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https://www.readbyqxmd.com/read/27911299/chronotropic-response-and-cognitive-function-in-a-cohort-at-risk-for%C3%A2-alzheimer-s-disease
#1
Lena L Law, Stephanie A Schultz, Elizabeth A Boots, Jean A Einerson, Ryan J Dougherty, Jennifer M Oh, Claudia E Korcarz, Dorothy F Edwards, Rebecca L Koscik, N Maritza Dowling, Catherine L Gallagher, Barbara B Bendlin, Cynthia M Carlsson, Sanjay Asthana, Bruce P Hermann, Mark A Sager, Sterling C Johnson, Dane B Cook, James H Stein, Ozioma C Okonkwo
The objective of this study was to examine the association of chronotropic response (CR) and heart rate (HR) recovery- two indices of cardiovascular function within the context of a graded exercise test- with cognitive performance in a cognitively healthy, late-middle-aged cohort at risk for Alzheimer's disease (AD). Ninety participants (age = 63.52±5.86 years; 65.6% female) from the Wisconsin Registry for Alzheimer's Prevention participated in this study. They underwent graded exercise testing and a comprehensive neuropsychological assessment that assessed the following four cognitive domains: Immediate Memory, Verbal & Learning Memory, Working Memory, and Speed & Flexibility...
December 1, 2016: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/27909799/thyroid-gland-visualization-with-3d-4d-ultrasound-integrated-hands-on-imaging-in-anatomical-dissection-laboratory
#2
John L Carter, Ankura Patel, Gabriel Hocum, Brion Benninger
PURPOSE: In teaching anatomy, clinical imaging has been utilized to supplement the traditional dissection laboratory promoting education through visualization of spatial relationships of anatomical structures. Viewing the thyroid gland using 3D/4D ultrasound can be valuable to physicians as well as students learning anatomy. The objective of this study was to investigate the perceptions of first-year medical students regarding the integration of 3D/4D ultrasound visualization of spatial anatomy during anatomical education...
December 1, 2016: Surgical and Radiologic Anatomy: SRA
https://www.readbyqxmd.com/read/27909395/reversal-learning-in-humans-and-gerbils-dynamic-control-network-facilitates-learning
#3
Christian Jarvers, Tobias Brosch, André Brechmann, Marie L Woldeit, Andreas L Schulz, Frank W Ohl, Marcel Lommerzheim, Heiko Neumann
Biologically plausible modeling of behavioral reinforcement learning tasks has seen great improvements over the past decades. Less work has been dedicated to tasks involving contingency reversals, i.e., tasks in which the original behavioral goal is reversed one or multiple times. The ability to adjust to such reversals is a key element of behavioral flexibility. Here, we investigate the neural mechanisms underlying contingency-reversal tasks. We first conduct experiments with humans and gerbils to demonstrate memory effects, including multiple reversals in which subjects (humans and animals) show a faster learning rate when a previously learned contingency re-appears...
2016: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/27909102/the-attraction-effect-modulates-reward-prediction-errors-and-intertemporal-choices
#4
Sebastian Gluth, Jared M Hotaling, Jörg Rieskamp
: Classical economic theory contends that the utility of a choice option should be independent of other options. This view is challenged by the attraction effect, in which the relative preference between two options is altered by the addition of a third, asymmetrically dominated option. Here, we leveraged the attraction effect in the context of intertemporal choices to test whether both decisions and reward prediction errors (RPE)-in the absence of choice-violate the independence of irrelevant alternatives principle...
December 1, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27906526/statistical-learning-a-powerful-mechanism-that-operates-by-mere-exposure
#5
REVIEW
Richard N Aslin
How do infants learn so rapidly and with little apparent effort? In 1996, Saffran, Aslin, and Newport reported that 8-month-old human infants could learn the underlying temporal structure of a stream of speech syllables after only 2 min of passive listening. This demonstration of what was called statistical learning, involving no instruction, reinforcement, or feedback, led to dozens of confirmations of this powerful mechanism of implicit learning in a variety of modalities, domains, and species. These findings reveal that infants are not nearly as dependent on explicit forms of instruction as we might have assumed from studies of learning in which children or adults are taught facts such as math or problem solving skills...
December 1, 2016: Wiley Interdisciplinary Reviews. Cognitive Science
https://www.readbyqxmd.com/read/27903731/memory-transformation-enhances-reinforcement-learning-in-dynamic-environments
#6
Adam Santoro, Paul W Frankland, Blake A Richards
: Over the course of systems consolidation, there is a switch from a reliance on detailed episodic memories to generalized schematic memories. This switch is sometimes referred to as "memory transformation." Here we demonstrate a previously unappreciated benefit of memory transformation, namely, its ability to enhance reinforcement learning in a dynamic environment. We developed a neural network that is trained to find rewards in a foraging task where reward locations are continuously changing...
November 30, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27896983/learning-parsimonious-ensembles-for-unbalanced-computational-genomics-problems
#7
Ana Stanescu, Gaurav Pandey
Prediction problems in biomedical sciences are generally quite difficult, partially due to incomplete knowledge of how the phenomenon of interest is influenced by the variables and measurements used for prediction, as well as a lack of consensus regarding the ideal predictor(s) for specific problems. In these situations, a powerful approach to improving prediction performance is to construct ensembles that combine the outputs of many individual base predictors, which have been successful for many biomedical prediction tasks...
2016: Pacific Symposium on Biocomputing
https://www.readbyqxmd.com/read/27896312/the-memory-trace-supporting-lose-shift-responding-decays-rapidly-after-reward-omission-and-is-distinct-from-other-learning-mechanisms-in-rats
#8
Aaron J Gruber, Rajat Thapa
The propensity of animals to shift choices immediately after unexpectedly poor reinforcement outcomes is a pervasive strategy across species and tasks. We report here that the memory supporting such lose-shift responding in rats rapidly decays during the intertrial interval and persists throughout training and testing on a binary choice task, despite being a suboptimal strategy. Lose-shift responding is not positively correlated with the prevalence and temporal dependence of win-stay responding, and it is inconsistent with predictions of reinforcement learning on the task...
November 2016: ENeuro
https://www.readbyqxmd.com/read/27894212/human-instrumental-performance-in-ratio-and-interval-contingencies-a-challenge-for-associative-theory
#9
Omar Pérez-Riveros, Michael R F Aitken, Peter Zhukovsky, Fabián A Soto, Gonzalo P Urcelay, Anthony Dickinson
Associative learning theories regard the probability of reinforcement as the critical factor determining responding. However, the role of this factor in instrumental conditioning is not completely clear. In fact, a wealth of evidence from instrumental free-operant experiments has shown that participants respond at a higher rate on variable ratio than on variable interval schedules even though the reinforcement probability on the interval schedule is the same as or greater than that on the ratio schedule. This difference has been attributed to the differential reinforcement of long inter-response times (IRT) by interval schedules, which acts to slow responding...
November 29, 2016: Quarterly Journal of Experimental Psychology: QJEP
https://www.readbyqxmd.com/read/27893230/ecological-momentary-assessment-of-negative-symptoms-in-schizophrenia-relationships-to-effort-based-decision-making-and-reinforcement-learning
#10
Erin K Moran, Adam J Culbreth, Deanna M Barch
Negative symptoms are a core clinical feature of schizophrenia, but conceptual and methodological problems with current instruments can make their assessment challenging. One hypothesis is that current symptom assessments may be influenced by impairments in memory and may not be fully reflective of actual functioning outside of the laboratory. The present study sought to investigate the validity of assessing negative symptoms using ecological momentary assessment (EMA). Participants with schizophrenia (N = 31) completed electronic questionnaires on smartphones 4 times a day for 1 week...
November 28, 2016: Journal of Abnormal Psychology
https://www.readbyqxmd.com/read/27891105/global-cue-inconsistency-diminishes-learning-of-cue-validity
#11
Tony S L Wang, Nicole Christie, Piers D L Howe, Daniel R Little
In daily life, we make decisions that are associated with probabilistic outcomes (e.g., the chance of rain today). People search for and utilize information that validly predicts an outcome (i.e., we look for dark clouds to indicate the possibility of rain). In the current study (N = 107), we present a two-stage learning task that examines how participants learn and utilize predictive information within a probabilistic learning environment. In the first stage, participants select one of three cues that gives predictive information about the outcome of the second stage...
2016: Frontiers in Psychology
https://www.readbyqxmd.com/read/27891082/reward-and-behavioral-factors-contributing-to-the-tonic-activity-of-monkey-pedunculopontine-tegmental-nucleus-neurons-during-saccade-tasks
#12
Ken-Ichi Okada, Yasushi Kobayashi
The pedunculopontine tegmental nucleus (PPTg) in the brainstem plays a role in controlling reinforcement learning and executing conditioned behavior. We previously examined the activity of PPTg neurons in monkeys during a reward-conditioned, visually guided saccade task, and reported that a population of these neurons exhibited tonic responses throughout the task period. These tonic responses might depend on prediction of the upcoming reward, successful execution of the task, or both. Here, we sought to further distinguish these factors and to investigate how each contributes to the tonic neuronal activity of the PPTg...
2016: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/27888041/understanding-the-contributions-of-visual-stimuli-to-contextual-fear-conditioning-a-proof-of-concept-study-using-lcd-screens
#13
Nathen J Murawski, Arun Asok
The precise contribution of visual information to contextual fear learning and discrimination has remained elusive. To better understand this contribution, we coupled the context pre-exposure facilitation effect (CPFE) fear conditioning paradigm with presentations of distinct visual scenes displayed on 4 LCD screens surrounding a conditioning chamber. Adult male Long-Evans rats received non-reinforced context pre-exposure on Day 1, an immediate 1.5mA foot shock on Day 2, and a non-reinforced context test on Day 3...
November 22, 2016: Neuroscience Letters
https://www.readbyqxmd.com/read/27888020/neural-correlates-of-affective-empathy-and-reinforcement-learning-in-boys-with-conduct-problems-fmri-evidence-from-a-gambling-task
#14
Christina Schwenck, Angela Ciaramidaro, Marina Selivanova, Jennifer Tournay, Christine M Freitag, Michael Siniatchkin
BACKGROUND: Conduct problems (CP) comprise abnormal behaviors associated with aberrant aspects of affective empathy as well as learning. However, behavioral measures for affective empathy are challenging, and previous results concerning learning in patients with CP are inconsistent. METHODS: Nineteen boys with CP and 24 typically developing (TD) boys aged 11-17 years (M=14.34, SD=1.93) participated in the study. An ultimatum-game was applied in order to elicit the feeling of like or dislike towards the opponent for a subsequent gambling task, which was played by the opponents (OTHER-condition) and by the participants themselves (SELF-condition)...
November 22, 2016: Behavioural Brain Research
https://www.readbyqxmd.com/read/27878890/a-qualitative-exploration-of-anesthesia-trainees-experiences-during-transition-to-a-children-s-hospital
#15
Peter W Howe, Koshila Kumar
BACKGROUND: The stresses of starting a new job can make anyone feel tired and inefficient. In health care, this may impair the ability to learn at a time when there is most to learn, and increase the risk of error in a context where errors may lead to patient harm. AIM: The aim of this study was to understand issues which influence anesthesia trainees' transition to a pediatric setting. METHODS: This qualitative study utilized in-depth semi-structured interviews to gather data from 31 anesthesia trainees who had commenced work at a tertiary children's hospital between 4 and 6 weeks previously...
November 22, 2016: Paediatric Anaesthesia
https://www.readbyqxmd.com/read/27878459/stapled-mesh-stoma-reinforcement-technique-smart-in-the-prevention-of-parastomal-hernia-a-single-centre-experience
#16
Z Q Ng, P Tan, M Theophilus
PURPOSE: Parastomal hernia remains a frequent complication following creation of an abdominal stoma. Previous interests have centred around the exploration of methods to repair; however, prophylactic mesh placement has demonstrated its efficacy in reduction of parastomal hernia. The aim of this retrospective analysis was to evaluate the outcomes of Stapled Mesh stomA Reinforcement Technique (SMART) in terms of parastomal hernia occurrence rate and mesh-related complications. METHODS AND MATERIALS: All patients operated with an abdominal perineal resection or Hartmann's procedure with SMART from November 2013 to March 2016 were included...
November 22, 2016: Hernia: the Journal of Hernias and Abdominal Wall Surgery
https://www.readbyqxmd.com/read/27876690/-mommy-blogs-and-the-vaccination-exemption-narrative-results-from-a-machine-learning-approach-for-story-aggregation-on-parenting-social-media-sites
#17
Timothy R Tangherlini, Vwani Roychowdhury, Beth Glenn, Catherine M Crespi, Roja Bandari, Akshay Wadia, Misagh Falahi, Ehsan Ebrahimzadeh, Roshan Bastani
BACKGROUND: Social media offer an unprecedented opportunity to explore how people talk about health care at a very large scale. Numerous studies have shown the importance of websites with user forums for people seeking information related to health. Parents turn to some of these sites, colloquially referred to as "mommy blogs," to share concerns about children's health care, including vaccination. Although substantial work has considered the role of social media, particularly Twitter, in discussions of vaccination and other health care-related issues, there has been little work on describing the underlying structure of these discussions and the role of persuasive storytelling, particularly on sites with no limits on post length...
November 22, 2016: JMIR Public Health and Surveillance
https://www.readbyqxmd.com/read/27875379/the-decision-neuroscience-perspective-on-suicidal-behavior-evidence-and-hypotheses
#18
Alexandre Y Dombrovski, Michael N Hallquist
PURPOSE OF REVIEW: Suicide attempts are usually regretted by people who survive them. Furthermore, addiction and gambling are over-represented among people who attempt or die by suicide, raising the question whether their decision-making is impaired. Advances in decision neuroscience have enabled us to investigate decision processes in suicidal people and to elucidate putative neural substrates of disadvantageous decision-making. RECENT FINDINGS: Early studies have linked attempted suicide to poor performance on gambling tasks...
January 2017: Current Opinion in Psychiatry
https://www.readbyqxmd.com/read/27870610/neural-circuits-trained-with-standard-reinforcement-learning-can-accumulate-probabilistic-information-during-decision-making
#19
Nils Kurzawa, Christopher Summerfield, Rafal Bogacz
Much experimental evidence suggests that during decision making, neural circuits accumulate evidence supporting alternative options. A computational model well describing this accumulation for choices between two options assumes that the brain integrates the log ratios of the likelihoods of the sensory inputs given the two options. Several models have been proposed for how neural circuits can learn these log-likelihood ratios from experience, but all of these models introduced novel and specially dedicated synaptic plasticity rules...
November 21, 2016: Neural Computation
https://www.readbyqxmd.com/read/27866283/learning-curves-of-theta-beta-neurofeedback-in-children-with-adhd
#20
Tieme W P Janssen, Marleen Bink, Wouter D Weeda, Katleen Geladé, Rosa van Mourik, Athanasios Maras, Jaap Oosterlaan
: Neurofeedback is widely applied as non-pharmacological intervention aimed at reducing symptoms of ADHD, even though efficacy has not been unequivocally established. Neuronal changes during the neurofeedback intervention that resemble learning can provide crucial evidence for the feasibility and specificity of this intervention. A total of 38 children (aged between 7 and 13 years) with a DSM-IV-TR diagnosis of ADHD, completed on average 29 sessions of theta (4-8 Hz)/beta (13-20 Hz) neurofeedback training...
November 19, 2016: European Child & Adolescent Psychiatry
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