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"Collet, Christian"
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Associating Vehicles Automation With Drivers Functional State Assessment Systems: A Challenge for Road Safety in the Future
In the near future, vehicles will gradually gain more autonomous functionalities. Drivers' activity will be less about driving than about monitoring intelligent systems to which driving action will be delegated. Road safety, therefore, remains dependent on the human factor and we should identify the limits beyond which driver's functional state (DFS) may no longer be able to ensure safety. Depending on the level of automation, estimating the DFS may have different targets, e.g., assessing driver's situation awareness in lower levels of automation and his ability to respond to emerging hazard or assessing driver's ability to monitor the vehicle performing operational tasks in higher levels of automation. Unfitted DFS (e.g., drowsiness) may impact the driver ability respond to taking over abilities. This paper reviews the most appropriate psychophysiological indices in naturalistic driving while considering the DFS through exogenous sensors, providing the more efficient trade-off between reliability and intrusiveness. The DFS also originates from kinematic data of the vehicle, thus providing information that indirectly relates to drivers behavior. The whole data should be synchronously processed, providing a diagnosis on the DFS, and bringing it to the attention of the decision maker in real time. Next, making the information available can be permanent or intermittent (or even undelivered), and may also depend on the automation level. Such interface can include recommendations for decision support or simply give neutral instruction. Mapping of relevant psychophysiological and behavioral indicators for DFS will enable practitioners and researchers provide reliable estimates, fitted to the level of automation.
Journal Article
Multiple roles of motor imagery during action observation
Over the last 20 years, the topics of action observation (AO) and motor imagery (MI) have been largely studied in isolation from each other, despite the early integrative account by Jeannerod (1994, 2001). Recent neuroimaging studies demonstrate enhanced cortical activity when AO and MI are performed concurrently (\"AO+MI\"), compared to either AO or MI performed in isolation. These results indicate the potentially beneficial effects of AO+MI, and they also demonstrate that the underlying neurocognitive processes are partly shared. We separately review the evidence for MI and AO as forms of motor simulation, and present two quantitative literature analyses that indeed indicate rather little overlap between the two bodies of research. We then propose a spectrum of concurrent AO+MI states, from congruent AO+MI where the contents of AO and MI widely overlap, over coordinative AO+MI, where observed and imagined action are different but can be coordinated with each other, to cases of conflicting AO+MI. We believe that an integrative account of AO and MI is theoretically attractive, that it should generate novel experimental approaches, and that it can also stimulate a wide range of applications in sport, occupational therapy, and neurorehabilitation.
Journal Article
Online and Offline Performance Gains Following Motor Imagery Practice: A Comprehensive Review of Behavioral and Neuroimaging Studies
There is now compelling evidence that motor imagery (MI) promotes motor learning. While MI has been shown to influence the early stages of the learning process, recent data revealed that sleep also contributes to the consolidation of the memory trace. How such \"online\" and \"offline\" processes take place and how they interact to impact the neural underpinnings of movements has received little attention. The aim of the present review is twofold: (i) providing an overview of recent applied and fundamental studies investigating the effects of MI practice (MIP) on motor learning; and (ii) detangling applied and fundamental findings in support of a sleep contribution to motor consolidation after MIP. We conclude with an integrative approach of online and offline learning resulting from intense MIP in healthy participants, and underline research avenues in the motor learning/clinical domains.
Journal Article
Impact of Neurologic Deficits on Motor Imagery: A Systematic Review of Clinical Evaluations
Motor imagery (MI, the mental representation of an action without engaging in its actual execution) is a therapeutically relevant technique to promote motor recovery after neurologic disorders. MI shares common neural and psychological bases with physical practice. Interestingly, both acute and progressive neurologic disorders impact brain motor networks, hence potentially eliciting changes in MI capacities. How experimental neuroscientists and medical practitioners should assess and take into account these changes in order to design fruitful interventions is largely unresolved. Understanding how the psychometric, behavioral and neurophysiological correlates of MI are impacted by neurologic disorders is required. To address this brain-behavior issue, we conducted a systematic review of MI data in stroke, Parkinson’s disease, spinal cord injury, and amputee participants. MI evaluation methods are presented. Redundant MI profiles, primarily based on psychometric and behavioral evaluations, emerged in each clinical population. When present, changes in the psychometric and behavioral correlates of MI were highly congruent with the corresponding motor impairments. Neurophysiological recordings yielded specific changes in cerebral activations during MI, which mirrored structural and functional reorganizations due to neuroplasticity. In this view, MI capacities may not be deteriorated
per se
by neurologic diseases resulting in chronic motor incapacities, but adjusted to the current state of the motor system. Literature-driven orientations for future clinical research are provided.
Journal Article
Stabilometric Correlates of Motor and Motor Imagery Expertise
Motor Imagery (MI) reproduces cognitive operations associated with the actual motor preparation and execution. Postural recordings during MI reflect somatic motor commands targeting peripheral effectors involved in balance control. However, how these relate to the actual motor expertise and may vary along with the MI modality is still debated. In the present experiment, two groups of expert and non-expert gymnasts underwent stabilometric assessments while performing physically and mentally a balance skill. We implemented psychometric measures of MI ability, while stabilometric variables were calculated from center of pressure (COP) oscillations. Psychometric evaluations revealed greater MI ability in experts, specifically for the visual modality. Experts exhibited reduced surface COP oscillations in the antero-posterior axis compared to non-experts during the balance skill (14.90 %, 95% CI 34.48 to 4.68, p < 0.05). Experts further exhibited reduced length of COP displacement in the antero-posterior axis and as a function of the displacement area during visual and kinesthetic MI compared to the control condition (20.51%, 95% CI 0.99 to 40.03 and 21.85%, 95% CI 2.33 to 41.37, respectively, both p < 0.05). Predictive relationships were found between the stabilometric correlates of visual MI and physical practice of the balance skill, as well as between the stabilometric correlates of kinesthetic MI and the training experience in experts. Present results provide original stabilometric insights into the relationships between MI and expertise level. While data support the incomplete inhibition of postural commands during MI, whether postural responses during MI of various modalities mirror the level of motor expertise remains unclear.
Journal Article
Grasping rehabilitation using motor imagery with or without neurofeedback after tetraplegia: a study protocol for a bicentric randomised controlled trial
IntroductionTetraplegia causes extensive sensorimotor deficits affecting activity, participation and quality of life. People with C6-C7 tetraplegia can learn to grasp objects by performing wrist extension movement (ie, tenodesis grasp), and motor imagery (MI) added to rehabilitation significantly improved tenodesis grasp. We hypothesise that this improvement can be further boosted by adding neurofeedback during MI. Thus, we design a randomised controlled trial investigating the effect of MI training on grasping ability in people with C6-C7 tetraplegia.Methods and analysisWe will perform a bicentric, assessor-blinded, randomised controlled study. During rehabilitation, 21 inpatients with C6-C7 tetraplegia will be allocated to MI with neurofeedback (MI training with graphical display on a computer screen based on mu (8–13 Hz) and beta (18–25 Hz) frequency rhythms measured with 32-channel electroencephalography), MI alone (only MI training) and control (watching movies and visualisation of geometric shapes). All participants will receive three 45-min training sessions per week for 5 weeks.The primary outcome measure will be wrist extension angle immediately after the intervention during tenodesis grasp measured with a 3D motion analysis system (VICON). Secondary outcomes will include a range of measures: kinematic, grip strength, upper limb range of motion, upper limb strength (manual muscle test and hand-held dynamometer measure), dexterity (box and block test, 9-hole peg test, Jebsen test, capabilities of upper extremity questionnaire), quality of life (WHOQOL-Bref), daily life autonomy (Quadriplegic Index of Function), MI capacity and brain reorganisation (magnetoencephalography only available in Lyon, n=15). We will measure all outcomes five times: during weeks 1, 3 and 5 (baseline), week 11 (immediately after the intervention end) and week 18 (8 weeks after the intervention end).Ethics and disseminationEthical approval was granted on 29 September 2017 (CPP Nord-Ouest-IV 17/25, N°2017-A00990-53). Dissemination will occur via presentation of results in scientific meetings and publication in peer-reviewed academic journals.Trial registration numberNCT03190863 (ClinicalTrials.gov).
Journal Article
Minority Candidates, Alternative Media, and Multiethnic America: Deracialization or Toggling?
Conceptualizing a political world “beyond black and white” is a familiar scholarly refrain, but theoretical relics of bipolarity remain. The deracialization concept, a much-discussed phenomenon in American elections, is one example. Asian American campaigns provide an interesting case for testing the utility of deracialization in multicultural urban milieus, given the overwhelming tendency for such candidates to be elected from predominantly non-Asian constituencies. Looking in depth at two successful campaigns by Vietnamese Americans in Northern and Southern California, I argue for a broadened approach that can better account for changes in the American political mosaic—namely, increases in immigration occurring in some of the country's fastest growing regions and the availability of alternative media. I call this approach toggling. In this article, I outline the toggling strategy. I conclude by considering the impact of toggling on equality in the American democratic process and suggest some directions for future research.
Journal Article
Anodal tDCS over the primary motor cortex improves motor imagery benefits on postural control: A pilot study
Performing everyday actions requires fine postural control, which is a major focus of functional rehabilitation programs. Among the various range of training methods likely to improve balance and postural stability, motor imagery practice (MIP) yielded promising results. Transcranial direct current stimulation (tDCS) applied over the primary motor cortex was also found to potentiate the benefits of MIP on upper-limb motor tasks. Yet, combining both techniques has not been tested for tasks requiring fine postural control. To determine the impact of MIP and the additional effects of tDCS, 14 participants performed a postural control task before and after two experimental (MIP + anodal or sham tDCS over the primary motor cortex) and one control (control task + sham tDCS) conditions, in a double blind randomized study. Data revealed a significant decrease of the time required to perform the postural task. Greater performance gains were recorded when MIP was paired with anodal tDCS and when the task involved the most complex postural adjustments. Altogether, findings highlight short-term effects of MIP on postural control and suggest that combining MIP with tDCS might also be effective in rehabilitation programs for regaining postural skills in easily fatigable persons and neurologic populations.
Journal Article