Analysis Of Activity Patterns Research Articles

Resting state of human brain measured by fMRI experiment is governed more dominantly by essential mode as a global signal rather than default mode network

Resting-state of the human brain has been described by a combination of various basis modes including the default mode network (DMN) identified by fMRI BOLD signals in human brains. Whether DMN is the most dominant representation of the resting-state has been under question. Here, we investigated the unexplored yet fundamental nature of the resting-state. In the absence of global signal regression for the analysis of brain-wide spatial activity pattern, the fMRI BOLD spatiotemporal signals during the rest were completely decomposed into time-invariant spatial-expression basis modes (SEBMs) and their time-evolution basis modes (TEBMs). Contrary to our conventional concept above, similarity clustering analysis of the SEBMs from 166 human brains revealed that the most dominant SEBM cluster is an asymmetric mode where the distribution of the sign of the components is skewed in one direction, for which we call essential mode (EM), whereas the second dominant SEBM cluster resembles the spatial pattern of DMN. Having removed the strong 1/f noise in the power spectrum of TEBMs, the genuine oscillatory behavior embedded in TEBMs of EM and DMN-like mode was uncovered around the low-frequency range below 0.2 Hz.

Cougar spatiotemporal response to human activities in a multi‐use forest landscape on southern Vancouver Island

Recreational activities have been shown to induce fear responses in carnivores, causing both spatial and temporal displacement that can have cascading effects on the wider ecological community. Cougars Puma concolor are one species that are particularly sensitive to human disturbances as they have been found to be impacted by various forms of recreational activities. This research aimed to quantify the spatial and temporal responses of cougars to human activities on southern Vancouver Island in British Columbia, Canada. Fifty camera traps were deployed in a systematic probabilistic sampling design and data from the summer season of 2022 was used for analyses. We modeled cougar weekly occurrence frequency in relation to human (hikers and bikers) occurrence frequency, vehicle occurrence frequency, and landscape features, using generalized linear mixed models. Temporal responses of cougars were investigated using activity pattern analysis to compare activity patterns within a recreation area and a restricted public access reserve. Cougars avoid occurring at sites where recreationalists frequently visited, but not sites frequented by vehicles on unpaved roads. We observed minimal influence of habitat features or prey availability on cougar occurrence frequency, as measured by information loss (AICc scores). Activity pattern analysis did not demonstrate significant differences in cougar daily activity patterns between the recreation area and no‐entry reserve, suggesting a lack of temporal response. These results suggest recreational activities on southern Vancouver Island are impacting cougar spatial – but not temporal – behavioral dynamics. Insights on how cougars respond to recreational activities can help inform landscape management and policies by providing information that can be used to mitigate negative impacts and thus ensure that recreational activities are remaining compatible with conservation efforts.

Semantic fMRI neurofeedback of emotions: from basic principles to clinical applications.

During fMRI neurofeedback participants learn to self-regulate activity in relevant brain areas and networks based on ongoing feedback extracted from measured responses in those regions. This closed-loop approach has been successfully applied to reduce symptoms in mood disorders such as depression by showing participants a thermometer-like display indicating the strength of activity in emotion-related brain areas. The hitherto employed conventional neurofeedback is, however, 'blind' with respect to emotional content, i.e. patients instructed to engage in a specific positive emotion could drive the neurofeedback signal by engaging in a different (positive or negative) emotion. In this future perspective, we present a new form of neurofeedback that displays semantic information of emotions to the participant. Semantic information is extracted online using real-time representational similarity analysis of emotion-specific activity patterns. The extracted semantic information can be provided to participants in a two-dimensional semantic map depicting the current mental state as a point reflecting its distance to pre-measured emotional mental states (e.g. 'happy', 'content', 'sad', 'angry'). This new approach provides transparent feedback during self-regulation training, and it has the potential to enable more specific training effects for future therapeutic applications such as clinical interventions in mood disorders.This article is part of the theme issue 'Neurofeedback: new territories and neurocognitive mechanisms of endogenous neuromodulation'.

Decoding and modifying dynamic attentional bias in gaming disorder.

With the spread of smartphones and computer games, concerns have escalated regarding the rising prevalence of gaming disorder. Patients often display attentional biases, unconsciously turning their attention towards gaming-related stimuli. However, attempts to discover and ameliorate these attentional deficits have yielded inconsistent outcomes, potentially due to the dynamic nature of attentional bias. This study investigated neural mechanisms underlying attentional bias state by combining neuroimaging (functional magnetic resonance imaging -fMRI) with an approach-avoidance task tailored to an individual's gaming preference. We conducted a multivariate pattern analysis of endogenous brain activity in 21 participants with probable gaming disorder. Our analyses revealed that activity patterns in the insula tracked temporal attentional bias states specific to gaming stimuli. A broad network of frontal and parietal regions instead appeared to predict a general temporal attentional bias state. Finally, we conducted a proof-of-concept study for 'just-in-time' attentional bias training through fMRI-decoded neurofeedback of insula activity patterns, named decoded attentional bias training (DecABT). Our preliminary results suggest that DecABT may help to decrease the attractiveness of gaming stimuli via a insula- and precuneus-based neural mechanism. This work provides new evidence for the insula as an endogenous regulator of attentional bias states in gaming disorder and a starting point to develop novel, individualized therapeutic approaches to treat addiction.This article is part of the theme issue 'Neurofeedback: new territories and neurocognitive mechanisms of endogenous neuromodulation'.

A Temporospatial Analysis of Activity Patterns for Fall Risk Assessment in Older Adults with Comorbid Type 2 Diabetes.

This study explores how daily activities, including duration and location within the home, affect fall risk in older adults with type 2 diabetes. Body-worn cameras on 26 participants provided data on activity (e.g. exercise), time and location (kitchen, living room). Demographics and health factors were considered to understand their influence. By visualising activity patterns, this study aimed to identify behaviours linked to falls to inform personalised fall prevention strategies and digital technologies for independent living.

Prioritized adjustments in posture stabilization and adaptive reaching during neuromuscular fatigue of lower-limb muscles.

Neuromuscular fatigue (NMF) induces temporary reductions in muscle force production capacity, affecting various aspects of motor function. Although studies have extensively explored NMF's impact on muscle activation patterns and postural stability, its influence on motor adaptation processes remains less understood. This article investigates the effects of localized NMF on motor adaptation during upright stance, focusing on reaching tasks. Using a force-field perturbation paradigm, participants performed reaching movements while standing upright before and after inducing NMF in the ankle dorsiflexor muscles. Results revealed that despite maintained postural stability, participants in the NMF group exhibited larger movement errors during reaching tasks, suggesting impaired motor adaptation. This was evident in both initial and terminal phases of adaptation, indicating a disruption in learning processes rather than a decreased adaptation rate. Analysis of electromyography activation patterns highlighted distinct strategies between groups, with the NMF group showing altered activation of both fatigued and nonfatigued muscles. In addition, differences in coactivation patterns suggested compensatory mechanisms to prioritize postural stability despite NMF-induced disruptions. These findings underscore the complex interplay between NMF, motor adaptation, and postural control, suggesting a potential role for central nervous system mechanisms in mediating adaptation processes. Understanding these mechanisms has implications for sports performance, rehabilitation, and motor skill acquisition, where NMF may impact the learning and retention of motor tasks. Further research is warranted to elucidate the transient or long-term effects of NMF on motor adaptation and its implications for motor rehabilitation interventions.NEW & NOTEWORTHY We assessed motor adaptation during force-field reaching following exercise-induced neuromuscular fatigue (NMF) on postural muscles. NMF impaired adaptation in performance. Similarly, diverging activation strategies were observed in the muscles. No effects were seen on measures of postural control. These results suggest the remodulation of motor commands to the muscles in the presence of NMF, which may be relevant in settings where participants could be exposed to NMF while learning, such as sports and rehabilitation.

Mnemonic brain state engagement is diminished in healthy aging.

Healthy older adults typically show impaired episodic memory - memory for when and where an event oc-curred - but intact semantic memory - knowledge for general information and facts. As older adults also have difficulty inhibiting the retrieval of prior knowledge from memory, their selective decline in episodic memory may be due to a tendency to over engage the retrieval state, a brain state in which attention is focused internally in an attempt to access prior knowledge. The retrieval state trades off with the encoding state, a brain state which supports the formation of new memories. Therefore, episodic memory declines in older adults may be the result of differential engagement in mnemonic brain states. Our hypothesis is that older adults are biased toward a retrieval state. We recorded scalp electroencephalography while young, middle-aged and older adults performed a memory task in which they were explicitly directed to either encode the currently presented object stimulus or retrieve a previously presented, categorically-related object stimulus. We used multivariate pattern analysis of spectral activity to decode engagement in the retrieval vs. encoding state. We find that all three age groups can follow top-down instructions to selectively engage in encoding or retrieval and that we can decode mnemonic states for all age groups. However, we find that mnemonic brain state engagement is diminished for older adults relative to middle-aged adults. Our interpretation is that a combination of executive control deficits and a modest bias to retrieve modulates older adults' mnemonic state engagement. Together, these findings suggest that dif-ferential mnemonic state engagement may underlie age-related memory changes.

Comparative Analysis of Neuromuscular Activation Patterns Associated with Force between Semi-Professional Female Soccer Players with Previous Anterior Cruciate Ligament Surgery and Healthy Players in Thigh Musculature Related to Valgus Collapse

This study investigates electromyography activation and force development differences in key lower limb muscles between female football players with previous anterior cruciate ligament injuries compared with healthy players. Twenty-two semi-professional players were divided into ACL-injured (n = 11) and non-injured groups (n = 11). Participants underwent maximal voluntary isometric contractions while electromyography activation, peak and average, and peak torque of force were measured. Results indicated significant differences in electromyography activation patterns between anterior cruciate ligament players and non-injured players, particularly in biceps femoris and gluteus maximus muscles. These differences were also evident when comparing between limbs within anterior cruciate ligament players. Interestingly, both groups exhibited similar peak torque of force during maximal contractions, suggesting a compensatory neuromuscular strategy that supports a return to sport based on kinetic and kinematic factors. However, these findings underscore persistent muscle integration imbalances potentially contributing to the high rate of anterior cruciate ligament reinjury. In conclusion, this study highlights the importance of evaluating electromyography activation alongside force development in understanding neuromuscular adaptations post anterior cruciate ligament injury. These insights emphasize the need for comprehensive rehabilitation strategies that address muscle imbalance to mitigate the risk of recurrent anterior cruciate ligament injuries in female football players.

Human motion activity recognition and pattern analysis using compressed deep neural networks

ABSTRACT This work presents an on-device machine learning model with the ability to identify different mobility gestures called human activity recognition (HAR), which includes running, walking, squatting, jumping, and others. The data is collected through an Arduino Nano 33 BLE Sense board with a sampling rate of 119 Hz, which is embedded with an Inertial Measurement Unit (IMU) sensor. The same board is used as a microcontroller to identify human gestures by developing an end-to-end edge computing application. A deep neural network model is trained and then compressed for deployment on the board to create a self-contained, embedded device capable of identifying the type of gesture performed. Three deep learning models, namely Multi-Layer Perceptron (MLP), Convolutional Neural Network – Long Short Term Memory (CNN-LSTM) & CNN-Gated Recurrent Unit (CNN-GRU), are evaluated in the identification of the mobility gestures. The observed accuracy of the models is 96%, 97.1% and 97.8%, respectively, MLP, CNN-LSTM & CNN-GRU across the different gesture categories. The study shows the utility of embedded devices with deep neural network-based models, which can provide low cost, minimal power usage, and meet data privacy requirements in HAR.

Empathy from dissimilarity: Multivariate pattern analysis of neural activity during observation of somatosensory experience

Abstract Empathy seems to rely on our ability to faithfully simulate multiple aspects of others’ inferred experiences, often using brain structures we would use during a similar experience. Much neuroimaging work in this vein has related empathic tendencies to univariate correlates of simulation strength or salience. However, novel evidence suggests that empathy may rely on the multivariate distinctiveness of these simulations. Someone whose representations of painful and non-painful stimulation are more distinct from each other may more accurately simulate that experience upon seeing somebody else experience it. We sought to predict empathic tendencies from the dissimilarity between neural activity patterns evoked by observing other people experience pain and touch and compared those findings to traditional univariate analyses. In support of a simulationist perspective, diverse observed somatosensory experiences were best classified by activation patterns in contralateral somatosensory and insular cortices, the same areas that would be active were the subject experiencing the stimuli themselves. In support of our specific hypothesis, the degree of dissimilarity between patterns for pain and touch in distinct areas was each associated with different aspects of trait empathy. Furthermore, the pattern dissimilarity analysis proved more informative regarding individual differences than analogous univariate analyses. These results suggest that multiple facets of empathy are associated with an ability to robustly distinguish between the simulated states of others at corresponding levels of the processing hierarchy, observable via the distinguishability of neural patterns arising with those states. Activation pattern dissimilarity may be a useful tool for parsing the neuroimaging correlates of complex cognitive functions like empathy.

Remote heart failure patient monitoring: A comprehensive analysis of physical activity patterns

Remote heart failure patient monitoring: A comprehensive analysis of physical activity patterns

Population size and social structure of lions in a west African protected area

AbstractTo inform the conservation of the Regionally Critically Endangered West African lion, we studied lion population size and social structure in Niokolo Koba National Park (NKNP), Senegal. Calling station and camera trap surveys were conducted and opportunistic lion observations were documented from 2015 to 2020. The average lion density was calculated as 0.50 lion/100 km2 and the population size was estimated as 28–56 individuals. Average lion group size was 2.1 ± 1.45 lions (range 1–8 lions). There were no significant differences between observations of single individuals (43%), groups of two (22%), three (19%), four (4%) and more than four (5%) individual lions (X2 = 30.021, p‐value = 0.06452). Sex ratio showed a ratio of male:female of 1:1.1 to 1:2.8. About 13.59% of the lion population was composed of cubs while, respectively, 81.22% and 5.17% were adults and subadults. Based on the analysis of activity patterns, lions in NKNP are mainly nocturno‐crepuscular (18:00–01:00) and matutinal (06:00–08:00). Lion population size and density are still low in NKNP compared to earlier estimates from the same area, in the late 1990s. We therefore conclude that the conservation of lions in NKNP must be further improved to safeguard this population in the long term.

TAO

Translating fine-grained activity detection (e.g., phone ring, talking interspersed with silence and walking) into semantically meaningful and richer contextual information (e.g., on a phone call for 20 minutes while exercising) is essential towards enabling a range of healthcare and human-computer interaction applications. Prior work has proposed building ontologies or temporal analysis of activity patterns with limited success in capturing complex real-world context patterns. We present TAO, a hybrid system that leverages OWL-based ontologies and temporal clustering approaches to detect high-level contexts from human activities. TAO can characterize sequential activities that happen one after the other and activities that are interleaved or occur in parallel to detect a richer set of contexts more accurately than prior work. We evaluate TAO on real-world activity datasets (Casas and Extrasensory) and show that our system achieves, on average, 87% and 80% accuracy for context detection, respectively. We deploy and evaluate TAO in a real-world setting with eight participants using our system for three hours each, demonstrating TAO's ability to capture semantically meaningful contexts in the real world. Finally, to showcase the usefulness of contexts, we prototype wellness applications that assess productivity and stress and show that the wellness metrics calculated using contexts provided by TAO are much closer to the ground truth (on average within 1.1%), as compared to the baseline approach (on average within 30%).

Mesocarnivores activity patterns in the Northern Colombian Andes

Temporal segregation plays an important role as a coexistence mechanism between potentially competing and closely related species, especially in species with similar morphology and ecological requirements, such as mesocarnivores. This study investigates the temporal niche ecology of mesocarnivores coexisting in the southeastern Aburrá Valley, northern Colombian Andes. Specifically, this study i) evaluated the daily activity patterns of six mesocarnivore species, ii) analyzed the influence of the lunar cycle on the activity patterns of nocturnal species, iii) estimated the temporal overlap between pairs of mesocarnivores, and iv) estimated the functional similarities of these species. We hypothesized that mesocarnivores with similar functional traits exhibit greater temporal niche segregation, thus showing low overlap in their activity patterns to reduce competition. We used data from tracking cameras (10,744 camera-days) and estimated daily activity patterns using Kernel density analysis, non-negative trigonometric summation, and overlap analysis with the Overlap package in R. Also, lunar influence was evaluated using circular statistics in the software Oriana 4.02. Functional similarity was analyzed by similarity clustering using Jaccard's index in PAST. Nine species were recorded; six were included in the analyses of daily activity patterns. Activity patterns were not uniform throughout the circadian cycle. Cerdocyon thous, Leopardus tigrinus, and Nasuella olivacea showed mainly nocturnal activity, while Eira barbara, Nasua nasua, and Neogale frenata displayed a diurnal activity pattern. Only Leopardus tigrinus showed significant activity related to the lunar cycle. The activity overlap between pairs of species was variable, with a tendency to a low overlap, showing a high ecological similarity between species. This study represents the first estimate of the activity patterns of mesocarnivore species in the southeastern Aburrá Valley. The observed activity patterns are similar to those reported in other works. Species with high overlap showed ecological differences, especially in size and diet. The low number of records for some species may be associated with poor detectability but also with low abundance as a result of urban development and anthropogenic disturbance (e. g., roadkills). Our results suggest that temporal segregation contributes to mediating intra-gremial interactions and coexistence between sympatric and potentially competing species. These results will hopefully contribute to the knowledge of the ecology of mesocarnivores, mainly in ecosystems surrounding large cities in the northern Andes.

Arctic shipping trends during hazardous weather and sea-ice conditions and the Polar Code’s effectiveness

The Arctic’s extreme environmental conditions and remoteness make it a complex and dynamic environment for maritime operators. We find that Arctic shipping has grown by 7% per year over the past decade, despite the hazardous weather and sea-ice conditions that pose risks to vessels operating in the region. As a result of a strong increase in winter sailing, the time ships operate in these extreme conditions has even tripled. To mitigate maritime risks, the Polar Code has been introduced. Among other things, it regulates Arctic shipping by specifying hazardous conditions with a sea-ice classification scheme and design temperature threshold. However, we argue that the Polar Code needs refinement through the integration of maritime warning systems and a broader description of hazardous conditions. This is supported by an analysis of shipping activity patterns in severe sea-spray icing conditions and a discussion of a recent sea-ice induced incident along the Northern Sea Route.

SEX DIFFERENCES IN SELECTIVE AUDITORY ATTENTION DURING DICHOTIC LISTENING WITH DIFFERENT LEVELS OF COMPLEXITY: AN FMRI STUDY

A group of 20 healthy subjects (11 males and 9 females) performed a selective auditory attention task in a dichotic listening paradigm with different levels of perceptual load. Analysis of brain activation patterns measured with fMRI during selective listening to fusion speech with distractors of varying strengths revealed statistically significant sex differences in the topography of cortical activity. “Female male” effects dominated in the left superior temporal gyrus and the left pre and postcentral gyrus; while the most pronounced “male female” effects were found in the left islet, shell and frontal lobule. Statistically significant effects were also obtained by comparing activation patterns according to the level of task complexity: It was shown that masking with a female speaker’s voice caused greater activation of additional high-level information processing areas. The findings indicate the presence of sexual dimorphism in the organization of the selective auditory attention system.

Where do we manage? Uncovering the hidden impact of human presence on mammal conservation in northern Myanmar

Species spatiotemporal responses to human presence and prioritizing conservation areas are essential for effective management and conservation planning. To address this information, we conducted a long-term large mammal survey in both protected areas (PAs) and outside of PAs (non-PA) in Northern Mountain Forest Complex (NMFC), Myanmar by using 174 camera traps from 2015 to 2019. We selected 14 common species for the single species occupancy model and activity pattern analysis to evaluate their spatiotemporal responses to different anthropogenic and environmental variables. Results showed that human presence did not have a significant impact on mammal occupancy, whereas at the community level, it had a significant influence on mammal abundance. Some variables, including distance to settlements, proximity to water sources and forest cover, shaped the habitat occupancy of mammals in NMFC. Regarding the temporal axis, only three out of 14 species had higher temporal activity overlap with humans, while the remaining species showed lower to medium overlap in both PAs and non-PA, confirming that most mammals avoided human presence through temporal rather than spatial scale. Moreover, our priority analysis revealed that non-PA supported a significant proportion of medium- to high-priority areas, particularly in the south-eastern part of NMFC. We concluded that preserving both PAs and non-PA are crucial and human activities have an implicit influence on large mammal conservation in NMFC. The government should prioritize the south-eastern region of outside of the current PAs network and adopt community-based conservation strategies to ensure the efficacy of PA networks and biodiversity conservation in NMFC.

Ventricular Electrograms Duration Map to Detect Ventricular Arrhythmia Substrate: the VEDUM Project Study.

The analysis of the wave-front activation patterns is crucial for the comprehension and treatment of ventricular tachycardia (VT). The ventricular electrograms duration map (VEDUM) is a potential method to identify areas (VEDUM area) with slow and inhomogeneous activation. There is no available data on the characteristics and the arrhythmogenic role of VEDUM areas identified during sinus/paced rhythm. Patients referred for VT ablation were enrolled at 3 different centers. VEDUM maps during sinus/paced rhythm as well as substrate and functional maps were created; activation mapping was performed for all hemodynamically tolerated VT. Thirty-two patients (mean age:70.1±9.4 years; males 93.8%) were enrolled. The VEDUM approach was achieved in all patients and the mean size of the VEDUM area was 12.1±6.9 cm2 (interquartile range, 7.8-14.9 cm2). A significative difference was observed between the electrogram duration in the VEDUM area and the normal tissue (163.7 ms [interquartile range, 142.3-199.2 ms]; versus 65.5 ms [interquartile range, 59.5-76.2 ms]; P<0.001). The VEDUM area was visualized in a dense scar (<0.5 mV) in 19 (59.4%) patients. A deceleration zone and late potentials were recorded inside the VEDUM area in 56.3% and 81.3%, respectively. When a complete VT activation mapping was available, the isthmus projected in the VEDUM area in 93.5% of patients; 8 of them had multiple VTs mapped and in the 87.5% all VT isthmuses were included in the VEDUM area. VEDUM maps allow the identification of discrete areas of inhomogeneous and slow conduction. They represent a potential target for VT ablation, including patients with multiple morphologies.

The effects of crank power and cadence on muscle fascicle shortening velocities, muscle activations and joint-powers during cycling.

Whilst people typically chose to locomote in most economical fashion, during bicycling they will, unusually, chose cadences that are higher than metabolically optimal. Empirical measurements of the intrinsic contractile properties of the vastus lateralis (VL) muscle during submaximal cycling suggest that the cadences that people self-selected (SSC) might allow for optimal muscle fascicle shortening velocity for the production of knee extensor muscle power. It remains unclear, however, whether this is consistent across different power outputs where the SSC varies. We examined the effect of cadence and external power requirements on muscle neuromechanics and joint powers during cycling. VL fascicle shortening velocities, muscle activations and joint-specific powers were measured during cycling between 60 and 120rpm (including SSC), while participants produced 10%, 30%, and 50% of peak maximal power. VL shortening velocity increased as cadence increased but was similar across the different power outputs. Although no differences were found in the distribution of joint powers across cadence conditions, the absolute knee joint power increased with increasing crank power output. Muscle fascicle shortening velocities increased in VL at the SSC as pedal power demands increased from submaximal towards maximal cycling. A secondary analysis of muscle activation patterns showed minimized activation of VL and other muscles near the SSC at the 10% and 30% power conditions. Minimization of activation with progressively increasing fascicle shortening velocities at the SSC may be consistent with the theory that the optimum shortening velocity for maximizing power increases with intensity of exercise and recruitment of fast twitch fibers.

Rare phenomena of central rhythm and pattern generation in a case of complete spinal cord injury

Lumbar central pattern generators (CPGs) control the basic rhythm and coordinate muscle activation underlying hindlimb locomotion in quadrupedal mammals. The existence and function of CPGs in humans have remained controversial. Here, we investigated a case of a male individual with complete thoracic spinal cord injury who presented with a rare form of self-sustained rhythmic spinal myoclonus in the legs and rhythmic activities induced by epidural electrical stimulation (EES). Analysis of muscle activation patterns suggested that the myoclonus tapped into spinal circuits that generate muscle spasms, rather than reflecting locomotor CPG activity as previously thought. The EES-induced patterns were fundamentally different in that they included flexor-extensor and left-right alternations, hallmarks of locomotor CPGs, and showed spontaneous errors in rhythmicity. These motor deletions, with preserved cycle frequency and period when rhythmic activity resumed, were previously reported only in animal studies and suggest a separation between rhythm generation and pattern formation. Spinal myoclonus and the EES-induced activity demonstrate that the human lumbar spinal cord contains distinct mechanisms for generating rhythmic multi-muscle patterns.