Selecting an appropriate control group for studying the effects of exercise on cognitive performance.

Differences in expectations between experimental and control groups can influence the outcomes of exercise interventions, emphasizing the need to match expectations across study groups. This online study examined whether the expectations to improve the performance of different cognitive tasks differ between various activities commonly used in research on the effects of exercise and cognitive function. Two hundred and five middle-aged adults performed two reaction-time tasks and one memory task. They were then asked to rate, on a 1-5 Likert scale, their expectations to improve performance in those tasks should they engage in six types of activities for three months: brisk walking, resistance exercise, stretching and balance exercises, watching videos with lectures on art, history, and science, a program of relaxation techniques, and yoga/tai chi/meditation. Results revealed that the highest expectations for improvement were associated with relaxation techniques and yoga/tai chi/meditation. Some activities, such as brisk walking and stretch and balance exercises, shared similar expectations. Previous knowledge of the possible beneficial effects of exercise on cognitive performance also led to higher expectations. To establish causal relationships, researchers should strive to use activities that share similar expectations to improve performance for the experimental and control groups. The findings of this study provide such activity pairs. Finally, researchers should also try to match participants with and without prior knowledge of the benefits of exercise to cognitive function between experimental and control groups.

The effect of acute exercise on cognitive and motor inhibition - Does fitness moderate this effect?

BACKGROUND: Given the extensive evidence on improvements in cognitive inhibition immediately following exercise, and the literature indicating that cognitive and motor inhibitory functions are mediated by overlapping brain networks, the aim of this study was to assess, for the first time, the effect of moderate intensity acute aerobic exercise on multi-limb motor inhibition, as compared to cognitive inhibition. METHOD: Participants were 36 healthy adults aged 40-60 years old (mean age 46.8 ± 5.7), who were randomly assigned to experimental or control groups. One-to-two weeks following baseline assessment, participants were asked to perform a three-limb (3-Limb) inhibition task and a vocal version of the Stroop before and after either acute moderate-intense aerobic exercise (experimental group) or rest (control). RESULTS: Similar rates of improvement were observed among both groups from baseline to the pre-test. Conversely, a meaningful, yet non-significant trend was seen among the experimental group in their pretest to posttest improvement in both cognitive and motor tasks. In addition, exploratory analysis revealed significant group differences in favor of the experimental group among highly fit participants on the 3-Limb task. A significant correlation was indicated between the inhibition conditions, i.e., choice in the motor inhibition and color/word (incongruent) in the cognitive inhibition, especially in the improvement observed following the exercise. DISCUSSION: Moderate-intensity acute aerobic exercise is a potential stimulator of both multi-limb motor inhibition and cognitive inhibition. It appears that high-fit participants benefit from exercise more than low-fit people. Additionally, performance on behavioral tasks that represent motor and cognitive inhibition is related. This observation suggests that fitness levels and acute exercise contribute to the coupling between cognitive and motor inhibition. Neuroimaging methods would allow examining brain-behavior associations of exercise-induced changes in the brain.

A preliminary examination of the contextual interference effect on trained trick retention in domestic dogs.

This study sought to enhance current dog training practices by determining whether a finding from human motor skill learning research, the contextual interference (CI) effect, could be replicated in a trick-training paradigm with companion dogs. In humans, research shows that practicing skills in random order, as compared with blocked order, improves learning of those skills. To test this question in dogs, we randomly allocated 17 dogs to blocked training (low CI) or random training (high CI). The dogs performed three behaviors of varying difficulty. After training, we conducted a retention test in which half of the dogs in each group performed the tasks in blocked order and the other half in random order. We scored each trick, measured duration, and measured whether dogs required one or two tries to perform a behavior. We found no significant differences between dogs who practiced three tricks in random or in blocked order during training and during a retention test. This study is the first to apply the CI effect to dog trick training. Although no evidence of the CI effect was found, the current research provides a preliminary framework for future studies with potential implications for increasing retention of trained skills.

An embodied and ecological approach to skill acquisition in racecar driving.

Racecar driving is a fast-paced sport that presents the driver-athlete with many perception-action coupling and decision-making challenges. One question that arises is how racecar drivers deal with the influx of perceptual information and manage to perform successfully in such high speeds and, as a result, very limited time to make decisions and act upon them. In this perspective paper, I suggest that the ecological approach is one theoretical framework that can help researchers understand how skill is acquired in racecar driving. I also suggest that an embodied perception of affordances can provide a good basis for research in the field. Specifically, it is an extended embodied cognition that includes not only the driver's mind and body, but the car itself. In a sense, the driver and the car are embodied into one unit and any perception of affordances should be based on this unit. This paper will also discuss the constraints during a race, the affordances the race driver must perceive and how they change over the course of a race, and how researchers can use a racecar driving paradigm to study human perception and action from an embodied and an ecological approach. Specifically, because the driver is seated, measuring EEG and eye movements is relatively simple and can provide additional information on drivers' visual perception of affordances, and their ability to act upon them.

Neurometabolic correlates of posturography in normal aging and older adults with mild cognitive impairment: Evidence from a 1H-MRS study.

Proton magnetic resonance spectroscopy (1H-MRS) holds promise for revealing and understanding neurodegenerative processes associated with cognitive and functional impairments in aging. In the present study, we examined the neurometabolic correlates of balance performance in 42 cognitively intact older adults (healthy controls - HC) and 26 older individuals that were diagnosed with mild cognitive impairment (MCI). Neurometabolite ratios of total N-acetyl aspartate (tNAA), glutamate-glutamine complex (Glx), total choline (tCho) and myo-inositol (mIns) relative to total creatine (tCr) were assessed using single voxel 1H-MRS in four different brain regions. Regions of interest were the left hippocampus (HPC), dorsal posterior cingulate cortex (dPCC), left sensorimotor cortex (SM1), and right dorsolateral prefrontal cortex (dlPFC). Center-of-pressure velocity (Vcop) and dual task effect (DTE) were used as measures of balance performance. Results indicated no significant group differences in neurometabolite ratios and balance performance measures. However, our observations revealed that higher tCho/tCr and mIns/tCr in hippocampus and dPCC were generic predictors of worse balance performance, suggesting that neuroinflammatory processes in these regions might be a driving factor for impaired balance performance in aging. Further, we found that higher tNAA/tCr and mIns/tCr and lower Glx/tCr in left SM1 were predictors of better balance performance in MCI but not in HC. The latter observation hints at the possibility that individuals with MCI may upregulate balance control through recruitment of sensorimotor pathways.

The effects of viewing cute images on the performance of simple computerized tasks in dog owners and non-dog owners.

Background: Viewing cute images of puppies or kittens can improve the performance of various motor tasks due to increased behavioral carefulness. It is possible, however, that this effect can be moderated by the affinity of individuals towards specific cute stimuli. The purpose of this pre-registered study was to examine whether dog ownership moderates the effect of viewing cute images of puppies on two computerized RT-based tasks. Methods: One-hundred and sixty-four participants were covertly recruited and randomly assigned to four groups: (1) dog owners viewing puppies' images (n = 35), (2) dog owners viewing adult dogs' images (n = 36), (3) non-dog owners viewing puppies' images (n = 48), and (4) non-dog owners viewing adult dogs' images (n = 45). The participants performed a Simon task and an alternate task-switching task before and after viewing seven images of puppies/adult dogs based on group affiliation. After performing the tasks, the participants rated each image on five characteristics: cuteness, infantility, pleasantness, excitability, and wanting to get closer. Results: The participants who viewed images of puppies rated those characteristics (e.g., cuter, more infantile, etc.) as higher than the participants who viewed images of adult dogs. There were no differences in the performance of the two tasks between participants who viewed images puppies and participants who viewed images of adult dogs. However, dog owners reacted faster than non-dog owners in the post-test of the alternate task-switching task. It is possible that showing images of dogs to dog owners increased their motivation and attention to the task.

Providing choice of feedback affects perceived choice but does not affect performance.

Background: Autonomy or choice can lead to improved learning in various educational domains. The purpose of this online study was to examine whether giving participants a choice regarding the frequency of their received feedback (either after each individual trial or after a block of trials) in a computerized alternate task-switching task, will affect their performance. Methods: Participants (n = 148) were randomly assigned to three groups: choice group (n = 49), online feedback group (n = 51), and summary feedback group (n = 48). From those three groups we created two groups: a choice group and a no-choice group (n = 49 in each group). All participants performed eight familiarization trials, a pre-test of 24 trials, five blocks of 24 trials for practice, and a post-test of 24 trials. After completing the task, the participants were asked about their perceived feeling of choice and completed the short form of the International Positive and Negative Affect Schedule. Results: The participants in the choice group had higher perceived choice compared with the participants in the no-choice group (8.41 vs 5.47 out of 10, respectively). However, this higher perceived choice did not materialize into better performance during practice or in the post-test.

Reaction time and working memory in middle-aged gamers and non-gamers.

The purpose of this study was to explore whether asking middle-aged gamers and non-gamers about their video games habits will affect their performance of cognitive-motor tasks. One-hundred and twenty-one participants were randomly assigned to four groups: (a) gamers who were asked about their playing habits prior to the study, (b) gamers who were asked about their playing habits following the study, (c) non-gamers who were asked about their playing habits prior to the study, and (d) non-gamers who were asked about their playing habits following the study. The participants performed three reaction time (RT) tasks and a digit-span memory task. In a task-switching task, gamers had more correct responses when they answered the questionnaire before performing the task compared with after the task. For the non-gamers, the opposite occurred. We conclude that some performance measures of cognitive-motor tasks could have been affected by the timing of the completion of the questionnaire. This finding should be known to researchers as it may lead to biases gaming research.

Parabens and Menopause-Related Health Outcomes in Midlife Women: A Pilot Study.

Background: Parabens are antimicrobial agents prevalently found in daily-use products that can interfere with the endocrine and reproductive systems. In this study, we examined the cross-sectional associations of parabens with hot flashes, hormone concentrations, and ovarian volume in a subsample of 101 nonsmoking, non-Hispanic 45- to 54-year-old women from the Midlife Women's Health Study. Materials and Methods: Women self-reported their hot flash history and underwent a transvaginal ultrasound to measure ovarian volume. Participants provided blood for quantification of serum hormones (by enzyme-linked immunosorbent assay or radioimmunoassay) and urine samples for measurements of urinary paraben biomarker levels (by high-performance liquid chromatography negative-ion electrospray ionization-tandem mass spectrometry). Linear or logistic regression models evaluated associations of specific gravity-adjusted paraben biomarker concentrations with hot flashes, hormone concentrations, and ovarian volume. Results: We observed marginal associations of propylparaben, methylparaben, and ∑parabens biomarkers (molar sum of four parabens) with hot flashes and follicle-stimulating hormone (FSH) concentrations, and of these paraben biomarkers and ethylparaben with ovarian volume. For example, women tended to have 32% (95% confidence intervals [CI]: 0.9 to 1.81), 40% (95% CI: 1.0 to 1.95), and 40% (95% CI: 0.98 to 2.01) higher odds of having recent, monthly, and mild hot flashes, respectively, for every two-fold increase in ∑parabens. Similarly, women tended to have 14.54% (95% CI: -0.10 to 31.32) higher FSH concentrations, but 5.67% (95% CI: -12.54 to 1.75) reduced ovarian volume for every two-fold increase in ∑parabens Conclusions: Overall, our preliminary findings suggest that urinary paraben biomarkers may be associated with menopause-related outcomes in midlife women. Additional studies in larger and diverse populations are needed to expand on these findings.

Reaction time and working memory in gamers and non-gamers.

The purpose of this pre-registered study was to examine whether asking gamers and non-gamers about their video game playing habits before or after they performed computerized cognitive-motor tasks affects their performance of those tasks. We recruited 187 participants from an online participants' recruitment platform. Out of those participants, 131 matched our criteria as gamers or non-gamers. They were then divided to two subgroups, and performed a choice-RT task, a Simon task, an alternate task-switching task, and a digit span memory task either before or after answering a video-game playing habits questionnaire. The results showed that gamers who completed a video-games questionnaire before performing the tasks had faster reaction times (RTs) in the Simon task compared with gamers who answered the questionnaire after performing the tasks. In contrast, non-gamers who answered the questionnaire before the task had slower RTs in the Simon task and the alternate task-switching task compared with non-gamers who answered the questionnaire after performing the tasks. The results suggest that answering a video-games questionnaire before the start of a study can lead to a response expectancy effect-positive for gamers and negative for non-gamers. This may bias findings of studies examining video games and the performance of cognitive-motor tasks.

Early-Life Exposure to Environmental Contaminants Perturbs the Sperm Epigenome and Induces Negative Pregnancy Outcomes for Three Generations via the Paternal Lineage.

Due to the grasshopper effect, the Arctic food chain in Canada is contaminated with persistent organic pollutants (POPs) of industrial origin, including polychlorinated biphenyls and organochlorine pesticides. Exposure to POPs may be a contributor to the greater incidence of poor fetal growth, placental abnormalities, stillbirths, congenital defects and shortened lifespan in the Inuit population compared to non-Aboriginal Canadians. Although maternal exposure to POPs is well established to harm pregnancy outcomes, paternal transmission of the effects of POPs is a possibility that has not been well investigated. We used a rat model to test the hypothesis that exposure to POPs during gestation and suckling leads to developmental defects that are transmitted to subsequent generations via the male lineage. Indeed, developmental exposure to an environmentally relevant Arctic POPs mixture impaired sperm quality and pregnancy outcomes across two subsequent, unexposed generations and altered sperm DNA methylation, some of which are also observed for two additional generations. Genes corresponding to the altered sperm methylome correspond to health problems encountered in the Inuit population. These findings demonstrate that the paternal methylome is sensitive to the environment and that some perturbations persist for at least two subsequent generations. In conclusion, although many factors influence health, paternal exposure to contaminants plays a heretofore-underappreciated role with sperm DNA methylation contributing to the molecular underpinnings involved.

Attentional Focus Instructions Do Not Affect Choice Reaction Time.

The majority of the studies on attentional focus have shown that participants who were instructed to focus externally performed better than those who were taught to focus internally. However, in most of these studies the participants performed complex motor tasks. Due to the scarcity of data on the effects of attentional focus specifically on simple motor tasks, our purpose in the current study was to examine these effects on two simple reaction time (RT) tasks. The study was conducted on a cloud-based experimental software. Participants were allocated to three experimental groups: an external focus group (n = 44), an internal focus group (n = 46), and a control group (no attentional instructions; n = 47). The participants performed two tasks: a choice-RT task and a Simon task. Participants in all three groups practiced eight blocks of 20 trials from each task in a counterbalanced order - a total of 180 trials for each task. The sole difference between the three groups was the administered attentional focus instructions. The findings suggest that attentional focus instructions do not affect the performance of a choice-RT task or a Simon-task in a computerized online study. It is possible that the simple RT-based tasks in the current study were not sensitive to the attentional focus manipulation, since in such simple tasks there are not many actions that internal focus can disrupt. Although we asked the participants to what extent they followed the instructions, we cannot say whether their responses represent their actual attentional focus when performing the tasks.

Autonomy support and preference-performance dissociation in choice-reaction time tasks.

The purpose of the current study was threefold: (a) to examine the effects of participants having the autonomy to choose the practice order of two reaction time (RT) tasks - a choice-RT task and a Simon task - on performance, (b) to examine whether one order of practice is better than the other, and (c) to examine whether participants might choose a practice order that hinders their performance. The study was conducted online and participants completed the tasks on their own computer. Fifty-nine participants were randomly assigned into three groups: (a) autonomy - participants chose which task they would like to practice first, (b) choice-first - participants practiced the choice-RT task first, and (c) Simon-first - participants practiced the Simon task first. Out of these three groups we created an autonomy group (n = 17) and a no-autonomy (yoked) group (n = 17). All participants performed eight familiarization trials of each task, practiced 160 trials (8 blocks × 20 trials) of each task, and performed a post-test of 20 additional trials of each task after a three-minute rest. The main findings were that (a) participants in the autonomy group had faster RTs compared with participants in the no-autonomy group, (b) performing the choice-RT task first led to faster RTs compared with performing the Simon task first, and (c) nine of the 17 participants in the autonomy group chose to practice the Simon task first. The findings of this study suggest that providing participants with autonomy can lead to improved performance. However, there may be a dissociation between participants' preference of practice order and their performance.

Training focal lung pathology detection using an eye movement modeling example.

Purpose: Published reports suggest that nonoptimal visual search behavior is associated with false negatives in chest x-ray interpretation. Eye movement modeling example (EMME)-based training interventions, that is, interventions showing models of visual search to trainees, have been shown to improve visual search as well as task accuracy. Approach: We examined the detection of focal lung pathology on chest x-rays before and after two different EMME training interventions that have been shown to be efficient: (i) an EMME showing moving fixations on a blurred background (spotlight group) and (ii) an EMME showing moving fixations on a nonblurred background (circle group). These two experimental groups were compared to a control group that was only provided with the correct location of pathologies on the chest x-rays. Results: Performance outcomes showed improved detection sensitivity and specificity in all groups (also the control group). It appears that repetitive exposure to pathologies on chest x-rays with feedback resulted in enhanced pattern recognition. In addition, visual search strategies became more efficient during post-tests. Conclusion: Repetitive exposure to a focal lung pathology detection task with feedback improves overall performance. However, the specific EMME training interventions did not add any further advantages. Similar training interventions can be provided online to assess feasibility and reproducibility of such (or similar) training formats. Such training can, for example, reduce the number of false negative errors, especially for novices.

Behavioral and Neurophysiological Aspects of Inhibition-The Effects of Acute Cardiovascular Exercise.

This review summarizes behavioral and neurophysiological aspects of inhibitory control affected by a single bout of cardiovascular exercise. The review also examines the effect of a single bout of cardiovascular exercise on these processes in young adults with a focus on the functioning of prefrontal pathways (including the left dorsolateral prefrontal cortex (DLPFC) and elements of the prefrontal-basal ganglia pathways). Finally, the review offers an overview on the potential effects of cardiovascular exercise on GABA-ergic and glutamatergic neurotransmission in the adult brain and propose mechanisms or processes that may mediate these effects. The main findings show that a single bout of cardiovascular exercise can enhance inhibitory control. In addition, acute exercise appears to facilitate activation of prefrontal brain regions that regulate excitatory and inhibitory pathways (specifically but not exclusively the prefrontal-basal-ganglia pathways) which appear to be impaired in older age. Based on the reviewed studies, we suggest that future work examine the beneficial effects of exercise on the inhibitory networks in the aging brain.

Viewing Cute Images Does Not Affect Performance of Computerized Reaction Time Tasks.

Humans are emotionally affected by cute or infantile appearances, typical of baby animals and humans, which in turn often leads to careful and cautious behavior. The purpose of this pre-registered study was to examine whether looking at cute images of baby pets improves performance of computerized cognitive-motor tasks. Ninety-eight participants were recruited for this online study and were randomly assigned to two experimental groups. The participants in one group performed two cognitive-motor tasks (Simon task and alternate task-switching task) before and after viewing images of adult pets and the participants in the other group performed the tasks before and after viewing images of baby pets. The participants who viewed images of baby pets rated them as significantly cuter (Cohen's d = 0.50) and more infantile (Cohen's d = 1.56) compared with those who viewed images of adult pets. All participants improved their performance from the pre-test to the post-test, but no differences in correct responses and reaction times were seen between the groups. However, pet ownership appeared to serve as a moderating variable with pet owners performing the Simon task faster than non-pet owners. In addition, pet owners reacted faster in the alternate task-switching task after viewing cute and infantile images but not after viewing images of adult pets. This effect was not found among non-pet owners. In conclusion, this study did not find that viewing cute images improves cognitive-motor performance, yet this may be dependent on moderators like pet ownership.

Paraben exposure alters cell cycle progression and survival of spontaneously immortalized secretory murine oviductal epithelial (MOE) cells.

The mammalian oviduct is a central organ for female reproduction as it is the site of fertilization and it actively transports the embryo to the uterus. The oviduct is responsive to ovarian steroids and thus, it is a potential target of endocrine disrupting chemicals. Parabens are antimicrobial compounds that are prevalently found in daily-used products. However, recent studies suggest that some parabens can impact female reproductive health. Yet, their effects on the oviduct are unknown. Here, we hypothesized that in vitro exposure of immortalized murine oviductal secretory epithelial (MOE) cells to methylparaben or propylparaben will result in disrupted cell cycle progression and increased cell death by dysregulation of molecular mechanisms that involve the cell cycle and apoptosis. Thus, we examined the effects of exposure to parabens on cell proliferation, cell cycle progression by flow cytometry, and mRNA levels of major cell cycle regulators and apoptotic factors, in MOE cells. Protein levels of estrogen and progesterone receptors were also quantified. Differences between treatments and controls were analyzed by linear mixed model followed by Dunnett post-hoc tests. The results indicate that methylparaben and propylparaben selectively reduce MOE cellular proliferation and colony numbers, compared to controls. Additionally, paraben exposure selectively dysregulates the progression through the cell cycle and decreases the levels of cell cycle regulators, compared to controls. Last, paraben selectively alters the levels of progesterone receptor. Overall, these findings suggest that parabens can affect mouse oviductal secretory epithelial cell proliferation and survival.

Gaze Behavior of Referees in Sport-A Review.

The purpose of this review was to examine the literature on gaze behavior in referees. A literature search found only 12 relevant studies. Five of those studies were conducted on referees in association football (soccer), three on judges in gymnastics, one on softball umpires, and one each on referees in team handball, rugby, and ice hockey. Seven studies reported differences in gaze behavior between referees of a higher skill level and those of a lower skill level, while four studies found no differences. In addition, five studies reported differences between referees of different skill levels in both gaze behavior and performance, while four studies found differences in performance only. A number of methodological concerns arise from the current review. Among them are the lack of studies conducted in ecologically valid conditions, the lack of studies on peripheral vision, and the lack of data on referees who are working together as teams. Based on this review, we conclude that additional research is needed to clarify the relationships between gaze behavior and performance in refereeing. Practitioners who work with referees should be cautious when adopting gaze training strategies to improve selective attention, since the data on their effectiveness are scarce and sometimes contradictory.

Potential Role of Lycopene in the Prevention of Postmenopausal Bone Loss: Evidence from Molecular to Clinical Studies.

Osteoporosis is a metabolic bone disease characterized by reduced bone mineral density, which affects the quality of life of the aging population. Furthermore, disruption of bone microarchitecture and the alteration of non-collagenous protein in bones lead to higher fracture risk. This is most common in postmenopausal women. Certain medications are being used for the treatment of osteoporosis; however, these may be accompanied by undesirable side effects. Phytochemicals from fruits and vegetables are a source of micronutrients for the maintenance of bone health. Among them, lycopene has recently been shown to have a potential protective effect against bone loss. Lycopene is a lipid-soluble carotenoid that exists in both all-trans and cis-configurations in nature. Tomato and tomato products are rich sources of lycopene. Several human epidemiological studies, supplemented by in vivo and in vitro studies, have shown decreased bone loss following the consumption of lycopene/tomato. However, there are still limited studies that have evaluated the effect of lycopene on the prevention of bone loss in postmenopausal women. Therefore, the aim of this review is to summarize the relevant literature on the potential impact of lycopene on postmenopausal bone loss with molecular and clinical evidence, including an overview of bone biology and the pathophysiology of osteoporosis.

Focal lung pathology detection in radiology: Is there an effect of experience on visual search behavior?

In radiology, 60% to 80% of diagnostic errors are perceptual. The use of more efficient visual search behaviors is expected to reduce these errors. We collected eye-tracking data from participants with different levels of experience when interpreting chest X-rays during the completion of a pathology-detection task. Eye-tracking measures were assessed in the context of three existing visual search theories from the literature to understand the association between visual search behavior and underlying processes: the long-term working memory theory, the information-reduction hypothesis, and the holistic model of image perception. The most experienced participants (radiology residents) showed the highest level of performance, albeit their visual search behaviors did not differ from the intermediate group. This suggests that radiology residents better processed the represented information on the X-ray, using a visual search strategy similar to the intermediate group. Since similar visual search resulted in more information extraction in the radiology residents compared with the intermediates, we suggest that this result might support the long-term working memory theory. Furthermore, compared with novices, intermediates and radiology residents fixated longer on areas that were more important to avoid missing any pathology, which possibly confirms the information-reduction hypothesis. Finally, the larger distances between fixations observed in more experienced participants could support the holistic model of image perception. In addition, measures of generic skills were related to a lower time cost for switching between global and local information processing. Our findings suggest that the three theories may be complementary in chest X-ray interpretation. Therefore, a unified theory explaining perceptual-cognitive superiority in radiology is considered.