Variation In Behavioral Responses Research Articles

A Network Model for Modulating Sensory Processing Sensitivity in Autism Spectrum Disorder: Epigenetics, Adaptivity, and Other Factors

Autism spectrum disorder (ASD) is a neurodevelopmental condition that can significantly affect an individual's behaviour and social interactions. Comprehending how various factors may influence these behaviours is vital for devising innovative intervention strategies to assist individuals with ASD. This study presents a computational agent model designed to investigate sensory processing sensitivity (SPS) and behavioural responses to stimuli in individuals with ASD. The model incorporates feedback loops to represent the diverse and adaptive behavioural responses observed in these individuals, illustrating the impact of various factors on these behaviours. We specifically explore how epigenetic mechanisms—modifications in gene expression influenced by environmental factors—affect SPS and responsiveness to subtle sensory stimuli in ASD. To evaluate our model and showcase its effectiveness in replicating and predicting the variability in behavioural responses among individuals with ASD, we conducted simulation experiments to reproduce scenarios depicting different responses to visual stimuli. The results highlight the potential of computational models in understanding the intricate sensory experiences in ASD and offer new perspectives for future research and interventions.

Impact of sleep deprivation on memory and learning

Sleep is understood as a natural process of reduction of the body's response to external stimuli, associated with the loss of consciousness, which is useful for several functions. However, there is currently an increase in the number of individuals who do not achieve a good sleep routine, which can be attributed to an increase in exposure to factors that hinder the achievement of adequate time and quality of sleep, leading to various impacts that affect cognitive health and the processes of knowledge acquisition and consolidation. Thus, it aims to clarify the mechanisms associated with sleep deprivation and its repercussions on memory and learning. It is a literature review based on the analysis of scientific articles published from 2012 to 2022, in PubMed and Science Direct, in which the key words "sleep deprivation" AND "memory" AND "learning" were used. It was verified that sleep deprivation can impair several cognitive and affective functions, such as reduced attention, psychomotor vigilance and increased variability in behavioral responses. In relation to memory processing, the decrease of the quantity and the quality sleep time can affect the ability to retain new information and make individuals more prone to develop false memories. Therefore, realizing the fundamental role of sleep in several functions of the human body, highlighting the consolidation of memory and learning, understand the various unfavorable impacts that a reduction in the number and quality of hours of sleep can have.

Population level behavioural responses to variation in habitat quality across multiple locations in a fragmented landscape

Population level behavioural responses to variation in habitat quality across multiple locations in a fragmented landscape

Inter-site variability in the Cape fur seal's behavioural response to boat noise exposure

The impact of man-made noise on wildlife is recognised as a major global concern affecting many taxa in both terrestrial and aquatic ecosystems, with the degree of impact varying among individuals or species. Understanding the factors inducing intra-species differences in response to noise is essential for the development of adapted and effective mitigation measures. This study compares the behavioural response of Cape fur seals to boat noise exposures at two study sites showing differences in their level of exposure to anthropogenic activities, and individual composition. Increased vigilance was found for Lambert's Bay seals exposed to high noise level (70–80 dB) compared to those tested at Cape Town harbour. Comparisons with a similar study performed in Namibia were made. Intrinsic factors such as individuals' age-class, sex or arousal state as well as extrinsic factors such as the ambient noise and the nature/extent of human-seal interactions were suggested to induce such variation.

Quantifying the behavioural consequences of shark ecotourism

Shark populations globally are facing catastrophic declines. Ecotourism has been posited as a potential solution to many of the issues facing shark conservation, yet increasingly studies suggest that such activity may negatively influence aspects of shark ecology and so further pressure declining populations. Here we combine UAV videography with deep learning algorithms, multivariate statistics and hidden Markov models (HMM) to quantitatively investigate the behavioural consequences of ecotourism in the whale shark (Rhincodon typus). We find that ecotourism increases the probability of sharks being in a disturbed behavioural state, likely increasing energetic expenditure and potentially leading to downstream ecological effects. These results are only recovered when fitting models that account for individual variation in behavioural responses and past behavioural history. Our results demonstrate that behavioural responses to ecotourism are context dependent, as the initial behavioural state is important in determining responses to human activity. We argue that models incorporating individuality and context-dependence should, wherever possible, be incorporated into future studies investigating the ecological impacts of shark ecotourism, which are only likely to increase in importance given the expansion of the industry and the dire conservation status of many shark species.

Aging and task design shape the relationship between response time variability and emotional response inhibition

ABSTRACT Intra-individual variability (IIV) refers to within-person variability in behavioural task responses. Several factors can influence IIV, including aging and cognitive demands. The present study investigated effects of aging on IIV of response times during executive functioning tasks. Known age-related differences in cognitive control and emotion processing motivated evaluating how varying the design of emotional response inhibition tasks would influence IIV in older and younger adults. We also tested whether IIV predicted inhibitory control across task designs and age groups. Older and younger adults (N = 237) completed one of three versions of a stop-signal task, which all displayed happy, fearful, or neutral faces in Stop trials. An independent group of older and younger adults (N = 80) completed a go/no-go task also employing happy, fearful and neutral faces. Results showed older adults had more consistent responses (lower IIV) than younger adults in the stop-signal task, but not the go/no-go task. Lower IIV predicted more efficient emotional response inhibition for fear faces in the stop-signal task, but only when attention to emotion was task-relevant. Collectively, this study clarifies effects of aging and task design on IIV and illustrates how task design impacts the relationship between IIV and emotional response inhibition in younger and older adults.

Maternal immune activation as an epidemiological risk factor for neurodevelopmental disorders: Considerations of timing, severity, individual differences, and sex in human and rodent studies.

Epidemiological evidence suggests that one's risk of being diagnosed with a neurodevelopmental disorder (NDD)-such as autism, ADHD, or schizophrenia-increases significantly if their mother had a viral or bacterial infection during the first or second trimester of pregnancy. Despite this well-known data, little is known about how developing neural systems are perturbed by events such as early-life immune activation. One theory is that the maternal immune response disrupts neural processes important for typical fetal and postnatal development, which can subsequently result in specific and overlapping behavioral phenotypes in offspring, characteristic of NDDs. As such, rodent models of maternal immune activation (MIA) have been useful in elucidating neural mechanisms that may become dysregulated by MIA. This review will start with an up-to-date and in-depth, critical summary of epidemiological data in humans, examining the association between different types of MIA and NDD outcomes in offspring. Thereafter, we will summarize common rodent models of MIA and discuss their relevance to the human epidemiological data. Finally, we will highlight other factors that may interact with or impact MIA and its associated risk for NDDs, and emphasize the importance for researchers to consider these when designing future human and rodent studies. These points to consider include: the sex of the offspring, the developmental timing of the immune challenge, and other factors that may contribute to individual variability in neural and behavioral responses to MIA, such as genetics, parental age, the gut microbiome, prenatal stress, and placental buffering.

Behavioral and Physiological Reactions to a Sudden Novel Object in the Weanling Horse: Quantitative Phenotypes for Future GWAS

The startle response can be defined as a reflexive reaction to the sudden appearance of a novel stimulus that influences the survival and resilience of animals. In domesticated species, the behavioral component of the startle response can, in some cases, cause serious injury to the animal or human handlers if inappropriately expressed. Here, we describe a longitudinal study in a population of stock-type horses that quantified behavioral startle responses elicited by the presentation of a sudden novel object (rapidly opening umbrella). The study was performed in weanling foals across four consecutive years (n = 74, mean age = 256 days). Behavioral assays for the startle response phenotype focused on six behavioral variables: latency to return to the feed pan (seconds), maximum distance fled (meters), proportion of time spent walking or trotting (seconds), and how long a horse spent standing facing away from or toward the novel object. We observed behavioral startle response variables in relation to cardiac response, age, and sex for each individual. Each horse's cardiac startle response pattern was determined and categorized into heart rate response cluster groups identified as accelerators and decelerators. Using principal component analysis (PCA) with a factor rotation, we identified "startle response" phenotypes that summarize the behavioral and physiological variables. The largest component of variation, Factor 1, comprised 32.5% of the behavioral variable with a positive correlation with latency and distance, and was not influenced by sex or age. Factor 2 comprised 23.2% of the variation, and was positively correlated with activity level performed such as proportion of time spent walking and/or trotting. Horses with the accelerator type cardiac response had significantly higher Factor 1 scores than decelerators but did not differ in Factor 2. Future work includes expanding our sample size to conduct a genome-wide association study (GWAS) to identify novel genetic loci influencing behavioral startle reactions using recorded behavioral and physiological phenotypes.

Review of individualized current flow modeling studies for transcranial electrical stimulation.

There is substantial intersubject variability of behavioral and neurophysiological responses to transcranial electrical stimulation (tES), which represents one of the most important limitations of tES. Many tES protocols utilize a fixed experimental parameter set disregarding individual anatomical and physiological properties. This one-size-fits-all approach might be one reason for the observed interindividual response variability. Simulation of current flow applying head models based on available anatomical data can help to individualize stimulation parameters and contribute to the understanding of the causes of this response variability. Current flow modeling can be used to retrospectively investigate the characteristics of tES effectivity. Previous studies examined, for example, the impact of skull defects and lesions on the modulation of current flow and demonstrated effective stimulation intensities in different age groups. Furthermore, uncertainty analysis of electrical conductivities in current flow modeling indicated the most influential tissue compartments. Current flow modeling, when used in prospective study planning, can potentially guide stimulation configurations resulting in individually effective tES. Specifically, current flow modeling using individual or matched head models can be employed by clinicians and scientists to, for example, plan dosage in tES protocols for individuals or groups of participants. We review studies that show a relationship between the presence of behavioral/neurophysiological responses and features derived from individualized current flow models. We highlight the potential benefits of individualized current flow modeling.

Dopamine in the rodent tail of striatum regulates behavioral variability in response to threatening novel objects

Mice display variability in fear-like responses to many external salient events, such as encountering unexpected novel objects, but the neural basis of this variability has been unclear. Akiti etal. (2022) demonstrate that dopamine in the tail of the rodent striatum predicts and regulates salience-related variability in individuals' behavioral responses to unexpected novel objects.

Foraging behavior of a mesopelagic predator, the northern elephant seal, in northeastern Pacific eddies

The role of mesoscale features in structuring trophic transfer in the mesopelagic zone is poorly understood. Deploying sensors on marine animals, or “biologging,” is a powerful tool to infer the organism's behavior and simultaneously collect high-resolution oceanographic data to describe physical-biological interactions. We investigated whether mesoscale eddies are used by a mesopelagic predator, the northern elephant seal (Mirounga angustirostris), and if so, what mechanisms might create beneficial foraging conditions in association with eddies. We hypothesized seals would increase their foraging behavior in both cyclonic and anticyclonic eddies due to nutrient enhancement and physical aggregation of prey and that seals would dive deeper in anticyclonic eddies in response to a deeper prey field. We used tracking data and continuous in situ temperature measurements from 221 adult female northern elephant seals collected between 2004 and 2019. These predators primarily targeted myctophid fishes and squid throughout the northeast Pacific mesopelagic zone, foraging between approximately 400–800 m. Eddy encounters were identified using remotely sensed sea level anomaly data and confirmed visually with collocated sea level anomaly, in situ temperature, and in situ temperature anomaly. Over more than 30,000 days of data and >3 million temperature casts collected by seals, we found 129 high confidence encounters with anticyclonic eddies and 83 with cyclonic eddies. Overall, seals traveled more slowly and in a less directed manner while associated with eddies, particularly anticyclonic eddies, suggesting increased foraging behavior, especially in the California Current. Elephant seals spent more time at the edges of cyclonic eddies than their center. In contrast, they utilized both the interior and edge of anticyclonic eddies. This suggests that the aggregation of prey at the frontal region of an eddy is an important mechanism, whereas nutrient upwelling associated with an eddy play a more minor role in enhancing the seals' prey field. Seal foraging behavior was not influenced by eddy age, size, amplitude, or rotational speed. The large sample size in this study showed considerable variation between individual behavioral responses, suggesting caution when extrapolating individual behavior to a population level. Our data show that both cyclonic and anticyclonic eddies can affect the seals' prey field as demonstrated by enhanced foraging behavior. Still, the variation in behavioral responses resulting from individual foraging strategies, eddy histories, and possible spatiotemporal mismatches between eddy physics and biological responses relevant to mesopelagic predators merit further investigation.

Environment-dependent benefits of interindividual variation in honey bee recruitment

Interindividual differences in behaviour within the members of a social group can affect the group's productivity. In eusocial insects, individual differences between workers in a colony play a central role in division of labour and task allocation. Extensive empirical and theoretical work has highlighted variation in response thresholds as a proximate mechanism underlying individual behavioural differences and hence division of labour. However, other response parameters, like response probability and intensity, can also affect these differences. In this study, we first extended a previously published agent-based model on honey bee, Apis mellifera , foraging to understand the relative importance of response (dance) probability and response (dance) intensity in the task of recruitment. Comparing variation obtained from the simulations with previously published empirical data, we found that response intensity played a more important role than probability in producing consistent interindividual differences in recruitment behaviour. We then explored the benefits provided by this individual variation in recruitment behaviour to the colony's collective foraging effort under different environmental conditions. We found that individual variation led to a greater energy yield per forager, but only when food was abundant. Our study highlights the need to consider all response parameters while studying division of labour and adds to the growing body of evidence linking individual variation in behavioural responses to the success of social groups. • A. mellifera foragers show consistent individual differences in recruitment. • Agent-based models were used to explore the role of these differences in the colony. • Empirical findings were reproduced by including response probability and intensity. • Individual variation reduced total recruitment and slightly increased energy yield. • Studies on division of labour should include thresholds, probability, and intensity.

State-dependent tDCS modulation of the somatomotor network: A MEG study

ObjectiveTranscranial direct current stimulation (tDCS) is a non-invasive technique widely used to investigate brain excitability and activity. However, the variability in both brain and behavioral responses to tDCS limits its application for clinical purposes.This study aims to shed light on state-dependency, a phenomenon that contributes to the variability of tDCS. MethodsTo this aim, we investigated changes in spectral activity and functional connectivity in somatomotor regions after Real and Sham tDCS using generalized additive mixed models (GAMMs), which allowed us to investigate how modulation depends on the initial state of the brain. ResultsResults showed that changes in spectral activity, but not connectivity, in the somatomotor regions depend on the initial state of the brain, confirming state-dependent effects. Specifically, we found a non-linear interaction between stimulation conditions (Real vs Sham) and initial state: a reduction of alpha and beta power was observed only in participants that had higher alpha and beta power before Real tDCS. ConclusionsThis study highlights the importance of considering state-dependency to tDCS and shows how it can be taken into account with appropriate statistical models. SignificanceOur findings bear insight into tDCS mechanisms, potentially leading to discriminate between tDCS responders and non-responders.

Predicting and mitigating fatigue effects due to sleep deprivation: A review.

The deleterious effects of insufficient sleep have been well-established in the literature and can lead to a wide range of adverse health outcomes. Some of the most replicated findings demonstrate significant declines in cognitive functions such as vigilance and executive attention, psychomotor and cognitive speed, and working memory. Consequently, these decrements often lead individuals who are in a fatigued state to engage in substandard performance on everyday tasks. In the interest of curtailing these effects, prior work has attempted to identify mechanisms that predict fatigue onset and develop techniques to mitigate its negative consequences. Nonetheless, these results are often confounded by variables such as an individual’s resistance to fatigue, sleep history, and unclear distinctions about whether certain performance decrements are present due to fatigue or due to other confounding factors. Similar areas of research have provided approaches to produce models for the prediction of cognitive performance decrements due to fatigue through the use of multi-modal recording and analysis of fatigue-related responses. Namely, gathering and combining response information from multiple sources (i.e., physiological and behavioral) at multiple timescales may provide a more comprehensive representation of what constitutes fatigue onset in the individual. Therefore, the purpose of this review is to discuss the relevant literature on the topic of fatigue-related performance effects with a special emphasis on a variety of physiological and behavioral response variables that have shown to be sensitive to changes in fatigue. Furthermore, an increasing reliance on sleep loss, meant to assist in meeting the demands of modern society, has led to an upsurge in the relevance of identifying dependable countermeasures for fatigued states. As such, we will also review methods for the mitigation of performance effects due to fatigue and discuss their usefulness in regulating these effects. In sum, this review aims to inspire future work that will create opportunities to detect fatigue and mitigate its effects prior to the onset of cognitive impairments.

Identifying Behavioral Response Profiles of Two Common Larval Fish Models to a Salinity Gradient.

Salinization of aquatic systems is an emerging global issue projected to increase in magnitude, frequency, and duration with climate change and landscape modifications. To consider influences of salinity on locomotor activity of common fish models, we examined behavioral response profiles of two species, zebrafish (Danio rerio) and fathead minnow (Pimephales promelas), across a gradient of sodium chloride. Following each experiment, behavior was recorded with automated tracking software and then behavioral response variables, including locomotor (e.g., distance traveled, number of movements, duration of movements) and photolocomotor changes, were examined at several speed thresholds (bursting, cruising, freezing) to identify potential salinity responses. Zebrafish responses were significantly (p < 0.05) reduced at the highest treatment level (5.78g/L) for multiple behavioral endpoints during both dark and light phases; however, fathead minnow responses were more variable and not consistently concentration dependent. Future efforts are needed to understand behavioral response profiles in combination with anthropogenic contaminants and natural toxins across the freshwater to marine continuum, considering salinization of inland waters, sea level rise, and transport of anthropogenic contaminants and algal toxins from inland waters to coastal systems.

Acute changes in oxytocin predict behavioral responses to foundation training in horses

Ensuring horse welfare is a central aim in equestrian activities. Training is an important context for welfare, as horses form long-lasting representations of people and actions at a young age. However, only a few studies have addressed horses’ emotional responses during early training with humans. In this study, we followed N = 19 young horses, including naïve yearlings and more experienced two- to three-year-olds, through five foundation training sessions over nine months. Our goal was to combine physiological and behavioral measures to assess emotional responses to early foundation training. Specifically, we measured salivary oxytocin (sOXT) in N = 100 samples and salivary cortisol (sCORT) in N = 96 samples before and after training sessions. We also recoded behavioral responses during training. Changes in sOXT during training predicted individual variation in behavioral responses: Horses who showed more affiliative human-directed behaviors during training had increases in sOXT, while horses who showed more behavioral indicators of discomfort during training had decreases in sOXT. Salivary cortisol was not related to individual behavioral responses, but experienced horses had lower sCORT concentrations both before and after training, and all horses showed decreases in sCORT and in behaviors indicative of fear or discomfort as training progressed. In addition, sCORT increased during longer training sessions, consistent with the established role of cortisol in responding to physical stressors. We conclude that individual variation in positive or negative behavioral responses to foundation training corresponds with acute changes in sOXT concentrations in young horses, suggesting that sOXT may be useful as a non-invasive indicator of emotional responses in young horses.

Variation in trauma-related behavioral effects using a preclinical rat model of three predator exposure stress

The underlying mechanisms of trauma-related disorders are challenging to discover and the disorders are difficult to treat, in part due to the complex and varied expressions of response to traumatic stress. These challenges will be easier to overcome as more is understood about the variability in response to trauma. Incorporating assessment of variability into animal models of traumatic stress may allow better translation to clinical research and treatment development. In this study, we characterized variability in behavioral responses following traumatic stress exposure using a predator exposure (PE) animal model. Elevated plus maze (EPM) and acoustic startle response (SR) were used to study avoidance and arousal symptoms in male Sprague–Dawley rats. Behavioral data were compared between control (n = 31) and predator-exposed (n = 30) rats. PE behavior was clustered using k-means principal components analysis. Four clusters and three distinct subgroups were identified and were characterized as avoidant (Cluster 4, 30%), moderately avoidant (Clusters 2 and 3, 49%), and unaffected (Cluster 1, 17%). These results demonstrate that rodent responses to PE are varied, similar to human presentations following traumatic stress, suggesting it may be possible to develop treatment strategies for varied symptom presentations using a preclinical animal model.

The teacher: A few words of appreciation for Iosif Markovich Paley

The article explores I.M. Paley, one of the most prominent representatives of the Ananyev psychological school. The scientific life of I. M. Paley focused on studies of individual differences. He made a significant contribution to the constitution of the Leningrad / St Petersburg differential psychological school. His intensive scientific communication with representatives of Moscow and Perm differential psychological schools (especially with V. D.Nebylitsyn and V. S.Merlin) contributed to the integration of Russian differential psychology and the creation of common theoretical guidelines and comparable diagnostic methods. His psychological and psychophysiological studies were devoted to describing individual differences, explaining their origins (based on inter-level associations), and predicting behavior (how differences in properties of the nervous system, temperament, intelligence, and personality lead to variation in behavioral responses). His research interests addressed the structure and functions of personality with specific interest in the developmental stability and plasticity. Paley believed that an analysis of interlevel relations in the structure of the personality, as well as the elucidation of reasons for the relationship, are the key to understanding the integrity of the individual. In studies conducted under his leadership not only nomothetic, but also idiographic methods of analysis were used, especially micro-longitudinal studies, which allowed the estimation of intraindividual variability. He paid much attention to the methodology of psychological research: the analysis of research schemes, the development and adaptation of diagnostic methods, and the adequate use of statistical methods. Paley was a talented lecturer who taught people to see both the variety of personality manifestations and the variety of their determinants. He designed the first course of lectures in Russia dedicated to differential psychology of the personality. Perhaps his greatest strength was his scientific supervision, in which professional competence, scientific honesty, and genuine interest were combined with an amazing ability to enthrall the students. Science is a dialogue between nature and humanity. Paley knew how to hear the questions that arise in this dialogue and helped us, his students, to master this ability.

It's in the Timing: Reduced Temporal Precision in Neural Activity of Schizophrenia.

Studies of perception and cognition in schizophrenia (SCZ) show neuronal background noise (ongoing activity) to intermittently overwhelm the processing of external stimuli. This increased noise, relative to the activity evoked by the stimulus, results in temporal imprecision and higher variability of behavioral responses. What, however, are the neural correlates of temporal imprecision in SCZ behavior? We first report a decrease in electroencephalography signal-to-noise ratio (SNR) in two SCZ datasets and tasks in the broadband (1-80Hz), theta (4-8Hz), and alpha (8-13Hz) bands. SCZ participants also show lower inter-trial phase coherence (ITPC)-consistency over trials in the phase of the signal-in theta. From these ITPC results, we varied phase offsets in a computational simulation, which illustrated phase-based temporal desynchronization. This modeling also provided a necessary link to our results and showed decreased neural synchrony in SCZ in both datasets and tasks when compared with healthy controls. Finally, we showed that reduced SNR and ITPC are related and showed a relationship to temporal precision on the behavioral level, namely reaction times. In conclusion, we demonstrate how temporal imprecision in SCZ neural activity-reduced relative signal strength and phase coherence-mediates temporal imprecision on the behavioral level.

Effects of Chord Inversion and Bass Patterns on Harmonic Expectancy in Musicians

This study tests the respective roles of pitch-class content and bass patterns within harmonic expectation using a mix of behavioral and computational experiments. In our first two experiments, participants heard a paradigmatic chord progression derived from music theory textbooks and were asked to rate how well different target endings completed that progression. The completion included the progression’s paradigmatic target, different inversions of that chord (i.e., different members of the harmony were heard in the lowest voice), and a “mismatched” target, a triad that shared its lowest pitch with the paradigmatic ending but altered other pitch-class content. Participants generally rated the paradigmatic target most highly, followed by other inversions of that chord, with lowest ratings generally elicited by the mismatched target. This suggests that listeners’ harmonic expectations are sensitive to both bass patterns and pitch-class content. However, these results did not hold in all cases. A final computational experiment was run to determine whether variations in behavioral responses could be explained by corpus statistics. To this end, n-gram chord-transition models and frequency measurements were compiled for each progression. Our findings suggest that listeners rate highly and have stronger expectations about chord progressions that occur frequently and behave consistently within tonal corpora.