Effects of Olfactory and Auditory Enrichment on the Behaviour of Shelter Dogs

Shelter environments are stressful for dogs, as they must cope with many stimuli over which they have little control. This can lead to behavioural changes, negatively affect their welfare and downgrade the human-animal bond, affecting re-homing success. Arousal is evident in their behaviour, particularly increased activity and frequent vocalisation. Environmental enrichment plays an important role in reducing arousal behaviour, either through direct physiological effects or by masking stressful stimuli. The present study focused on sensory environmental enrichment, using olfactory and auditory stimuli under shelter conditions. Sixty dogs were allocated to one of four treatments: three types of enrichment, Lavender, Dog appeasing pheromone (DAP) and Music, and a Control group. Stimuli were applied for 3 h/d on five consecutive days. Dogs exposed to DAP lay down more, and those exposed to Music lay down more with their head down, compared to the Control. Those in the Control stood more on their hind legs with their front legs on the exit door, compared to those exposed to Music and DAP, particularly if they had only been in the shelter for a short time. They also panted and vocalised much more than dogs in the three enrichment treatments, which tended to persist during the 4 h period post treatment, and in the case of vocalisation into the subsequent night. The study suggests that all three enrichments had some positive benefits for dogs in shelters, as well as being non-invasive and easy to apply in the shelter environment.

Arousal State-Dependent Alterations in VTA-GABAergic Neuronal Activity

Decades of research have implicated the ventral tegmental area (VTA) in motivation, learning and reward processing. We and others recently demonstrated that it also serves as an important node in sleep/wake regulation. Specifically, VTA-dopaminergic neuron activation is sufficient to drive wakefulness and necessary for the maintenance of wakefulness. However, the role of VTA-GABAergic neurons in arousal regulation is not fully understood. It is still unclear whether VTA-GABAergic neurons predictably alter their activity across arousal states, what is the nature of interactions between VTA-GABAergic activity and cortical oscillations, and how activity in VTA-GABAergic neurons relates to VTA-dopaminergic neurons in the context of sleep/wake regulation. To address these, we simultaneously recorded population activity from VTA subpopulations and electroencephalography/electromyography (EEG/EMG) signals during spontaneous sleep/wake states and in the presence of salient stimuli in freely-behaving mice. We found that VTA-GABAergic neurons exhibit robust arousal-state-dependent alterations in population activity, with high activity and transients during wakefulness and REM sleep. During wakefulness, population activity of VTA-GABAergic neurons, but not VTA-dopaminergic neurons, was positively correlated with EEG γ power and negatively correlated with θ power. During NREM sleep, population activity in both VTA-GABAergic and VTA-dopaminergic neurons negatively correlated with δ, θ, and σ power bands. Salient stimuli, with both positive and negative valence, activated VTA-GABAergic neurons. Together, our data indicate that VTA-GABAergic neurons, like their dopaminergic counterparts, drastically alter their activity across sleep-wake states. Changes in their activity predicts cortical oscillatory patterns reflected in the EEG, which are distinct from EEG spectra associated with dopaminergic neural activity.

Napping in high-performance athletes: Sleepiness or sleepability?

Daytime napping is a common practice in high-performance athletes, and is widely assumed to reflect sleepiness arising from sports-related sleep debt. The possibility that athlete naps may also be indicative of 'sleepability', a capacity to nap on demand that is only weakly related to homeostatic sleep pressure, has not previously been tested. The present study compared daytime sleep latencies in high-performance athletes and non-athlete controls using a single nap opportunity model. Elite (n = 10), and sub-elite (n = 10) athletes, and non-athlete controls (n = 10) attended the laboratory for a first adaption trial, and a subsequent experimental trial. Subjective sleepiness was assessed using the Karolinska Sleepiness Scale (KSS) at 14:00, 14:30 and immediately prior to a 20-minute nap opportunity at 15:00. Sleep latencies were measured using polysomnography, and defined as the time from lights out to the first epoch of any stage of sleep (N1, N2, N3, REM). In unadjusted comparisons with non-athlete controls, elite athletes showed significantly shorter sleep latencies in both the adaptation (p < 0.05) and experimental trials (p < 0.05). These significant differences were maintained in models controlling for pre-trial KSS scores and pre-trial total sleep time (all p < 0.05). Sleep latency scores for sub-elite athletes showed similar trends, but were more labile. These results are consistent with a conclusion that, among elite athletes, napping behaviour can reflect sleepability and may not necessarily result from nocturnal sleep disruption and daytime sleepiness.

Attentional blink with emotional faces depends on emotional expressions: a relative positive valence advantage

Contribution of emotional valence and arousal to attentional processing over time is not fully understood. We employed a rapid serial visual paradigm (RSVP) in three experiments to investigate the role of valence and arousal. In three experiments, participants had to identify the expression of the two targets (experiment 1 - happy and angry; experiment 2 - angry and surprise; experiment 3 - happy and surprise) presented among neutral upright face distracters. In the first and third experiments, the two targets differed both in valence and arousal ratings. In experiment 2, the surprise and angry expressions differed in terms of valence but were matched for arousal. There was a happy expression advantage (lesser attentional blink) when the first target was anger (experiment 1) or surprise (experiment 3) and a surprise expression advantage when the first target was anger (experiment 2). There was a backward blink with reduced detection of the first target primarily by the relatively more positive valence second target. These results indicate that the benefit for happy and surprise expressions in comparison to angry expression identification is probably due to valence (more positive) and not arousal. Our results demonstrate a novel dynamic interplay of emotional information on temporal attention.

Cognitive and Emotional Aspects of Cupping Therapy

Cupping therapy has recently gained public attention and is widely used in many regions. Some patients are resistant to being treated with cupping therapy, as visually unpleasant marks on the skin may elicit negative reactions. This study aimed to identify the cognitive and emotional components of cupping therapy. Twenty-five healthy volunteers were presented with emotionally evocative visual stimuli representing fear, disgust, happiness, neutral emotion, and cupping, along with control images. Participants evaluated the valence and arousal level of each stimulus. Before the experiment, they completed the Fear of Pain Questionnaire-III. In two-dimensional affective space, emotional arousal increases as hedonic valence ratings become increasingly pleasant or unpleasant. Cupping therapy images were more unpleasant and more arousing than the control images. Cluster analysis showed that the response to cupping therapy images had emotional characteristics similar to those for fear images. Individuals with a greater fear of pain rated cupping therapy images as more unpleasant and more arousing. Psychophysical analysis showed that individuals experienced unpleasant and aroused emotional states in response to the cupping therapy images. Our findings suggest that cupping therapy might be associated with unpleasant-defensive motivation and motivational activation. Determining the emotional components of cupping therapy would help clinicians and researchers to understand the intrinsic effects of cupping therapy.

The link between auditory salience and emotion intensity

To ensure that listeners pay attention and do not habituate, emotionally intense vocalizations may be under evolutionary pressure to exploit processing biases in the auditory system by maximising their bottom-up salience. This "salience code" hypothesis was tested using 128 human nonverbal vocalizations representing eight emotions: amusement, anger, disgust, effort, fear, pain, pleasure, and sadness. As expected, within each emotion category salience ratings derived from pairwise comparisons strongly correlated with perceived emotion intensity. For example, while laughs as a class were less salient than screams of fear, salience scores almost perfectly explained the perceived intensity of both amusement and fear considered separately. Validating self-rated salience evaluations, high- vs. low-salience sounds caused 25% more recall errors in a short-term memory task, whereas emotion intensity had no independent effect on recall errors. Furthermore, the acoustic characteristics of salient vocalizations were similar to those previously described for non-emotional sounds (greater duration and intensity, high pitch, bright timbre, rapid modulations, and variable spectral characteristics), confirming that vocalizations were not salient merely because of their emotional content. The acoustic code in nonverbal communication is thus aligned with sensory biases, offering a general explanation for some non-arbitrary properties of human and animal high-arousal vocalizations.

Feeling excited or taking a bath: Do distinct pathways underlie the positive affect-health link in the U.S. and Japan?

Feeling good is linked to better health in Western contexts. Recent studies show, however, that the affect-health link is not consistent across cultures. We suggest two reasons for such inconsistency. The first follows from research showing that North American (vs. East Asian) cultures tend to value high arousal positive (HAP) states, for example, excited, more than low arousal positive (LAP) states, for example, calm. The second is one we propose for the first time. Positive affective experience is manifest in internal feelings but also in affective practices, such as taking a bath (a highly valued affective experience in Japan) or a fitness workout (a highly valued affective experience in the United States). We hypothesized that the HAP feelings/practices-health link would be stronger in the United States versus Japan, and the LAP feelings/practices-health link would be stronger in Japan versus the United States. Using survey samples from the United States (N = 640) and Japan (N = 382), we examined how health outcomes are shaped by positive affective feelings and practices varying in arousal. In a first set of analyses, HAP feelings predicted better physical and biological health in the United States but not in Japan. No cultural differences were consistently found for the effect of LAP feelings on health. In addition, engaging in HAP practices predicted better physical and biological health in the United States whereas engaging in LAP practices predicted better physical health in Japan but not in the United States. These findings suggest that the pathways underlying the culture-health link are culturally variable. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Sleep disruption is not observed with brain-responsive neurostimulation for epilepsy

OBJECTIVE

Neurostimulation devices that deliver electrical impulses to the nervous system are widely used to treat seizures in patients with medically refractory epilepsy, but the effects of these therapies on sleep are incompletely understood. Vagus nerve stimulation can contribute to obstructive sleep apnea, and thalamic deep brain stimulation can cause sleep disruption. A device for brain-responsive neurostimulation (RNS^® System, NeuroPace, Inc) is well tolerated in clinical trials, but potential effects on sleep are unknown.

METHODS

Six adults with medically refractory focal epilepsy treated for at least six months with the RNS System underwent a single night of polysomnography (PSG). RNS System lead locations included mesial temporal and neocortical targets. Sleep stages and arousals were scored according to standard guidelines. Stimulations delivered by the RNS System in response to detections of epileptiform activity were identified by artifacts on scalp electroencephalography.

RESULTS

One subject was excluded for technical reasons related to unreliable identification of stimulation artifact on EEG during PSG. In the remaining five subjects, PSG showed fragmented sleep with frequent arousals. Arousal histograms aligned to stimulations revealed a significant peak in arousals just before stimulation. In one of these subjects, the arousal peak began before stimulation and extended ~1 seconds after stimulation. A peak in arousals occurring only after stimulation was not observed.

SIGNIFICANCE

In this small cohort of patients, brain-responsive neurostimulation does not appear to disrupt sleep. If confirmed in larger studies, this could represent a potential clinical advantage of brain-responsive neurostimulation over other neurostimulation modalities.

Activation of Preoptic GABAergic or Glutamatergic Neurons Modulates Sleep-Wake Architecture, but Not Anesthetic State Transitions

The precise mechanism of general anesthesia remains unclear. In the last two decades, there has been considerable focus on the hypothesis that anesthetics co-opt the neural mechanisms regulating sleep. This hypothesis is supported by ample correlative evidence at the level of sleep-promoting nuclei, but causal investigations of potent inhaled anesthetics have not been conducted. Here, we tested the hypothesis that chemogenetic activation of discrete neuronal subpopulations within the median preoptic nucleus (MnPO) and ventrolateral preoptic nucleus (VLPO) of the hypothalamus would modulate sleep/wake states and alter the time to loss and resumption of consciousness associated with isoflurane, a potent halogenated ether in common clinical use. We show that activating MnPO/VLPO GABAergic or glutamatergic neurons does not alter anesthetic induction or recovery time. However, activation of these neuronal subpopulations did alter sleep-wake architecture. Notably, we report the novel finding that stimulation of VLPO glutamatergic neurons causes a strong increase in wakefulness. We conclude that activation of preoptic GABAergic or glutamatergic neurons that increase sleep or wakefulness does not substantively influence anesthetic state transitions. These data indicate that the correlative evidence for a mechanistic overlap of sleep and anesthesia at the level of an individual nucleus might not necessarily have strong causal significance.

Emotion and conflict adaptation: the role of phasic arousal and self-relevance

Conflict adaptation reflects the increase in cognitive control after previous conflict between task-relevant and task-irrelevant information. Tonic (sustained) arousal elicited by emotional words embedded in a conflict task has previously been shown to increase conflict adaptation. However, the role of phasic (transient) emotional arousal remains unclear. In Experiment 1 (N = 55), we therefore investigated the effect of phasic arousal using a colour flanker task with negative, positive, and neutral words as stimuli. We hypothesised that phasic arousal elicited in this context will increase conflict adaptation in the subsequent trial. Indeed, when the words were positive or negative as compared to neutral, we observed increased conflict adaptation. In Experiment 2 (N = 54), we examined the role of the self-relevance by presenting words with a self-related pronoun ("my") or sender-related pronoun ("his"/"her"). We expected that emotional words with high self-relevance would lead to stronger effects of emotional arousal on conflict adaptation. Confirming this hypothesis, results showed that emotional words within a self-related context again increased conflict adaptation, whereas this effect was not observed in the sender-related context. Taken together, these results are the first to show that phasic arousal elicited by emotional words increases conflict adaptation, in particular when these words have high self-relevance.

Striatal Beta Oscillation and Neuronal Activity in the Primate Caudate Nucleus Differentially Represent Valence and Arousal Under Approach-Avoidance Conflict

An approach-avoidance (Ap–Av) conflict arises when an individual has to decide whether to accept or reject a compound offer that has features indicating both reward and punishment. During value judgments of likes and dislikes, arousal responses simultaneously emerge and influence reaction times and the frequency of behavioral errors. In Ap–Av decision-making, reward and punishment differentially influence valence and arousal, allowing us to dissociate their neural processing. The primate caudate nucleus (CN) has been implicated in affective judgment, but it is still unclear how neural responses in the CN represent decision-related variables underlying choice. To address this issue, we recorded spikes and local field potentials (LFPs) from the CN while macaque monkeys performed an Ap–Av decision-making task. We analyzed 450 neuronal units and 667 beta oscillatory activities recorded during the performance of the task. To examine how these activities represented valence, we focused on beta-band responses and unit activities that encoded the chosen value (ChV) of the compound offer as derived from an econometric model. Unit activities exhibited either positive (65.0% = 26/40) or negative (35.0% = 14/40) correlations with the ChV, whereas beta responses exhibited almost exclusively positive correlations with the ChV (98.4% = 62/63). We examined arousal representation by focusing on beta responses and unit activities that encoded the frequency of omission errors (FOE), which were negatively correlated with arousal. The unit activities were either positively (65.3% = 17/26) or negatively (34.6% = 9/26) correlated with the FOE, whereas the beta responses were almost entirely positively correlated with the FOE (95.8% = 23/24). We found that the temporal onset of the beta-band responses occurred sequentially across conditions: first, the negative-value, then low-arousal, and finally, high-value conditions. These findings suggest the distinctive roles of CN beta oscillations that were sequentially activated for the valence and arousal conditions. By identifying dissociable groups of CN beta-band activity responding in relation to valence and arousal, we demonstrate that the beta responses mainly exhibited selective activation for the high-valence and low-arousal conditions, whereas the unit activities simultaneously recorded in the same experiments responded to chosen value and other features of decision-making under approach-avoidance conflict.

Neural entrainment to music is sensitive to melodic spectral complexity

During auditory perception, neural oscillations are known to entrain to acoustic dynamics but their role in the processing of auditory information remains unclear. As a complex temporal structure that can be parameterized acoustically, music is particularly suited to address this issue. In a combined behavioral and EEG experiment in human participants, we investigated the relative contribution of temporal (acoustic dynamics) and nontemporal (melodic spectral complexity) dimensions of stimulation on neural entrainment, a stimulus-brain coupling phenomenon operationally defined here as the temporal coherence between acoustical and neural dynamics. We first highlight that low-frequency neural oscillations robustly entrain to complex acoustic temporal modulations, which underscores the fine-grained nature of this coupling mechanism. We also reveal that enhancing melodic spectral complexity, in terms of pitch, harmony, and pitch variation, increases neural entrainment. Importantly, this manipulation enhances activity in the theta (5 Hz) range, a frequency-selective effect independent of the note rate of the melodies, which may reflect internal temporal constraints of the neural processes involved. Moreover, while both emotional arousal ratings and neural entrainment were positively modulated by spectral complexity, no direct relationship between arousal and neural entrainment was observed. Overall, these results indicate that neural entrainment to music is sensitive to the spectral content of auditory information and indexes an auditory level of processing that should be distinguished from higher-order emotional processing stages.NEW & NOTEWORTHY Low-frequency (<10 Hz) cortical neural oscillations are known to entrain to acoustic dynamics, the so-called neural entrainment phenomenon, but their functional implication in the processing of auditory information remains unclear. In a behavioral and EEG experiment capitalizing on parameterized musical textures, we disentangle the contribution of stimulus dynamics, melodic spectral complexity, and emotional judgments on neural entrainment and highlight their respective spatial and spectral neural signature.

Contactless detection of periodic leg movements during sleep: A 3D video pilot study

In clinical practice, the quality of polysomnographic recordings in children and patients with neurodegenerative diseases may be affected by sensor displacement and diminished total sleep time due to stress during the recording. In the present study, we investigated if contactless three‐dimensional (3D) detection of periodic leg movements during sleep was comparable to polysomnography. We prospectively studied a sleep laboratory cohort from two Austrian sleep laboratories. Periodic leg movements during sleep were classified according to the standards of the World Association of Sleep Medicine and served as ground truth. Leg movements including respiratory‐related events (A1) and excluding respiratory‐related events (A2 and A3) were presented as A1, A2 and A3. Three‐dimensional movement analysis was carried out using an algorithm developed by the Austrian Institute of Technology. Fifty‐two patients (22 female, mean age 52.2 ± 15.1 years) were included. Periodic leg movement during sleep indexes were significantly higher with 3D detection compared to polysomnography (33.3 [8.1–97.2] vs. 30.7 [2.9–91.9]: +9.1%, p = .0055/27.8 [4.5–86.2] vs. 24.2 [0.00–88.7]: +8.2%, p = .0154/31.8 [8.1–89.5] vs. 29.6 [2.4–91.1]: +8.9%, p = .0129). Contactless automatic 3D analysis has the potential to detect restlessness mirrored by periodic leg movements during sleep reliably and may especially be suited for children and the elderly.

Two genetically, anatomically and functionally distinct cell types segregate across anteroposterior axis of paraventricular thalamus

Unlike the sensory thalamus, studies on the functional organization of the midline and intralaminar nuclei are scarce, and this has hindered the establishment of conceptual models of the function of this brain region. We investigated the functional organization of the paraventricular nucleus of the thalamus (PVT), a midline thalamic structure that is increasingly being recognized as a critical node in the control of diverse processes such as arousal, stress, emotional memory and motivation, in mice. We identify two major classes of PVT neurons-termed type I and type II-that differ in terms of gene expression, anatomy and function. In addition, we demonstrate that type II neurons belong to a previously neglected class of PVT neurons that convey arousal-related information to corticothalamic neurons of the infralimbic cortex. Our results uncover the existence of an arousal-modulated thalamo-corticothalamic loop that links the PVT and the ventromedial prefrontal cortex.

The Influence of Empathy Trait and Gender on Empathic Responses. A Study With Dynamic Emotional Stimulus and Eye Movement Recordings

Previous studies have suggested that empathic process involve several components such as cognitive empathy, affective empathy, and prosocial concern. It has also been reported that gender and empathy trait can influence empathic responses such as emotional recognition, which requires an appropriate scanning of faces. However, the degree to which these factors influence the empathic responses, which include emotion recognition, affective empathy, and cognitive empathy, has not yet been specified. Aim: The aim of the present study was to identify the differences between individuals with high and low level of empathy trait, as well as differences between men and women, in an explicit task in order to evaluate the empathic responses. Methods: With this goal in mind, we recorded eye movements during the presentation of dynamic emotional stimuli (joy, anger, fear, and neutral videos). After watching each video, participants had to rate the valence and arousal dimensions of emotional content and explicit empathy responses were assessed. Thirty participants (15 women) were included in a High Empathy group (HE; mean age = 21.0) and 30 participants (16 women) in the Low Empathy group (LE; mean age = 21.2), according to their scores in the Interpersonal Reactivity Index (IRI) scale. Results: As expected, the HE group showed higher scores than the LE group in the explicit empathy responses. These differences, based on global scores, were mainly explained by affective empathy and cognitive empathy responses but not by emotional recognition one. No differences were observed by gender in these measures. Regarding eye movements in the dynamic emotional stimuli, HE group had longer fixation duration on the eyes area than LE group. In addition, women spent more time on the eyes area in comparison to men. Discussion: Our findings suggest that both men and women with high empathy trait are more accurate to empathizing but not on the basis of the emotional recognition response. The fact that women spent more time on the eyes area did not seem to affect the empathic responses to the dynamic emotional stimulus. Overall, empathic responses of both men and women are modulated by their empathic trait. In addition, empathic trait and gender seem to impact strategies to deal with emotional facial information.

Comparing three models of arousal in the human brain

The bipolar valence-arousal model is assumed by many to be an underlying structure of conscious experience of core affect and emotion. In this work, we compare three versions of the bipolar valence-arousal model at the neural domain, using functional magnetic resonance imaging (fMRI). Specifically, we systematically contrast three models of arousal: model 1-'arousal as a separate quale from valence', model 2-'arousal as intensity of bipolar valence' and model 3-'arousal as a linear combination of unipolar pleasant and unpleasant'. Using parametric modulation analysis, we estimated the ability of each model to predict activation in arousal-related brain regions, in response to affective stimuli. The results suggest that arousal is not separable from valence in its ability to predict arousal-related neural activity. The relevance of the results to the theory of conscious affect is discussed.

Effect of a Single Bout of Acute Aerobic Exercise at Moderate-to-Vigorous Intensities on Motor Learning, Retention and Transfer

Acute exercise influences human cognition, and evidence suggests that learning can be improved. According to the cognitive–energetic approach towards exercise cognition, exercise represents a stressor that elevates physiological arousal, which, in turn, increases the availability of mental resources. However, the degree of arousal is hypothesized to have optimal and suboptimal states, and moderate intensity exercise is thus considered to be favorable compared to low intensity and vigorous exercise. The current evidence for such a moderating effect of exercise intensity on motor learning, however, appears somewhat mixed. Therefore, the purpose of this study was to explore the effect of aerobic exercise conducted with different exercise intensities on immediate practice, transfer, and 24-h retention of a motor skill. To this end, young adults (n  =  40, mean (SD) age: 23.80 (1.98) years) were randomized to exercise at either 50% or 75% of age-predicted maximal heart rate according to the Karvonen formulae. Immediately after exercising, participants practiced a high-precision golf putting task in a blocked design. Retention and transfer of skill were assessed after 24 h. Results indicated that both groups demonstrated motor learning, retention, and transfer at a similar level. Further works are thus needed to establish the specific relationship between exercise and learning and establish the factors that have an influence.

Association Between Level of Arousal and 30-Day Survival in Acutely Ill Older Adults

OBJECTIVE

To investigate the association between impaired arousal on admission and 30-day mortality in acutely ill older adults.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Patients age +65 years admitted to the geriatric ward of a tertiary university hospital from 2010 to 2018 in Sao Paulo, Brazil.

METHODS

Participants were evaluated on admission according to a standardized comprehensive geriatric assessment model. Delirium was detected using the short version of the Confusion Assessment Method (Short-CAM). We used 2 alternative criteria to define impaired arousal: lethargy, stupor, or coma according to the Short-CAM; and a Glasgow Coma Scale (GCS) score of ≤13. Our primary outcome was time-to-death in 30 days, and we used Cox proportional hazards models to explore the association between impaired arousal and decreased survival.

RESULTS

We included 1554 admissions with a mean age of 81 years and of whom 61% were women. Overall, prevalent delirium was observed in 28% of the cases. We found that in 33% of admissions, patients were lethargic, stuporous, or comatose, and that in 23%, they had GCS scores of ≤13. General 30-day mortality was 19% but reached 32% in patients with GCS scores of ≤13. Impaired arousal was independently associated with lower survival in 30 days, both when defined using Short-CAM criteria [lethargy + stupor + coma: hazard ratio (HR) 2.33, 95% confidence interval (CI) 1.66‒3.27] and GCS scores (GCS 12‒13: HR 1.62, 95% CI 1.13‒2.33; GCS ≤ 11: HR 2.53, 95% CI 1.68‒3.80). In interaction analyses, we confirmed our results in patients who had impaired arousal but were neither delirious (lethargy + stupor + coma: HR 2.16, 95% CI 1.44‒3.24; GCS ≤ 11: HR 3.07; 95% CI 1.50‒6.29) nor demented (lethargy + stupor + coma: HR 1.95, 95% CI 1.15‒3.28).

CONCLUSIONS AND IMPLICATIONS

Level of arousal on admission was an independent predictor of 30-day survival in acutely ill older adults, regardless of delirium or baseline dementia. Clinicians should be aware that even if unsure of whether a patient has delirium, arousal assessment can provide crucial clinical and prognostic insight.

The Role of Emotional Landmarks in Embodied and Not-Embodied Tasks

The role of emotional landmarks in navigation has been scarcely studied. Previous findings showed that valence and arousal of landmarks increase landmark’s salience and improve performance in navigational memory tasks. However, no study has directly explored the interplay between valence and arousal of emotionally laden landmarks in embodied and not-embodied navigational tasks. At the aim, 115 college students have been subdivided in five groups according to the landmarks they were exposed (High Positive Landmarks HPL; Low Positive Landmarks LPL; High Negative Landmarks HNL; Low Negative Landmarks LNL and Neutral Landmarks NeuL). In the embodied tasks participants were asked to learn a path in a first-person perspective and to recall it after five minutes, whereas in the not-embodied tasks participants were asked to track the learned path on a silent map and to recognize landmarks among distractors. Results highlighted firstly the key role of valence in the embodied task related to the immediate learning, but not to the delayed recall of the path, probably because of the short retention interval used. Secondly, results showed the importance of the interplay between valence and arousal in the non-embodied tasks, specifically, neutral and high negative emotional landmarks yielded the lowest performance probably because of the avoidance learning effect. Implications for future research directions are discussed.

Influence of the Competition Context on Arousal in Agility Dogs

To determine whether participation in dog agility has an impact on canine arousal and welfare, this study aimed firstly to identify the effect of the competition context on arousal changes experienced by dogs, as distinct from purely physical participation in agility, and secondly to assess the handlers' ability to recognize this. Behaviors indicative of changes in arousal were recorded for twenty dogs immediately before completion of both a competition and a training run, whilst the accuracy of handlers' observations of their dogs' behavior was examined via questionnaire. Whilst a moderate number of behaviors presented with greater frequency or duration in competition, the total number of different arousal behaviors performed was higher for dogs in competition (p < 0.01). Context had a relatively modest effect on the level of arousal of agility dogs, with a greater number of behaviors indicating increased arousal in competition. Such increased arousal may adversely influence the success of dog-handler partnerships in competition.  In both contexts, handlers observed fewer behaviors than their dogs performed and this finding may have implications for dog welfare.

Impaired vigilance networks in temporal lobe epilepsy: Mechanisms and clinical implications

Mesial temporal lobe epilepsy (mTLE) is a neurological disorder in which patients suffer from frequent consciousness-impairing seizures, broad neurocognitive deficits, and diminished quality of life. Although seizures in mTLE originate focally in the hippocampus or amygdala, mTLE patients demonstrate cognitive deficits that extend beyond temporal lobe function-such as decline in executive function, cognitive processing speed, and attention-as well as diffuse decreases in neocortical metabolism and functional connectivity. Given prior observations that mTLE patients exhibit impairments in vigilance, and that seizures may disrupt the activity and long-range connectivity of subcortical brain structures involved in vigilance regulation, we propose that subcortical activating networks underlying vigilance play a critical role in mediating the widespread neural and cognitive effects of focal mTLE. Here, we review evidence for impaired vigilance in mTLE, examine clinical implications and potential network underpinnings, and suggest neuroimaging strategies for determining the relationship between vigilance, brain connectivity, and neurocognition in patients and healthy controls.

A comparison of methods used for inducing mental fatigue in performance research: individualised, dual-task and short duration cognitive tests are most effective

Despite research indicating the negative impact that mental fatigue has on physical and cognitive performance, whether this is a result of mental fatigue or a state of under-arousal remains unclear. The current research aimed to explore the effectiveness of the methods being used to induce mental fatigue. Twelve participants attended six sessions in which two cognitive tests, the AX-continuous performance test (AX-CPT) and the TloadDback test, were compared for their effectiveness in inducing mental fatigue. Both tests were set at a standard processing speed (1.2 ms) for two conditions, and a further condition involved the individualisation of the TloadDback test. Participants presented significantly higher physiological and psychological arousal (p < 0.05) in the individualised dual-task test compared to the AX-CPT. The individualised TloadDback test is a more effective method of inducing mental fatigue compared to the AX-CPT, as it sustains physiological arousal whilst inducing measurable reductions in mental resources. Practitioner summary: Mental fatigue negatively impacts physical and cognitive performance. It is unclear whether the current methods being used to induce mental fatigue are effective. This study compared different methods and confirmed that short, individualised and dual-task tests are most effective for inducing mental fatigue whilst maintaining arousal.

Hyperarousal captured in increased number of arousal events during pre-REM periods in individuals with frequent nightmares

The aim of this study was to investigate hyperarousal in individuals with frequent nightmares (NM participants) by calculating arousal events during nocturnal sleep. We hypothesized an increased number of arousals in NM participants compared with controls, especially during those periods where the probability of spontaneous arousal occurrence is already high, such as non-rapid eye movement to rapid eye movement transitions (pre-rapid eye movement periods). Twenty-two NM participants and 23 control participants spent two consecutive nights in our sleep laboratory, monitored by polysomnography. Arousal number and arousal length were calculated only for the second night, for 10 min before rapid eye movement (pre-rapid eye movement) and 10 min after rapid eye movement (post-rapid eye movement) periods, as well as non-rapid eye movement and rapid eye movement phases separately. Repeated-measures ANOVA model testing revealed significant Group (NM participants, controls) × Phase (pre-rapid eye movement, post-rapid eye movement) interaction in case of the number of arousals. Furthermore, post hoc analysis showed a significantly increased number of arousals during pre-rapid eye movement periods in NM participants, compared with controls, a difference that disappeared in post-rapid eye movement periods. We propose that focusing the analyses of arousals specifically on state transitory periods offers a unique perspective into the fragile balance between the sleep-promoting and arousal systems. This outlook revealed an increased number of arousals in NM participants, reflecting hyperarousal during pre-rapid eye movement periods.

Mice Reach Higher Visual Sensitivity at Night by Using a More Efficient Behavioral Strategy

Circadian clocks predictively adjust the physiology of organisms to the day/night cycle. The retina has its own clock, and many diurnal changes in its physiology have been reported. However, their implications for retinal functions and visually guided behavior are largely unresolved. Here, we study the impact of diurnal rhythm on the sensitivity limit of mouse vision. A simple photon detection task allowed us to link well-defined retinal output signals directly to visually guided behavior. We show that visually guided behavior at its sensitivity limit is strongly under diurnal control, reaching the highest sensitivity and stability at night. The diurnal differences in visual sensitivity did not arise in the retina, as assessed by spike recordings from the most sensitive retinal ganglion cell types: ON sustained, OFF sustained, and OFF transient alpha ganglion cells. Instead, we found that mice, as nocturnal animals, use a more efficient search strategy for visual cues at night. Intriguingly, they can switch to the more efficient night strategy even at their subjective day after first having performed the task at night. Our results exemplify that the shape of visual psychometric functions depends robustly on the diurnal state of the animal, its search strategy, and even its diurnal history of performing the task. The results highlight the impact of the day/night cycle on high-level sensory processing, demonstrating a direct diurnal impact on the behavioral strategy of the animal.

Why doesn't emotional valence affect subitising and counting in simple enumeration?

Accurate visual-spatial enumeration involves either the subitising process (for 1-4 items) or the counting process (for larger numbers of items). Although these processes differ, both are thought to involve attentional selection. Many studies show that emotional valence, the negativity or positivity of a stimulus, influences attention and yet Watson and Blagrove found valence had no effect on simple enumeration (enumeration without distractors). To shed light on this surprising finding, we had participants enumerate 1 to 9 dots after viewing emotional scenes, using images from the International Affective Picture System (IAPS) to manipulate valence and arousal. To ensure valence and arousal categorisations were valid for each participant, we individualised them based on their own ratings. Results indicated that both valence and arousal affected enumeration latencies, with enumeration fastest after positive high arousal images and slowest after negative low arousal images. Disengagement deficits were apparent from slowed enumeration after negative images, but there was no evidence that valence affected the breadth of the attentional focus (no interactions with display area). Despite hints that valence may affect subitising and counting differently (weak trends to a cross-over interaction in RT slopes), no firm conclusions can be made because differences were small (<20 ms/item).