Movement Responses Research Articles

Fence types influence pronghorn movement responses

AbstractImpediments that constrain animal movements across spatiotemporally heterogeneous landscapes can result in reduced or complete loss of access to critical resources. Across their range in North America, pronghorn (Antilocapra americana) are exposed to fences that can affect their ability to permeate the landscape, access critical resources, and respond to climatic variations. Understanding pronghorn movement responses to fences is essential for improving landscape permeability; however, prior studies provide only limited insight due to lack of information on fence characteristics and small sample sizes. Our study used hourly collar locations from adult female pronghorn in six herds in Montana, USA, and identified encounters with mapped fences to evaluate three movement responses (i.e., probability of an unaltered initial response, probability of crossing following an altered initial response, and passage time following an altered initial response) as a function of fence and landscape attributes. Based on 5581 encounters identified from movement pathways of 265 collared pronghorn and 979 km of mapped fences, we found that variability in pronghorn fence response was correlated with fence type. Woven wire fences substantially reduced unaltered initial and crossing responses and increased passage times as compared with low (i.e., average lowest wire height <41 cm) or high (i.e., average lowest wire height ≥41 cm) strand fences. Both low and high strand fences elicited similar responses of being relatively permeable at the initial encounter with reduced permeability thereafter. Fence crossing probabilities following altered initial responses increased through time modestly for strand fences but only negligibly for woven wire fences, with passage times averaging approximately 14 h. Pronghorn knowledge of and fidelity to specific permeable locations along fences, which may be due to inconsistent fence and landscape characteristics along the fence stretch, likely allow some woven wire fences and most strand fences, regardless of the average lowest wire height, to be permeable. Improving landscape permeability for pronghorn should focus on removing woven wire fences, replacing woven wire fences with strand fences, and incorporating variation in the lowest wire heights into new fence designs or modifications of existing fences.

Fish movements in response to environmental flow releases in intermittent rivers

Abstract Variation in river flow is a strong behavioural determinant for the movement of many freshwater fish species and often is linked to key aspects of their life cycle. The alteration of natural flow regimes to meet human water demands can result in changes to this variability, and cause declines in water‐dependent biota. Environmental flows are used as a remediation tool in some regulated rivers with the intention of restoring aspects of the natural flow regime to benefit riverine species, although empirical data are required to inform the efficacy of these interventions. Using acoustic telemetry, we quantified the movement responses of two large‐bodied native fish species (freshwater catfish, Tandanus tandanus and Murray cod, Maccullochella peelii) to variations in river flow over 4 years in two intermittent regulated rivers in the northern Murray–Darling Basin, Australia. Both rivers received periodic environmental flow releases and also there were several large natural flow events during the study period. Both species displayed a range of intra‐specific movement behaviours. Analysis of individuals' movements revealed five distinct functional groups, which were represented in both species. We found that periods of environmental flow delivery played an important role in the movement behaviour of both species. Murray cod were more likely to move during periods of environmental flow releases, whereas freshwater catfish were less likely to move on an environmental release following higher antecedent flows. No large‐scale philopatric movements were observed, yet Murray cod were more likely to move during the breeding period, indicative of nest site selection. We also found that the likelihood of movement in both species was higher in the smaller of the two rivers for a given magnitude of flow. Our results suggest that environmental flows may benefit certain fish species by facilitating, rather than cueing breeding behaviours, allowing individuals improved access to, and provision of, higher‐quality nesting habitats. These findings will aid water managers in creating economical and targeted environmental flow releases, timing larger flow pulses for the species with flow‐cued reproductive strategies, and providing a continuity of smaller baseflows for species whose reproduction is not dependent on flow cues but may be enhanced by greater connectivity.

New pulse profile variability associated with a glitch of PSR J0738-4042

ABSTRACT The close correlation observed between emission state and spin-down rate change of pulsars has many implications both for the magnetospheric physics and the neutron star interior. The middle-aged pulsar PSR J0738-4042, which had been observed to display variations in the pulse profile associated with its spin-down rate change due to external effects, is a remarkable example. In this study, based on the 12.5 yr combined public timing data from UTMOST and Parkes, we have detected a new emission-rotation correlation in PSR J0738-4042 concurrent with a glitch. A glitch that occurred at MJD 57359 (5) (2015 December 3) with Δν/ν ∼ 0.36(4) × 10−9 is the first glitch event observed in this pulsar, and is probably the underlying cause of the emission-rotation correlation. Unlike the usual post-glitch behaviours, the braking torque on the pulsar has continued to increase over 1380 d, corresponding to a significant decrease in $\ddot{\nu }$. As for changes in the pulse profile after the glitch, the relative amplitude of the leading component weakens drastically, while the middle component becomes stronger. A combined model of crustquake induced platelet movement and vortex creep response is invoked to account for this rare correlation. In this scenario, magnetospheric state-change is naturally linked to the pulsar-intrinsic processes that give rise to a glitch.

Ribosomal stress couples with the hypoxia response in Dec1-dependant orthodontic tooth movement

Ribosomal stress couples with the hypoxia response in Dec1-dependant orthodontic tooth movement

Detection of visual field defects using Eye Movement Pediatric Perimetry in children with intracranial lesions: feasibility and applicability

The study aimed at evaluating the feasibility of Eye Movement Pediatric Perimetry (EMPP) among children in detecting Visual Field Defects (VFDs) associated with Intracranial Lesions (IL). Healthy controls (n = 35) and patients diagnosed with IL (n = 19) underwent a comprehensive clinical evaluation followed by a Goldmann Visual Field (GVF) and a customised EMPP protocol. During EMPP, all the participants were encouraged to fixate on a central target and initiate Saccadic Eye Movement (SEM) responses towards randomly appearing peripheral stimuli. The SEM responses were recorded using an eye-tracking device and further inspected to calculate Performance Scores (PS), Saccadic Reaction Times (SRTs), and an EMPP Index (EMPI). The mean age (years) of the controls and cases were 7.3 (SD: 1.5) and 9.4 (SD: 2.4) respectively. Among the controls, the older children (≥7 years) showed statistically significantly faster SRTs (p = 0.008) compared to the younger group. The binocular EMPP measurements compared between the controls and the cases revealed no statistically significant differences in PS (p = 0.34) and SRT (p = 0.51). EMPP failed in 4 children because of data loss or unacceptably poor PS whereas GVF failed in 7 children due to unreliable subjective responses. Of the 16 reports, with regard to the central 30-degree VF, 63% of the outputs obtained from both methods were comparable. EMPP is a reliable method to estimate and characterise the central 30-degree VF in greater detail in children with IL. EMPP can supplement the conventional methods, especially in those children who fail to complete a long duration GVF test.

Immersive Real-Time Biofeedback Optimized With Enhanced Expectancies Improves Motor Learning: A Feasibility Study.

An Optimizing Performance through Intrinsic Motivation and Attention for Learning theory-based motor learning intervention delivering autonomy support and enhanced expectancies (EE) shows promise for reducing cognitive-motor dual-task costs, or the relative difference in primary task performance when completed with and without a secondary cognitive task, that facilitate adaptive injury-resistant movement response. The current pilot study sought to determine the effectiveness of an autonomy support versus an EE-enhanced virtual reality motor learning intervention to reduce dual-task costs during single-leg balance. Within-subjects 3 × 3 trial. Twenty-one male and 24 female participants, between the ages of 18 and 30years, with no history of concussion, vertigo, lower-extremity surgery, or lower-extremity injuries the previous 6months, were recruited for training sessions on consecutive days. Training consisted of 5 × 8 single-leg squats on each leg, during which all participants mimicked an avatar through virtual reality goggles. The autonomy support group chose an avatar color, and the EE group received positive kinematic biofeedback. Baseline, immediate, and delayed retention testing consisted of single-leg balancing under single- and dual-task conditions. Mixed-model analysis of variances compared dual-task costs for center of pressure velocity and SD between groups on each limb. On the right side, dual-task costs for anterior-posterior center of pressure mean and SD were reduced in the EE group (mean Δ = -51.40, Cohen d = 0.80 and SD Δ = -66.00%, Cohen d = 0.88) compared with the control group (mean Δ = -22.09, Cohen d = 0.33 and SD Δ = -36.10%, Cohen d = 0.68) from baseline to immediate retention. These findings indicate that EE strategies that can be easily implemented in a clinic or sport setting may be superior to task-irrelevant AS approaches for influencing injury-resistant movement adaptations.

The protein kinase FvRIPK1 regulates plant morphogenesis by ABA signaling using seed genetic transformation in strawberry.

A strawberry RIPK1, a leu-rich repeat receptor-like protein kinase, is previously demonstrated to be involved in fruit ripening as a positive regulator; however, its role in vegetable growth remains unknown. Here, based on our first establishment of Agrobacterium-mediated transformation of germinating seeds in diploid strawberry by FvCHLH/FvABAR, a reporter gene that functioned in chlorophyll biosynthesis, we got FvRIPK1-RNAi mutants. Downregulation of FvRIPK1 inhibited plant morphogenesis, showing curled leaves; also, this silencing significantly reduced FvABAR and FvABI1 transcripts and promoted FvABI4, FvSnRK2.2, and FvSnRK2.6 transcripts. Interestingly, the downregulation of the FvCHLH/ABAR expression could not affect FvRIPK1 transcripts but remarkably reduced FvABI1 transcripts and promoted FvABI4, FvSnRK2.2, and FvSnRK2.6 transcripts in the contrast of the non-transgenic plants to the FvCHLH/FvABAR-RNAi plants, in which chlorophyll contents were not affected but had abscisic acid (ABA) response in stomata movement and drought stress. The distinct expression level of FvABI1 and FvABI4, together with the similar expression level of FvSnRK2.2 and FvSnRK2.6 in the FvRIPK1- and FvABAR/CHLH-RNAi plants, suggested that FvRIPK1 regulated plant morphogenesis probably by ABA signaling. In addition, FvRIPK1 interacted with FvSnRK2.6 and phosphorylated each other, thus forming the FvRIPK1-FvSnRK2.6 complex. In conclusion, our results provide new insights into the molecular mechanism of FvRIPK1 in plant growth.

Ribosomal stress couples with the hypoxia response in Dec1-dependant orthodontic tooth movement

Ribosomal stress couples with the hypoxia response in Dec1-dependant orthodontic tooth movement

Attenuation of neural responses in subthalamic nucleus during internally guided voluntary movements in Parkinson's disease.

The proposed models of segregated functional loops describe the organization of motor control over externally triggered (ET) and internally guided (IG) movements. The dopamine deficiency in Parkinson’s disease (PD) is considered to cause a disturbance in the functional loop regulating IG movements. At the same time, the neural mechanisms of movement performance and the role of basal ganglia in motor control remain unclear.The aim of this study was to compare neuronal responses in the subthalamic nucleus (STN) during ET and IG movements in PD. We found and analyzed 26 sensitive neurons in 12 PD patients who underwent surgery for implantation of electrodes for deep brain stimulation. We also analyzed the local field potentials (LFP) of the STN of six patients during the postoperative period. Patients were asked to perform voluntary movements (clenching and unclenching the fist) evoked by verbal command (ET) or self-initiated (IG). We showed heterogeneity of neuronal responses and did not find sensitive neurons associated with only one type of movement. Most cells were characterized by leading responses, indicating that the STN has an important role in movement initiation. At the same time, we found attenuation of motor responses during IG movement vs. stable responses during ET movements. LFP analysis also showed attenuation of beta desynchronization during multiple IG movements.We propose that stable neuronal response to ET movements is associated with the reboot of the motor program for each movement, while attenuation of responses to IG movement is associated with single motor program launching for multiple movements.

Highly sensitive temperature-independent FBG-based sensor embedded in thermoplastic polyurethane using 3D printing technology for the measurements of torsion

A new design of optical Fiber Bragg Grating (FBG)-based sensor for the measurement of torsion (twist) has been developed, which, while offering a high level of accuracy, can be fabricated inexpensively using 3D printing technology. In this sensor design, an FBG is embedded inside the thermoplastic polyurethane (TPU) filament, which acts as the sensing pad for the FBG, taking advantage of its highly elastic properties and excellent sensitivity to variations in local strain. Experiments conducted have shown that the embedded FBG-based sensor can be used effectively in the measurements of torsion or rotation, at a bonding angle of 45°, giving an average responsivity of 0.95 pm/deg in both the clockwise and anticlockwise direction over the range of − 100° to + 100°, with good linearity of up to 99%. Furthermore, the device has been developed to allow for the effects of any temperature changes to be compensated by including an additional but 'untwisted' FBG in the sensor design. It provides a temperature sensitivity of 18.90 pm/°C. This design of twist measurement sensor described in this work also shows a good response in the underground soil movement, giving an average responsivity of 0.95 pm/deg in both the clockwise and anticlockwise direction over the range of − 100° to + 100°, with good linearity of up to 99%. This proves that this fabricated device can be made applicable to a wide range of engineering applications reliably and inexpensively.

Chemonastic Stalked Glands in the Carnivorous Rainbow Plant Byblis gigantea LINDL. (Byblidaceae, Lamiales).

Carnivorous rainbow plants (Byblis, Byblidaceae, Lamiales) possess sticky flypaper traps for the capture, retention, and digestion of prey (mainly small insects). The trapping system is based on a multitude of millimeter-sized glandular trichomes (also termed stalked glands), which produce adhesive glue drops. For over a century, the trapping system of Byblis was considered passive, meaning that no plant movement is involved. Recently, a remarkable discovery was made: the stalked glands of Byblis are indeed capable of reacting to chemical (protein) stimuli with slow movement responses. This prompted us to investigate this phenomenon further with a series of experiments on the stimulation, kinematics, actuation, and functional morphology of the stalked glands of cultivated Byblis gigantea plants. Measured stalked gland lengths and densities on the trap leaves are similar to the data from the literature. Motion reactions could only be triggered with chemical stimuli, corroborating the prior study on the stalked gland sensitivity. Reaction time (i.e., time from stimulation until the onset of motion) and movement duration are temperature-dependent, which hints towards a tight physiological control of the involved processes. The stalked gland movement, which consist of a sequence of twisting and kinking motions, is rendered possible by the components of the stalk cell wall and is furthermore anatomically and mechanically predetermined by the orientation of cellulose microfibrils in the cell wall. Successive water displacement processes from the stalk cell into the basal cells actuate the movement. The same kinematics could be observed in stalked glands drying in air or submersed in a saturated salt solution. Stimulated and dried stalked glands as well as those from the hypertonic medium were capable of regaining their initial shape by rehydration in water. However, no glue production could be observed afterwards. The long-time overlooked chemonastic movements of stalked glands may help Byblis to retain and digest its prey; however, further research is needed to shed light on the ecological characteristics of the rainbow plant’s trapping system.

Research on the generality of icon sizes based on visual attention

AbstractIcon size is one of the key factors affecting the efficiency of information search. The advent of the era of intelligent interaction has made it difficult for icon design to meet the requirements of noncontact, large information volume, and high precision proposed by natural interaction technology in the future. At the same time, with the continuous improvement of display technology, the display resolution has been increased from 720 P to 8 K. Different sizes of display carriers use different resolutions. In order for icons to have efficient recognition at different display resolutions, it is necessary to obtain the best proportional relationship between icon size and display resolution. This paper summarizes the existing relevant research, calculates the ratio of recommended icon size and display resolution as the research variables, and comprehensively evaluates the recommended optimal ratio range of 1:641–1:334 through eye movement, EEG and behavioral response experiments and entropy‐weight TOPSIS method, providing a reference for icon design in various forms of interactive interfaces in the future.

Wheelchair control system for the disabled based on EMOTIV sensor gyroscope

In this study, a wheelchair control system (WCS) was designed and constructed that utilizes an EMOTIV gyroscope sensor for comfortable wheelchair movement. The proposed WCS involves an electroencephalograph (EEG), DC motors, an electronic wheelchair, a microcontroller, and a laptop. The control system algorithm is bulit in Arduino microcontroller using C++ language. The WCS comprises 15 states and is dependent on head motions. There are 12 motor speed settings and eight wheel rotary radius cases. The WCS was tested by 10 women and men aged between 20 and 70 years. The system was implemented and tested in both indoor and outdoor environments to represent smooth and rough surfaces. It was also evaluated at various directions and speeds as well as at rotational radii (interior and exterior areas), and it prevented collisions with barriers using an ultrasonic sensor and reduced the wheelchair movement response time. The control system algorithm achieves an average response time of approximately 1–2 s to move the wheelchair in the specified direction. The performance metrics were also investigated and included sensitivity, specificity, and accuracy with encouraging results: The average WCS accuracy is 99.16%, sensitivity is 99.2%, and specificity is 99.15%. The overall performance is approximately 98%. The accuracy and response times of this WCS outperforms previous research findings.

Ribosomal stress couples with the hypoxia response in Dec1-dependant orthodontic tooth movement

Ribosomal stress couples with the hypoxia response in Dec1-dependant orthodontic tooth movement

Comparison of EOG and VOG obtained eye movements during horizontal head impulse testing.

IntroductionVideo head impulse testing is frequently used to evaluate the vestibular function. During this test, eye movement responses are recorded with video-oculography (VOG). However, the use of VOG can sometimes be challenging, especially due to pupil detection problems (e.g., blinking, droopy eyelids, etc.). Therefore, this study investigated whether electro-oculography (EOG), a technique that does not depend on pupil tracking but on the orientation of the corneoretinal potential, might be an alternative to VOG for quantifying eye movement responses during head impulse testing.Subjects and methodsHead impulse testing was performed in 19 healthy subjects without a prior history of vestibular symptoms. Horizontal eye movements were recorded simultaneously with EOG (using an EOG system) and VOG (using a VHIT system: ICS Impulse). The eye movement responses to each side of both techniques were compared using a concordance correlation coefficient (rc), t-testing, and Bayes Factor (BF) paired t-testing.ResultsEOG and VOG obtained eye movement traces that correlated well with each other during head impulse testing (average rc = 0.89). Average VOR gains obtained with EOG and VOG were not significantly different from each other for all subjects during left head impulses. However, VOG gains differed between both techniques regarding right head impulses. VOG showed significant VOR gain asymmetry (5% to the right), whereas EOG showed no significant asymmetry (1% to the right).ConclusionThis study demonstrated the use of EOG to record eye movements during head impulse testing for the first time. EOG and VOG obtained eye movement traces that correlated well with each other during horizontal head impulse testing. In addition, EOG showed smaller VOR gain asymmetry in healthy individuals, in contrast to VOG. These findings indicate that EOG might potentially be applicable as an alternative to VOG for collecting eye movement responses during head impulse testing.Trial registration number10192021-38 dated 19.10.21.

Western gray whale behavioral response to seismic surveys during their foraging season

Gray whales utilizing their foraging grounds off northeastern Sakhalin Island, Russia, have been increasingly exposed to anthropogenic activities related to oil and gas development over the past two decades. In 2015, four seismic vessels, contracted by two operators, conducted surveys near and within the gray whale feeding grounds. Mitigation and monitoring plans were developed prior to the survey and implemented in the field, with real-time data transfers to assist the implementation of measures aimed at minimizing impacts of acoustic exposure. This study examined the behavioral response of gray whales relative to vessel proximities and sounds generated during seismic exploration. Five shore-based teams monitored gray whale behavior from 1 June to 30 September using theodolite tracking and focal follow methodologies. Behavioral data were combined with acoustic and benthic information from studies conducted during the same period. A total of 1270 tracks (mean duration = 0.9 h) and 401 focal follows (1.1 h) were collected with gray whales exposed to sounds ranging from 59 to 172 dB re 1 μPa2 SPL. Mixed models were used to examine 13 movement and 10 respiration response variables relative to “natural,” acoustic, and non-acoustic explanatory variables. Water depth and behavioral state were the largest predictors of gray whale movement and respiration patterns. As vessels approached whales with increasing seismic/vessel sound exposure levels and decreasing distances, several gray whale movement and respiration response variables significantly changed (increasing speed, directionality, surface time, respiration intervals, etc.). Although the mitigation measures employed could have reduced larger/long-term responses and sensitization to the seismic activities, this study illustrates that mitigation measures did not eliminate behavioral responses, at least in the short-term, of feeding gray whales to the activities.

The Nationalist Critique of Female Double Suicide in Colonial Korea

During the colonial period, the double love suicides of young “new women” were sensationalized by media outlets and became the object of discussion at a national level, triggering discourse over the role and value of women in Colonial Korea. This sense of involvement in the life and death of women was even more prominent when these suicides involved young women of child-bearing age, whose deaths could be collectively perceived as a loss of an important human resource for the country. This article will examine why the media focus was on young, educated upper-class women and how the discourse about their suicides expanded beyond a moral cautionary tale and was coopted by the Korean nationalist movement. We analyze the discourse that followed two representative female double suicides, the Yun/Kim suicide of 1926, and the Hong/Kim homosexual double suicide of 1931, focusing on the critique published mainly in the Tonga Ilbo newspaper. We also examine the response of the feminist movements, or lack thereof, and the development of the ideological conflict between feminist and nationalist movements. Female suicide was one of the many battlefields between the nationalist and the feminist movements during the colonial period. As an issue involving women at every level of society, it had the potential to challenge the Confucian patriarchal system and bring to light the new needs of Korean women. However, as this analysis has shown, it was dismissed as a personal and trivial matter compared with the urgent public issue of national liberation. The rise of women's movements in Korea, fueled by a small clique of educated women, was ultimately subsumed by the nationalist movement and relegated to the realm of the private and inconsequential.

From minding the gap to widening the gap: Paralympic athletes' experiences of wellbeing during the postponement of the Tokyo 2020 games.

In March 2020, it was announced that the Tokyo Games would be postponed for one year due to the COVID-19 pandemic. While athletes commonly face challenges in sport such as injuries, the pandemic and rescheduling of the Games was an unexpected event that had serious potential to challenge the psychological wellbeing of athletes. Furthermore, it was an event that was simultaneously experienced by all athletes preparing for the Games. It provided a novel opportunity to explore how athletes navigated this challenging environment and the subsequent potential impact on their psychological wellbeing. It also provided a unique opportunity to engage para-athletes and explore how they experienced the pandemic and postponement. This manuscript draws on a larger qualitative study of 21 Canadian athletes (14 Olympic and seven Paralympic) who were on target to compete at the 2020 Games when the postponement was announced. For this manuscript, we focus on the accounts of seven Paralympic hopefuls and their experiences of adjusting to the postponement, while attending to the unique social identities of athletes with disabilities. Adopting a constructionist lens, semi-structured interviews were conducted at two time points. Through reflexive thematic analysis, we developed three themes. “We are all in the same boat. . . or are we?” describes the Paralympic hopefuls experiences early in the pandemic and how they felt united by the Canadian response to withdraw from the Games. It then discusses how, over time, they started to understand athletes with disabilities were being inequitably impacted by the pandemic and related public health measures. “Maybe it means more to them than us” examines how their perceptions changed as they acknowledged that although all athletes were facing a disruption to their sport careers, the implications were not the same for all. “Vulnerability and the Paralympic athlete” addresses how Paralympic athletes engaged with societal narratives about risk, vulnerability and disability and what this meant for the Paralympic Movement's response to the pandemic. “Honestly, I've experienced it before” examines how the Paralympic hopefuls drew on past experiences of injury to navigate the pandemic and the protective impact on their psychological wellbeing. Findings shed light on how systemic ableism interacted with the pandemic to magnify feelings of inferiority and further marginalization but also how para-athletes drew on past experiences to navigate challenges to their psychological wellbeing.

Factors affecting follower responses to movement calls in cooperatively breeding dwarf mongooses

In social species, individuals maximize the benefits of group living by remaining cohesive and coordinating their actions. Communication is key to collective action, including ensuring that group members move together; individuals often produce signals when attempting to lead a group to a new area. However, the function of these signals, and how responses to them are affected by intrinsic characteristics of the caller and extrinsic factors, has rarely been experimentally tested. We conducted a series of field-based playback experiments with habituated wild dwarf mongooses, Helogale parvula , a cooperatively breeding and territorial species, to investigate follower responses to movement calls. In our first experiment, we found that focal individuals were more likely to respond to playback of ‘movement calls’ than control ‘close calls’, indicating movement calls function as recruitment signals. In a second experiment, we found that focal individuals responded similarly to the movement calls of dominant and subordinate groupmates, suggesting that dominance status (an intrinsic factor) does not influence receiver responses. In a final experiment, we found that individuals responded to the simulated presence of a rival group, but that this outgroup conflict (an extrinsic factor) did not affect responses to movement calls compared to a control situation. This may be because attention is instead focused on the potential presence of an imminent threat. By using playbacks to isolate the acoustic signal from physical movement cues, our results provide experimental evidence of how movement calls help leaders to attract followers and thus adds to our understanding of recruitment signals more generally. • We used playback experiments to study responses to dwarf mongoose movement calls. • Movement calls elicited a movement response in focal subordinate group members. • Receivers responded equally to calls of dominant and subordinate groupmates. • A simulated rival group threat did not affect responses to movement calls.

Baseline hippocampal beta band power is lower in the presence of movement uncertainty

Objective. This study aimed to characterize hippocampal neural signatures of uncertainty by measuring beta band power in the period prior to movement cue. Approach. Participants with epilepsy were implanted with hippocampal depth electrodes for stereo electroencephalographic (SEEG) monitoring. Hippocampal beta (13–30 Hz) power changes have been observed during motor tasks such as the direct reach (DR) and Go/No-Go (GNG) tasks. The primary difference between the tasks is the presence of uncertainty about whether movement should be executed. Previous research on cortical responses to uncertainty has found that baseline beta power changes with uncertainty. SEEG data were sampled throughout phases of the DR and GNG tasks. Beta-band power during the fixation phase was compared between the DR and GNG task using a Wilcoxon rank sum test. This unpaired test was also used to analyze response times from cue to task completion between tasks. Main results. Eight patients who performed both reaching tasks were analyzed in this study. Movement response times in the GNG task were on average 210 milliseconds slower than in the DR task. All patients exhibited a significantly increased response latency in the GNG task compared to the DR task (Wilcoxon rank-sum p-value < 0.001). Six out of eight patients demonstrated statistically significant differences in beta power in single hippocampal contacts between the fixation phases of the GNG and DR tasks. At the group level, baseline beta power was significantly lower in the GNG task than in the DR task (Wilcoxon rank-sum p-value < 0.001). Significance. This novel study found that, in the presence of task uncertainty, baseline beta power in the hippocampus is lower than in its absence. This finding implicates movement uncertainty as an important factor in baseline hippocampal beta power during movement preparation.