Irrelevant Movements Research Articles

The Relation Between Complexity and Resilient Motor Performance and the Effects of Differential Learning.

Complex systems typically demonstrate a mixture of regularity and flexibility in their behavior, which would make them adaptive. At the same time, adapting to perturbations is a core characteristic of resilience. The first aim of the current research was therefore to test the possible relation between complexity and resilient motor performance (i.e., performance while being perturbed). The second aim was to test whether complexity and resilient performance improve through differential learning. To address our aims, we designed two parallel experiments involving a motor task, in which participants moved a stick with their non-dominant hand along a slider. Participants could score points by moving a cursor as fast and accurately as possible between two boxes, positioned on the right- and left side of the screen in front of them. In a first session, we determined the complexity by analyzing the temporal structure of variation in the box-to-box movement intervals with a Detrended Fluctuation Analysis. Then, we introduced perturbations to the task: We altered the tracking speed of the cursor relative to the stick-movements briefly (i.e., 4 s) at intervals of 1 min (Experiment 1), or we induced a prolonged change of the tracking speed each minute (Experiment 2). Subsequently, participants had three sessions of either classical learning or differential learning. Participants in the classical learning condition were trained to perform the ideal movement pattern, whereas those in the differential learning condition had to perform additional and irrelevant movements. Finally, we conducted a posttest that was the same as the first session. In both experiments, results showed moderate positive correlations between complexity and points scored (i.e., box touches) in the perturbation-period of the first session. Across the two experiments, only differential learning led to a higher complexity index (i.e., more prominent patterns of pink noise) from baseline to post-test. Unexpectedly, the classical learning group improved more in their resilient performance than the differential learning group. Together, this research provides empirical support for the relation between complexity and resilience, and between complexity and differential learning in human motor performance, which should be examined further.

Noise segmentation for step detection and distance estimation using smartphone sensor data

As for the low-cost and accuracy benefits of integrating Artificial Intelligence (AI) technologies in smartphones, the embedded smart sensors have been utilized in indoor localization and distance estimation applications rather than the requirement of wearable sensors. However, the effect of a potential noise during the user’s movement is still an issue, i.e. irrelevant movements. Knowing that the noise can severely impair the accuracy of distance estimation by increasing or decreasing the number of estimated steps. Therefore, this paper proposes a distance estimation method based on dynamic step size and shape. It aims at removing the noise from the bit signal and detecting the number of steps regardless of the noise using the magnitude value for the three-axis accelerometer data. Furthermore, it involves the variables of the user's height with relation to the step size to estimate the walking distance. The experiment sets allow four phases including data collection and filtering, peak detection, dynamic step size detection, and distance estimation. The low-pass filter is applied to remove the resultant noise of irrelevant movements such as handshaking, texting, swinging, etc. The experimental results showed that the proposed method of step detection, step size, and walking distance estimations achieved significant accuracy improvement over existing current approaches reaches (98%) when a pedestrian was walking in multiple mode changes.

The moving learner: Object manipulation in virtual reality improves vocabulary learning

AbstractA challenging aspect of foreign language acquisition is learning new vocabulary. Research has demonstrated the benefits of motor action to vocabulary learning, though these findings are rarely translated into teaching and learning practices. In this work, we present a novel paradigm for vocabulary learning in a virtual reality environment, capitalizing on the prominent advantages of this technology as an ‘embodied learning’ tool. Hebrew‐speaking adults explored a virtual room and learned the Finnish names of 40 daily objects. Every participant learned the new object names under three conditions: (1) Watch‐only: watching the object without performing any movement (2) performing an irrelevant movement or (3) performing a manipulation movement that implied its habitual use. Participants completed a word–picture matching test after each training block, as well as additional word–picture matching and recall tests a week after the initial training session. The overall results demonstrate improved comprehension rates for items that were learned in the manipulation movement condition compared to the irrelevant movement condition, both in the initial learning session and 1 week following it. These initial findings suggest that VR technology may indeed hold the potential to offer a more authentic, multisensory and motor context to efficient foreign language learning.

Age Effects on Spatiotemporal Dynamics of Response Inhibition: An MEG Study

Inhibition, the ability to suppress irrelevant information, thoughts or movements, is crucial for humans to perform context-appropriate behaviors. It was suggested that declined cognitive performance in older adults might be attributed to inhibitory deficiencies. Although previous studies have shown an age-associated reduction in inhibitory ability, the understanding regarding its cortical spatiotemporal maps remained limited. Thus, we used a whole-head magnetoencephalography (MEG) to elucidate the age effects on response inhibition, and to explore the brain activation differences in high- and low-performing seniors. We recruited 22 younger and 22 older adults to participate in the visual Go/No-go task. Both behavioral performance and neuromagnetic responses to No-go stimuli were analyzed. The behavioral results showed that the older adults made more false alarm (FA) errors than the younger adults did. The MEG results showed that the seniors exhibited declined cortical activities in middle temporal gyrus (MTG) and delayed activation in MTG, prefrontal cortex (PFC) and pre-supplementary motor area (pre-SMA). Furthermore, among the older adults, more recruitment of the left PFC was found in the high-performers than in the lower-performers. In conclusion, age-related deficiencies in response inhibition were observed in both behavioral performance and neurophysiological measurement. Our results also suggested that frontal recruitment plays a compensatory role in successful inhibition.

A hierarchical clustering of features approach for vehicle tracking in traffic environments

Purpose Developing algorithms for automated detection and tracking of multiple objects is one challenge in the field of object tracking. Especially in a traffic video monitoring system, vehicle detection is an essential and challenging task. In the previous studies, many vehicle detection methods have been presented. These proposed approaches mostly used either motion information or characteristic information to detect vehicles. Although these methods are effective in detecting vehicles, their detection accuracy still needs to be improved. Moreover, the headlights and windshields, which are used as the vehicle features for detection in these methods, are easily obscured in some traffic conditions. The paper aims to discuss these issues. Design/methodology/approach First, each frame will be captured from a video sequence and then the background subtraction is performed by using the Mixture-of-Gaussians background model. Next, the Shi-Tomasi corner detection method is employed to extract the feature points from objects of interest in each foreground scene and the hierarchical clustering approach is then applied to cluster and form them into feature blocks. These feature blocks will be used to track the moving objects frame by frame. Findings Using the proposed method, it is possible to detect the vehicles in both day-time and night-time scenarios with a 95 percent accuracy rate and can cope with irrelevant movement (waving trees), which has to be deemed as background. In addition, the proposed method is able to deal with different vehicle shapes such as cars, vans, and motorcycles. Originality/value This paper presents a hierarchical clustering of features approach for multiple vehicles tracking in traffic environments to improve the capability of detection and tracking in case that the vehicle features are obscured in some traffic conditions.

Moving to Learn: How Guiding the Hands Can Set the Stage for Learning.

Previous work has found that guiding problem-solvers' movements can have an immediate effect on their ability to solve a problem. Here we explore these processes in a learning paradigm. We ask whether guiding a learner's movements can have a delayed effect on learning, setting the stage for change that comes about only after instruction. Children were taught movements that were either relevant or irrelevant to solving mathematical equivalence problems and were told to produce the movements on a series of problems before they received instruction in mathematical equivalence. Children in the relevant movement condition improved after instruction significantly more than children in the irrelevant movement condition, despite the fact that the children showed no improvement in their understanding of mathematical equivalence on a ratings task or on a paper-and-pencil test taken immediately after the movements but before instruction. Movements of the body can thus be used to sow the seeds of conceptual change. But those seeds do not necessarily come to fruition until after the learner has received explicit instruction in the concept, suggesting a "sleeper effect" of gesture on learning.

The influence of Oxytocin on automatic motor simulation.

Motor simulation is important for imitation, action understanding, and a wide range of social cognitive skills. Furthermore, the neuropeptide hormone Oxytocin (OT) has also been related to social information processing in humans, improving perception of social stimuli and increasing altruism and trust. Surprisingly, however, a direct link between OT and motor simulation has never been systematically investigated. The current study examined this question using the imitation-inhibition task, a paradigm used to investigate automatic imitation behaviour and motor simulation. In this task, participants carry out simple finger movements while observing irrelevant movements that either match (congruent condition) or do not match (incongruent condition) the instructed movements. In a double-blind, placebo-controlled design, male participants were administered either OT (N=24) or placebo (N=24), and subsequently performed the imitation-inhibition task. To ensure specificity of OT effects to imitative behaviour, participants additionally performed a Stroop colour-word interference task (adapted to optimize similarities with the imitation inhibition task) to rule out general effects on cognitive control. As predicted, OT selectively influenced the congruency effect in the imitation-inhibition task but not the congruency effect in the Stroop task. This effect showed that OT led to a larger congruency effect by slowing down reaction times on incongruent trials when observed and own actions did not match. The findings suggest that OT leads to a decrease of control over automatic imitative behaviour mediated by increased self-other merging. Thus, for the first time, a link between OT and motor simulation is demonstrated, providing a window into the role of OT in motoric aspects of social cognition.

Observation and action priming in anticipative tasks implying biological movements.

The purpose of this study was to assess the effect of short-term priming in perceptual anticipation tasks involving point-light biological motions. After the production or the observation of a relevant or an irrelevant movement (action vs. observation priming), 11 right-handed volunteers were asked to anticipate, as quickly and accurately as possible, the end point of a pointing movement after the stimulus vanished upon completion of 60% of the total movement. Our results indicate that perceptual accuracy is significantly affected only with relevant observation priming. This suggests that perceptual anticipation tasks' involving point-light biological motions implies specific perceptual competencies. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Top-Down Modulation of Motor Priming by Belief About Animacy

There is recent evidence that we directly map observed actions of other agents onto our own motor repertoire, referred to as direct matching (Iacoboni et al., 1999). This was shown when we are actively engaged in joint action with others' (Sebanz et al. 2003) and also when observing irrelevant movements while executing congruent or incongruent movements (Brass et al., 2000). However, an open question is whether direct matching in human beings is limited to the perception of intentional agents. Recent research provides contradictory evidence with respect to the question whether the direct matching system has a biological bias possibly emerging from perceptual differences of the stimulus display. In this study all participants performed a motor priming task observing the identical animation showing finger lifting movements of a hand in a leather glove. Before running the experiment we presented either a human hand or a wooden analog hand wearing the leather glove. We found a motor priming effect for both human and wooden hands. However, motor priming was larger when participants believed that they interacted with a human hand than when they believed to interact with a wooden hand. The stronger motor priming effect for the biological agent suggests that the "direct matching system" is tuned to represent actions of animate agents.

Spatial recall improved by retrieval enactment

Evidence from studies of intentional learning suggests that the accuracy of recall is not assisted by appropriate enactment at retrieval, as opposed to encoding. In the present study, long-term recall of spatial arrays following incidental learning (text messaging or calculator use) was tested under three different motor conditions at retrieval. For both letter and number arrays, the accuracy of recall was found to be improved by relevant enactment at the time of retrieval, relative to retrieval with no movement. In contrast, irrelevant movement was found to produce an impairment in accuracy. The overall accuracy of recalling a letter array was found to be a power-law function of the frequency of exposure to the array. The findings are discussed in terms of the hypothesis that appropriate movement during memory retrieval recruits egocentric representations that supplement allocentric representations subserving longer term spatial recall.

Operation compatibility: A neglected contribution to dual-task costs.

Traditionally, dual-task interference has been attributed to the consequences of task load exceeding capacity limitations. However, the current study demonstrates that in addition to task load, the mutual compatibility of the concurrent processes modulates whether 2 tasks can be performed in parallel. In 2 psychological refractory period experiments, task load and process compatibility were independently varied. In Experiment 1, participants performed 2 mental rotation tasks. Task load (rotation angle) and between-task compatibility in rotation direction were varied. Results suggest more considerable parallel execution of compatible than of incompatible operations, arguing for the need to attribute dual-task interference not only to structural but also to functional capacity limitations. Experiment 2 tested whether functional capacity limitations to dual-task performance can be caused only by demanding processes or whether they are also induced by relatively automatic processes. Results indicate that an irrelevant circular movement of Stimulus 2 interfered more with mental rotation of Stimulus 1 if the rotation directions were opposite than if they were equal. In conclusion, compatibility of concurrent processes constitutes an indispensable element in explaining dual-task performance.

Relevance of Error: What Drives Motor Adaptation?

During motor adaptation the nervous system constantly uses error information to improve future movements. Today's mainstream models simply assume that the nervous system adapts linearly and proportionally to errors. However, not all movement errors are relevant to our own action. The environment may transiently disturb the movement production-for example, a gust of wind blows the tennis ball away from its intended trajectory. Apparently the nervous system should not adapt its motor plan in the subsequent tennis strokes based on this irrelevant movement error. We hypothesize that the nervous system estimates the relevance of each observed error and adapts strongly only to relevant errors. Here we present a Bayesian treatment of this problem. The model calculates how likely an error is relevant to the motor plant and derives an ideal adaptation strategy that leads to the most precise movements. This model predicts that adaptation should be a nonlinear function of the size of an error. In reaching experiments we found strong evidence for the predicted nonlinear strategy. The model also explains published data on saccadic gain adaptation, adaptation to visuomotor rotations, and force perturbations. Our study suggests that the nervous system constantly and effortlessly estimates the relevance of observed movement errors for successful motor adaptation.

The Effect of Variation in Prey Movement on the Predatory Response of Jacky Lizards (Amphibolurus muricatus)

The sensory systems of animals have evolved to meet the demands of functionally critical events. Animals that rely on visual motion cues must ignore irrelevant movement and only attend to certain characteristics that warrant further consideration. For the Australian jacky lizard (Amphibolurus muricatus), movement is essential for detecting potential prey. Here we examine whether differences in the actual motion characteristics of a simulated prey item influence predatory behaviour. We begin with direct observations of responses to live prey items to define an ordinal scale for subsequent video playback experiments involving a synthetic prey item (an animated cricket). In expt 1, we show that the responses of lizards to the synthetic prey were matched to those given in response to video of an actual cricket. In expt 2 we manipulated the movement patterns of the synthetic cricket based on motion analysis of actual prey movement. Manipulating motion characteristics did not influence the level of predatory behaviour observed, however, lizards showed sustained predatory behaviour to stimuli with speed characteristics that were matched to those of real crickets. We discuss the possibility that recent experience of prey movement in captivity has influenced the foraging behaviour of these lizards.

Activation in Posterior Superior Temporal Sulcus Parallels Parameter Inducing the Percept of Animacy

An essential, evolutionarily stable feature of brain function is the detection of animate entities, and one of the main cues to identify them is their movement. We developed a model of a simple interaction between two objects, in which an increase of the correlation between their movements varied the amount of interactivity and animacy observers attributed to them. Functional magnetic resonance imaging revealed that activation in the posterior superior temporal sulcus and gyrus (pSTS/pSTG) increased in relation to the degree of correlated motion between the two objects. This activation increase was not different when subjects performed an explicit or implicit task while observing these interacting objects. These data suggest that the pSTS and pSTG play a role in the automatic identification of animate entities, by responding directly to an objective movement characteristic inducing the percept of animacy, such as the amount of interactivity between two moving objects.

Path integration while ignoring irrelevant movement.

Participants attempted to return to the origin of travel after following an outbound path by locomotion on foot (Experiments 1-3) or in a virtual visual environment (Experiment 4). Critical conditions interrupted the outbound path with verbal distraction or irrelevant, to-be-ignored movements. Irrelevant movement, real or virtual, had greater effects than verbal or cognitive distraction, indicating inability to ignore displacement during path integration. Effects of the irrelevant movement's direction (backward vs. rightward) and location (1st vs. 2nd leg of path) indicated that participants encoded a configural representation of the pathway and then cognitively compensated for the movement, producing errors directly related to the demands of compensation. An encoding-error model fit to the data indicated that backward movement produced downward rescaling, whereas movement that led to implied rotation (rightward on 2nd leg) produced distortions of shape and scale.

Path integration while ignoring irrelevant movement.

Participants attempted to return to the origin of travel after following an outbound path by locomotion on foot (Experiments 1-3) or in a virtual visual environment (Experiment 4). Critical conditions interrupted the outbound path with verbal distraction or irrelevant, to-be-ignored movements. Irrelevant movement, real or virtual, had greater effects than verbal or cognitive distraction, indicating inability to ignore displacement during path integration. Effects of the irrelevant movement's direction (backward vs. rightward) and location (1st vs. 2nd leg of path) indicated that participants encoded a configural representation of the pathway and then cognitively compensated for the movement, producing errors directly related to the demands of compensation. An encoding-error model fit to the data indicated that backward movement produced downward rescaling, whereas movement that led to implied rotation (rightward on 2nd leg) produced distortions of shape and scale.

Is one hand always better than two? A replication study

Recently, it has been shown that the active movement of the left hand in the left hemispace reduces left neglect in visual exploratory tasks. Despite the important theoretical and practlcal implications, there exists no direct confirmation of these findings in the literature. To verify the presence of the beneficial effect of left hand movement in left space, we replicated three of the nine experiments devised by Robertson and North (Neuropsychologia 1992; 30: 553-63, Neuropsychologia 1994; 32: 1-11). To this end, we tested 10 consecutive patients with right brain damage and left neglect. We found the expected pattern of performance in only one patient: on reading and cancellation the total number of omissions significantly decreased when irrelevant movements were performed with the left hand in the left space. This finding underlines the importance of replication studies in cognitive neuropsychology.

Alien Hand Syndrome: Influence of Neglect on the Clinical Presentation of Frontal and Callosal Variants

Three patients with mesial frontal and extensive callosal lesions due to anterior cerebral artery infarction manifested an alien hand syndrome (AHS) with varied features. Patient 1 with left hemispheric lesion showed right hand's impulsive reaching and grasping and left hand's antagonistic movements to the right (intermanual conflict; IMC). Patients 2 and 3 with right hemispheric lesion manifested a left hemihypokinesia which was thought to have suppressed the frequency and amplitude or even the occurrence of left hand's reaching and grasping. IMC and other left hand's non-antagonistic, irrelevant movements to the right remained. Because the term “IMC” is often misused and not strictly defined, its association with right hand's reaching and grasping is quite uncommon, its significance as a sign of callosal disconnection is not well validated, and because left hand's reaching and grasping tend to be suppressed by motor neglect, a trend may then develop for the right hand to be the sole focus of pathological behaviour in patients with the so-called frontal AHS (Feinberg, Schindler, Flanagan et al., 1992)

Movement Imagery in Young and Congenitally Blind Children: Mental Practice without Visuo-spatial Information

The study explored whether young children and congenitally totally blind children show mental practice effects for blind movements which cross the body midline. Experiment 1 tested blindfolded sighted children, with a mean age of 7 years and 11 months, on recall of a linear movement. Prior to recall, subjects either had to perform, or to imagine irrelevant (larger/smaller/same) movements. Irrelevant movements produced significant bias (CE/Constant Errors), whether carried out or imaged, although bias from imagined movements was smaller. The VE (variance/consistency) scores improved with (actual and mental) rehearsal. Articulatory suppression during delays had no effect. Experiment 2 used the same paradigm to test three groups of congenitally totally blind children with respective mean Mental Ages (MA) of 10 years and 7 months, 13 years and 7 months, and 16 years and 4 months, based on IO scores on the Williams Intelligence Test (1956) for visually handicapped children. Irrelevant movements during delays produced bias (CE) in recall, whether the movements were carried out or imagined, although bias was smaller in imagery conditions. The (CE) bias effects did not interact with MA. Mental Age interacted significantly with Delay Tasks in VE scores. The lowest MA group was less efficient (more variable) than the others, particularly in (actual and imagined) rehearsal. Articulatory suppression had no effect. The results suggest that young children can show mental practice effects in the absence of current visual cues, and that visuospatial imagery is not a necessary condition, because imagined movements also biased recall by the congenitally totally blind. It was argued that movement as well as cognitive factors can be involved in mental practice effects, and that the nature of mediation depends on the available information.

Diagonistic dyspraxia

We report unusual motor behavior of the left hand dissociated from conscious volition in a 51-year-old right-handed man. This patient had sustained damage to the anterior two-thirds of the corpus callosum, the rostral and lower parts of the right medial frontal lobe, and a small portion of the left medial frontal lobe. He subsequently showed 4 types of abnormal motor behavior in the left hand that were triggered by voluntary activities of the right hand: symmetric or antagonistic left hand movements; irrelevant movements of the left hand to the right hand; and a tendency to close the fingers of the left hand into a fist. Recordings of movement-related potentials revealed a marked attenuation of the Bereitschaftspotential (BP) over the right hemisphere observed only when the patient initiated voluntary activity with the right hand. Since the BP is believed to represent a cerebral cortical activity preparatory for voluntary movement, we infer that the level of dysfunction in this patient is at the motor preparatory level caused by a disconnection of the right hemisphere from the left.