Prefrontal-subcortical pathways mediating successful emotion regulation

Although prefrontal cortex has been implicated in the cognitive regulation of emotion, the cortical-subcortical interactions that mediate this ability remain poorly understood. To address this issue, we identified a right ventrolateral prefrontal region (vlPFC) whose activity correlated with reduced negative emotional experience during cognitive reappraisal of aversive images. We then applied a pathway-mapping analysis on subcortical regions to locate mediators of the association between vlPFC activity and reappraisal success (i.e., reductions in reported emotion). Results identified two separable pathways that together explained approximately 50% of the reported variance in self-reported emotion: (1) a path through nucleus accumbens that predicted greater reappraisal success, and (2) a path through ventral amygdala that predicted reduced reappraisal success (i.e., more negative emotion). These results provide direct evidence that vlPFC is involved in both the generation and regulation of emotion through different subcortical pathways, suggesting a general role for this region in appraisal processes.     

Extended charge banking model of dual path shocks for implantable cardioverter defibrillators

Background  

Single path defibrillation shock methods have been improved through the use of the Charge Banking Model of defibrillation, which predicts the response of the heart to shocks as a simple resistor-capacitor (RC) circuit. While dual path defibrillation configurations have significantly reduced defibrillation thresholds, improvements to dual path defibrillation techniques have been limited to experimental observations without a practical model to aid in improving dual path defibrillation techniques.     

Path Models of Vocal Emotion Communication

We propose to use a comprehensive path model of vocal emotion communication, encompassing encoding, transmission, and decoding processes, to empirically model data sets on emotion expression and recognition. The utility of the approach is demonstrated for two data sets from two different cultures and languages, based on corpora of vocal emotion enactment by professional actors and emotion inference by naïve listeners. Lens model equations, hierarchical regression, and multivariate path analysis are used to compare the relative contributions of objectively measured acoustic cues in the enacted expressions and subjective voice cues as perceived by listeners to the variance in emotion inference from vocal expressions for four emotion families (fear, anger, happiness, and sadness). While the results confirm the central role of arousal in vocal emotion communication, the utility of applying an extended path modeling framework is demonstrated by the identification of unique combinations of distal cues and proximal percepts carrying information about specific emotion families, independent of arousal. The statistical models generated show that more sophisticated acoustic parameters need to be developed to explain the distal underpinnings of subjective voice quality percepts that account for much of the variance in emotion inference, in particular voice instability and roughness. The general approach advocated here, as well as the specific results, open up new research strategies for work in psychology (specifically emotion and social perception research) and engineering and computer science (specifically research and development in the domain of affective computing, particularly on automatic emotion detection and synthetic emotion expression in avatars).     

How phenological tracking shapes species and communities in non-stationary environments

Climate change alters the environments of all species. Predicting species responses requires understanding how species track environmental change, and how such tracking shapes communities. Growing empirical evidence suggests that how species track phenologically – how an organism shifts the timing of major biological events in response to the environment – is linked to species performance and community structure. Such research tantalizingly suggests a potential framework to predict the winners and losers of climate change, and the future communities we can expect. But developing this framework requires far greater efforts to ground empirical studies of phenological tracking in relevant ecological theory. Here we review the concept of phenological tracking in empirical studies and through the lens of coexistence theory to show why a community-level perspective is critical to accurate predictions with climate change. While much current theory for tracking ignores the importance of a multi-species context, basic community assembly theory predicts that competition will drive variation in tracking and trade-offs with other traits. We highlight how existing community assembly theory can help understand tracking in stationary and non-stationary systems. But major advances in predicting the species- and community-level consequences of climate change will require advances in theoretical and empirical studies. We outline a path forward built on greater efforts to integrate priority effects into modern coexistence theory, improved empirical estimates of multivariate environmental change, and clearly defined estimates of phenological tracking and its underlying environmental cues.     

Response waveforms of vertebrate photoreceptors: What are the underlying mechanisms?

A class of models is investigated using computer simulation in which the inner and outer segments of the vertebrate photoreceptor are coupled through a pump. The outer segment membrane conductance is controlled by an internal transmitter, activated by photolysis of the photosensitive molecules in the cell. Several possibilities for the coupling dynamics are investigated. The analysis favors the conclusion that the hyperpolarizing transient at high intensity stimuli arises from the coupling dynamics, (unless there is an extracellular current shunt path). It predicts, moreover, that the transient shold be observed intracellularly, but not extracellularly to the outer segment, This is, in fact, the case. It also predicts that the trasient should become more marked, as the steady state ratio of inner to outer segment currents decreases. The computer simulations are concerned with the intracellularly recorded responses; the long term adaptation parallel to pigment bleaching and regeneration is not considered explicitly here. In conclusion, it is shown that the state conditions as well as the response waveforms can be related to physiologically significant variables.     

Photosensory transduction in the flagellated alga, Euglena gracilis I. Action of divalent cations, Ca2+ antagonists and Ca2+ ionophore on motility and photobehavior.

1. The flagellated alga, Euglena gracilis, swims forward essentially in a straight path under constant light intensity. Strong motility of the cells can be supported by Mg2+ alone but optimum motility is found in the presence of Mg2+, Ca2+ and K+. 2. Ca2+, Co2+, Mn2+ and Ba2+ induce a concentration-dependent increase in the rate at which the cells change the direction of their swimming path (a klinokinesis). Ni2+ immobilizes the flagellum. 3. On perception of a reduction ('step-down stimulus') in blue light intensity in their environment, Euglena rotate in place (tumble) for a finite period (the step-down photophobic response). 4. The duration of the tumbling is enhanced in the presence of divalent cations following the series Ca2+ greater than Ba2+ greater than Mn2+ greater than Co2+ greater than Mg2+ = Ni2+ = 0. 5. Neither the tumbling response in the presence of low concentrations of Ca2+ or the Ca2+-stimulated response is altered by verapamil (a Ca2+ conductance antagonist). The Ca2+ conductance/active transport antagonist, ruthenium red, is also inactive. 6. The Ca2+ ionophore, A23187, has little effect on flagellar activity in the absence of extracellular Ca2+. However, in the presence of A23187, Ca2+ induces a specific light-independent, concentration-dependent discontinuous tumbling response of the cells. 7. The data support a role for Ca2+ and Mg2+ in control of flagellar activity. However, blue light-induced tumbling behavior would not appear to be the direct result of a light-mediated alteration in the Ca2+ conductance of the flagellar membrane to affect flagellar reorientation. The results are discussed in connection with previous theories on control of flagella activity in green alga.     

Attentional Modulation of Emotional Conflict Processing with Flanker Tasks

Emotion processing has been shown to acquire priority by biasing allocation of attentional resources. Aversive images or fearful expressions are processed quickly and automatically. Many existing findings suggested that processing of emotional information was pre-attentive, largely immune from attentional control. Other studies argued that attention gated the processing of emotion. To tackle this controversy, the current study examined whether and to what degrees attention modulated processing of emotion using a stimulus-response-compatibility (SRC) paradigm. We conducted two flanker experiments using color scale faces in neutral expressions or gray scale faces in emotional expressions. We found SRC effects for all three dimensions (color, gender, and emotion) and SRC effects were larger when the conflicts were task relevant than when they were task irrelevant, suggesting that conflict processing of emotion was modulated by attention, similar to those of color and face identity (gender). However, task modulation on color SRC effect was significantly greater than that on gender or emotion SRC effect, indicating that processing of salient information was modulated by attention to a lesser degree than processing of non-emotional stimuli. We proposed that emotion processing can be influenced by attentional control, but at the same time salience of emotional information may bias toward bottom-up processing, rendering less top-down modulation than that on non-emotional stimuli.     

Sex Differences and Emotion Regulation: An Event-Related Potential Study

Difficulties in emotion regulation have been implicated as a potential mechanism underlying anxiety and mood disorders. It is possible that sex differences in emotion regulation may contribute towards the heightened female prevalence for these disorders. Previous fMRI studies of sex differences in emotion regulation have shown mixed results, possibly due to difficulties in discriminating the component processes of early emotional reactivity and emotion regulation. The present study used event-related potentials (ERPs) to examine sex differences in N1 and N2 components (reflecting early emotional reactivity) and P3 and LPP components (reflecting emotion regulation). N1, N2, P3, and LPP were recorded from 20 men and 23 women who were instructed to “increase,” “decrease,” and “maintain” their emotional response during passive viewing of negative images. Results indicated that women had significantly greater N1 and N2 amplitudes (reflecting early emotional reactivity) to negative stimuli than men, supporting a female negativity bias. LPP amplitudes increased to the “increase” instruction, and women displayed greater LPP amplitudes than men to the “increase” instruction. There were no differences to the “decrease” instruction in women or men. These findings confirm predictions of the female negativity bias hypothesis and suggest that women have greater up-regulation of emotional responses to negative stimuli. This finding is highly significant in light of the female vulnerability for developing anxiety disorders.     

I know it when I quantify it: ecological momentary assessment and recurrence quantification analysis of emotion dysregulation in children with ADHD

Two studies examined the feasibility, utility, and validity of Ecological Momentary Assessment (EMA) and Recurrence Quantification Analysis (RQA) in assessing emotion dysregulation in children with Attention-Deficit/Hyperactivity Disorder (ADHD). In Study 1, 11 parents of children with ADHD ages 8–11 completed EMA-based ratings of their children’s mood three times daily for 28 days (84 ratings total) and questionnaires regarding their children’s emotion dysregulation. RQA was used to quantify the temporal patterning of dysregulation of the children’s mood. In Study 2, five children ages 8–11 completed EMA-based ratings of their mood three times daily for 28 days. Results supported the feasibility and validity of the parent report EMA protocol, with greater intensity, variability, and persistent patterning of variability associated with greater emotion dysregulation. Results did not support the validity of the child report protocol, as children were less likely to complete ratings when emotionally distressed and demonstrated substantial response bias.     

What visual information is used for navigation around obstacles in a cluttered environment?

The goal of this study was to determine what visual information is used to navigate around barriers in a cluttered terrain. Twelve traffic pylons were arranged randomly in a 4.55 x 3.15 m travel area: there were 20 different arrangements. For each arrangement, individuals (N = 6) were positioned in 1 of 3 locations on the outside border with their eyes closed: on verbal command they were instructed to open their eyes and quickly go to 1 of 2 specified goals (2 vertical posts defining a door) located on one edge of the travel area. The movement of the body was tracked using the OPTOTRAK system, with the IREDS placed on a collar worn by the subjects. Experimental data of travel path chosen were compared with those predicted by models that incorporated different types of visual information to control path trajectory. The 6 models basically use 2 different strategies for route selection: reactive control based on visual input about the obstacle encountered in the line-of-sight travel path (Model # 1) and path planning based on different visual information (Model # 2, 3, 4, 5, and 6). The models that involve path planning are grouped into 2 categories: models 2, 3, 4, and 5 need detailed geometrical configuration of the obstacles to plan a route while model 6 plans a route based on identifying and avoiding a cluster of obstacles in the travel path. Two measures were used to compare model performance with the actual travel path: the difference in area between predicted and actual travel path and the number of trials that accurately predicted the number of turns during travel. The results suggest that route selection is not based on reactive control, but does involve path planning. The model that best predicts the travel paths taken by the individuals uses visual information about cluster of obstacles and identification of safe corridors to plan a route.     

Experiments and a model examining learning in the area-restricted search behavior of ferrets (Mustela putorius furo)

Area-restricted searches have been described as important componentsof the foraging behavior of many organisms. It is unclear, however,whether individual foragers can use learning to fine-tune theirsearches, or even whether these searches are efficiently performed.I used a simulation model to make qualitative predictions aboutsearch behavior in a laboratory system. The simulation modelindicates that the sinuosity and path length of searches stronglyaffect search efficiency. The model predicts that, for a rate-maximizingforager, path length should increase and search sinuosity shoulddecrease as prey become less clumped. Foraging animals may thereforebe selected to learn the path length and sinuosity of searchesin response to changing degrees of dumping of prey. These predictionswere tested in a laboratory system involving ferrets (Mustelaputorius furo) foraging for oil-drop "prey items." Search pathschanged in a graded manner to experimental manipulations ofthe dumping of prey. As predicted by the model, ferrets learnedto perform longer and less sinuous search paths as prey becameless clumped. This study provides the first evidence that area-restrictedsearch behavior is learned and can be fine-tuned to efficientlyexploit different spatial distributions of food.     

Rapid evolution of sperm length in response to increased temperature in an ectothermic fish

The Intergovernmental Panel on Climate Change predicts an average global temperature increase of 1.8–4.0 °C by 2100. Tropical ectotherms are expected to be particularly sensitive to this temperature increase because they live close to their thermal limits. We investigated the phenotypic plasticity and evolutionary response of sperm traits in guppies (Poecilia reticulata) to increased temperatures after 6, 18, and 24 months. Guppies with evolution temperatures of 25 °C (control) or 28 °C were reared in either 25 or 28 °C in a 2 × 2 common garden design. The plastic response to increased temperature was a decreased sperm length, velocity, and path linearity. The evolutionary response was a subsequent increase in sperm length, resulting in complete compensation after just 6 months (at most four generations) in 28 °C water. Sperm velocity and linearity showed no sign of evolution even after 24 months. This study provides evidence that some reproductive traits can respond via rapid evolution to the temperature increase associated with climate change.     

A Diffusion Model Analysis of Decision Biases Affecting Delayed Recognition of Emotional Stimuli

Previous empirical work suggests that emotion can influence accuracy and cognitive biases underlying recognition memory, depending on the experimental conditions. The current study examines the effects of arousal and valence on delayed recognition memory using the diffusion model, which allows the separation of two decision biases thought to underlie memory: response bias and memory bias. Memory bias has not been given much attention in the literature but can provide insight into the retrieval dynamics of emotion modulated memory. Participants viewed emotional pictorial stimuli; half were given a recognition test 1-day later and the other half 7-days later. Analyses revealed that emotional valence generally evokes liberal responding, whereas high arousal evokes liberal responding only at a short retention interval. The memory bias analyses indicated that participants experienced greater familiarity with high-arousal compared to low-arousal items and this pattern became more pronounced as study-test lag increased; positive items evoke greater familiarity compared to negative and this pattern remained stable across retention interval. The findings provide insight into the separate contributions of valence and arousal to the cognitive mechanisms underlying delayed emotion modulated memory.     

Effects of low-spatial frequency components of fearful faces on fusiform cortex activity

Emotive faces elicit neural responses even when they are not consciously perceived. We used faces hybridized from spatial frequency-filtered individual stimuli to study processing of facial emotion. Employing event-related functional magnetic resonance imaging (fMRI), we show enhanced fusiform cortex responses to hybrid faces containing fearful expressions when such emotional cues are present in the low-spatial frequency (LSF) range. Critically, this effect is independent of whether subjects use LSF or high-spatial frequency (HSF) information to make gender judgments on the hybridized faces. The magnitude of this fusiform enhancement predicts behavioral slowing in response times when participants report HSF information of the hybrid stimulus in the presence of fear in the unreported LSF components. Thus, emotional modulation of a face-responsive region of fusiform is driven by the low-frequency components of the stimulus, an effect independent of subjects' reported perception but evident in an incidental measure of behavioral performance.     

Testing the Threat‐Sensitive Hypothesis with Predator Familiarity and Dietary Specificity

In a system with multiple predators, the threat‐sensitive predator avoidance hypothesis predicts that prey respond differently to predators relative to the risks each poses (e.g., degree of dietary specialization). Aquatic animals often rely heavily on detecting predators via chemical cues (kairomones) and respond with a suite of behaviors including detection and avoidance. However, little is known about how animals respond to kairomones of specialist versus generalist predators. In laboratory experiments, we compared behavioral responses of a poorly studied aquatic salamander, the greater siren (Siren lacertina), to cues from specialist and generalist predator snakes to evaluate threat‐sensitive responses. Sirens exhibited a novel behavior (gill‐flushing) most often in the presence of specialist predator cues. Avoidance behavior (reversing direction following cue detection) was higher in response to specialist predator and novel animal control cues and lowest in response to generalist predator cues. An intermediate response to the animal control, an unfamiliar amphibian predator, indicated that sirens respond cautiously to a novel cue. The gradient of observed responses to different snake cues indicates that sirens may be evaluating predation potential of animals based on their foraging specificity and familiarity.     

How to make a mesodiencephalic dopaminergic neuron

Dopaminergic neurons located in the ventral mesodiencephalon are essential for the control of voluntary movement and the regulation of emotion, and are severely affected in neurodegenerative diseases such as Parkinson's disease. Recent advances in molecular biology and mouse genetics have helped to unravel the mechanisms involved in the development of mesodiencephalic dopaminergic (mdDA) neurons, including their specification, migration and differentiation, as well as the processes that govern axonal pathfinding and their specific patterns of connectivity and maintenance. Here, we follow the developmental path of these neurons with the goal of generating a molecular code that could be exploited in cell-replacement strategies to treat diseases such as Parkinson's disease.     

不同心理素质水平军人在厌恶情绪条件下自主神经反应特点

目的：探讨不同心理素质水平军人在厌恶情绪条件下自主神经反应特点。方法：用军人心理素质量表筛选出54名部队官兵,其中高、中、低心理素质组军人各18名。采用3份情绪视频材料,诱导被试的中性和厌恶情绪,利用八通道多参数生物反馈仪,记录自主神经反应的十个指标和相应自主神经反应指标的平均恢复时间。结果：（1）在中性情绪条件下,低心理素质组[（12．06±4．89）b／min]的心率（HR）的变化上显著大于高心理素质组[（5．75±2．80）b／min];（2）在厌恶情绪条件下,低心理素质组f（7．09±2．02）nU]的心率变异性（rmv）频谱归-化低频功率（Lfnorm）的变化显著大于中等[（3．43±1．70）nU]与高心理素质组[（2．66±1．50）nU];低心理素质组[（357．94±129．33）Hz]的总功率（TP）的变化显著大于中等[（171．1±73．02）ms。]与高心理素质组[（167．84±86．38）ms／];（3）在自主神经反应指标的恢复时间上,低心理素质组[（49．98±10．96）秒]在厌恶情绪条件下其心率（HR）的恢复时间显著大于高心理素质组[（24．65±9．38）see];低心理素质组[（37．84±21．33）sec]在厌恶情绪条件下其皮电（SC）、皮温（TEMP）、指端血容振幅（BVP）、心率（HR）四个自主神经反应指标的平均恢复时间上显著大于高心理素质组[（18．57±10．15）秒]。（4）在情绪的愉悦度、唤醒度的上,低心理素质组（0．88±1．11）在中性条件下其唤醒度的变化明显大于中等（0．50±0．70）与高心理素质组（0．12±0．33）;低心理素质组（-2．11±0．90）在厌恶条件下愉悦度的变化明显大于中等（-1．56±0．86）与高心理素质组（-1．33±0．84）。结论：在中性条件下,低心理素质军人更容易出现生理上的唤醒警觉状态。在厌恶情绪条件下,低心理素质军人是副交感神经伴有较强交感神经兴奋的自主神经反应模式;高、中等心理素质军人副交感神经伴有较弱的交感神经兴奋。     

Differential Brain Activation to Angry Faces by Elite Warfighters: Neural Processing Evidence for Enhanced Threat Detection

Background

Little is known about the neural basis of elite performers and their optimal performance in extreme environments. The purpose of this study was to examine brain processing differences between elite warfighters and comparison subjects in brain structures that are important for emotion processing and interoception.

Methodology/Principal Findings

Navy Sea, Air, and Land Forces (SEALs) while off duty (n = 11) were compared with n = 23 healthy male volunteers while performing a simple emotion face-processing task during functional magnetic resonance imaging. Irrespective of the target emotion, elite warfighters relative to comparison subjects showed relatively greater right-sided insula, but attenuated left-sided insula, activation. Navy SEALs showed selectively greater activation to angry target faces relative to fearful or happy target faces bilaterally in the insula. This was not accounted for by contrasting positive versus negative emotions. Finally, these individuals also showed slower response latencies to fearful and happy target faces than did comparison subjects.

Conclusions/Significance

These findings support the hypothesis that elite warfighters deploy greater processing resources toward potential threat-related facial expressions and reduced processing resources to non-threat-related facial expressions. Moreover, rather than expending more effort in general, elite warfighters show more focused neural and performance tuning. In other words, greater neural processing resources are directed toward threat stimuli and processing resources are conserved when facing a nonthreat stimulus situation.     

Coping with complexity: machine learning optimization of cell-free protein synthesis

Biological systems contain complex metabolic pathways with many nonlinearities and synergies that make them difficult to predict from first principles. Protein synthesis is a canonical example of such a pathway. Here we show how cell-free protein synthesis may be improved through a series of iterated high-throughput experiments guided by a machine-learning algorithm implementing a form of evolutionary design of experiments (Evo-DoE). The algorithm predicts fruitful experiments from statistical models of the previous experimental results, combined with stochastic exploration of the experimental space. The desired experimental response, or evolutionary fitness, was defined as the yield of the target product, and new experimental conditions were discovered to have ～ 350% greater yield than the standard. An analysis of the best experimental conditions discovered indicates that there are two distinct classes of kinetics, thus showing how our evolutionary design of experiments is capable of significant innovation, as well as gradual improvement.