Piecing together the role of a spatial assembly intervention in preschoolers' spatial and mathematics learning: Influences of gesture, spatial language, and socioeconomic status.

Spatial skills are associated with mathematics skills, but it is unclear if spatial training transfers to mathematics skills for preschoolers, especially from underserved communities. The current study tested (a) whether spatial training benefited preschoolers' spatial and mathematics skills, (b) if the type of feedback provided during spatial training differentially influenced children's spatial and mathematics skills, and (c) if the spatial training's effects varied by socioeconomic status (SES). Preschoolers (N = 187) were randomly assigned to either a 'business-as-usual' control or one of three spatial training groups (modeling and feedback [MF]; gesture feedback [GF]; spatial language feedback [SLF]). Three-year-olds were trained to construct puzzles to match a model composed of various geometric shapes. New models were created similar to the 2-dimensional trials of the Test of Spatial Assembly (TOSA). Training was given once per week for 5 weeks. Preschoolers were pretested and posttested on 2D and 3D TOSA trials, spatial vocabulary, shape identification, and 2 mathematics assessments. Results indicate that first, any spatial training improved preschoolers' 2D TOSA performance, although a significant interaction with SES indicated improvement was driven by low-SES children. Furthermore, low-SES children showed greatest gains on the 2D TOSA with MF and GF. Second, MF and GF improved low-SES children's performance on the 3D TOSA. Third, only low-SES children with MF saw improvements in far-transfer to mathematics (Woodcock-Johnson: Applied Problems, but not the Test of Early Mathematical Ability). Results indicate that, especially for low-income learners, spatial training can improve children's early spatial and mathematics skills. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Design of Intermittent Control for Cortisol Secretion Under Time-Varying Demand and Holding Cost Constraints.

OBJECTIVE: We take the release of stress hormone cortisol as a part of an intermittent control feedback system in contrast to the existing continuous models. By modeling cortisol secretion as an impulsive system, we design an impulsive controller as opposed to a continuous controller for adjusting cortisol levels while maintaining the blood cortisol levels within bounds that satisfy circadian demand and cost constraints. METHODS: We develop an analytical approach along with an algorithm for identifying both the timing and amplitude of the control. RESULTS: The model and the algorithm are tested by two examples to illustrate that the proposed approach achieves impulsive control and that the obtained blood cortisol levels render the circadian rhythm and the ultradian rhythm consistent with the known physiology of cortisol secretion. CONCLUSIONS: The approach successfully achieves the desired circadian impulsive control, which has great potential to be used in personalizing the medications in order to control the cortisol levels optimally. SIGNIFICANCE: This type of bioinspired intermittent controllers can be employed for designing noncontinuous controllers in treating Addisonian disease, which is caused by the adrenal deficiency.

Gonadotropin-Releasing Hormone (GnRH) Neuron Excitability Is Regulated by Estradiol Feedback and Kisspeptin.

Gonadotropin-releasing hormone (GnRH) neurons produce the central output controlling fertility and are regulated by steroid feedback. A switch from estradiol negative to positive feedback initiates the GnRH surge, ultimately triggering ovulation. This occurs on a daily basis in ovariectomized, estradiol-treated (OVX+E) mice; GnRH neurons are suppressed in the morning and activated in the afternoon. To test the hypotheses that estradiol and time of day signals alter GnRH neuron responsiveness to stimuli, GFP-identified GnRH neurons in brain slices from OVX+E or OVX female mice were recorded during the morning or afternoon. No differences were observed in baseline membrane potential. Current-clamp revealed GnRH neurons fired more action potentials in response to current injection during positive feedback relative to all other groups, which were not different from each other despite reports of differing ionic conductances. Kisspeptin increased GnRH neuron response in cells from OVX and OVX+E mice in the morning but not afternoon. Paradoxically, excitability in kisspeptin knock-out mice was similar to the maximum observed in control mice but was unchanged by time of day or estradiol. A mathematical model applying a Markov Chain Monte Carlo method to estimate probability distributions for estradiol- and time of day-dependent parameters was used to predict intrinsic properties underlying excitability changes. A single identifiable distribution of solutions accounted for similar GnRH neuron excitability in all groups other than positive feedback despite different underlying conductance properties; this was attributable to interdependence of voltage-gated potassium channel properties. In contrast, redundant solutions may explain positive feedback, perhaps indicative of the importance of this state for species survival.SIGNIFICANCE STATEMENT Infertility affects 15%-20% of couples; failure to ovulate is a common cause. Understanding how the brain controls ovulation is critical for new developments in both infertility treatment and contraception. Gonadotropin-releasing hormone (GnRH) neurons are the final common pathway for central neural control of ovulation. We studied how estradiol feedback regulates GnRH excitability, a key determinant of neural firing rate using laboratory and computational approaches. GnRH excitability is upregulated during positive feedback, perhaps driving increased neural firing rate at this time. Kisspeptin increased GnRH excitability and was essential for estradiol regulation of excitability. Modeling predicts that multiple combinations of changes to GnRH intrinsic conductances can produce the firing response in positive feedback, suggesting the brain has many ways to induce ovulation.

Applied Interventions in the Prevention and Treatment of Obesity Through the Research of Professor Jane Wardle.

PURPOSE OF REVIEW: Obesity presents a challenge for practitioners, policy makers, researchers and for those with obesity themselves. This review focuses on psychological approaches to its management and prevention in children and adults. RECENT FINDINGS: Through exploring the work of the late Professor Jane Wardle, we look at the earliest behavioural treatment approaches and how psychological theory has been used to develop more contemporary approaches, for example incorporating genetic feedback and habit formation theory into interventions. We also explore how Jane has challenged thinking about the causal pathways of obesity in relation to eating behaviour. Beyond academic work, Jane was an advocate of developing interventions which had real-world applications. Therefore, we discuss how she not only developed new interventions but also made these widely available and the charity that she established.

The Neural Mechanism Exploration of Adaptive Motor Control: Dynamical Economic Cell Allocation in the Primary Motor Cortex.

Adaptive flexibility is of significance for the smooth and efficient movements in goal attainment. However, the underlying work mechanism of the cerebral cortex in adaptive motor control still remains unclear. How does the cerebral cortex organize and coordinate the activity of a large population of cells in the implementation of various motor strategies? To explore this issue, single-unit activities from the M1 region and kinematic data were recorded simultaneously in monkeys performing 3D reach-to-grasp tasks with different perturbations. Varying motor control strategies were employed and achieved in different perturbed tasks, via the dynamic allocation of cells to modulate specific movement parameters. An economic principle was proposed for the first time to describe a basic rule for cell allocation in the primary motor cortex. This principle, defined as the Dynamic Economic Cell Allocation Mechanism (DECAM), guarantees benefit maximization in cell allocation under limited neuronal resources, and avoids committing resources to uneconomic investments for unreliable factors with no or little revenue. That is to say, the cells recruited are always preferentially allocated to those factors with reliable return; otherwise, the cells are dispatched to respond to other factors about task. The findings of this study might partially reveal the working mechanisms underlying the role of the cerebral cortex in adaptive motor control, wherein is also of significance for the design of future intelligent brain-machine interfaces and rehabilitation device.

Are Nonlinear Model-Free Conditional Entropy Approaches for the Assessment of Cardiac Control Complexity Superior to the Linear Model-Based One?

OBJECTIVE: We test the hypothesis that the linear model-based (MB) approach for the estimation of conditional entropy (CE) can be utilized to assess the complexity of the cardiac control in healthy individuals. METHODS: An MB estimate of CE was tested in an experimental protocol (i.e., the graded head-up tilt) known to produce a gradual decrease of cardiac control complexity as a result of the progressive vagal withdrawal and concomitant sympathetic activation. The MB approach was compared with traditionally exploited nonlinear model-free (MF) techniques such as corrected approximate entropy, sample entropy, corrected CE, two k -nearest-neighbor CE procedures and permutation CE. Electrocardiogram was recorded in 17 healthy subjects at rest in supine position and during head-up tilt with table angles of 15°, 30°, 45°, 60°, and 75°. Heart period (HP) was derived as the temporal distance between two consecutive R-wave peaks and analysis was carried out over stationary sequences of 256 successive HPs. RESULTS: The performance of the MB method in following the progressive decrease of HP complexity with tilt table angles was in line with those of MF approaches and the MB index was remarkably correlated with the MF ones. CONCLUSION: The MB approach can be utilized to monitor the changes of the complexity of the cardiac control, thus speeding up dramatically the CE calculation. SIGNIFICANCE: The remarkable performance of the MB approach challenges the notion, generally assumed in cardiac control complexity analysis based on CE, about the need of MF techniques and could allow real-time applications.

Fairness influences early signatures of reward-related neural processing.

Many humans exhibit a strong preference for fairness during decision-making. Although there is evidence that social factors influence reward-related and affective neural processing, it is unclear if this effect is mediated by compulsory outcome evaluation processes or results from slower deliberate cognition. Here we show that the feedback-related negativity (FRN) and late positive potential (LPP), two signatures of early hedonic processing, are modulated by the fairness of rewards during a passive rating task. We find that unfair payouts elicit larger FRNs than fair payouts, whereas fair payouts elicit larger LPPs than unfair payouts. This is true both in the time-domain, where the FRN and LPP are related, and in the time-frequency domain, where the two signals are largely independent. Ultimately, this work demonstrates that fairness affects the early stages of reward and affective processing, suggesting a common biological mechanism for social and personal reward evaluation.

Concurrent activation of multiple vasoactive signaling pathways in vasoconstriction caused by tubuloglomerular feedback: a quantitative assessment.

Tubuloglomerular feedback (TGF) describes the negative relationship between (a) NaCl concentration at the macula densa and (b) glomerular filtration rate or glomerular capillary pressure. TGF-induced vasoconstriction of the afferent arteriole results from the enhanced effect of several vasoconstrictors with an effect size sequence of adenosine = 20-HETE > angiotensin II > thromboxane = superoxide > renal nerves > ATP. TGF-mediated vasoconstriction is limited by the simultaneous release of several vasodilators with an effect size sequence of nitric oxide > carbon monoxide = kinins > adenosine. The sum of the constrictor effects exceeds that of the dilator effects by the magnitude of the TGF response. The validity of the additive model used in this analysis can be tested by determining the effect of combined inhibition of some or all agents contributing to TGF. Multiple independent contributors to TGF are consistent with the variability of TGF and of the factors contributing to TGF resetting.

A system for predicting musculoskeletal disorders among dental students.

OBJECTIVE: This study aimed to develop a system for predicting work-related musculoskeletal disorders (WMSD) among dental students. MATERIALS AND METHODS: The system comprised 2 accelerometer sensors to register neck and upper back postures and movements, and software developed to collect and process the data. Hidden Markov models (HMMs) were used to predict the likelihood of WMSD in dental students by comparing their neck and upper back movement patterns with WMSD and non-WMSD HMMs learned from previous data. To evaluate the performance of the system, 16 participants were randomly assigned into a 2 × 2 crossover trial scheduled for each sequence of working: receiving feedback or no-feedback from the system. The primary outcome measure was the extension of the neck and upper back, before (pre-test) and after (posttest) receiving feedback or no-feedback from the system. The secondary outcome measure was the log likelihood of classifying the movements as WMSD. RESULTS AND DISCUSSION: The results showed that in the group that received feedback, the extension of the neck in the y axis and of the upper back in the y axis decreased significantly (t test, p < .05) on the post-test. CONCLUSION: The system for predicting and preventing WMSD aids the correction of the extension of the neck and upper back in the y axis.

Maximization, learning, and economic behavior.

The rationality assumption that underlies mainstream economic theory has proved to be a useful approximation, despite the fact that systematic violations to its predictions can be found. That is, the assumption of rational behavior is useful in understanding the ways in which many successful economic institutions function, although it is also true that actual human behavior falls systematically short of perfect rationality. We consider a possible explanation of this apparent inconsistency, suggesting that mechanisms that rest on the rationality assumption are likely to be successful when they create an environment in which the behavior they try to facilitate leads to the best payoff for all agents on average, and most of the time. Review of basic learning research suggests that, under these conditions, people quickly learn to maximize expected return. This review also shows that there are many situations in which experience does not increase maximization. In many cases, experience leads people to underweight rare events. In addition, the current paper suggests that it is convenient to distinguish between two behavioral approaches to improve economic analyses. The first, and more conventional approach among behavioral economists and psychologists interested in judgment and decision making, highlights violations of the rational model and proposes descriptive models that capture these violations. The second approach studies human learning to clarify the conditions under which people quickly learn to maximize expected return. The current review highlights one set of conditions of this type and shows how the understanding of these conditions can facilitate market design.

Development of a novel approach to the assessment of eye-hand coordination.

BACKGROUND: Current methods to measure eye-hand coordination (EHC) have been widely applied in research and practical fields. However, some aspects of the methods, such as subjectivity, high price, portability, and high appraisal contribute to difficulties in EHC testing. NEW METHODS: The test was developed on an Apple iPad(®) and involves tracing up to 13 shapes with a stylus pen. The time taken to complete each trace and the spatial accuracy of the tracing is automatically recorded. The difficulty level for each shape was evaluated theoretically based on the complexity and length of outline. Ten adults aged 31.5±7.8 years and five children aged 9.4±1.1 years with normal vision participated. RESULTS: In adults, the time taken to trace and number of errors significantly decreased from the first to the second attempt (p<0.05) but not thereafter, suggesting a learning effect with repeatability after a practice attempt. Time taken and number of errors in children were both higher in monocular than binocular viewing conditions (p=0.02 and p<0.01, respectively) while adults' performance was similar in both viewing conditions. COMPARISON WITH EXISTING METHODS: Existing EHC tests are subjective in clinics and require higher skills and cost in research, and measure gross EHC. This novel test has been developed to address some of the limitations. CONCLUSIONS: The test is engaging for children and adults and is an objective method with potential for the assessment of fine EHC, suited to clinic-based and research use in ophthalmic or brain trauma settings, and in developmental disorders.

Application of decision-making theory to the regulation of muscular work rate during self-paced competitive endurance activity.

Successful participation in competitive endurance activities requires continual regulation of muscular work rate in order to maximise physiological performance capacities, meaning that individuals must make numerous decisions with regards to the muscular work rate selected at any point in time. Decisions relating to the setting of appropriate goals and the overall strategic approach to be utilised are made prior to the commencement of an event, whereas tactical decisions are made during the event itself. This review examines current theories of decision-making in an attempt to explain the manner in which regulation of muscular work is achieved during athletic activity. We describe rational and heuristic theories, and relate these to current models of regulatory processes during self-paced exercise in an attempt to explain observations made in both laboratory and competitive environments. Additionally, we use rational and heuristic theories in an attempt to explain the influence of the presence of direct competitors on the quality of the decisions made during these activities. We hypothesise that although both rational and heuristic models can plausibly explain many observed behaviours in competitive endurance activities, the complexity of the environment in which such activities occur would imply that effective rational decision-making is unlikely. However, at present, many proposed models of the regulatory process share similarities with rational models. We suggest enhanced understanding of the decision-making process during self-paced activities is crucial in order to improve the ability to understand regulation of performance and performance outcomes during athletic activity.

Evolutionary tradeoffs between economy and effectiveness in biological homeostasis systems.

Biological regulatory systems face a fundamental tradeoff: they must be effective but at the same time also economical. For example, regulatory systems that are designed to repair damage must be effective in reducing damage, but economical in not making too many repair proteins because making excessive proteins carries a fitness cost to the cell, called protein burden. In order to see how biological systems compromise between the two tasks of effectiveness and economy, we applied an approach from economics and engineering called Pareto optimality. This approach allows calculating the best-compromise systems that optimally combine the two tasks. We used a simple and general model for regulation, known as integral feedback, and showed that best-compromise systems have particular combinations of biochemical parameters that control the response rate and basal level. We find that the optimal systems fall on a curve in parameter space. Due to this feature, even if one is able to measure only a small fraction of the system's parameters, one can infer the rest. We applied this approach to estimate parameters in three biological systems: response to heat shock and response to DNA damage in bacteria, and calcium homeostasis in mammals.

Direct assessment of tubuloglomerular feedback responsiveness in connexin 40-deficient mice.

Participation of connexin 40 (Cx40) in the regulation of renin secretion and in the tubuloglomerular feedback (TGF) component of renal autoregulation suggests that gap junctional coupling through Cx40 contributes to the function of the juxtaglomerular apparatus. In the present experiments, we determined the effect of targeted Cx40 deletion in C57BL/6 and FVB mice on TGF responsiveness. In C57BL/6 mice, stop-flow pressure (PSF) fell from 40.3 ± 2 to 34.5 ± 2 mmHg in wild-type (WT) and from 31 ± 1.06 to 26.6 ± 0.98 mmHg in Cx40-/- mice. PSF changes of 5.85 ± 0.67 mmHg in WT and of 4.3 ± 0.55 mmHg in Cx40-/- mice were not significantly different (P = 0.08). In FVB mice, PSF fell from 37.4 ± 1.5 to 31.6 ± 1.5 mmHg in WT and from 28.1 ± 1.6 to 25.4 ± 1.7 mmHg in Cx40-/-, with mean TGF responses being significantly greater in WT than Cx40-/- (5.5 ± 0.55 vs. 2.7 ± 0.84 mmHg; P = 0.002). In both genetic backgrounds, PSF values were significantly lower in Cx40-/- than WT mice at all flow rates. Arterial blood pressure in the animals prepared for micropuncture was not different between WT and Cx40-/- mice. We conclude that the TGF response magnitude in superficial cortical nephrons is reduced by 30-50% in mice without Cx40, but that with the exception of a small number of nephrons, residual TGF activity is maintained. Thus gap junctional coupling appears to modulate TGF, perhaps by determining the kinetics of signal transmission.

The balance of striatal feedback transmission is disrupted in a model of parkinsonism.

Inhibitory connections among striatal projection neurons (SPNs) called "feedback inhibition," have been proposed to endow the striatal microcircuit with computational capabilities, such as motor sequence selection, filtering, and the emergence of alternating network states. These properties are disrupted in models of Parkinsonism. However, the impact of feedback inhibition in the striatal network has remained under debate. Here, we test this inhibition at the microcircuit level. We used optical and electrophysiological recordings in mice and rats to demonstrate the action of striatal feedback transmission in normal and pathological conditions. Dynamic calcium imaging with single-cell resolution revealed the synchronous activation of a pool of identified SPNs by antidromic stimulation. Using bacterial artificial chromosome-transgenic mice, we demonstrate that the activated neuron pool equally possessed cells from the direct and indirect basal ganglia pathways. This pool inhibits itself because of its own GABA release when stimuli are frequent enough, demonstrating functional and significant inhibition. Blockade of GABAA receptors doubled the number of responsive neurons to the same stimulus, revealing a second postsynaptic neuron pool whose firing was being arrested by the first pool. Stronger connections arise from indirect SPNs. Dopamine deprivation impaired striatal feedback transmission disrupting the ability of a neuronal pool to arrest the firing of another neuronal pool. We demonstrate that feedback inhibition among SPNs is strong enough to control the firing of cell ensembles in the striatal microcircuit. However, to be effective, feedback inhibition should arise from synchronized pools of SPNs whose targets are other SPNs pools.

Monovalent and multivalent ligation of the B cell receptor exhibit differential dependence upon Syk and Src family kinases.

The Src and Syk families of kinases are two distinct sets of kinases that play critical roles in initiating membrane-proximal B cell receptor (BCR) signaling. However, unlike in other lymphocytes, such as T cells, the "division of labor" between Src family kinases (SFKs) and Syk in B cells is not well separated because both Syk and SFKs can phosphorylate immunoreceptor tyrosine-based activation motifs (ITAMs) present in proteins comprising the BCR. To understand why B cells require both SFKs and Syk for activation, we investigated the roles of both families of kinases in BCR signaling with computational modeling and in vitro experiments. Our computational model suggested that positive feedback enabled Syk to substantially compensate for the absence of SFKs when spatial clustering of BCRs was induced by multimeric ligands. We confirmed this prediction experimentally. In contrast, when B cells were stimulated by monomeric ligands that failed to produce BCR clustering, both Syk and SFKs were required for complete and rapid BCR activation. Our data suggest that SFKs could play a pivotal role in increasing BCR sensitivity to monomeric antigens of pathogens and in mediating a rapid response to soluble multimeric antigens of pathogens that can induce spatial BCR clustering.

Calcium feedback to cGMP synthesis strongly attenuates single-photon responses driven by long rhodopsin lifetimes.

Rod photoreceptors generate amplified, reproducible responses to single photons via a G protein signaling cascade. Surprisingly, genetic perturbations that dramatically alter the deactivation of the principal signal amplifier, the GPCR rhodopsin (R∗), do not much alter the amplitude of single-photon responses (SPRs). These same perturbations, when crossed into a line lacking calcium feedback regulation of cGMP synthesis, produced much larger alterations in SPR amplitudes. Analysis of SPRs from rods with and without feedback reveal that the consequences of trial-to-trial fluctuations in R∗ lifetime in normal rods are also dampened by feedback regulation of cGMP synthesis. Thus, calcium feedback trumps the mechanisms of R∗ deactivation in determining the SPR amplitude, attenuating responses arising from longer R∗ lifetimes to a greater extent than those arising from shorter ones. As a result, rod SPRs achieve a more stereotyped amplitude, a characteristic considered important for reliable transmission through the visual system.

Task-switching in oculomotor control: unidirectional switch-cost when alternating between pro- and antisaccades.

The antisaccade task requires the suppression of a reflexive prosaccade (i.e., response suppression) and the remapping of a target location to mirror-symmetrical space (i.e., vector inversion). Moreover, antisaccades are associated with increased activation of cortical oculomotor networks: a finding attributed to the top-down requirements of response suppression and vector inversion. The goal of the present study was to determine if the increased cortical activity associated with antisaccades elicits a residual inhibition of oculomotor planning networks. To that end, each trial in this investigation entailed the onset of a single and exogenously presented target (i.e., archetypical antisaccade task) and participants were instructed to alternate between pro- and antisaccades in blocked and random task-switching schedules. In the blocked schedule, the saccade tasks (i.e., pro- and antisaccades) alternated on every second trial (AABB paradigm) whereas in the random schedule the saccade tasks were pseudo-randomly interleaved on a trial-by-trial basis. Reaction times for task-switch prosaccades were longer and more variable than their task-repetition counterparts, whereas antisaccades did not vary as a function of task-switch and task-repetition trials: a finding that was consistent across blocked and random presentation schedules. In other words, results demonstrate a unidirectional switch-cost for prosaccades. As such, we propose that the top-down processes required to complete an antisaccade results in residual inhibition of oculomotor networks supporting a subsequent prosaccade.

[The assessment of reactions of polygraphic parameters at HRV-biofeedback training in adolescents with different variants of cardiac autonomic nervous system tone].

There is examine a character of change of brain bioelectric activity and polygraphic indicators at sessions of biofeedback by heart rhythm variability parameters (HRV-biofeedback) in 15-17 years adolescents who have different variants of cardiac autonomic nervous system tone. It is taped, that adolescents with cardiac balanced tone have more intensive optimization of functional brain activity in comparison with adolescents who have cardiac sympathetic tone - increase on alpha-activity and theta-activity depression in electroencephalogram structure. There were optimization of neurodynamic processes and most expressed stabilization of the hemodynamics indicators in adolescents with cardiac sympathetic tone after HRV-biofeedback training.