The Relationship Between Early Life Stress and Microstructural Integrity of the Corpus Callosum in a Non-Clinical Population

Background: Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain. Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain. Methods: In the present study we evaluated this relationship in healthy non-clinical participants using diffusion tensor imaging (DTI) and self-reported history of ELS. Results: Regression analyses revealed significant reductions in fractional anisotropy (FA) within the genu of the corpus callosum among those exposed to the greatest number of early life stressors, suggesting reduced microstructural integrity associated with increased ELS. These effects were most pronounced in the genu of the corpus callosum compared to the body and splenium, and were evident for females rather than males despite no differences in total ELS exposure between the sexes. In addition, a further comparison of those participants who were exposed to no ELS vs. three or more ELS events revealed lower FA in the genu of the corpus callosum among the ELS-exposed group, with trends of FA reduction in the body and the whole corpus callosum. By contrast, there were no relationships between ELS and volumetric analysis of the CC regions. The two group did not differ significantly on measures of current depression, stress or anxiety. Conclusion: Our results reveal that greater exposure to ELS is associated with microstructural alterations in the white matter in the absence of significant volumetric changes. Importantly, our results indicate that exposure to ELS is associated with abnormalities on DTI despite the absence of clinically significant psychiatric symptoms. Future studies are needed to determine whether specific types of ELS are more likely to impact brain structure and function

The relationship between early life stress and microstructural integrity of the corpus callosum in a non-clinical population

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Nunataryuk field campaigns: understanding the origin and fate of terrestrial organic matter in the coastal waters of the Mackenzie Delta region

Climate warming and related drivers of soil thermal change in the Arctic are expected to modify the distribution and dynamics of carbon contained in perennially frozen grounds. Thawing of permafrost in the Mackenzie River watershed of northwestern Canada, coupled with increases in river discharge and coastal erosion, triggers the release of terrestrial organic matter (OMt) from the largest Arctic drainage basin in North America into the Arctic Ocean. While this process is ongoing and its rate is accelerating, the fate of the newly mobilized organic matter as it transits from the watershed through the delta and into the marine system remains poorly understood. In the framework of the European Horizon 2020 Nunataryuk programme, and as part of the Work Package 4 (WP4) Coastal Waters theme, four field expeditions were conducted in the Mackenzie Delta region and southern Beaufort Sea from April to September 2019. The temporal sampling design allowed the survey of ambient conditions in the coastal waters under full ice cover prior to the spring freshet, during ice breakup in summer, and anterior to the freeze-up period in fall. To capture the fluvial–marine transition zone, and with distinct challenges related to shallow waters and changing seasonal and meteorological conditions, the field sampling was conducted in close partnership with members of the communities of Aklavik, Inuvik and Tuktoyaktuk, using several platforms, namely helicopters, snowmobiles, and small boats. Water column profiles of physical and optical variables were measured in situ, while surface water, groundwater, and sediment samples were collected and preserved for the determination of the composition and sources of OMt, including particulate and dissolved organic carbon (POC and DOC), and colored dissolved organic matter (CDOM), as well as a suite of physical, chemical, and biological variables. Here we present an overview of the standardized datasets, including hydrographic profiles, remote sensing reflectance, temperature and salinity, particle absorption, nutrients, dissolved organic carbon, particulate organic carbon, particulate organic nitrogen, CDOM absorption, fluorescent dissolved organic matter intensity, suspended particulate matter, total particulate carbon, total particulate nitrogen, stable water isotopes, radon in water, bacterial abundance, and a string of phytoplankton pigments including total chlorophyll. Datasets and related metadata can be found in Juhls et al. (2021) (https://doi.org/10.1594/PANGAEA.937587).</p

Characteristics of Neuropsychologists Who Prefer the Halstead-Reitan or the Luria-Nebraska Neuropsychological Battery

As part of a national survey of psychologists who offer neuropsychological services, 398 subjects responded to questions about their use of, training in, and preference for the Halstead-Reitan (HR) or the Luria-Nebraska (LN) Neuropsychological Battery. Of the 222 subjects who were trained in both batteries, 26% preferred neither battery, 51% preferred the HR, and 23% preferred the LN. The education and training of the latter two groups did not differ. However, clinicians who preferred the HR devoted a greater percentage of their overall practice to neuropsychology, performed more clinical and forensic evaluations, and used more supplemental assessment instruments. Preference for one battery over the other appears to be based on practical, clinical, and experiential factors

To Say It\u27s Not So Doesn\u27t Prove That It Isn\u27t: Research on the Detection of Malingering. Reply to Bigler

Research that directly examines clinicians\u27 capacity to detect malingering creates doubt about their success in this endeavor and about confident self-appraisals of detective abilities. We argue that Bigler\u27s counterassertions lack supportive evidence or conflict with research on such topics as clinicians\u27 level of training and experience and their judgmental accuracy. We further note that lack of both base rate information and definitive outcome information compound doubts about clinicians\u27 capacity to detect malingering

Comparison of time and error rates on the trail making test among patients with head injuries, experimental malingerers, patients with suspect effort on testing, and normal controls

Clinical utility of completion time and performance errors was investigated for the Trail Making Test (TMT; Reitan, 1958). Archival neuropsychological files for patients with mild and moderate/severe head injuries, as well as patients with suspect effort on neuropsychological testing, were examined and compared to controls and experimental malingerers. Time-to-completion scores differentiated the participants who were malingering and who gave suspect effort from those patients with head injuries. There were no differences in error rates among the head-injury groups or controls for either the TMT-A or TMT-B. Errors were also not uncommon among normal controls; 12% and 35% of the controls made at least one error on TMT-A and TMT-B, respectively. However, error rates for both the suspect-effort and malingering groups were inflated on TMT-B as compared to the head-injured and control groups. Results suggest that performance errors on the TMT lack diagnostic utility for persons with head injuries, and time-to-completion is still the best indicator of neuropathology. However, performance errors, in conjunction with inflated time scores on the TMT, may be useful in the assessment of malingering

A national survey of psychologists who offer neuropsychological services

We conducted a national survey of psychologists who offer neuropsychological services to determine levels of training, current practices, and views on professional issues. All subjects were listed in the National Register of Health Service Providers in Psychology and/or the American Psychological Association Directory as having some affiliation with neuropsychology. Results suggest marked diversity within the field, with the modal practitioner being minimally involved in neuropsychological activities. We also compare clinicians with varying involvement and experience in neuropsychology and analyze the concentration of practitioners by geographic regions. We compare our results to those obtained in prior surveys and discuss implications of the findings. © 1990

The relationship between early life stress and microstructural integrity of the corpus callosum in a non-clinical population

Robert Paul1, Lorrie Henry2, Stuart M Grieve3, Thomas J Guilmette2,4, Raymond Niaura4, Richard Bryant5, Steven Bruce1, Leanne M Williams3,6, Clark C Richard7, Ronald A Cohen4, Evian Gordon3,71University of Missouri, St. Louis, St. Louis, MO, USA; 2Providence College, Providence, RI, USA; 3The Brain Resource International Database, The Brain Resource Company, Ultimo, NSW, Australia; 4Brown Medical School, Department of Psychiatry, Providence, RI, USA; 5School of Psychology, University of New South Wales, Sydney, NSW, Australia; 6Brain Dynamics Centre, Westmead Millennium Institute, Westmead Hospital, Westmead, NSW, Australia; 7Cognitive Neuroscience Laboratory and School of Psychology, Flinders University, Adelaide, SA, AustraliaBackground: Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain.Methods: In the present study we evaluated this relationship in healthy non-clinical participants using diffusion tensor imaging (DTI) and self-reported history of ELS.Results: Regression analyses revealed significant reductions in fractional anisotropy (FA) within the genu of the corpus callosum among those exposed to the greatest number of early life stressors, suggesting reduced microstructural integrity associated with increased ELS. These effects were most pronounced in the genu of the corpus callosum compared to the body and splenium, and were evident for females rather than males despite no differences in total ELS exposure between the sexes. In addition, a further comparison of those participants who were exposed to no ELS vs. three or more ELS events revealed lower FA in the genu of the corpus callosum among the ELS-exposed group, with trends of FA reduction in the body and the whole corpus callosum. By contrast, there were no relationships between ELS and volumetric analysis of the CC regions. The two groups did not differ significantly on measures of current depression, stress or anxiety.Conclusion: Our results reveal that greater exposure to ELS is associated with microstructural alterations in the white matter in the absence of significant volumetric changes. Importantly, our results indicate that exposure to ELS is associated with abnormalities on DTI despite the absence of clinically significant psychiatric symptoms. Future studies are needed to determine whether specific types of ELS are more likely to impact brain structure and function