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Journal of Neurophysiology Jan 2023Real-world search behavior often involves limb movements, either during search or after search. Here we investigated whether movement-related costs influence search...
Real-world search behavior often involves limb movements, either during search or after search. Here we investigated whether movement-related costs influence search behavior in two kinds of search tasks. In our visual search tasks, participants made saccades to find a target object among distractors and then moved a cursor, controlled by the handle of a robotic manipulandum, to the target. In our manual search tasks, participants moved the cursor to perform the search, placing it onto objects to reveal their identity as either a target or a distractor. In all tasks, there were multiple targets. Across experiments, we manipulated either the effort or time costs associated with movement such that these costs varied across the search space. We varied effort by applying different resistive forces to the handle, and we varied time costs by altering the speed of the cursor. Our analysis of cursor and eye movements during manual and visual search, respectively, showed that effort influenced manual search but did not influence visual search. In contrast, time costs influenced both visual and manual search. Our results demonstrate that, in addition to perceptual and cognitive factors, movement-related costs can also influence search behavior. Numerous studies have investigated the perceptual and cognitive factors that influence decision making about where to look, or move, in search tasks. However, little is known about how search is influenced by movement-related costs associated with acting on an object once it has been visually located or acting during manual search. In this article, we show that movement time costs can bias visual and manual search and that movement effort costs bias manual search.
Topics: Humans; Eye Movements; Movement; Saccades; Visual Perception; Psychomotor Performance
PubMed: 36475897
DOI: 10.1152/jn.00305.2022 -
ENeuro 2022Navigation through complex environments requires motor planning, motor preparation, and the coordination between multiple sensory-motor modalities. For example, the...
Navigation through complex environments requires motor planning, motor preparation, and the coordination between multiple sensory-motor modalities. For example, the stepping motion when we walk is coordinated with motion of the torso, arms, head, and eyes. In rodents, movement of the animal through the environment is coordinated with whisking. Even head-fixed mice navigating a plus maze position their whiskers asymmetrically with the bilateral asymmetry signifying the upcoming turn direction. Here we report that, in addition to moving their whiskers, on every trial mice also move their eyes conjugately in the direction of the upcoming turn. Not only do mice move their eyes, but they coordinate saccadic eye movement with the asymmetric positioning of the whiskers. Our analysis shows that asymmetric positioning of whiskers predicted the turn direction that mice will make at an earlier stage than eye movement. Consistent with these results, our observations also revealed that whisker asymmetry increases before saccadic eye movement. Importantly, this work shows that when rodents plan for active behavior, their motor plans can involve both eye and whisker movement. We conclude that, when mice are engaged in and moving through complex real-world environments, their behavioral state can be read out in the movement of both their whiskers and eyes.
Topics: Animals; Eye Movements; Mice; Movement; Touch; Vibrissae
PubMed: 35961771
DOI: 10.1523/ENEURO.0089-22.2022 -
Sensors (Basel, Switzerland) Jan 2022A Drift-Free 3D Orientation and Displacement estimation method (DFOD) based on a single inertial measurement unit (IMU) is proposed and validated. Typically, body...
A Drift-Free 3D Orientation and Displacement estimation method (DFOD) based on a single inertial measurement unit (IMU) is proposed and validated. Typically, body segment orientation and displacement methods rely on a constant- or zero-velocity point to correct for drift. Therefore, they are not easily applicable to more proximal segments than the foot. DFOD uses an alternative single sensor drift reduction strategy based on the quasi-cyclical nature of many human movements. DFOD assumes that the quasi-cyclical movement occurs in a quasi-2D plane and with an approximately constant cycle average velocity. DFOD is independent of a constant- or zero-velocity point, a biomechanical model, Kalman filtering or a magnetometer. DFOD reduces orientation drift by assuming a cyclical movement, and by defining a functional coordinate system with two functional axes. These axes are based on the mean acceleration and rotation axes over multiple complete gait cycles. Using this drift-free orientation estimate, the displacement of the sensor is computed by again assuming a cyclical movement. Drift in displacement is reduced by subtracting the mean value over five gait cycle from the free acceleration, velocity, and displacement. Estimated 3D sensor orientation and displacement for an IMU on the lower leg were validated with an optical motion capture system (OMCS) in four runners during constant velocity treadmill running. Root mean square errors for sensor orientation differences between DFOD and OMCS were 3.1 ± 0.4° (sagittal plane), 5.3 ± 1.1° (frontal plane), and 5.0 ± 2.1° (transversal plane). Sensor displacement differences had a root mean square error of 1.6 ± 0.2 cm (forward axis), 1.7 ± 0.6 cm (mediolateral axis), and 1.6 ± 0.2 cm (vertical axis). Hence, DFOD is a promising 3D drift-free orientation and displacement estimation method based on a single IMU in quasi-cyclical movements with many advantages over current methods.
Topics: Acceleration; Biomechanical Phenomena; Humans; Movement; Rotation; Running
PubMed: 35161701
DOI: 10.3390/s22030956 -
Equine Veterinary Journal May 2016Lungeing is commonly used as part of standard lameness examinations in horses. Knowledge of how lungeing influences motion symmetry in sound horses is needed.
REASONS FOR PERFORMING STUDY
Lungeing is commonly used as part of standard lameness examinations in horses. Knowledge of how lungeing influences motion symmetry in sound horses is needed.
OBJECTIVES
The aim of this study was to objectively evaluate the symmetry of vertical head and pelvic motion during lungeing in a large number of horses with symmetric motion during straight line evaluation.
STUDY DESIGN
Cross-sectional prospective study.
METHODS
A pool of 201 riding horses, all functioning well and considered sound by their owners, were evaluated in trot on a straight line and during lungeing to the left and right. From this pool, horses with symmetric vertical head and pelvic movement during the straight line trot (n = 94) were retained for analysis. Vertical head and pelvic movements were measured with body mounted uniaxial accelerometers. Differences between vertical maximum and minimum head (HDmax, HDmin) and pelvic (PDmax, PDmin) heights between left and right forelimb and hindlimb stances were compared between straight line trot and lungeing in either direction.
RESULTS
Vertical head and pelvic movements during lungeing were more asymmetric than during trot on a straight line. Common asymmetric patterns seen in the head were more upward movement during push-off of the outside forelimb and less downward movement during impact of the inside limb. Common asymmetric patterns seen in the pelvis were less upward movement during push-off of the outside hindlimb and less downward movement of the pelvis during impact of the inside hindlimb. Asymmetric patterns in one lunge direction were frequently not the same as in the opposite direction.
CONCLUSIONS
Lungeing induces systematic asymmetries in vertical head and pelvic motion patterns in horses that may not be the same in both directions. These asymmetries may mask or mimic fore- or hindlimb lameness.
Topics: Animals; Biomechanical Phenomena; Cross-Sectional Studies; Forelimb; Gait; Head; Hindlimb; Horses; Movement; Pelvis; Prospective Studies
PubMed: 25808700
DOI: 10.1111/evj.12446 -
Human Brain Mapping Dec 2023Self-initiated movements are accompanied by an efference copy, a motor command sent from motor regions to the sensory cortices, containing a prediction of the movement's...
Self-initiated movements are accompanied by an efference copy, a motor command sent from motor regions to the sensory cortices, containing a prediction of the movement's sensory outcome. Previous studies have proposed pre-motor event-related potentials (ERPs), including the readiness potential (RP) and its lateralized sub-component (LRP), as potential neural markers of action feedback prediction. However, it is not known how specific these neural markers are for voluntary (active) movements as compared to involuntary (passive) movements, which produce much of the same sensory feedback (tactile, proprioceptive) but are not accompanied by an efference copy. The goal of the current study was to investigate how active and passive movements are distinguishable from premotor electroencephalography (EEG), and to examine if this change of neural activity differs when participants engage in tasks that differ in their expectation of sensory outcomes. Participants made active (self-initiated) or passive (finger moved by device) finger movements that led to either visual or auditory stimuli (100 ms delay), or to no immediate contingency effects (control). We investigated the time window before the movement onset by measuring pre-movement ERPs time-locked to the button press. For RP, we observed an interaction between task and movement. This was driven by movement differences in the visual and auditory but not the control conditions. LRP conversely only showed a main effect of movement. We then used multivariate pattern analysis to decode movements (active vs. passive). The results revealed ramping decoding for all tasks from around -800 ms onwards up to an accuracy of approximately 85% at the movement. Importantly, similar to RP, we observed lower decoding accuracies for the control condition than the visual and auditory conditions, but only shortly (from -200 ms) before the button press. We also decoded visual vs. auditory conditions. Here, task is decodable for both active and passive conditions, but the active condition showed increased decoding shortly before the button press. Taken together, our results provide robust evidence that pre-movement EEG activity may represent action-feedback prediction in which information about the subsequent sensory outcome is encoded.
Topics: Humans; Evoked Potentials; Electroencephalography; Movement; Fingers; Upper Extremity
PubMed: 37792296
DOI: 10.1002/hbm.26506 -
Trends in Cognitive Sciences Jan 2010Optimal control theory and its more recent extension, optimal feedback control theory, provide valuable insights into the flexible and task-dependent control of... (Review)
Review
Optimal control theory and its more recent extension, optimal feedback control theory, provide valuable insights into the flexible and task-dependent control of movements. Here, we focus on the problem of coordination, defined as movements that involve multiple effectors (muscles, joints or limbs). Optimal control theory makes quantitative predictions concerning the distribution of work across multiple effectors. Optimal feedback control theory further predicts variation in feedback control with changes in task demands and the correlation structure between different effectors. We highlight two crucial areas of research, hierarchical control and the problem of movement initiation, that need to be developed for an optimal feedback control theory framework to characterise movement coordination more fully and to serve as a basis for studying the neural mechanisms involved in voluntary motor control.
Topics: Animals; Feedback; Humans; Models, Neurological; Movement; Psychomotor Performance
PubMed: 20005767
DOI: 10.1016/j.tics.2009.11.004 -
Sensors (Basel, Switzerland) Oct 2021Human movement patterns were shown to be as unique to individuals as their fingerprints. However, some movement characteristics are more important than other...
Human movement patterns were shown to be as unique to individuals as their fingerprints. However, some movement characteristics are more important than other characteristics for machine learning algorithms to distinguish between individuals. Here, we explored the idea that movement patterns contain unique characteristics that differentiate between individuals and generic characteristics that do not differentiate between individuals. Layer-wise relevance propagation was applied to an artificial neural network that was trained to recognize 20 male triathletes based on their respective movement patterns to derive characteristics of high/low importance for human recognition. The similarity between movement patterns that were defined exclusively through characteristics of high/low importance was then evaluated for all participants in a pairwise fashion. We found that movement patterns of triathletes overlapped minimally when they were defined by variables that were very important for a neural network to distinguish between individuals. The movement patterns overlapped substantially when defined through less important characteristics. We concluded that the unique movement characteristics of elite runners were predominantly sagittal plane movements of the spine and lower extremities during mid-stance and mid-swing, while the generic movement characteristics were sagittal plane movements of the spine during early and late stance.
Topics: Biomechanical Phenomena; Humans; Lower Extremity; Male; Movement; Running; Spine
PubMed: 34770451
DOI: 10.3390/s21217145 -
Journal of Neurophysiology Sep 2021On average, we redirect our gaze with a frequency at about 3 Hz. In real life, gaze shifts consist of eye and head movements. Much research has focused on how the...
On average, we redirect our gaze with a frequency at about 3 Hz. In real life, gaze shifts consist of eye and head movements. Much research has focused on how the accuracy of eye movements is monitored and calibrated. By contrast, little is known about how head movements remain accurate. I wondered whether serial dependencies between artificially induced errors in head movement targeting and the immediately following head movement might recalibrate movement accuracy. I also asked whether head movement targeting errors would influence visual localization. To this end, participants wore a head-mounted display and performed head movements to targets, which were displaced as soon as the start of the head movement was detected. I found that target displacements influenced head movement amplitudes in the same trial, indicating that participants could adjust their movement online to reach the new target location. However, I also found serial dependencies between the target displacement in trial -1 and head movements amplitudes in the following trial . I did not find serial dependencies between target displacements and visuomotor localization. The results reveal that serial dependencies recalibrate head-movement accuracy. Head movements are recalibrated by serial dependencies by errors between consecutive trials. Head movements are subject to a regression of the average target location.
Topics: Adult; Eye Movements; Female; Head Movements; Humans; Male; Psychomotor Performance; Sensorimotor Cortex; Visual Perception
PubMed: 34259049
DOI: 10.1152/jn.00231.2021 -
Annual Review of Neuroscience 2011The mammalian superior colliculus (SC) and its nonmammalian homolog, the optic tectum, constitute a major node in processing sensory information, incorporating cognitive... (Review)
Review
The mammalian superior colliculus (SC) and its nonmammalian homolog, the optic tectum, constitute a major node in processing sensory information, incorporating cognitive factors, and issuing motor commands. The resulting action-to orient toward or away from a stimulus-can be accomplished as an integrated movement across oculomotor, cephalomotor, and skeletomotor effectors. The SC also participates in preserving fixation during intersaccadic intervals. This review highlights the repertoire of movements attributed to SC function and analyzes the significance of results obtained from causality-based experiments (microstimulation and inactivation). The mechanisms potentially used to decode the population activity in the SC into an appropriate movement command are also discussed.
Topics: Animals; Eye Movements; Head Movements; Humans; Models, Biological; Movement; Oculomotor Muscles; Psychomotor Performance; Superior Colliculi; Vibrissae; Vocalization, Animal
PubMed: 21456962
DOI: 10.1146/annurev-neuro-061010-113728 -
Cell Reports Jul 2018Our sensorimotor system appears to be influenced by the recent history of our movements. Repeating movements toward a particular direction is known to have a dramatic...
Our sensorimotor system appears to be influenced by the recent history of our movements. Repeating movements toward a particular direction is known to have a dramatic effect on involuntary movements elicited by cortical stimulation-a phenomenon that has been termed use-dependent plasticity. However, analogous effects of repetition on behavior have proven elusive. Here, we show that movement repetition enhances the generation of similar movements in the future by reducing the time required to select and prepare the repeated movement. We further show that this reaction time advantage for repeated movements is attributable to more rapid, but still flexible, preparation of the repeated movement rather than anticipation and covert advance preparation of the previously repeated movement. Our findings demonstrate a powerful and beneficial effect of movement repetition on response preparation, which may represent a behavioral counterpart to use-dependent plasticity effects in primary motor cortex.
Topics: Female; Humans; Male; Movement; Psychomotor Performance; Reaction Time
PubMed: 30044977
DOI: 10.1016/j.celrep.2018.06.097