scholarly journals Awareness of the Outcome of Self-Initiated Pointing Actions

2017 ◽  
Author(s):  
Andrei Gorea ◽  
Lionel Granjon ◽  
Dov Sagi
Keyword(s):  
Simple Model ◽  
Visual Feedback ◽  
Visual Target ◽  
Time Constraints ◽  
Motor Plan ◽  
Screen Location

ABSTRACTAre we aware of the outcome of our actions? The participants pointed rapidly at a screen location marked by a transient visual target (T), with and without seeing their hand, and were asked to estimate (E) their landing location (L) using the same finger but without time constraints. We found that L and E are systematically and idiosyncratically shifted away from their corresponding targets (T, L), suggesting unawareness. Moreover, E was biased away from L, toward T (21% and 37%, with and without visual feedback), in line with a putative Bayesian account of the results, assuming a strong prior in the absence of vision. However, L (the assumed prior) and E (the assumed posterior) precisions were practically identical, arguing against such an account of the results. Instead, the results are well accounted for by a simple model positing that the participants’ E is set to the planned rather than the actual L. When asked to estimate their landing location, participants appeared to reenact their original motor plan.

Motor skill training without online visual feedback enhances feedforward control

2021 ◽  
Author(s):  
Adi Raichin ◽  
Anat Shkedy Rabani ◽  
Lior Shmuelof
Keyword(s):  
Feedback Control ◽  
Visual Feedback ◽  
Performance Feedback ◽  
Motor Skill ◽  
Feedforward Control ◽  
Skill Training ◽  
Skill Learning ◽  
Motor Skill Learning ◽  
Motor Plan ◽  
Before And After

Motor skill learning involves improvement in feedforward control, the ability to execute a motor plan more reliably, and feedback control, the ability to adjust the motor plan on the fly. The dependence between these control components and the association between training conditions and their improvement have not been directly examined. This study characterizes the contribution of feedforward and feedback control components to motor skill learning using the Arc Pointing Task (APT), a drawing task that requires high motor acuity. In experiment 1, 3 groups of subjects were tested with online visual feedback before and after training with online visual feedback (OF group), with knowledge of performance feedback that was presented after movement completion (KP group), and with both online and KP feedback (KP+OF group). While the improvement of OF group was not different from the improvement of KP+OF group, comparison of the KP and KP+OF groups revealed an advantage to the KP group in the fast test speed, suggesting that training without online feedback leads to a greater improvement in feedforward control. In experiment 2, subject's improvement was examined using test probes for estimating feedback and feedforward control. Both KP+OF and KP groups showed improvement in feedforward and feedback conditions with a trend toward a greater improvement of the KP group. Our results suggest that online visual feedback suppresses improvement in feedforward control during motor skill learning.

Predictive Smooth Ocular Pursuit During the Transient Disappearance of a Visual Target

2004 ◽  
Vol 92 (1) ◽  
pp. 578-590 ◽  
Author(s):  
Simon J. Bennett ◽  
Graham R. Barnes
Keyword(s):  
Visual Feedback ◽  
Visual Target ◽  
Target Velocity ◽  
Moving Target ◽  
Stimulus Interval ◽  
Ocular Pursuit ◽  
Velocity Error ◽  
Inter Stimulus Interval ◽  
Initial Reduction ◽  
Eye Velocity

When a moving target disappears and there is a complete absence of visual feedback signals, eye velocity decays rapidly but often recovers to previous levels if there is an expectation the target will reappear further along its trajectory Given that eye velocity cannot be maintained under such circumstances, the anticipatory recovery may function to minimize the developing velocity error. When there is a change in target velocity during a transient, any recovery should ideally be scaled and hence predictive of the expected target velocity at reappearance. This study confirmed that subjects did not maintain eye velocity close to target velocity for the duration of the inter-stimulus interval (ISI). The majority of subjects exhibited an initial reduction in eye velocity followed by a scaled recovery prior to target reappearance. Eye velocity during the ISI was, therefore, predictive of the expected change in target velocity. These behavioral data were simulated using a model in which gain applied to the visuomotor drive is reduced after the loss of visual feedback and then modulated depending on subject’s expectation regarding the target’s future trajectory.

scholarly journals Eye-hand coordination during online reach corrections is task-dependent

2021 ◽  
Author(s):  
Anouk J. de Brouwer ◽  
Miriam Spering
Keyword(s):  
Cognitive Processing ◽  
Visual Feedback ◽  
Motor System ◽  
Target Location ◽  
Visual Target ◽  
The Body ◽  
Hand Position ◽  
Double Step ◽  
Hand Coordination ◽  
Visual Characteristics

AbstractTo maintain accurate movements, the motor system needs to deal with errors that can occur due to inherent noise, changes in the body, or disturbances in the environment. Here, we investigated the temporal coordination of rapid corrections of the eye and hand in response to a change in visual target location during the movement. In addition to a ‘classic’ double-step task in which the target stepped to a new position, participants performed a set of modified double-step tasks in which the change in movement goal was indicated by the appearance of an additional target, or by a spatial or symbolic cue. We found that both the absolute correction latencies of the eye and hand and the relative eye-hand correction latencies were dependent on the visual characteristics of the target change, with increasingly longer latencies in tasks that required more visual and cognitive processing. Typically, the hand started correcting slightly earlier than the eye, especially when the target change was indicated by a symbolic cue, and in conditions where visual feedback of the hand position was provided during the reach. Our results indicate that the oculomotor and limb-motor system can be differentially influenced by processing requirements of the task and emphasize that temporal eye-hand coordination is flexible rather than rigid.

Shape Distortion Produced by Isolated Mismatch Between Vision and Proprioception

2008 ◽  
Vol 99 (1) ◽  
pp. 231-243 ◽  
Author(s):  
Nicole Malfait ◽  
Denise Y. Henriques ◽  
Paul L. Gribble
Keyword(s):  
Visual Feedback ◽  
Visual Target ◽  
Single Point ◽  
Visual Display ◽  
Matching Task ◽  
Two Dimensional ◽  
Visuomotor Transformation ◽  
Shape Distortion ◽  
Geometrical Form ◽  
Limb Posture

To investigate the nature of the visuomotor transformation, previous studies have used pointing tasks and examined how adaptation to a spatially localized mismatch between vision and proprioception generalizes across the workspace. Whereas some studies found extensive spatial generalization of single-point remapping, consistent with the hypothesis of a global realignment of visual and proprioceptive spaces, other studies reported limited transfer associated with variations in initial limb posture. Here, we investigated the effects of spatially localized remapping in the context of a visuomanual tracking task. Subjects tracked a visual target tracing a simple two-dimensional geometrical form without visual feedback except at a single point, where the visual display of the hand was shifted relative to its actual position. After adaptation, hand paths exhibited distortions relative to the visual templates that were inconsistent with the idea of a global realignment of visual and proprioceptive spaces. Results of a visuoproprioceptive matching task showed that these distortions were not limited to active movements but also affected perception of passive limb movements.

A simple model of optimal territory size for drift-feeding fish

1987 ◽  
Vol 65 (2) ◽  
pp. 270-276 ◽  
Author(s):  
James W. A. Grant ◽  
David L. G. Noakes
Keyword(s):  
Simple Model ◽  
Territory Size ◽  
Time Constraints ◽  
Food Density ◽  
Daily Ration ◽  
Natural Manner ◽  
Drift Feeding ◽  
Feeding Territory ◽  
The Cost ◽  
Simple Models

A simple model of optimal feeding-territory size is developed for drift-feeding fish by modifying Hixon's (M. A. Hixon. 1980. Am. Nat. 115: 510–530) model for energy maximizers. Our model predicts that territory size should vary directly with food density when the fish is subject to time constraints, and directly with intruder pressure when the fish is subject to processing constraints. These unique predictions arise because any food not immediately eaten is carried downstream out of the territory. Our model also predicts that territory size should vary inversely with intruder pressure when the fish is subject to time constraints, and inversely with food density when the fish is subject to processing constraints. The qualitative predictions of the model are not affected by changes in the shape of the cost or benefit curves, unlike other simple models. A review of studies of salmonid territory size indicates that most are inadequate tests of the model because (i) food was not presented in a natural manner, (ii) ration levels were not controlled at levels that were clearly above or below a maximum daily ration, and (iii) the confounding effects of intruder pressure were not controlled. Future experiments will have to incorporate these factors to distinguish between the competing predictions posed by this and previous models.

Clinical Success Using the Audio-Visual Feedback Training for Cluttering

2019 ◽  
Vol 4 (6) ◽  
pp. 1589-1594
Author(s):  
Yvonne van Zaalen ◽  
Isabella Reichel
Keyword(s):  
Visual Feedback ◽  
Clinical Success ◽  
Pause Duration ◽  
Digital Audio ◽  
Male Adolescents ◽  
Feedback Training ◽  
Positive Effects ◽  
Speech Monitoring ◽  
Adolescents And Adults

Purpose Among the best strategies to address inadequate speech monitoring skills and other parameters of communication in people with cluttering (PWC) is the relatively new but very promising auditory–visual feedback (AVF) training ( van Zaalen & Reichel, 2015 ). This study examines the effects of AVF training on articulatory accuracy, pause duration, frequency, and type of disfluencies of PWC, as well as on the emotional and cognitive aspects that may be present in clients with this communication disorder ( Reichel, 2010 ; van Zaalen & Reichel, 2015 ). Methods In this study, 12 male adolescents and adults—6 with phonological and 6 with syntactic cluttering—were provided with weekly AVF training for 12 weeks, with a 3-month follow-up. Data was gathered on baseline (T0), Week 6 (T1), Week 12 (T2), and after follow-up (T3). Spontaneous speech was recorded and analyzed by using digital audio-recording and speech analysis software known as Praat ( Boersma & Weenink, 2017 ). Results The results of this study indicated that PWC demonstrated significant improvements in articulatory rate measurements and in pause duration following the AVF training. In addition, the PWC in the study reported positive effects on their ability to retell a story and to speak in more complete sentences. PWC felt better about formulating their ideas and were more satisfied with their interactions with people around them. Conclusions The AVF training was found to be an effective approach for improving monitoring skills of PWC with both quantitative and qualitative benefits in the behavioral, cognitive, emotional, and social domains of communication.

The Use of Neuroplastic Principles Affects the Swallow Motor Plan of a Patient in Severe Cognitive Decline: A Case Study

2016 ◽  
Vol 1 (15) ◽  
pp. 79-83
Author(s):  
Ed Bice ◽  
Kristine E. Galek
Keyword(s):  
Central Nervous System ◽  
Cognitive Decline ◽  
Full Range ◽  
Movement Speed ◽  
Positive Outcomes ◽  
Verbal Cues ◽  
Motor Plan ◽  
Bolus Size ◽  
The Central Nervous System

Dysphagia is common in patients with dementia. Dysphagia occurs as a result of changes in the sensory and motor function of the swallow (Easterling, 2007). It is known that the central nervous system can undergo experience-dependent plasticity, even in those individuals with dementia (Park & Bischof, 2013). The purpose of this study was to explore whether or not the use of neuroplastic principles would improve the swallow motor plan and produce positive outcomes of a patient in severe cognitive decline. The disordered swallow motor plan was manipulated by focusing on a neuroplastic principles of frequency (repetition), velocity of movement (speed of presentation), reversibility (Use it or Lose it), specificity and adaptation, intensity (bolus size), and salience (Crary & Carnaby-Mann, 2008). After five therapeutic sessions, the patient progressed from holding solids in her mouth with decreased swallow initiation to independently consuming a regular diet with full range of liquids with no oral retention and no verbal cues.

The Influences of Goal and Laterality of a Prepared Hand Response on a Co-Occurring Visual Search

2015 ◽  
Vol 74 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Alexandre Coutté ◽  
Gérard Olivier ◽  
Sylvane Faure
Keyword(s):  
Visual Search ◽  
Visual Target ◽  
Motor Planning ◽  
Search Performance ◽  
Response Preparation ◽  
Manual Response ◽  
Response Hand ◽  
Computer Screen ◽  
Left Hand ◽  
Manual Interaction

Computer use generally requires manual interaction with human-computer interfaces. In this experiment, we studied the influence of manual response preparation on co-occurring shifts of attention to information on a computer screen. The participants were to carry out a visual search task on a computer screen while simultaneously preparing to reach for either a proximal or distal switch on a horizontal device, with either their right or left hand. The response properties were not predictive of the target’s spatial position. The results mainly showed that the preparation of a manual response influenced visual search: (1) The visual target whose location was congruent with the goal of the prepared response was found faster; (2) the visual target whose location was congruent with the laterality of the response hand was found faster; (3) these effects have a cumulative influence on visual search performance; (4) the magnitude of the influence of the response goal on visual search is marginally negatively correlated with the rapidity of response execution. These results are discussed in the general framework of structural coupling between perception and motor planning.

Gender Differences in the Mental Rotations Test (MRT) Are Not Due to Task Complexity

2008 ◽  
Vol 29 (3) ◽  
pp. 130-133 ◽  
Author(s):  
Corinna Titze ◽  
Martin Heil ◽  
Petra Jansen
Keyword(s):  
Gender Differences ◽  
Mental Rotation ◽  
Task Complexity ◽  
Time Constraints ◽  
Medium Effects ◽  
Performance Factors ◽  
Mental Rotations ◽  
Sufficient Power ◽  
Forced Choice Tasks ◽  
Choice Tasks

Gender differences are one of the main topics in mental rotation research. This paper focuses on the influence of the performance factor task complexity by using two versions of the Mental Rotations Test (MRT). Some 300 participants completed the test without time constraints, either in the regular version or with a complexity reducing template creating successive two-alternative forced-choice tasks. Results showed that the complexity manipulation did not affect the gender differences at all. These results were supported by a sufficient power to detect medium effects. Although performance factors seem to play a role in solving mental rotation problems, we conclude that the variation of task complexity as realized in the present study did not.

Sign in / Sign up

Export Citation Format

Share Document