Using EEG to decode semantics during an artificial language learning task.

Background: As we learn a new nonnative language (L2), we begin to build a new map of concepts onto orthographic representations. Eventually, L2 can conjure as rich a semantic representation as our native language (L1). However, the neural processes for mapping a new orthographic representation to a familiar meaning are not well understood or characterized.

Words as a window: Using word embeddings to explore the learned representations of Convolutional Neural Networks.

As deep neural net architectures minimize loss, they accumulate information in a hierarchy of learned representations that ultimately serve the network's final goal. Different architectures tackle this problem in slightly different ways, but all create intermediate representational spaces built to inform their final prediction. Here we show that very different neural networks trained on two very different tasks build knowledge representations that display similar underlying patterns.

Functional Connectivity Within and Between -Back Modulated Regions: An Adult Lifespan Psychophysiological Interaction Investigation.

Working memory (WM) and its blood-oxygen-level-dependent-related parametric modulation under load decrease with age. Functional connectivity (FC) generally increases with WM load; however, how aging impacts connectivity and whether this is load-dependent, region-dependent, or associated with cognitive performance is unclear. This study examines these questions in 170 healthy adults (mean = 52.

Pediatric Patient With Concurrent Eosinophilic Esophagitis, Erosive Reflux Esophagitis, and Barrett's Esophagus.

Eosinophilic esophagitis and Barrett's esophagus are believed to be separate disease processes, with erosive esophagitis leading to Barrett's esophagus. We report a rare case of concurrent diagnoses in a pediatric patient and examine the relevant genetic profiles in the esophagus.

Contribution of iron and Aβ to age differences in entorhinal and hippocampal subfield volume.

Objective: To test the hypothesis that the combination of elevated global β-AMYLOID (Aβ) burden and greater striatal iron content would be associated with smaller entorhinal cortex (ERC) volume, but not hippocampal subfield volumes, we measured volume and iron content using high-resolution MRI and Aβ using PET imaging in a cross-sectional sample of 70 cognitively normal older adults.

Methods: Participants were scanned with florbetapir F PET to obtain Aβ standardized uptake value ratios. Susceptibility-weighted MRI was collected and processed to yield R2* images, and striatal regions of interest (ROIs) were manually placed to obtain a measure of striatal iron burden.

Greater BOLD Variability is Associated With Poorer Cognitive Function in an Adult Lifespan Sample.

Moment-to-moment fluctuations in brain signal assessed by functional magnetic resonance imaging blood oxygenation level dependent (BOLD) variability is increasingly thought to represent important "signal" rather than measurement-related "noise." Efforts to characterize BOLD variability in healthy aging have yielded mixed outcomes, demonstrating both age-related increases and decreases in BOLD variability and both detrimental and beneficial associations. Utilizing BOLD mean-squared-successive-differences (MSSD) during a digit n-back working memory (WM) task in a sample of healthy adults (aged 20-94 years; n = 171), we examined effects of aging on whole-brain 1) BOLD variability during task (mean condition MSSD across 0-2-3-4 back conditions), 2) BOLD variability modulation to incrementally increasing WM difficulty (linear slope from 0-2-3-4 back), and 3) the association of age-related differences in variability with in- and out-of-scanner WM performance.

Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults.

One of the earliest indicators of Alzheimer's disease pathology is the presence of beta-amyloid (Αβ) protein deposition. Significant amyloid deposition is evident even in older adults who exhibit little or no overt cognitive or memory impairment. Hippocampal-based processes that help distinguish between highly similar memory representations may be the most susceptible to early disease pathology.

Domain general processes moderate age-related performance differences on the mnemonic similarity task.

Several prominent domain general theories (e.g., processing speed and inhibitory function) have been developed to explain cognitive changes associated with aging.

Winter Wheat Yield Response to Plant Density as a Function of Yield Environment and Tillering Potential: A Review and Field Studies.

Wheat ( L.) grain yield response to plant density is inconsistent, and the mechanisms driving this response are unclear. A better understanding of the factors governing this relationship could improve plant density recommendations according to specific environmental and genetics characteristics.

Increasing beta-amyloid deposition in cognitively healthy aging predicts nonlinear change in BOLD modulation to difficulty.

Recent evidence indicates that the relationship between increased beta-amyloid (Aβ) deposition and functional task-activation can be characterized by a non-linear trajectory of change in functional activation (Foster et al., 2017), explaining mixed results in prior literature showing both increases and decreases in activation as a function of beta-amyloid burden in cognitively normal adults. Here we sought to replicate this nonlinear effect in the same sample using a different functional paradigm to test the generalizability of this phenomenon.

Both hyper- and hypo-activation to cognitive challenge are associated with increased beta-amyloid deposition in healthy aging: A nonlinear effect.

Beta-amyloid (Aβ) positive individuals hyper-activate brain regions compared to those not at-risk; however, hyperactivation is then thought to diminish as Alzheimer's disease symptomatology begins, evidencing eventual hypoactivation. It remains unclear when in the disease staging this transition occurs. We hypothesized that differential levels of amyloid burden would be associated with both increased and decreased activation (i.

Dynamic range in BOLD modulation: lifespan aging trajectories and association with performance.

Alteration of dynamic range of modulation to cognitive difficulty has been proposed as a salient predictor of cognitive aging. Here, we examine in 171 adults (aged 20-94 years) the effects of age on dynamic modulation of blood oxygenation-level dependent activation to difficulty in parametrically increasing working memory (WM) load (0-, 2-, 3-, and 4-back conditions). First, we examined parametric increases and decreases in activation to increasing WM load (positive modulation effect and negative modulation effect).

Differential Aging Trajectories of Modulation of Activation to Cognitive Challenge in APOE ε4 Groups: Reduced Modulation Predicts Poorer Cognitive Performance.

The present study was designed to investigate the effect of a genetic risk factor for Alzheimer's disease (AD), ApolipoproteinE ε4 (APOEε4), on the ability of the brain to modulate activation in response to cognitive challenge in a lifespan sample of healthy human adults. A community-based sample of 181 cognitively intact, healthy adults were recruited from the Dallas-Fort Worth metroplex. Thirty-one APOEε4+ individuals (48% women), derived from the parent sample, were matched based on sex, age, and years of education to 31 individuals who were APOEε4-negative (APOEε4-).

The effect of age on relational encoding as revealed by hippocampal functional connectivity.

The neural processes mediating cognition occur in networks distributed throughout the brain. The encoding and retrieval of relational memories, memories for multiple items or multifeatural events, is supported by a network of brain regions, particularly the hippocampus. The hippocampal coupling hypothesis suggests that the hippocampus is functionally connected with the default mode network (DMN) during retrieval, but during encoding, decouples from the DMN.

Prefrontal contributions to relational encoding in amnestic mild cognitive impairment.

Relational memory declines are well documented as an early marker for amnestic mild cognitive impairment (aMCI). Episodic memory formation relies on relational processing supported by two mnemonic mechanisms, generation and binding. Neuroimaging studies using functional magnetic resonance imaging (fMRI) have primarily focused on binding deficits which are thought to be mediated by medial temporal lobe dysfunction.

The effect of presentation rate on implicit sequence learning in aging.

Implicit sequence learning is thought to be preserved in aging when the to-be learned associations are first-order; however, when associations are second-order, older adults (OAs) tend to experience deficits as compared to young adults (YAs). Two experiments were conducted using a first (Experiment 1) and second-order (Experiment 2) serial-reaction time task. Stimuli were presented at a constant rate of either 800 milliseconds (fast) or 1200 milliseconds (slow).

Prospective analysis of pulmonary hypertension in extremely low birth weight infants.

Objectives: Pulmonary hypertension is associated with bronchopulmonary dysplasia in extremely low birth weight (ELBW) infants and contributes to morbidity and mortality. The objective was to determine the prevalence of pulmonary hypertension among ELBW infants by screening echocardiography and evaluate subsequent outcomes.

Methods: All ELBW infants admitted to a regional perinatal center were evaluated for pulmonary hypertension with echocardiography at 4 weeks of age and subsequently if clinical signs suggestive of right-sided heart failure or severe lung disease were evident.