Memory For Emotional Expressions In Adults With Acquired Brain Injuries

Introduction: Memory for emotions expressed by others forms the continuity that characterizes unique and intimate relationships. Successful memory for facial expressions requires the ability to remember the identity of the face (who showed the emotion) as well as the emotion (which emotion they showed). People with acquired brain injuries (ABI) frequently have problems with social cognition, which involves understanding cues that communicate emotional and interpersonal information. ABI is commonly associated with trouble perceiving emotional expressions and recognizing the identity of faces; however, research on memory for emotions after ABI is sparse. This study examined cognitive and emotional characteristics that contribute to face emotion processing and psychometric properties of tests that assess those phenomena among adults with and without history of ABI. Method: 115 adults with ABI and 116 neurologically healthy (NH) adults completed tests of attention, memory, and processing speed, as well as self-report measures of mood and emotional functioning. Emotion perception, face recognition, and memory for emotions were assessed with the Multicultural Facial Emotion Perception Test (MFEPT), Warrington Recognition Memory Test (RMT), and Multicultural Facial Recognition Test, (MCFR), respectively. Rasch analyses evaluated psychometric properties of the MFEPT, RMT, and MCFR. Results: ABI participants performed worse than NH participants on the MFEPT, RMT, and MCFR, even after accounting for component cognitive skills, mood, and experienced emotions. Diagnostic group moderated the effect of mood on the MFEPT, MCFR, and RMT: experienced negative affect (symptoms of depression and anxiety) facilitated performance among NH adults but hindered performance among adults with ABI. Rasch analyses characterized the psychometric profiles of the tasks and informed ways to improve the measurement of emotion processing. Conclusions: Memory for emotions appears to be a unique area of impairment following ABI. Adults with ABI may have difficulty differentiating their own emotions from the emotions of others, which in turn may disrupt their perception and memory of emotions. Improved measurement guided by item response theory can enhance understanding of emotion processing. Nuanced assessment of emotion perception and memory can be used to guide targeted interventions, which may improve social cognition following ABI

The Contribution of Missouri River Reservoir Side-Channel and Floodplain Habitats to Mainstem Fish Populations: The Effects of Losing Connectivity Between Hipple Lake and Lake Sharpe

Catastrophic flooding of the Missouri River in 2011 has had lasting effects on floodplain habitats (i.e. floodplain lakes) and side-channel habitats (e.g. canals, side-channel embayments, stilling basins, and tributaries) in Lake Sharpe, SD. Floodplain and side-channel habitats are rare habitat in Lake Sharpe, a mainstem Missouri River reservoir, and are thought to be crucial habitat for prey and sport fish. Hipple Lake, the only warm-water floodplain embayment in Lake Sharpe, is in danger of losing connectivity to the reservoir because of sedimentation resulting from the 2011 flood. To evaluate Hipple Lake’s natal and adult contribution to Lake Sharpe’s fishery, otolith microchemistry was used to quantify fish movement and natal origins. This data will be used to inform management decisions regarding restoring Hipple Lake’s connectivity to the main channel. Water trace element chemistry (e.g., Sr:Ca, Ba:Ca) among a cold-water side-channel embayment, warm-water floodplain embayment, canal complex, tributary, and the main channel of Lake Sharpe were spatially variable. Significant positive linear relationships existed between otolith trace element concentrations and water trace element concentrations for many species, but not for all species. Natal Sr:Ca and Ba:Ca ratios of adults varied spatially, which allowed for identification of natal origins of fish hatched in a warm-water floodplain embayment, a cold-water side-channel embayment, a tributary, a stilling basin, a canal complex, or the main channel. K-nearest neighbor discriminant analysis reclassified age-0 fish with sufficient accuracy for habitat-type scale classification (\u3e75% accuracy). Canals were important only for Gizzard Shad (Dorosoma cepedianum), whereas a tributary was important only for White Bass (Morone chrysops). A warm-water floodplain embayment, Hipple Lake, was important for natal recruitment of Bluegill (Lepomis macrochirus), Crappies (Pomoxis spp.), Largemouth Bass (Micropterus dolomieu), and Gizzard Shad. A cold-water side-channel embayment, La Framboise, was important for White Bass, Sauger (Sander canadensis), and Walleye (Sander vitreus) natal recruitment and adult use, as well as adult use for Bluegill, Yellow Perch (Perca flavescens), and Largemouth Bass. A stilling basin was important for Yellow Perch and Gizzard Shad. The main channel was equal or more important than side-channel and floodplain habitats for Bluegill, Crappie, Yellow Perch, Smallmouth Bass, Largemouth Bass and Sauger natal recruitment, and more important than side-channel and floodplain habitats for Crappie, Yellow Perch and Smallmouth Bass adult movement. Gizzard Shad collected at all sites moved frequently throughout the entire reservoir. At least 6% of adult Gizzard Shad in Lake Sharpe (~25,000 ha) originated in Hipple Lake (178 ha), and at least 17% of adult Gizzard Shad in Hipple Lake originated in Hipple Lake. Considering that Hipple Lake makes up only 0.77% of Lake Sharpe’s surface area, 6-17% of Lake Sharpe’s natal recruitment occurring in the floodplain lake is substantial. Nearly two-thirds (65.57%) of all Gizzard Shad recruitment in Lake Sharpe occurred in side-channel and floodplain habitats. This research shows the disproportional importance of warm-water floodplain embayments, canals, stilling basins and tributaries to Gizzard Shad recruitment in large reservoirs. Sport fish were found to utilize different habitats, with the floodplain and side-channel contribution to natal recruitment and adult movement varying from negligible to significant, dependent on species. Natal recruitment and movement patterns varied to a small extent on an annual scale for some species, and movements have changed to a small extent for some species since the 2011 flood

Discovery of a Visual T-Dwarf Triple System and Binarity at the L/T Transition

We present new high contrast imaging of 8 L/T transition brown dwarfs using the NIRC2 camera on the Keck II telescope. One of our targets, the T3.5 dwarf 2MASS J08381155 + 1511155, was resolved into a hierarchal triple with projected separations of 2.5+/-0.5 AU and 27+/-5 AU for the BC and A(BC) components respectively. Resolved OSIRIS spectroscopy of the A(BC) components confirm that all system members are T dwarfs. The system therefore constitutes the first triple T-dwarf system ever reported. Using resolved photometry to model the integrated-light spectrum, we infer spectral types of T3, T3, and T4.5 for the A, B, and C components respectively. The uniformly brighter primary has a bluer J-Ks color than the next faintest component, which may reflect a sensitive dependence of the L/T transition temperature on gravity, or alternatively divergent cloud properties amongst components. Relying on empirical trends and evolutionary models we infer a total system mass of 0.034-0.104 Msun for the BC components at ages of 0.3-3 Gyr, which would imply a period of 12-21 yr assuming the system semi-major axis to be similar to its projection. We also infer differences in effective temperatures and surface gravities between components of no more than ~150 K and ~0.1 dex. Given the similar physical properties of the components, the 2M0838+15 system provides a controlled sample for constraining the relative roles of effective temperature, surface gravity, and dust clouds in the poorly understood L/T transition regime. Combining our imaging survey results with previous work we find an observed binary fraction of 4/18 or 22_{-8}^{+10}% for unresolved spectral types of L9-T4 at separations >~0.1 arcsec. This translates into a volume-corrected frequency of 13^{-6}_{+7}%, which is similar to values of ~9-12% reported outside the transition. (ABRIDGED)Comment: Accepted for publication in the Astrophysical Journal. 23 pages, 12 figure