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Implicit theories and psychological essentialism are valuable frameworks used to model how changeable many traits are perceived to be. These frameworks, however, characterise changeability as a broad and generalised construct and do not fully capture the nuance and specificity involved in personality changeability. We therefore sought to deconstruct implicit theories about changeability into underlying more specific aspects of changeability. We measured how changeable people theorise personality traits to be according to three underlying specific factors: volitional control, context and age. We investigated how specific implicit theories about changeability vary across different personality traits. We show that two personality traits (agreeableness and conscientiousness) are linked to dissociable patterns of specific factors used to explain how changeable they are. These findings yield new insight into the way people explain why personality traits are changeable and demonstrate that different types of reasons are used to explain the changeability of agreeableness and conscientiousness.

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Volitional control of local field potential oscillations in low gamma band via brain machine interface can not only uncover the relationship between low gamma oscillation and neural synchrony but also suggest a therapeutic potential to reverse abnormal local field potential oscillation in neurocognitive disorders. In nonhuman primates, the volitional control of low gamma oscillations has been demonstrated by brain machine interface techniques in the primary motor and visual cortex. However, it is not clear whether this holds in other brain regions and other species, for which gamma rhythms might involve in highly different neural processes. Here, we established a closed-loop brain-machine interface and succeeded in training mice to volitionally elevate low gamma power of local field potential in the primary motor and visual cortex. We found that the mice accomplished the task in a goal-directed manner and spiking activity exhibited phase-locking to the oscillation in local field potential in both areas. Moreover, long-term training made the power enhancement specific to direct and adjacent channel, and increased the transcriptional levels of NMDA receptors as well as that of hypoxia-inducible factor relevant to metabolism. Our results suggest that volitionally generated low gamma rhythms in different brain regions share similar mechanisms and pave the way for employing brain machine interface in therapy of neurocognitive disorders.

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Breathing is the only vital function that can be volitionally controlled. However, a detailed understanding how volitional (cortical) motor commands can transform vital breathing activity into adaptive breathing patterns that accommodate orofacial behaviors such as swallowing, vocalization or sniffing remains to be developed. Recent neuroanatomical tract tracing studies have identified patterns and origins of descending forebrain projections that target brain nuclei involved in laryngeal adductor function which is critically involved in orofacial behavior. These nuclei include the midbrain periaqueductal gray and nuclei of the respiratory rhythm and pattern generating network in the brainstem, specifically including the pontine Kölliker-Fuse nucleus and the pre-Bötzinger complex in the medulla oblongata. This review discusses the functional implications of the forebrain-brainstem anatomical connectivity that could underlie the volitional control and coordination of orofacial behaviors with breathing.

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Task-dependent volitional control of the selected neural activity in the cortex is critical to neuroprosthetic learning to achieve reliable and robust control of the external device. The volitional control of neural activity is driven by a motivational factor (volitional motivation), which directly reinforces the target neurons via real-time biofeedback. However, in the absence of motor behaviour, how do we evaluate volitional motivation? Here, we defined the criterion (ΔF/F) of the calcium fluorescence signal in a volitionally controlled neural task, then escalated the efforts by progressively increasing the number of reaching the criterion or holding time after reaching the criterion. We devised calcium-based progressive threshold-crossing events (termed 'Calcium PTE') and calcium-based progressive threshold-crossing holding-time (termed 'Calcium PTH') for quantitative assessment of volitional motivation in response to progressively escalating efforts. Furthermore, we used this novel neural representation of volitional motivation to explore the neural circuit and neuromodulator bases for volitional motivation. As with behavioural motivation, chemogenetic activation and pharmacological blockade of the striatopallidal pathway decreased and increased, respectively, the breakpoints of the 'Calcium PTE' and 'Calcium PTH' in response to escalating efforts. Furthermore, volitional and behavioural motivation shared similar dopamine dynamics in the nucleus accumbens in response to trial-by-trial escalating efforts. In general, the development of a neural representation of volitional motivation may open a new avenue for smooth and effective control of brain-machine interface tasks. KEY POINTS: Volitional motivation is quantitatively evaluated by M1 neural activity in response to progressively escalating volitional efforts. The striatopallidal pathway and adenosine A2A receptor modulate volitional motivation in response to escalating efforts. Dopamine dynamics encode prediction signal for reward in response to repeated escalating efforts during motor and volitional conditioning. Mice learn to modulate neural activity to compensate for repeated escalating efforts in volitional control.

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Self-control is typically attributed to "cold" cognitive control mechanisms that top-down influence "hot" affective impulses or emotions. In this study we tested an alternative view, assuming that self-control also rests on the ability to anticipate emotions directed toward future consequences. Using a behavioral within-subject design including an emotion regulation task measuring the ability to voluntarily engage anticipated emotions towards an upcoming event and a self-control task in which subjects were confronted with a variety of everyday conflict situations, we examined the relationship between self-control and anticipated emotions. We found that those individuals (n = 33 healthy individuals from the general population) who were better able to engage anticipated emotions to an upcoming event showed stronger levels of self-control in situations where it was necessary to resist short-term temptations or to endure short-term aversions to achieve long-term goals. This finding suggests that anticipated emotions may play a functional role in self-control-relevant deliberations with respect to possible future consequences and are not only inhibited top-down as implied by "dual system" views on self-control.

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[Purpose] This study aimed to evaluate the improvement in lower extremity hemiplegia following brain tumor operation with an integrated volitional control electrical stimulator (IVES). [Participant and Methods] A 40 year-old male with anaplasic oligodendroglioma in the right frontal lobe underwent IVES in the rectus femoris and tibialis anterior muscles using the power-assist and sensor-trigger modes. Lower extremity motor function was assessed before and after the therapy sessions. An assessment was conducted using various techniques, including static posturography and surface electromyography. [Results] Static posturography showed an improvement in the center of pressure and sway area after IVES gait training. Based on a time-series statistical parametric mapping analysis, the activation pattern of each muscle after the treatment was different. Muscle synergy analysis revealed decreased total variance accounted for by a single synergy in the affected and normal sides after the treatment. [Conclusion] Patients with chronic hemiplegic lower extremity impairment responded well to IVES gait training. Electromyography-triggered functional electrical stimulation may enhance sensory-motor integration. Proprioceptive feedback plays a crucial role in improving motor control.

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BACKGROUND: Neurofeedback training is a closed-loop neuromodulatory technique in which real-time feedback of brain activity and connectivity is provided to the participant for the purpose of volitional neural control. Through practice and reinforcement, such learning has been shown to facilitate measurable changes in brain function and behavior. OBJECTIVES: In this review, we examine how neurofeedback, coupled with motor imagery training, has the potential to improve or normalize motor function in neurological diseases such as Parkinson disease and chronic stroke. We will also explore neurofeedback in the context of brain-machine interfaces (BMIs), discussing both noninvasive and invasive methods which have been used to power external devices (eg, robot hand orthosis or exoskeleton) in the context of motor neurorehabilitation. CONCLUSIONS: The published literature provides mounting high-quality evidence that neurofeedback and BMI control may lead to clinically relevant changes in brain function and behavior.

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Vocal plasticity can occur in response to environmental and biological factors, including conspecifics' vocalizations and noise. Pinnipeds are one of the few mammalian groups capable of vocal learning, and are therefore relevant to understanding the evolution of vocal plasticity in humans and other animals. Here, we investigate the vocal plasticity of harbour seals (Phoca vitulina), a species with vocal learning abilities observed in adulthood but not puppyhood. To evaluate early mammalian vocal development, we tested 1-3 weeks-old seal pups. We tailored noise playbacks to this species and age to induce seal pups to shift their fundamental frequency (f0), rather than adapt call amplitude or temporal characteristics. We exposed individual pups to low- and high-intensity bandpass-filtered noise, which spanned-and masked-their typical range of f0; simultaneously, we recorded pups' spontaneous calls. Unlike most mammals, pups modified their vocalizations by lowering their f0 in response to increased noise. This modulation was precise and adapted to the particular experimental manipulation of the noise condition. In addition, higher levels of noise induced less dispersion around the mean f0, suggesting that pups may have actively focused their phonatory efforts to target lower frequencies. Noise did not seem to affect call amplitude. However, one seal showed two characteristics of the Lombard effect known for human speech in noise: significant increase in call amplitude and flattening of spectral tilt. Our relatively low noise levels may have favoured f0 modulation while inhibiting amplitude adjustments. This lowering of f0 is unusual, as most animals commonly display no such f0 shift. Our data represent a relatively rare case in mammalian neonates, and have implications for the evolution of vocal plasticity and vocal learning across species, including humans. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.

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Eupnea is generated by neural circuits located in the ponto-medullary brainstem, but can be modulated by higher brain inputs which contribute to volitional control of breathing and the expression of orofacial behaviors, such as vocalization, sniffing, coughing, and swallowing. Surprisingly, the anatomical organization of descending inputs that connect the forebrain with the brainstem respiratory network remains poorly defined. We hypothesized that descending forebrain projections target multiple distributed respiratory control nuclei across the neuroaxis. To test our hypothesis, we made discrete unilateral microinjections of the retrograde tracer cholera toxin subunit B in the midbrain periaqueductal gray (PAG), the pontine Kölliker-Fuse nucleus (KFn), the medullary Bötzinger complex (BötC), pre-BötC, or caudal midline raphé nuclei. We quantified the regional distribution of retrogradely labeled neurons in the forebrain 12-14 days postinjection. Overall, our data reveal that descending inputs from cortical areas predominantly target the PAG and KFn. Differential forebrain regions innervating the PAG (prefrontal, cingulate cortices, and lateral septum) and KFn (rhinal, piriform, and somatosensory cortices) imply that volitional motor commands for vocalization are specifically relayed via the PAG, while the KFn may receive commands to coordinate breathing with other orofacial behaviors (e.g., sniffing, swallowing). Additionally, we observed that the limbic or autonomic (interoceptive) systems are connected to broadly distributed downstream bulbar respiratory networks. Collectively, these data provide a neural substrate to explain how volitional, state-dependent, and emotional modulation of breathing is regulated by the forebrain.

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Objective：We aimed to examine the effects of a transcranial direct current stimulation (tDCS) performed prior to occupational therapy and combined with an Integrated Volitional control Electrical Stimulation (IVES) therapy on the upper extremity function for patients with chronic stroke. We also aimed to detect the longitudinal changes of hemodynamic responses in the sensorimotor cortex area (SMC) following successive tDCS prior to IVES therapy.Methods：Seven subjects with moderate upper extremity (UE) paresis in chronic stroke were enrolled in this study. The patients received coupled tDCS and IVES therapy five times a week. UE function was estimated by Simple Test for Evaluating Hand Function (STEF). Functional near-infrared spectroscopy (fNIRS) was used to detect the long-term changes of hemodynamic responses in bilateral SMC during opening and closing of the affected fingers, assisted by IVES. Lastly, the SMC responses after the first tDCS were compared with those obtained after the fifth tDCS.Results：Coupled tDCS and IVES therapy was effective for improving the UE paresis. fNIRS demonstrated a significantly increased hemodynamic responses in bilateral SMC, following IVES therapy with the fifth tDCS relative to those with the first tDCS.Conclusion：The findings suggested that tDCS prior to IVES therapy might improve UE function of the patients with chronic stroke, presumably by augmenting hemodynamic responses in bilateral SMC.

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The surface electromyography (sEMG) signal has been used for volitional control of robotic assistive devices. There are still challenges in improving system performance accuracy and signal processing to remove systematic noise. This study presents procedures and a pilot validation of the EMG-driven speed-control of exoskeleton and integrated treadmill with a goal to provide better interaction between a user and the system. The gait cycle duration (GCD) was extracted from sEMG signals using the autocorrelation algorithm and Bayesian fusion algorithm. GCDs of various walking speeds were then programmed to control the motion speed of exoskeleton robotic system. The performance and efficiency of this sEMG-controlled robotic assistive ambulation system was tested and validated among 6 healthy volunteers. The results demonstrated that the autocorrelation algorithm extracted the GCD from individual muscle contraction. The GCDs of individual muscles had variability between different walking steps under a designated walking speed. Bayesian fusion algorithms processed the GCDs of multiple muscles yielding a final GCD with the least variance. The fused GCD effectively controlled the motion speeds of exoskeleton and treadmill. The higher amplitude of EMG signals with shorter GCD was found during a faster walking speed. The algorithms using fused GCDs and gait stride length yielded trajectory joint motion tracks in a shape of sine curve waveform. The joint angles of the exoskeleton measured by a decoder mounted on the hip turned out to be in sine waveforms. The hip joint motion track of the exoskeleton matched the angles projected by trajectory curve generated by computer algorithms based on the fused GCDs with high agreement. The EMG-driven speed-control provided the human-machine inter-limb coordination mechanisms for an intuitive speed control of the exoskeleton-treadmill system at the user's intents. Potentially the whole system can be used for gait rehabilitation of incomplete spinal cord hemispheric stroke patients as goal-directed and task-oriented training tool.

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Volitional control is at the core of brain-machine interfaces (BMI) adaptation and neuroprosthetic-driven learning to restore motor function for disabled patients, but neuroplasticity changes and neuromodulation underlying volitional control of neuroprosthetic learning are largely unexplored. To better study volitional control at annotated neural population, we have developed an operant neuroprosthetic task with closed-loop feedback system by volitional conditioning of population calcium signal in the M1 cortex using fiber photometry recording. Importantly, volitional conditioning of the population calcium signal in M1 neurons did not improve within-session adaptation, but specifically enhanced across-session neuroprosthetic skill learning with reduced time-to-target and the time to complete 50 successful trials. With brain-behavior causality of the neuroprosthetic paradigm, we revealed that proficiency of neuroprosthetic learning by volitional conditioning of calcium signal was associated with the stable representational (plasticity) mapping in M1 neurons with the reduced calcium peak. Furthermore, pharmacological blockade of adenosine A2A receptors facilitated volitional conditioning of neuroprosthetic learning and converted an ineffective volitional conditioning protocol to be the effective for neuroprosthetic learning. These findings may help to harness neuroplasticity for better volitional control of neuroprosthetic training and suggest a novel pharmacological strategy to improve neuroprosthetic learning in BMI adaptation by targeting striatal A2A receptors.

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The volitional control of piloerection has been previously reported in a small subset of individuals. Although this ability may be useful to study the mechanism underlying piloerection, there is little existing research on this ability, neither objective evidence at a group-level, nor information about its stability under experimental constraints. The present study aimed to validate existing findings of voluntarily generated piloerection (VGP) and to examine its potential contribution to neuroscientific research based on objective evidence of this ability. In Study 1, to confirm the characteristics of VGP reported in previous studies and identify individuals with VGP capability, an online survey of VGP candidates was conducted. In Study 2, 18 VGP holders participated in a mail-based piloerection measurement experiment, and the nature of VGP was examined based on the objective data obtained by image-based analysis (GooseLab). Study 1 largely confirmed the characteristics of VGP reported in previous studies, and Study 2 demonstrated VGP at a group-level and provided information about the temporal characteristics of this ability, which supports the utility of VGP in neuroscientific research. For some participants, VGP appeared to be emotionally promoted, which suggests that VGP has some relationship with the emotional nature of involuntary piloerection. Although the studies did not tightly control the environment in which VGP was elicited, the findings nonetheless demonstrate the possible contribution of VGP to elucidating the mechanism of involuntary emotional piloerection and the neural basis of piloerection itself.

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BACKGROUND: Volitional control of involuntary movements has so far been considered a hallmark of tic disorders. However, modulation of involuntary movements can also be observed in other hyperkinesias. CASES: Here, we present 6 patients with chorea able to suppress their involuntary movements, on demand. In 3 of them, surface electromyography was used to quantify degree of suppression and confirmed a reduction of muscle activity up to 68%, during volitional control. CONCLUSION: This observation represents a first step toward a description of a new clinical feature in choreic syndromes and an opportunity to redefine the role of volitional inhibition in hyperkinetic movement disorders.

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Previous research has demonstrated that gambling cues (e.g., flashing lights on poker-machines) can trigger an urge to gamble in poker-machine gamblers. However, the psychological mechanisms that promote the urge to gamble remain poorly understood. The present study explored whether reward responsiveness predicted urge to gamble and positive affect, and whether cue-reactive rationality, volitional control and imagery mediated these relationships. Ninety-three (45% male and 55% female) Australian regular poker-machine gamblers aged between 18 and 77 participated in an online cue-reactivity experiment. Participants initially completed the Problem Gambling Severity Index and Reward Responsiveness scale. Subsequently, at three time points (i.e., baseline, directly after a neutral cue and directly after a gambling cue) participants completed the rationality, volitional control and imagery subscales of the Phenomenology of Consciousness Inventory and two visual analogue scales that measured urge to gamble and positive affect. Analyses indicated that gambling cues triggered statistically significant increases in both urge to gamble and positive affect and these variables were statistically significantly positively correlated with reward responsiveness. Furthermore, only cue-reactive imagery mediated the relationships between reward responsiveness and the two outcome variables (i.e., cue-reactive urge to gamble and positive affect). These findings highlight the potential importance of targeting reward responsiveness and cue-reactive mental imagery in the context of exposure therapies for poker-machine problem gamblers.

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Objective：We aimed to examine the effects of a transcranial direct current stimulation (tDCS) performed prior to occupational therapy and combined with an Integrated Volitional control Electrical Stimulation (IVES) therapy on the upper extremity function for patients with chronic stroke. We also aimed to detect the longitudinal changes of hemodynamic responses in the sensorimotor cortex area (SMC) following successive tDCS prior to IVES therapy.Methods：Seven subjects with moderate upper extremity (UE) paresis in chronic stroke were enrolled in this study. The patients received coupled tDCS and IVES therapy five times a week. UE function was estimated by Simple Test for Evaluating Hand Function (STEF). Functional near-infrared spectroscopy (fNIRS) was used to detect the long-term changes of hemodynamic responses in bilateral SMC during opening and closing of the affected fingers, assisted by IVES. Lastly, the SMC responses after the first tDCS were compared with those obtained after the fifth tDCS.Results：Coupled tDCS and IVES therapy was effective for improving the UE paresis. fNIRS demonstrated a significantly increased hemodynamic responses in bilateral SMC, following IVES therapy with the fifth tDCS relative to those with the first tDCS.Conclusion：The findings suggested that tDCS prior to IVES therapy might improve UE function of the patients with chronic stroke, presumably by augmenting hemodynamic responses in bilateral SMC.

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[Purpose] Integrated volitional control electrical stimulation (IVES) is a type of electrical stimulation therapy that promotes agonist muscle contraction in limbs with motion paralysis. This case study describes the improvement in the paretic hand with stroke hemiplegia, eight years after the onset, with IVES for one month in the extrinsic and intrinsic muscles, including change of mode of stimulation based on the degree of improvement. [Participant and Methods] A 76 year-old male with hemiplegia for eight years. The patient was evaluated for two weeks and performed IVES in the right flexor pollicis brevis, abductor pollicis brevis, and extensor carpi ulnaris with the change of mode of IVES. [Results] The upper limb function improved in a short period of time. The hemiplegia test showed Brunnstrom stages II-III and II-IV for the right upper limb and right hand and fingers, respectively, 28 days after IVES initiation. [Conclusion] After one month of undergoing IVES, the patient showed improvement in hand and finger motor function, which was maintained even after IVES was completed. In this case, there was improvement with a short-term intervention using appropriately combined IVES modes.

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[Purpose] The aim of this study was to investigate whether the combination of integrated volitional control functional electrical stimulation and tilt sensor functional electrical stimulation training affected brain activation during the subacute phase following a stroke. [Participant and Methods] The patient was a 60-year-old male with right hemiparesis, secondary to stroke in the left thalamus. Conventional intervention was performed for 60 minutes per day during the first two weeks of treatment (the control condition). Functional electrical stimulation intervention, including integrated volitional control functional electrical stimulation and tilt sensor functional electrical stimulation training, was then performed for 60 minutes per day for two weeks (the experimental condition). These sessions were repeated four times. Brain activity was measured during voluntary right ankle dorsiflexion in both sessions, using functional magnetic resonance imaging. Brain activity measurements were obtained a total of eight times every two weeks (34, 48, 62, 76, 90, 104, 118, and 132 days following the stroke). [Results] There was a significantly higher level of activation in the bilateral cerebellum and the left side of the supplementary motor area in the experimental condition than in the control condition. [Conclusion] The present study demonstrates that the combination of integrated volitional control functional.

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BACKGROUND: Gait training for individuals with neurological disorders is challenging in providing the suitable assistance and more adaptive behaviour towards user needs. The user specific adaptation can be defined based on the user interaction with the orthosis and by monitoring the user intentions. In this paper, an adaptive control model, commanded by the user intention, is evaluated using a lower limb exoskeleton with incomplete spinal cord injury individuals (SCI). METHODS: A user intention based adaptive control model has been developed and evaluated with 4 incomplete SCI individuals across 3 sessions of training per individual. The adaptive control model modifies the joint impedance properties of the exoskeleton as a function of the human-orthosis interaction torques and the joint trajectory evolution along the gait sequence, in real time. The volitional input of the user is identified by monitoring the neural signals, pertaining to the user's motor activity. These volitional inputs are used as a trigger to initiate the gait movement, allowing the user to control the initialization of the exoskeleton movement, independently. A Finite-state machine based control model is used in this set-up which helps in combining the volitional orders with the gait adaptation. RESULTS: The exoskeleton demonstrated an adaptive assistance depending on the patients' performance without guiding them to follow an imposed trajectory. The exoskeleton initiated the trajectory based on the user intention command received from the brain machine interface, demonstrating it as a reliable trigger. The exoskeleton maintained the equilibrium by providing suitable assistance throughout the experiments. A progressive change in the maximum flexion of the knee joint was observed at the end of each session which shows improvement in the patient performance. Results of the adaptive impedance were evaluated by comparing with the application of a constant impedance value. Participants reported that the movement of the exoskeleton was flexible and the walking patterns were similar to their own distinct patterns. CONCLUSIONS: This study demonstrates that user specific adaptive control can be applied on a wearable robot based on the human-orthosis interaction torques and modifying the joints' impedance properties. The patients perceived no external or impulsive force and felt comfortable with the assistance provided by the exoskeleton. The main goal of such a user dependent control is to assist the patients' needs and adapt to their characteristics, thus maximizing their engagement in the therapy and avoiding slacking. In addition, the initiation directly controlled by the brain allows synchronizing the user's intention with the afferent stimulus provided by the movement of the exoskeleton, which maximizes the potentiality of the system in neuro-rehabilitative therapies.

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