functional connections among groups of brain areas give insight into the brain’s organization, and the cognitive effects of aging may relate to this large-scale organization. To follow-up on our prior work, we sought to replicate our findings regarding network segregation’s relationship with processing speed. In order to address possible influences of node location or network membership we replicated the analysis across 4 different node sets.
Participants and Methods:Data were acquired as part of a multi-center study of 85+ cognitively normal individuals, the McKnight Brain Aging Registry (MBAR). For this analysis, we included 146 community-dwelling, cognitively unimpaired older adults, ages 85-99, who had undergone structural and BOLD resting state MRI scans and a battery of neuropsychological tests. Exploratory factor analysis identified the processing speed factor of interest. We preprocessed BOLD scans using fmriprep, Ciftify, and XCPEngine algorithms. We used 4 different sets of connectivity-based parcellation: 1)MBAR data used to define nodes and Power (2011) atlas used to determine node network membership, 2) Younger adults data used to define nodes (Chan 2014) and Power (2011) atlas used to determine node network membership, 3) Older adults data from a different study (Han 2018) used to define nodes and Power (2011) atlas used to determine node network membership, and 4) MBAR data used to define nodes and MBAR data based community detection used to determine node network membership.
Segregation (balance of within-network and between-network connections) was measured within the association system and three wellcharacterized networks: Default Mode Network (DMN), Cingulo-Opercular Network (CON), and Fronto-Parietal Network (FPN). Correlation between processing speed and association system and networks was performed for all 4 node sets.
Results:We replicated prior work and found the segregation of both the cortical association system, the segregation of FPN and DMN had a consistent relationship with processing speed across all node sets (association system range of correlations: r=.294 to .342, FPN: r=.254 to .272, DMN: r=.263 to .273). Additionally, compared to parcellations created with older adults, the parcellation created based on younger individuals showed attenuated and less robust findings as those with older adults (association system r=.263, FPN r=.255, DMN r=.263).
Conclusions:This study shows that network segregation of the oldest-old brain is closely linked with processing speed and this relationship is replicable across different node sets created with varied datasets. This work adds to the growing body of knowledge about age-related dedifferentiation by demonstrating replicability and consistency of the finding that as essential cognitive skill, processing speed, is associated with differentiated functional networks even in very old individuals experiencing successful cognitive aging.
13 Regional White Matter Hyperintensities are Associated with Cognition in Prospective Alzheimer’s Clinical Trial Participants
- Clarissa D. Morales, Dejania Cotton-Samuel, Kay C. Igwe, Patrick J. Lao, Julia F. Chang, Amirreza Sedaghat, Mohamad J. Alshikho, Rafael Lippert, Kelsang C. Bista, Kacie Deters, Molly E. Zimmerman, Adam M. Brickman
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 224-225
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Objective:
Previous research established that white matter hyperintensities (WMH), a biomarker of small vessel cerebrovascular disease, are strong predictors of cognitive function in older adults and associated with clinical presentation of Alzheimer’s disease (AD), particularly when distributed in posterior brain regions. Secondary prevention clinical trials, such as the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s (A4) study, target amyloid accumulation in asymptomatic amyloid positive individuals, but it is unclear the extent to which small vessel cerebrovascular disease accounts for performance on the primary cognitive outcomes in these trials. The purpose of this study was to examine the relationship between regional WMH volume and performance on the Preclinical Alzheimer Cognitive Composite (PACC) among participants screened for participation in the A4 trial. We also determined whether the association between WMH and cognition is moderated by amyloid positivity status.
Participants and Methods:We assessed demographic, amyloid PET status, cognitive screening, and raw MRI data for participants in the A4 trial and quantitated regional (by cerebral lobe) WMH volumes from T2-weighted FLAIR in amyloid positive and amyloid negative participants at screening. Cognition was assessed using PACC scores, a z-score sum of four cognitive tests: The Mini-Mental State Examination (MMSE), the Free and Cued Selective Reminding Test, Logical Memory Test, and Digit Symbol Substitution Test. We included 1329 amyloid positive and 329 amyloid negative individuals (981 women; mean age=71.79 years; mean education=16.58 years) at the time of the analysis. The sample included Latinx (n=50; 3%), non-Latinx (n=1590; 95.9%), or unspecified ethnicity (n=18; 1.1%) individuals who identified as American Indian/Alaskan Native (n=7; 0.4%), Asian (n=38; 2.3%), Black/African American (n=41; 2.5%), White (n=1551 ; 93.5%), or unspecified (n=21; 1.3%) race. We first examined the associations of total and regional WMH volume and amyloid positivity on PACC scores (the primary cognitive outcome measure for A4) using separate general linear models and then determined whether amyloid positivity status and regional WMH statistically interacted for those WMH regions that showed significant main effects.
Results:Both increased WMH, in the frontal and parietal lobes particularly, and amyloid positivity were independently associated with poorer performance on the PACC, with similar magnitude. In subsequent models, WMH volume did not interact with amyloid positivity status on PACC scores.
Conclusions:Regionally distributed WMH are independently associated with cognitive functioning in typical participants enrolled in a secondary prevention clinical trial for AD. These effects are of similar magnitude to the effects of amyloid positivity on cognition, highlighting the extent to which small vessel cerebrovascular disease potentially drives AD-related cognitive profiles. Measures of small vessel cerebrovascular disease should be considered explicitly when evaluating outcomes in trials, both as potential effect modifiers and as possible targets for intervention or prevention. The findings from this study cannot be generalized widely, as the participants are not representative of the overall population.
44 Can Clinical Trial data Inform our Understanding of the role of Depressive Symptoms in Alzheimer's Disease?
- Munira Z Urmi, Dejania Cotton-Samuel, Clarissa D Morales, Kay C Igwe, Julia F Chang, Amirreza Sedaghat, Patrick J Lao, Rafael V Lippert, Adam M Brickman
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 252-253
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Objective:
Neuropsychiatric symptoms concerning mood are common in Alzheimer's disease (AD), but it is unclear if they are etiologically related to AD pathophysiology or due to factors considered to be non-pathogenic, such as small vessel cerebrovascular disease. New generation clinical trials for AD often enroll participants with evidence of AD pathophysiology, indexed by amyloid PET scanning, but who are cognitively asymptomatic. We used screening data from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) study to examine the extent to which depressive symptoms are associated with amyloid pathophysiology and small vessel cerebrovascular disease, in the form of white matter hyperintensities (WMH).
Participants and Methods:The A4 study randomizes cognitively healthy older adults with evidence of amyloid pathophysiology on PET scanning. We used screening data, which included amyloid status (positive, negative) by visual read, amyloid PET standard uptake value ratio (SUVR) in cortical regions, and MRI data acquired in a subset (n=1,197, mean age 71.6 +/- 4.8 years, 57% women) to quantitate total WMH volume. Depressive symptoms were evaluated with the 15-item Geriatric Depression Scale, which we used both as a continuous variable and to define 'depressed' and 'non-depressed' groups, based on a cut score of > 5. We examined whether 1) depressive symptoms and proportion of depressed individuals differed between amyloid positive and negative groups, 2) there is a relationship between amyloid SUVR and depressive symptoms that differs as a function of amyloid positivity status, and 3) there is a relationship between WMH volume and depressive symptoms that differs as a function of amyloid positivity status.
Results:Although depressive symptom severity did not differ between groups (t=0.14, p=0.88), a greater proportion of individuals were classified as depressed in the amyloid negative group than the amyloid positive group (3.5% vs. 1.9%, X2=4.60, p=0.032). Increased amyloid SUVR was associated with increased GDS scores among amyloid positive individuals (r=0.117, p=0.002) but not among amyloid negative individuals (r=0.006, p=0.68, Positivity Status x SUVR interaction on GDS: ß=0.817, p=0.029). Increased WMH was associated with higher GDS scores (ß=0.105, p=0.017) but not differentially in amyloid positive and negative participants (Positivity Status x WMH interaction on GDS: ß=-0.010, p=0.243).
Conclusions:These analyses have several implications. First, individuals who are screened to participate in a clinical trial but do not have evidence of amyloidosis may be misattributing concerns about underlying AD pathophysiology to depressive symptoms. Second, the severity of AD pathophysiology, indexed by amyloid PET SUVR, may drive a small increase in depressive symptomatology among individuals over visual diagnostic thresholds. Third, small vessel cerebrovascular changes are additionally associated with depressive symptoms but in a manner that is independent of AD pathophysiology. Overall, depressive symptoms and depression are likely multiply determined among prospective clinical trial participants for preclinical AD.
2 Higher White Matter Hyperintensity Load Adversely Affects Pre-Post Proximal Cognitive Training Performance in Healthy Older Adults
- Emanuel M Boutzoukas, Andrew O’Shea, Jessica N Kraft, Cheshire Hardcastle, Nicole D Evangelista, Hanna K Hausman, Alejandro Albizu, Emily J Van Etten, Pradyumna K Bharadwaj, Samantha G Smith, Hyun Song, Eric C Porges, Alex Hishaw, Steven T DeKosky, Samuel S Wu, Michael Marsiske, Gene E Alexander, Ronald Cohen, Adam J Woods
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 671-672
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Objective:
Cognitive training has shown promise for improving cognition in older adults. Aging involves a variety of neuroanatomical changes that may affect response to cognitive training. White matter hyperintensities (WMH) are one common age-related brain change, as evidenced by T2-weighted and Fluid Attenuated Inversion Recovery (FLAIR) MRI. WMH are associated with older age, suggestive of cerebral small vessel disease, and reflect decreased white matter integrity. Higher WMH load associates with reduced threshold for clinical expression of cognitive impairment and dementia. The effects of WMH on response to cognitive training interventions are relatively unknown. The current study assessed (a) proximal cognitive training performance following a 3-month randomized control trial and (b) the contribution of baseline whole-brain WMH load, defined as total lesion volume (TLV), on pre-post proximal training change.
Participants and Methods:Sixty-two healthy older adults ages 65-84 completed either adaptive cognitive training (CT; n=31) or educational training control (ET; n=31) interventions. Participants assigned to CT completed 20 hours of attention/processing speed training and 20 hours of working memory training delivered through commercially-available Posit Science BrainHQ. ET participants completed 40 hours of educational videos. All participants also underwent sham or active transcranial direct current stimulation (tDCS) as an adjunctive intervention, although not a variable of interest in the current study. Multimodal MRI scans were acquired during the baseline visit. T1- and T2-weighted FLAIR images were processed using the Lesion Segmentation Tool (LST) for SPM12. The Lesion Prediction Algorithm of LST automatically segmented brain tissue and calculated lesion maps. A lesion threshold of 0.30 was applied to calculate TLV. A log transformation was applied to TLV to normalize the distribution of WMH. Repeated-measures analysis of covariance (RM-ANCOVA) assessed pre/post change in proximal composite (Total Training Composite) and sub-composite (Processing Speed Training Composite, Working Memory Training Composite) measures in the CT group compared to their ET counterparts, controlling for age, sex, years of education and tDCS group. Linear regression assessed the effect of TLV on post-intervention proximal composite and sub-composite, controlling for baseline performance, intervention assignment, age, sex, years of education, multisite scanner differences, estimated total intracranial volume, and binarized cardiovascular disease risk.
Results:RM-ANCOVA revealed two-way group*time interactions such that those assigned cognitive training demonstrated greater improvement on proximal composite (Total Training Composite) and sub-composite (Processing Speed Training Composite, Working Memory Training Composite) measures compared to their ET counterparts. Multiple linear regression showed higher baseline TLV associated with lower pre-post change on Processing Speed Training sub-composite (ß = -0.19, p = 0.04) but not other composite measures.
Conclusions:These findings demonstrate the utility of cognitive training for improving postintervention proximal performance in older adults. Additionally, pre-post proximal processing speed training change appear to be particularly sensitive to white matter hyperintensity load versus working memory training change. These data suggest that TLV may serve as an important factor for consideration when planning processing speed-based cognitive training interventions for remediation of cognitive decline in older adults.
9 Connecting memory and functional brain networks in older adults: a resting state fMRI study
- Jori L Waner, Hanna K Hausman, Jessica N Kraft, Cheshire Hardcastle, Nicole D Evangelista, Andrew O’Shea, Alejandro Albizu, Emanuel M Boutzoukas, Emily J Van Etten, Pradyumna K Bharadwaj, Hyun Song, Samantha G Smith, Steven T DeKosky, Georg A Hishaw, Samuel S Wu, Michael Marsiske, Ronald Cohen, Gene E Alexander, Eric C Porges, Adam J Woods
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 527-528
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Objective:
Nonpathological aging has been linked to decline in both verbal and visuospatial memory abilities in older adults. Disruptions in resting-state functional connectivity within well-characterized, higherorder cognitive brain networks have also been coupled with poorer memory functioning in healthy older adults and in older adults with dementia. However, there is a paucity of research on the association between higherorder functional connectivity and verbal and visuospatial memory performance in the older adult population. The current study examines the association between resting-state functional connectivity within the cingulo-opercular network (CON), frontoparietal control network (FPCN), and default mode network (DMN) and verbal and visuospatial learning and memory in a large sample of healthy older adults. We hypothesized that greater within-network CON and FPCN functional connectivity would be associated with better immediate verbal and visuospatial memory recall. Additionally, we predicted that within-network DMN functional connectivity would be associated with improvements in delayed verbal and visuospatial memory recall. This study helps to glean insight into whether within-network CON, FPCN, or DMN functional connectivity is associated with verbal and visuospatial memory abilities in later life.
Participants and Methods:330 healthy older adults between 65 and 89 years old (mean age = 71.6 ± 5.2) were recruited at the University of Florida (n = 222) and the University of Arizona (n = 108). Participants underwent resting-state fMRI and completed verbal memory (Hopkins Verbal Learning Test - Revised [HVLT-R]) and visuospatial memory (Brief Visuospatial Memory Test - Revised [BVMT-R]) measures. Immediate (total) and delayed recall scores on the HVLT-R and BVMT-R were calculated using each test manual’s scoring criteria. Learning ratios on the HVLT-R and BVMT-R were quantified by dividing the number of stimuli (verbal or visuospatial) learned between the first and third trials by the number of stimuli not recalled after the first learning trial. CONN Toolbox was used to extract average within-network connectivity values for CON, FPCN, and DMN. Hierarchical regressions were conducted, controlling for sex, race, ethnicity, years of education, number of invalid scans, and scanner site.
Results:Greater CON connectivity was significantly associated with better HVLT-R immediate (total) recall (ß = 0.16, p = 0.01), HVLT-R learning ratio (ß = 0.16, p = 0.01), BVMT-R immediate (total) recall (ß = 0.14, p = 0.02), and BVMT-R delayed recall performance (ß = 0.15, p = 0.01). Greater FPCN connectivity was associated with better BVMT-R learning ratio (ß = 0.13, p = 0.04). HVLT-R delayed recall performance was not associated with connectivity in any network, and DMN connectivity was not significantly related to any measure.
Conclusions:Connectivity within CON demonstrated a robust relationship with different components of memory function as well across verbal and visuospatial domains. In contrast, FPCN only evidenced a relationship with visuospatial learning, and DMN was not significantly associated with memory measures. These data suggest that CON may be a valuable target in longitudinal studies of age-related memory changes, but also a possible target in future non-invasive interventions to attenuate memory decline in older adults.
Evaluation of global sensitivity analysis methods for computational structural mechanics problems
- Cody R. Crusenberry, Adam J. Sobey, Stephanie C. TerMaath
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- Journal:
- Data-Centric Engineering / Volume 4 / 2023
- Published online by Cambridge University Press:
- 09 November 2023, e28
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The curse of dimensionality confounds the comprehensive evaluation of computational structural mechanics problems. Adequately capturing complex material behavior and interacting physics phenomenon in models can lead to long run times and memory requirements resulting in the need for substantial computational resources to analyze one scenario for a single set of input parameters. The computational requirements are then compounded when considering the number and range of input parameters spanning material properties, loading, boundary conditions, and model geometry that must be evaluated to characterize behavior, identify dominant parameters, perform uncertainty quantification, and optimize performance. To reduce model dimensionality, global sensitivity analysis (GSA) enables the identification of dominant input parameters for a specific structural performance output. However, many distinct types of GSA methods are available, presenting a challenge when selecting the optimal approach for a specific problem. While substantial documentation is available in the literature providing details on the methodology and derivation of GSA methods, application-based case studies focus on fields such as finance, chemistry, and environmental science. To inform the selection and implementation of a GSA method for structural mechanics problems for a nonexpert user, this article investigates five of the most widespread GSA methods with commonly used structural mechanics methods and models of varying dimensionality and complexity. It is concluded that all methods can identify the most dominant parameters, although with significantly different computational costs and quantitative capabilities. Therefore, method selection is dependent on computational resources, information required from the GSA, and available data.
Changing stereotypes of partisans in the Trump Era
- Ethan C. Busby, Adam J. Howat, C. Daniel Myers
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- Journal:
- Political Science Research and Methods , First View
- Published online by Cambridge University Press:
- 24 August 2023, pp. 1-8
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Stereotypes of the two parties play an important role in political cognition, and a range of recent studies have examined the content and effects of partisan stereotypes. However, little work has studied change in partisan stereotypes over time. We address this question by comparing data on stereotypes of partisans collected before and after the Trump presidency, a time when we might expect individuals' images of the two parties to undergo significant change. Using a structural topic model, we compare responses to open-ended questions asking respondents to list words describing members of the two parties from 2016 and 2021. We find that partisan stereotypes in the 2021 sample are less group- and issue-based and focused more on personal traits. These results suggest that, during the Trump era, members of the mass public came to see the parties in more personalized, character-focused terms, potentially contributing to affective polarization.
Efficacy of maintenance electroconvulsive therapy in recurrent depression: a case series
- G. Guerra Valera, Ó. Martín Santiago, M. Esperesate Pajares, Q. D. L. de la Viuda, A. A. Gonzaga Ramírez, C. Vallecillo Adame, C. de Andrés Lobo, T. Jiménez Aparicio, N. Navarro Barriga, B. Rodríguez Rodríguez, M. Fernández Lozano, M. J. Mateos Sexmero, A. Aparicio Parras, M. Calvo Valcárcel, M. A. Andreo Vidal, P. Martínez Gimeno, M. P. Pando Fernández, M. D. L. Á. Guillén Soto
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S832
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Introduction
Maintenance electroconvulsive therapy (mECT) is an option in the treatment of affective disorders which progress is not satisfactory. It is certainly neglected and underused during the clinical practice.
ObjectivesTo evaluate the efficacy of mECT in reducing recurrence and relapse in recurrent depression within a sample of three patients.
MethodsWe followed up these patients among two years since they received the first set of electroconvulsive sessions. We applied the Beck Depression Inventory (BDI) in the succesives consultations for evaluating the progress.
ResultsThe three patients were diagnosed with Recurrent Depressive Disorder (RDD). One of them is a 60 year old man that received initially a cycle of 12 sessions; since then he received 10 maintenance sessions. Other one is a 70 year old woman that received initially a cycle of 10 sessions; since then she received 6 maintenance sessions. The last one is a 55 year old woman that received initially a cycle of 14 sessions; since then she received 20 maintenance sessions.
All of them showed a significant reduction in depressive symptoms evaluated through BDI and clinical examination. In the first case, we found a reduction in the BDI from the first consultation to the last that goes from 60 to 12 points; in the second case, from 58 to 8 points; and in the last case, from 55 to 10 points. The main sections that improved were emotional, physical and delusional.
As side-effects of the treatment, we found anterograde amnesia, lack of concentration and loss of focus at all of them.
ConclusionsWe find mECT as a very useful treatment for resistant cases of affective disorders like RDD.
It should be considered as a real therapeutic option when the first option drugs have been proved without success.
Disclosure of InterestNone Declared
UNTIL IT BURSTS OR ALL OF US BURST. A SCHIZOTYPICAL CASE.
- B. Rodríguez Rodríguez, N. Navarro Barriga, M. Fernández Lozano, M. J. Mateos Sexmero, M. A. Andreo Vidal, M. Calvo Valcárcel, P. Martínez Gimeno, M. P. Pando Fernández, A. Aparicio Parras, M. D. L. Á. Guillén Soto, T. Jiménez Aparicio, M. D. C. Vallecillo Adame, C. de Andrés Lobo, A. A. Gonzaga Ramírez, G. Guerra Valera, M. Queipo de Llano de la Viuda, M. Esperesate Pajares
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S967
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Introduction
Schizotypal disorder is conceptualized as a stable personality pathology (Cluster A) and as a latent manifestation of schizophrenia. It can be understood as an attenuated form of psychosis or high-risk mental state, which may precede the onset of schizophrenia or represent a more stable form of psychopathology that doesn’t necessarily progress to psychosis.
ObjectivesTo exemplify the continuum of psychosis
MethodsReview of scientific literature based on a relevant clinical case.
Results39-year-old male living with his parents. He started studying philosophy. He is a regular cannabis user and has an aunt with schizophrenia. He’s admitted to psychiatry for behavioral disturbance in public. He refers to having been hearing a beeping noise in his street for months, what he interprets as a possible way of being watched due to his past ideology. Without specifying who and why, he sometimes shouts “until it bursts” to stop the noise and he thinks that his neighbours alerted the police about his behavior. During the interview he alludes to Milgram’s experiment, saying that throughout history there have been crimes against humanity and those who pointed them out were labeled “crazy”. His father refers that he has always been “strange” and with certain extravagant revolutionary ideas and thoughts. He doesn’t maintain social relationships and dedicates himself to reading and writing.
ConclusionsIt’s important to understand psychosis as a continuum to advance the understanding of etiology, pathophysiology and resilience of psychotic disorders and to develop strategies for prevention and early intervention
Disclosure of InterestNone Declared
Delirious episode secondary to rotigotine: the psychotic patch
- M. A. Andreo Vidal, M. Calvo Valcárcel, P. Martínez Gimeno, P. Pando Fernández, B. Rodríguez Rodríguez, N. Navarro Barriga, M. Fernández Lozano, M. J. Mateos Sexmero, T. Jiménez Aparicio, M. D. C. Valdecillo Adame, C. de Andrés Lobo, G. Guerra Valera, M. Queipo de Llano de la Viuda, A. A. Gonzaga Ramirez, M. D. L. Á. Guillén Soto, A. Aparicio Parras, M. Esperesate Pajares
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S626
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Introduction
There is a fine line separating psychiatry and neurology. Most movement disorders can have psychiatric symptoms, not only those caused by the disease itself, but also those induced by the drugs used to treat them.
ObjectivesPresentation of a clinical case about a patient diagnosed with Parkinson’s disease presenting a several-month-long delirious episode due to dopaminergic drugs.
MethodsLiterature review on drug-induced psychosis episodes in Parkinson’s disease.
ResultsA 57-year-old patient with diagnosis of Parkinson’s disease for six years, who went to the emergency room accompanied by his wife due to delirious ideation. He was being treated with levodopa, carbidopa and rasagiline for years, and rotigotine patches whose dosage was being increased over the last few months.
His wife reported celotypical clinical manifestations and multiple interpretations of different circumstances occurring around her. He chased her on the street, had downloaded an app to look for a second cell phone because he believed she was cheating on him, and was obsessed with sex. He had no psychiatric background. It was decided to prescribe quetiapine.
The following day, he returned because he refused to take the medication since he thought he was going to be put to sleep or poisoned. It was decided to admit him to Psychiatry.
During the stay, rasagiline and rotigotine were suspended. Olanzapine and clozapine were introduced, with behavioral improvement and distancing from the psychotic symptoms which motivated the admission. The patient was also motorically stable. Although levodopa is best known for causing psychotic episodes, the symptons were attributed to rotigotine patches for temporally overlapping the dose increase.
ConclusionsPsychiatric symptoms are the third most frequent group of complications in Parkinson’s disease after gastrointestinal complications and abnormal movements. All medication used to control motor disorders can lead to psychosis, not only dopaminergics, but also selegiline, amantadine and anticholinergics.
Excessive stimulation of mesocortical and mesolimbic dopaminergic pathways can lead to psychosis, which is the most common psychiatric problem related to dopaminergic treatment.
In the face of a psychotic episode, antiparkinsonian drugs which are not strictly necessary for motor control should be withdrawn. If this is not sufficient, levodopa dose should be reduced, considering the side effects that may occur. When the adjustment of antiparkinsonian treatment is not effective, neuroleptics, especially quetiapine or clozapine, should be administered. In a recent study, pimavanserin, a serotonin 5-HT2 antagonist, was associated with approximately 35% lower mortality than atypical antipsychotic use during the first 180 days of treatment in community-dwelling patients.
Medication should always be tailor-made to suit each patient and we usually have to resort to lowering or withdrawing the dopaminergic medication.
Disclosure of InterestNone Declared
Bipolar disorder and substance use: Risk factors and prognosis
- M. Fernández Lozano, B. Rodríguez Rodríguez, M. J. Mateos Sexmero, N. Navarro Barriga, C. Vallecillo Adame, C. de Andrés Lobo, T. Jimenez Aparicio, M. Queipo de Llano de la Viuda, G. Guerra Valera, A. A. Gonzaga Ramírez, M. P. Pando Fernández, M. Calvo Valcárcel, M. A. Andreo Vidal, P. Martínez Gimeno
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S704
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Introduction
Bipolar disorder comorbidity rates are the highest among the major mental disorders. In addition to other intoxicants, alcohol is the most abused substance because it is socially accepted and can be legally bought and consumed. Estimates are between 40-70% with male predominance, which further influences the severity with a more complicated course of both disorders.
ObjectivesThe objective of this article is to highlight the impact of substance use on the course and prognosis of bipolar disorder, as well as to make a differential diagnosis of a manic episode in this context.
MethodsBibliographic review of scientific literature based on a relevant clinical case.
ResultsWe present the case of a 45-year-old male patient. Single with no children. Unemployed. History of drug use since he was young: alcohol, cannabis and amphetamines. Diagnosed with bipolar disorder in 2012 after a manic episode that required hospital admission. During his evolution he presented two depressive episodes that required psychopharmacological treatment and follow-up by his psychiatrist of reference. Since then, he has been consuming alcohol and amphetamines occasionally, with a gradual increase until it became daily in the last month. He went to the emergency department for psychomotor agitation after being found in the street. He reported feeling threatened by a racial group presenting accelerated speech, insomnia and increased activity.
ConclusionsThe presence of substance abuse complicates the clinical presentation, treatment and development of bipolar disorder. It is associated with a worse prognosis with multiple negative consequences including worsening symptom severity, increased risk of suicide and hospitalization, increased medical morbidity and complication of social problems. In addition, this comorbidity delays both the diagnosis and treatment, by masking the symptoms, and making more difficult an adequate differential diagnosis.
Disclosure of InterestNone Declared
I don’t know where I’m going or where I come from. Self-disorders in schizophrenia.
- M. D. C. Vallecillo Adame, L. Rodríguez Andrés, C. de Andrés Lobo, T. Jimenez Aparicio, M. Queipo de Llano de la Viuda, G. Guerra Valera, A. A. Gonzaga Ramirez, M. Fernández Lozano, M. J. Mateos Sexmero, N. Navarro Barriga, B. Rodríguez Rodríguez, M. P. Pando Fernández, M. Calvo Valcárcel, P. Martínez Gimeno, M. A. Andreo Vidal, I. D. L. M. Santos Carrasco
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S1069-S1070
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Introduction
In the early stages of schizophrenia the person experiences feelings of strangeness about themselves, difficulty in making sense of things and difficulty in interacting with their environment. Based on this, self-disorder assessment instruments have been developed and empirical studies have been conducted to assess people at risk of developing a schizophrenia spectrum disorder. These studies show that self-disorders are found in pre-psychotic stages and that their manifestation can predict the transition to schizophrenia spectrum disorders.
ObjectivesWe present the case of a patient with multiple diagnoses and mainly dissociative symptoms who, after years of evolution, was diagnosed with schizophrenia.
MethodsBibliographic review including the latest articles in Pubmed about self-disorders and schizophrenia.
ResultsWe present the clinical case of a 51-year-old woman with a long history of follow-up in mental health consultations and with multiple hospital admissions to the psychiatric unit, with several diagnoses including: dissociative disorder, histrionic personality disorder, adaptive disorder unspecified psychotic disorder and, finally, schizophrenia. The patient during the first hospital admissions showed a clinical picture of intense anxiety, disorientation and claiming to be a different person. The patient related these episodes to stressors she had experienced, and they improved markedly after a short period of hospital admission. Later, psychotic symptoms appeared in the form of auditory and visual hallucinations and delusional ideation, mainly of harm, so that after several years of follow-up and study in mental health consultations and in the psychiatric day hospital, she was diagnosed with schizophrenia and treatment with antipsychotics was introduced, with a marked clinical improvement being observed.
ConclusionsIt is important to take into account this type of symptoms (self-disorders), as they allow the identification of individuals in the early stages of the disorder and create the opportunity for early therapeutic interventions.
Disclosure of InterestNone Declared