Changes In Behavioral Activity Research Articles

Bidirectional relationship between intraindividual changes in behavioral activation and intraindividual changes in postpartum depressive symptoms: A random intercept cross-lagged panel model.

According to Lewisohn's model of depression, decreases in behavioral activation (BA) occurring after facing a vital stressor may increase the risk of depression. Transition to parenthood is a potentially stressful life event that increases the risks of postpartum depression. We aimed to (a) describe the changes in BA and depressive symptomatology between the prepartum period, 1 month, 3 months, and 6 months postpartum and (b) evaluate the bidirectionality of the relationship between intraindividual changes in BA and intraindividual changes in depressive symptoms longitudinally. Chilean pregnant women (N = 503) completed a battery of questionnaires when they were between 32 and 37 weeks of gestation and 1, 3, and 6 months after delivery. A repeated measures analysis of variance showed that BA significantly decreased from prepartum to 1 month postpartum. A random intercept cross-lagged panel model supported the bidirectional inverse relationship between intraindividual changes in BA and intraindividual changes in depressive symptoms. The effect sizes of these associations were large (βs ranging from -.141 to -.243) according to Orth et al. (2022)'s recommendations for cross-lagged effect benchmarks. This relationship showed robustness when multigroup random intercept cross-lagged panel models were conducted to adjust for several covariates (i.e., marital status, the type of health insurance, type of delivery, primiparous vs. multiparous participants, and pregnancy or delivery complication or newborn health problem). Nonetheless, reporting a previous history of major depression moderated this relationship so that intraindividual decreases in BA more likely led to intraindividual increases in depressive symptoms in people with a history of depression than in people without such a history. We discuss implications for behavioral models of depression. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Supplemental Material for Bidirectional Relationship Between Intraindividual Changes in Behavioral Activation and Intraindividual Changes in Postpartum Depressive Symptoms: A Random Intercept Cross-Lagged Panel Model

Supplemental Material for Bidirectional Relationship Between Intraindividual Changes in Behavioral Activation and Intraindividual Changes in Postpartum Depressive Symptoms: A Random Intercept Cross-Lagged Panel Model

Mechanisms of Change in Behavioral Activation: Adapting Depression Treatment for Autistic People

Despite high rates of co-occurring depression, few studies have developed or adapted treatments targeting depressive symptoms for autistic adults. Behavioral activation is widely accepted as an empirically supported approach for treating depression in other populations. Careful attention to the mechanisms targeted by behavioral activation is an essential step toward adapting behavioral activation protocols for use with autistic adults. We consider the mechanisms targeted by behavioral activation and provide a framework for research to explore facilitators and barriers to the use of behavioral activation to treat depression in autistic adults. Drawing upon clinical experience and extant literature, the suggestions presented are aimed at highlighting considerations for clinicians wanting to use behavioral activation programs in their clinical practices with autistic adults and to promote the research needed to establish behavioral activation as an evidence-based practice for treating depression in adults on the autism spectrum.

Влияние модели разового вахтового труда в высокогорье на поведение и структурную организацию мозжечка

In Kyrgyzstan, 94% of the entire territory of the country is occupied by mountains. There are significant resources located here, the development of which is often associated with the temporary ascent to significant heights and descent to the low mountains of specialists in various fields of work. At the same time, information about the state of brain structures and the behavior of animals and humans in these conditions is scarce. Objective: to study the influence of the model of a one-time 8-hour shift work in the highlands on the histophysiology of the cerebellum and individual behavior of rats. The work was performed on 28 white mongrel male rats weighing 250–310 g. The low-mountain series of the experiment was carried out at an altitude of 760 m above sea level (Bishkek). The high-altitude series was modeled on the Tuya-Ashu pass-3200 m above sea level (Kyrgyzstan). Behavioral activity was evaluated using the Open field method, muscle strength according to the S. V. Speransky method on the 3rd day of the experiment. The microcirculation of the cerebellum was studied microscopically under the Olympus B×40 light microscope (Japan). Statistical processing of the obtained data was carried out in the SPSS 16.0 program. In the highlands, the indicators of the mink reflex increase by 1.43 times, and the level of defecation increases by 8.5 times, which is a marker of increased vegetative activity of the body. Remodeling of cerebellar angioarchitectonics in the highlands is characterized by hypercapillarization, signs of blood stagnation, perivascular edema, enlargement of nucleoli, moderate hyperchromia of neurons of the molecular and granular layers. Thus, in the highlands, changes in behavioral activity are more pronounced than the remodeling of capillaries, neurons and glial elements, which are adaptive in nature.

A Modelling of Context-Aware Elderly Healthcare Eco-System-(CA-EHS) Using Signal Analysis and Machine Learning Approach

Advances in digital and communication technologies have led to the rapid development of advanced technologies such as machine learning, the Internet of Things, and cloud systems that automate the work process in healthcare, education, and multiple industries. Nowadays, the elderly are often left alone at home, so it is necessary to track their health and behavioral activity. In this paper, modeling a context-aware automated elderly activity monitoring system is proposed to monitor elderly biological conditions and behavioral activity changes uninterruptedly. In the proposed system, sensory data is collected through a variety of sensor devices. Based on captured sensory signals, elderly health forecasting is performed using signal processing, machine learning approaches of support vector machine, and cloud-assisted context-aware on-demand and pro-active healthcare support. The simulation outcome exhibits better performance achieved by the proposed system for elderly activity recognition and healthcare than the existing Random forest classifier. The comparative analysis shows that SVM's proposed system achieves a 94% accuracy rate in activity recognition.

Silver gull harassment of humpback whales in Exmouth Gulf, Western Australia

We share observations of silver gulls (Chroicocephalus novaehollandiae) harassing humpback whales (Megaptera novaeangliae) in Exmouth Gulf, Western Australia, between August and October in 2018 and 2019. Sixteen events were recorded of gulls pecking at the skin of 16 mothers and 2 calves resting on the surface. Data were collected opportunistically from a research vessel covering 5474.2km (565h). Events were documented through photographs and unmanned aerial vehicle video recordings and persisted for an average minimum time of 20.73min (range 2.50–46.85min). At least one event of a gull consistently gouging in a pre-existing lesion was recorded on a mother. Changes in behavioural activity from the whales, which varied from slipping under the surface to travelling and performing instantaneous behavioural events, were observed in 94% (15/16) of events. These are the first known records of birds attacking humpback whales. The results are comparable to early events of kelp gull (Larus dominicanus) harassment of southern right whales (Eubalaena australis) off Península Valdés, Argentina, where events have escalated over the past 50 years to consistent attacks on the whales’ skin and blubber. Future research is required to monitor the trajectory of these interactions to inform management.

Ayahuasca’s Antidepressant Effects Covary with Behavioral Activation as Well as Mindfulness

ABSTRACT Ayahuasca, a plant-based hallucinogen that serves as a spiritual medicine in South America, has improved depression in at least one placebo-controlled clinical trial. Case studies suggest that dramatic behavioral changes often follow the Ayahuasca ceremony, but most explanations of antidepressant effects focus on changes in mindfulness. This study investigated whether both mindfulness and behavioral activation might contribute to these anti-depressant effects. We surveyed individuals (N = 152) about their changes in depressive symptoms, behavioral activation, and mindfulness after an Ayahuasca experience. Mindfulness was strongly associated with reduced depression severity (r = − .670, p < .001), while behavioral activation was moderately linked (r = − .474, p < .001). Changes in depressive symptoms (Center for Epidemiological Sciences Depression Short Form [CES-D-10]) covaried with subscales from the Five Facet Mindfulness Questionnaire [FFMQ] and Experiences Questionnaire [EQ], confirming previous findings (β = −.57, 95% CI −5.70, −3.25), p < .001). In addition, a modification of the Behavioral Activation for Depression Scale-Short Form [BADS-SF] accounted for significant unique variance in the improvements in depression (β = − .16, 95% CI −6.32, −0.08), p < .05). Changes in behavioral activation likely serve as a mechanism underlying Ayahuasca’s antidepressant effects. Future clinical trials could benefit from tracking behavioral activation.

Exploring Mediators of a Guided Web-Based Self-Help Intervention for People With HIV and Depressive Symptoms: Randomized Controlled Trial.

BackgroundCognitive behavioral therapy (CBT) is frequently used to treat depressive symptoms in people living with HIV. We developed an internet-based cognitive behavioral intervention for people with HIV and depressive symptoms, which was based on an effective self-help booklet. The Web-based intervention was previously found to be effective.ObjectiveThe objective of this study was to investigate potential mediators of the Web-based intervention.MethodsThis study was part of a randomized controlled trial, in which the intervention was compared with an attention-only waiting list control condition. Participants were 188 (97 in intervention group and 91 in control group) people with HIV and mild to moderate depressive symptoms recruited in HIV treatment centers in the Netherlands. A total of 22 participants (22/188, 11.7%) in the study were female and 166 (166/188, 88.3%) were male. The average age of the participants was 46.30 years (SD 10.63). The intervention comprised Web-based self-help CBT for 8 weeks, 1 to 2 hours a week, including minimal telephone support from a coach. The participants received Web-based questionnaires at pretest, 3 times during the intervention/or waiting period, and post intervention. The outcome was depressive symptoms. Factors tested as potential mediators were changes in behavioral activation, relaxation, the cognitive coping strategies catastrophizing and positive refocusing, goal re-engagement, and coping self-efficacy.ResultsUsing multilevel structural equation modeling, changes in behavioral activation (P=.006) and goal re-engagement (P=.009) were found to be significant mediators of the intervention effect. The mediation effect seemed to occur between weeks 3 and 5 for behavioral activation and weeks 1 and 3 for goal re-engagement. Using (bivariate) autoregressive latent trajectory analysis, we found a return effect (from the dependent variable to the mediator) for goal re-engagement but not for behavioral activation, which suggested that the mediation effect of changes in behavioral activation was stronger than that in goal re-engagement.ConclusionsThe results suggest that changes in behavioral activation and goal re-engagement may mediate the effect of the Web-based intervention for people with HIV and depressive symptoms. The results may lead to possible mechanisms of change of the intervention and improvement of therapy outcomes.Clinical TrialNetherlands Trial Register NTR5407; https://www.trialregister.nl/trial/5298

Neurophysiological and morphological effects in the post-exposure vibration period during experimental modeling

Introduction. Vibration disease continues to occupy one of the leading places in the structure of professional pathology. In workers after the termination of contact with vibration generalization and progression of violations in an organism is noted. The pathogenetic mechanisms of the progredient course of disturbances in the nervous system in the post-contact period of vibration exposure remain insufficiently studied.The aim of the study was to test an experimental model of vibration exposure to assess the neurophysiological and morphological effects of vibration in rats in the dynamics of the post-contact period.Materials and methods. The work was performed on 168 white male outbred rats aged 3 months weighing 180–260 g. The vibration effect was carried out on a 40 Hz vibrating table for 60 days 5 times a week for 4 hours a day. Examination of animals was performed after the end of the physical factor, on the 30th, 60th and 120th day of the post-contact period. To assess the long-term neurophysiological and morphofunctional effects of vibration in rats, we used indicators of behavioral reactions, bioelectric activity of the somatosensory zone of the cerebral cortex, somatosensory and visual evoked potentials, parameters of muscle response, morphological parameters of nervous tissue.Results. In the dynamics of the post-contact period observed the preservation of violations of tentatively research, motor and emotional components of behavior. In the Central nervous system instability of activity of rhythms of an electroencephalogram, decrease in amplitude of visual evoked potentials, lengthening of latency of somatosensory evoked potentials, decrease in total number of normal neurons and astroglia is established. In the peripheral nervous system remained changes in indicators: increasing duration and latency, reducing the amplitude of the neuromuscular response.Conclusions: The experimental model allows us to study the long-term neurophysiological and morphological effects of vibration on the body. The formation and preservation of changes in behavioral activity, neurophysiological and morphological effects of vibration from the 30th to the 120th day of the post-contact period were confirmed.

Reward Network Modulation as a Mechanism of Change in Behavioral Activation.

Behavioral Activation (BA) is a contemporary third-wave psychosocial treatment approach that emphasizes helping individuals become more active in ways that are meaningful to them as a means of improving mood and quality of life. BA has been designated as a well-established, validated treatment for depression by the American Psychological Association following several decades of accumulated empirical support demonstrating that BA techniques successfully reduce depression symptoms and produce other desirable outcomes across a variety of populations and contexts. The purported mechanism of change underlying BA treatment lies in increasing activation, which in turn increases contact with positive reinforcement thereby reversing the cycle of depression. Current studies are further investigating how increasing activation and subsequent contact with mood reinforcers can influence mood and behavior. Specifically, there is growing evidence that BA modifies function of reward-related networks in the brain, and that these changes are associated with clinical improvement. Herein, we provide a brief history of BA, describe the primary components of BA treatment, and describe BA's purported mechanisms of change at behavioral, neural, and subjective activation levels. We present limitations as well as gaps in the current state of knowledge regarding mechanisms of action of BA.

Rapid 18F-FDG Uptake in Brain of Awake, Behaving Rat and Anesthetized Chicken has Implications for Behavioral PET Studies in Species With High Metabolisms.

Brain-behavior studies using 18F-FDG PET aim to reveal brain regions that become active during behavior. In standard protocols, 18F-FDG is injected, the behavior is executed during 30–60 min of tracer uptake, and then the animal is anesthetized and scanned. Hence, the uptake of 18F-FDG is not itself observed and could, in fact, be complete in very little time. This has implications for behavioral studies because uptake is assumed to reflect concurrent behavior. Here, we utilized a new, miniature PET scanner termed RatCAP to measure uptake simultaneously with behavior. We employed a novel injection protocol in which we administered 18F-FDG (i.v.) four times over two 2 h to allow for repeated measurements and the correlation of changes in uptake and behavioral activity. Furthermore, using standard PET methods, we explored the effects of injection route on uptake time in chickens, a model for avians, for which PET studies are just beginning. We found that in the awake, behaving rat most of the 18F-FDG uptake occurred within minutes and overlapped to a large extent with 18F-FDG data taken from longer uptake periods. By contrast, behavior which occurred within minutes of the 18F-FDG infusion differed markedly from the behavior that occurred during later uptake periods. Accordingly, we found that changes in 18F-FDG uptake in the striatum, motor cortex and cerebellum relative to different reference regions significantly predicted changes in behavioral activity during the scan, if the time bins used for correlation were near the injection times of 18F-FDG. However, when morphine was also injected during the scan, which completely abolished behavioral activity for over 50 min, a large proportion of the variance in behavioral activity was also explained by the uptake data from the entire scan. In anesthetized chickens, tracer uptake was complete in about 80 min with s.c. injection, but 8 min with i.v. injection. In conclusion, uptake time needs to be taken into account to more accurately correlate PET and behavioral data in mammals and avians. Additionally, RatCAP together with multiple, successive injections of 18F-FDG may be useful to explore changes in uptake over time in relation to changes in behavior.

Tributyltin induces premature hatching and reduces locomotor activity in zebrafish (Danio rerio) embryos/larvae at environmentally relevant levels

Tributyltin (TBT) is an organotin compound that is the active ingredient of many biocides and antifouling agents. In addition to its well established role as an endocrine disruptor, TBT is also associated with adverse effects on the nervous system and behavior. In this study, zebrafish (Danio rerio) embryos were exposed to environmentally relevant concentrations of TBT (0.01, 0.1, 1 nM) to determine how low levels affected development and behavior. Fish exposed to 1 nM TBT hatched earlier when compared to controls. Following a 96-h exposure, total swimming distance, velocity, and activity of zebrafish larvae were reduced compared to controls. To identify putative mechanisms for these altered endpoints, we assessed embryo bioenergetics and gene expression. We reasoned that the accelerated hatch time could be related to ATP production and energy, thus embryos were exposed to TBT for 24 and 48-h exposure prior to hatch. There were no differences among groups for endpoints related to bioenergetics (i.e. basal, ATP-dependent, and maximal respiration). To address mechanisms related to changes in behavioral activity, we measured transcripts associated with muscle function (myf6, myoD, and myoG) and dopamine signaling (th, dat, dopamine receptors) as dopamine regulates behavior. No transcript was altered in expression by TBT in larvae, suggesting that other mechanisms exist that may explain changes in higher level endpoints. These results suggest that endpoints related to the whole animal (i.e. timing of hatch and locomotor behavior) are more sensitive to environmentally-relevant concentrations of TBT compared to the molecular and metabolic endpoints examined here.

Trigeminal Neuralgia Induced by Cobra Venom Leads to Cognitive Deficits Associated with Downregulation of CREB/BDNF Pathway

Background: Chronic pain often results in cognitive impairment. Our previous study showed that trigeminal neuralgia induced by cobra venom leads to spatial learning and memory deficits, although the underlying mechanism remains unclear. However, recent evidence indicates that the c-AMP-responsive element binding protein (CREB)/brain derived neurotrophic factor (BDNF) pathway plays a critical role in various etiologies of cognitive deficits. Objectives: Our aim was to explore the CREB/BDNF pathway to determine the molecular mechanisms involved in the pathogenesis of cognitive impairment caused by cobra venominduced trigeminal neuralgia. Study Design: A randomized, controlled animal study. Setting: Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University. Methods: Fifty male Sprague–Dawley rats were randomly divided into 3 groups: cobra venom group, sham group, and control group. Cobra venom or saline was injected into the sheath of the infraorbital nerve (ION), respectively. Video recordings and mechanical thresholds were used to analyze changes in behavioral activity 3 days before surgery and 4, 7, 14, 21, 28, and 56 days after surgery. Morris water maze tests were conducted at 4- and 8-week time points after surgery to evaluate spatial learning and memory. We also investigated expression changes of phosphorylated CREB (p-CREB) and BDNF in the hippocampus and prefrontal cortex (PFC) using western blotting and immunohistochemistry. Results: Cobra venom-treated rats exhibited significant changes in face grooming, as well as exploratory and resting behaviors, compared with the control group and sham group (both P &lt; 0.001). Rats in the cobra venom group exhibited slightly impaired acquisition (P &lt; 0.05) without memory deficits (P &gt; 0.05) in the first water maze protocol. In the second water maze test, rats in the cobra venom group exhibited spatial learning and memory deficits, with fewer platform site crossings during the probe trial (P &lt; 0.05). Moreover, results showed decreased p-CREB and BDNF expressions in the hippocampus and PFC in the cobra venom group, with significant differences at 9 weeks post-surgery (P &lt; 0.05). Limitations: No signaling inhibitor or genetic manipulation was administered to further confirm upstream factors of the CREB/BDNF pathway in cognitive deficits caused by chronic trigeminal neuralgia. Conclusions: The findings suggest that cognitive impairment caused by cobra venom-induced trigeminal neuralgia is associated with downregulation of the CREB/BDNF pathway in the hippocampus and PFC. Key words: Cognitive impairment, the CREB/BDNF pathway, cobra venom, trigeminal neuralgia, hippocampus, prefrontal cortex, free behavior, Morris water maze

“Engage” Therapy: Behavioral Activation and Improvement of Late-Life Major Depression

Engage is a treatment for late-life depression developed to match the skills of community clinicians based on the theory that dysfunction in the Research Domain Criteria Project positive valence systems is a critical mechanism of late-life depression. Accordingly, it uses "reward exposure" (engagement in meaningful, rewarding activities) as its principal intervention. This study tests the hypothesis that change in behavioral activation, an index of positive valence systems function, during successive treatment periods with Engage and during follow-up predicts depression at the end of each period. Forty-eight nondemented, older adults with unipolar major depression were treated openly with 9 weekly sessions of Engage and assessed 36 weeks after entry. Depression severity was assessed with the 24-item Hamilton Depression Rating Scale (HAM-D) and behavioral activation with the Behavioral Activation for Depression Scale (BADS) at baseline, 6 weeks (mid-treatment), 9 weeks (end of treatment), and 36 weeks. A mixed-effects model examined whether change in BADS in successive periods occurring during Engage treatment and during follow-up predicts depression at the end of each period. Both BADS change (F1,52 = 18.63, p < 0.0001) and time (F2,52 = 7.68, p = 0.0012) predicted HAM-D scores at the end of each observation period. Every point of increase in BADS change reduced the HAM-D by 0.105 points. HAM-D at each point did not predict subsequent change in BADS (F1,52 = 2.17, p = 0.146). During Engage treatment and follow-up, change in behavioral activation is followed by improvement of depressive symptoms and signs.

Optimal migration energetics of humpback whales and the implications of disturbance.

Whales migrate long distances and reproduce on a finite store of energy. Budgeting the use of this limited energy reserve is an important factor to ensure survival over the period of migration and to maximize reproductive investment. For some whales, migration routes are closely associated with coastal areas, exposing animals to high levels of human activity. It is currently unclear how various forms of human activity may disturb whales during migration, how this might impact their energy balance and how this could translate into long-term demographic changes. Here, we develop a theoretical bioenergetic model for migrating humpback whales to investigate the optimal migration strategy that minimizes energy use. The average migration velocity was an important driver of the total energy used by a whale, and an optimal velocity of 1.1 m s(-1) was determined. This optimal velocity is comparable to documented observed migration speeds, suggesting that whales migrate at a speed that conserves energy. Furthermore, the amount of resting time during migration was influenced by both transport costs and feeding rates. We simulated hypothetical disturbances to the optimal migration strategy in two ways, by altering average velocity to represent changes in behavioural activity and by increasing total travelled distance to represent displacement along the migration route. In both cases, disturbance increased overall energy use, with implications for the growth potential of calves.

Influence of Panax ginseng on the offspring of adult rats exposed to prenatal stress.

The exposure of pregnant females to stress during a critical period of fetal brain development is an environmental risk factor for the development of schizophrenia in adult offspring. Schizophrenia is a group of common mental disorders of unclear origin, affecting approximately 1% of the global population, showing a generally young age at onset. In the present study, a repeated variable stress paradigm was applied to pregnant rats during the final week of gestation. The effects of an extract of Panax ginseng C.A. Meyer (PG) on rats exposed to prenatal stress (PNS) were investigated in terms of behavioral activity and protein expression analyses. In the behavioral tests, grooming behavior in a social interaction test, line-crossing behavior in an open-field test and swimming activity in a forced-swim test were decreased in the rats exposed to PNS compared with the non-stressed offspring; the changes in behavioral activity were reversed upon oral treatment with PG (300 mg/kg). Subsequently, western blot analysis and immunohistochemical analyses of the prefrontal cortex and hippocampus revealed that the downregulation of several neurodevelopmental genes which occurred following exposure to PNS was reversed upon treatment with PG. The current findings demonstrate that the downregulation of several genes following exposure to PNS may affect subsequent behavioral changes, and that these phenomena are reversed following treatment with PG during pregnancy. Our results suggest that oral treatment with PG reduces the incidence of psychiatric disorders, such as schizophrenia.

Psychometric properties of the French translation of the Behavioral Activation for Depression Scale–Short Form (BADS-SF) in non-clinical adults

A decrease in the level of engagement in activities (“behavioral activation”) is usually observed in major depressive disorder. Because behavioral treatments of depression aim to counteract that mechanism, assessing changes in behavioral activation during treatment is of great interest. Therefore, Manos et al. (2011) developed a scale that assesses these changes, which was called the Behavioral Activation for Depression Scale–Short Form (BADS-SF). The aim of this study is to present a French version of this scale and to discuss its psychometric properties. The BADS-SF was translated into French, and 504 non-clinical adults completed an online survey that was composed of that scale and convergent measures. Exploratory and confirmatory factor analyses were performed in two independent samples, and a two-factor solution was recommended, which references two functions of the engagement in activities (i.e., “activation” and “avoidance”). The results showed high levels of internal consistency and satisfying scores in terms of skewness and kurtosis. Moreover, relationships with measures of depression and behavioral systems indicated a good convergent validity. Therefore, the French BADS-SF can be seen as a reliable and valid instrument.

Effects of Antiglutamate Antibodies on the Development of Stress Response and Neurotransmitter Content in the Hippocampus and Hypothalamus of Rats with Different Behavioral Activity

We studied the effects of intranasal administration of antiglutamate antibodies on the development of stress response and level of neurotransmitter amino acids and monoamines in brain structures of rats with different initial behavioral activity. The stress exposure was followed by significant changes in behavioral activity and concentration of neurotransmitters in rat hippocampus and hypothalamus. The changes in the level of neurotransmitter amino acids and monoamines were more pronounced in the hippocampus. Antiglutamate antibodies administered intranasally in a single dose of 250 μg/kg immediately after stress exposure prevented the development of the stress response and normalized the level of neurotransmitters in the brain structures of rats. The effect of antibodies was the most pronounced in behaviorally active rats.

Is there a secular decline in motor skills in preschool children?

Current research seems to confirm a secular decline in movement skills in school children. Only few data are available for preschool children and no clear trend can be identified. In the year 2007, height, weight, and motor performance were determined in 726 preschool children [Prevention through Activity in Kindergarten Trial (PAKT)] and compared with historical samples from 1973, 1985, and 1989. There was no difference in height and weight between the samples of 1973 and 2007. Older boys of today were smaller and lighter than those of 1989. Regardless of age, PAKT children fared significantly better in standing long jump than those assessed in 1989. Compared with the sample of 1973, PAKT children did equally well in this task. There were no differences in performance in an obstacle course between children of 1989 and 2007. In balancing backwards, PAKT children performed significantly worse than those in 1985. Regarding target throwing only the PAKT 4-year-olds achieved significantly worse results than those in 1985.Therefore, in preschool children, a secular decline is only evident in some, but not all, motor skills, which may indicate a change in behavior activity over the last decades.

Evidence for the possible existence of a second polarization-vision pathway in the locust brain

For spatial orientation and navigation, many insects derive compass information from the polarization pattern of the blue sky. The desert locust Schistocerca gregaria detects polarized light with a specialized dorsal rim area of its compound eye. In the locust brain, polarized-light signals are passed through the anterior optic tract and tubercle to the central complex which most likely serves as an internal sky compass. Here, we suggest that neurons of a second visual pathway, via the accessory medulla and posterior optic tubercle, also provide polarization information to the central complex. Intracellular recordings show that two types of neuron in this posterior pathway are sensitive to polarized light. One cell type connects the dorsal rim area of the medulla with the medulla and accessory medulla, and a second type connects the bilaterally paired posterior optic tubercles. Given the evidence for a role of the accessory medulla as the master clock controlling circadian changes in behavioral activity in flies and cockroaches, our data open the possibility that time-compensated polarized-light signals may reach the central complex via this pathway for time-compensated sky-compass navigation.