Manual Aiming Task Research Articles

Comparison between manual aiming control and sex in different task constraints

Abstract AIMS This study aimed to investigate the comparison between sex and manual aiming control in different cognitive and motor constraints of the task. METHODS Eighty-four right-handed participants (42 women) performed 110 trials of a manual aiming task with a non-inking pen on a digitizing tablet. The aiming task required four different conditions of execution. The control condition appeared on the computer screen in 70% of the trials, and the other three conditions, (a) distractor, (b) inhibition of response and (c) higher index of difficulty, each appeared in 10% of the trials. RESULTS Compared with women, men produced shorter movement and response times, as well as higher peak velocity in the control and distractor conditions. When the index of difficulty of the task increased, men produced only higher peak velocity. Women produced more corrective movements to achieve the target only in the control condition. CONCLUSION Our results corroborate those of previous studies that indicate sex-specific response strategies when the sensory motor system is challenged by different task constraints.

Postural Precursors of Postboxing Motion Sickness in a Manual Aiming Task

We asked whether body sway during performance of a visual-manual task would differ between boxers who experienced post-match motion sickness and those who did not. Before and after boxing we measured standing body sway while participants performed a manual precision aiming task. After boxing, participants stated, yes/no, whether they were motion sick; they also reported motion sickness symptoms, and concussion-related symptoms. Seven of thirteen boxers reported motion sickness after boxing. We compared boxers who reported post-boxing motion sickness versus those who did not. Body sway before boxing differed between boxers who reported post-bout motion sickness and those who did not. Immediately after boxing, motion sickness symptoms and concussion-related symptoms were elevated among boxers who stated that they were motion sick. The results suggest that patterns of body sway may be related to individual differences in susceptibility to motion sickness and concussion-like symptoms in adult male boxers, such that objective measurements of body sway might be used to predict susceptibility in individuals.

People are better at maximizing expected gain in a manual aiming task with rapidly changing probabilities than with rapidly changing payoffs

Previous research has shown that humans can select movements that achieve their goals, while avoiding negative outcomes, by selecting an "optimal movement endpoint." This optimal endpoint is modeled based on the participants' endpoint variability and the payoffs associated with the target and penalty regions within the environment. Although the values associated with our goals vary on a moment-to-moment basis in our daily interactions, the adaptation of endpoint selection to changing payoffs in laboratory-based tasks has been examined by varying contexts between blocks of trials. The present study was designed to determine whether participants adjust endpoints and aim to optimal endpoints and whether performance differs when probability or payoff parameters change from trial to trial. Participants aimed to a target circle that was partially overlapped by a penalty circle. They received 100 points for hitting the target and lost points for hitting the penalty area. The magnitude of the penalty value or the distance between the centers of the circles (related to the probability of target and penalty contact) was changed randomly from trial to trial in separate blocks. Results revealed that participants shifted their endpoint and generally aimed optimally when the distance between the circles was varied but did not optimally shift their endpoints when the penalty value was varied. The results suggest that participants rapidly adapted endpoints when the probabilities associated with the task change, because the spatial parameters are an intrinsic property of the visual stimuli that are tightly linked with the motor system, whereas consistent feedback may be necessary to adjust to value parameters effectively.

Integration of Alternating Monocular Samples During Goal-Directed Aiming

The current study examined the effect of interocular delay in a manual aiming task that required accurate end-point placement, but not precise control of a grip aperture. Participants aimed in binocular, monocular, or alternating monocular vision conditions. For the latter, 25ms monocular samples were provided to alternate eyes without delay (0ms), or a delay of 25 or 50ms. The interocular delay resulted in a longer movement time, caused by a longer time-to-peak and time-after-peak velocity, and a reduction in peak velocity. We suggest that the change in kinematics reflect a strategic response to preserve terminal aiming accuracy and variability when faced with an informational perturbation. These findings indicate that the response to the interocular delay between alternating monocular samples depends on the task-specific information used to control that behavior.

A kinematic analysis of manual aiming control on euthymic bipolar disorder

Motor deficits in tasks that require force steadiness or scaling of movement velocity have been found in bipolar disorder (BD). A potential explanation for these results is the abnormal functioning of the frontostriatal circuitry. We designed this study to investigate the possible impairments in a manual aiming task. Participants comprised 15 euthymic BD patients and 15 healthy controls, who performed 100 trials of a goal-directed manual movement with a non-inking pen on a digitizing tablet. Four different conditions of execution were required. The control condition appeared on the computer screen in 70% of the trials, and the other three conditions, (a) distractor, (b) inhibition of response and (c) higher index of difficulty, each appeared in 10% of the trials. Compared to the controls, the BD patients were less fluent in their movements, relied more heavily on visual feedback to control their manual movements and presented a lower spatial accuracy. We found that motor deficits in euthymic BD were observed in the kinematic analysis of manual aiming. Our findings are consistent with the hypothesis of abnormal functioning of the frontostriatal circuitry in euthymic BD.

Effects of camera arrangement on perceptual-motor performance in minimally invasive surgery.

Minimally invasive surgery (MIS) is performed for a growing number of treatments. Whereas open surgery requires large incisions, MIS relies on small incisions through which instruments are inserted and tissues are visualized with a camera. MIS results in benefits for patients compared with open surgery, but degrades the surgeon's perceptual-motor performance. We used a laparoscopic simulator to measure effects of type (top, front, side) and number (1, 3) of camera views on manual manipulation and manual aiming tasks. These experimental manipulations had implications for perceptual and cognitive processing including frame of reference, movement compatibility, compression, task-information specificity, information integration, attentional demands, and information extraction. Camera views generally degraded performance compared with direct viewing, but learning occurred. Generally, a top view resulted in the best performance, followed by front and side views. Benefits of multiple views depended on practice and the direction of grasper movement. Mappings between movement direction and camera view, the consistency of those mappings, and task difficulty affected performance. The benefits and costs for perceptual and cognitive processing that were introduced by a given camera view were not necessarily weighted equally. Costs and benefits must be considered specifically for each task and for each combination of camera view and movement direction. Surgeons may consider using a top view, using side views only when necessary, and using a consistent view when performing repetitive movements.

Effects of hand termination and accuracy requirements on eye–hand coordination in older adults

This study investigated how aging compromises the control of saccades and eye–hand coordination when accuracy constraints and termination requirements of hand movement are altered. Seventeen older adults and seventeen young controls performed two-segment aiming movements. The first segment had two target sizes to alter accuracy constraints. Two-segment eye movements were always made to first and second targets, whereas hand movements were varied across three hand-movement types with different termination requirements: (1) stop both at the first and second targets, (2) stop at the first target and discontinue, and (3) move through the first target and discontinue. Compared to the young adults, the older adults produced hypometric primary saccades and delayed gaze fixation to the first target. The older adults also modified eye movements less depending on the hand termination and accuracy requirements. After pointing completion to the first target, the older adults maintained their gaze fixation to that target for a longer duration than young adults. However, this prolonged gaze fixation was minimized when a hand termination was not required. Conversely, the prolongation of gaze fixation was magnified when the hand termination was required at the first target while the eye movement was continuing to the next target. Thus, older adults have difficulties in concurrent control of inhibiting hand movement and initiating eye movement at a target within a sequence. Taken together, it is suggested that aging reduces the ability to modify eye movements to meet various behavioral constraints imposed on manual aiming tasks.

Electroencephalographic correlates of target and outcome errors

Different neural systems underlie the evaluation of different types of errors. Recent electroencephalographic evidence suggests that outcome errors -- errors indicating the failure to achieve a movement goal -- are evaluated within medial-frontal cortex (Krigolson and Holroyd 2006, 2007a, b). Conversely, evidence from a variety of manual aiming studies has demonstrated that target errors -- discrepancies between the actual and desired motor command brought about by an unexpected change in the movement environment -- are mediated within posterior parietal cortex (e.g., Desmurget et al. 1999, 2001; Diedrichsen et al. 2005). Here, event-related brain potentials (ERP) were recorded to assess medial-frontal and parietal ERP components associated with the evaluation of outcome and target errors during performance of a manual aiming task. In line with previous results (Krigolson and Holroyd 2007a), we found that target perturbations elicited an ERP component with a parietal scalp distribution, the P300. However, the timing of kinematic changes associated with accommodation of the target perturbations relative to the timing of the P300 suggests that the P300 component was not related to the online control of movement. Instead, we believe that the P300 evoked by target perturbations reflects the updating of an internal model of the movement environment. Our results also revealed that an error-related negativity, an ERP component typically associated with the evaluation of speeded response errors and error feedback, was elicited when participants missed the movement target. Importantly, this result suggests that a reinforcement learning system within medial-frontal cortex may play a role in improving subsequent motor output.

Specificity of practice results from differences in movement planning strategies

Withdrawing visual feedback after practice of a manual aiming task results in a severe decrease in aiming accuracy. This decrease in accuracy is such that participants are often less accurate than controls who are beginning practice of the task without visual feedback. These results have been interpreted as evidence that motor learning is specific to the sources of afferent information optimizing performance, because it could be processed at the exclusion of other sources of afferent information. The goal of the present study was to test this hypothesis. To reach our goal we evaluated whether online visual feedback prevented kinesthetic information to be used for: (1) eliminating movement anisotropy resulting from difference in limb inertia when aiming in different directions and (2) creating an internal model of limb mechanics. Participants practiced a manual aiming task with or without visual feedback and with knowledge of results. After this acquisition phase, participants performed two transfer tests. The first transfer test was performed without visual feedback and/or knowledge of results. The second transfer test was similar to the first one but participants initiated their movements from a different starting base. The results showed strong specificity effects in that withdrawing visual feedback resulted in large pointing bias and variability. However, the results of the two transfer tests showed that the processing of visual feedback did not prevent the processing of kinesthetic information used to eliminate movement anisotropy or to create an internal model of limb mechanics. Rather, specificity of practice effects resulted from participants using the same motor plan in transfer as they did in acquisition even though they had no longer access to visual feedback to modulate their movement online. These results indicate that during acquisition participants adopted different movement planning strategies depending on the source of afferent information available.

Movement planning of video and of manual aiming movements

We studied aiming performance of adults for video- and manual aiming tasks when they had visual information about the location of the starting base or when they had not. In video-aiming, foveating the starting base and then the target prior to movement initiation (Foveation) resulted in less aiming bias and variability than when the starting base was not visible (PNV), or visible without the participants foveating it prior to movement initiation (PSV). In manual aiming, Foveation and PSV procedures resulted in identical results but reduced aiming bias and variability in comparison to the PNV procedures. The results indicate that participants had difficulty in transforming the locations of the starting base and of the target when seen on a vertical screen into an appropriate movement trajectory. Successive foveation of the starting base and of the target facilitated this transformation, resulting in direction variability being reduced by more than half in comparison to the PNV and PSV conditions. This suggests that in video-aiming the efference copy of the saccade can be used by the CNS to approximate the hand trajectory in the workspace and/or in joint coordinates (Jouffrais and Boussaoud, 1999). Hand trajectory could be readily available in manual aiming if the target location can be recoded directly in hand-coordinates as recently suggested by Buneo et al. (2002).

Analysis of Aiming with Tools: Proprioception

One of the major areas of interest in the field of ergonomics is the design of hand tools. Though considerable research has produced more user-friendly tools, there has been some reluctance to use them for some tasks. It is hypothesized that this reluctance on the part of the user may be partly due to the reduction of accuracy while using those handles. A pilot study employing twenty subjects (10 males, 10 females) was undertaken to evaluate three different grip angles, between the tool and handle axis, combined with four visual availability of the target conditions. Each subject was asked to aim at the center of the target under all the twelve test scenarios, with each subject performing ten trials in each scenario. The target was a touch screen monitor. The interface was a black screen background with the center indicated by a red cross-hair. The results of this study showed that the dependent variable, accuracy, was primarily effected by the angle of the of the handle grip with respect to the tool axis and by the visual availability of the target in a manual-aiming task. The tool with the least ergonomically correct wrist position yielded the best accuracy. As expected, the blind condition was the worst, but seeing the points that had been previously hit as additional visual feedback did not improve performance. The overall implication being that the most ergonomically correct tool might not lead to the best performance unless proprioception or feedback is taken into consideration. This has direct implications for tasks such as laparoscopic surgery where a long shafted tool is used with little visual feedback.

Specificity of Learning in Adults with and Without Down Syndrome

Adults with Down syndrome (DS), an undifferentiated developmental delay (UnD) and no developmental delay practiced a manual target aiming task either with or without on-line visual feedback. Following acquisition, participants performed a retention test involving the same sensory condition available during practice, followed by a transfer test under the other sensory condition. Although the participants with UnD were highly dependent on visual feedback for movement accuracy, participants with DS relied more on either kinesthetic feedback or feedforward control for spatial precision. Participants in all three groups improved their movement times with practice. This improvement was associated both with an increase in peak velocity and a reduction in the time required to decelerate their aiming movements. Contrary to our expectations, improvements in performance were not specific to the sensory conditions available during practice.

A distance effect in a manual aiming task to remembered targets: a test of three hypotheses.

It has been noted that manual aiming error and variability when pointing to remembered targets increase as a function of target eccentricity. In the present study we evaluated which one of three hypotheses (target localization, motor, or movement duration) best explains this 'distance effect'. In experiment 1, older and younger participants aimed with their unseen hand at the remembered location of targets distributed between 129 and 309 mm from the starting base. Target presentation time was of either 50 or 500 ms and aiming movements could be initiated following either a 100- or a 10,000-ms recall delay. Participants had either no constraints concerning movement time or were asked to reach the near target in a longer movement time than the farther targets. The results revealed a significant distance effect when no time constraints were imposed but showed a significantly reversed distance effect when the instructions were to reach the near targets in a longer movement time than the far targets. The same results were obtained regardless of target presentation time, recall delay, or age of the participants. These results supported a movement duration interpretation of the distance effect. In experiment 2, a distance effect was replicated when pointing with one's unseen hand toward a remembered target but did not take place when pointing to visible targets. Taken together these results suggest that prolonged movement execution interferes with the stored egocentric target representation.

What Causes Specificity of Practice in a Manual Aiming Movement: Vision Dominance or Transformation Errors?

The withdrawal of vision of the arm during a manual aiming task has been found to result in a large increase in aiming error, regardless of the amount of practice in normal vision before its withdrawal. In the present study, the authors investigated whether the increase in error reflects the domination of visual afferent information over the movement representation developed during practice to the detriment of other sources of afferent information or whether it reflects only transformation errors of the location of the target from an allocentric to an egocentric frame of reference. Participants (N = 40) performed aiming movements with their dominant or nondominant arm in a full-vision or target-only condition. The results of the present experiment supported both of those hypotheses. The data indicated that practice does not eliminate the need for visual information for optimizing movement accuracy and that learning is specific to the source or sources of afferent information more likely to ensure optimal accuracy during practice. In addition, the results indicated that movement planning in an allocentric frame of reference might require simultaneous vision of the arm and the target. Finally, practice in a target-only condition, with knowledge of results, was found to improve recoding of the target in an egocentric frame of reference.

Manipulating peripheral visual information in manual aiming: Exploring the notion of specificity of learning

The purpose of this study was to determine the effects of the addition and removal of peripheral vision in a simple manual aiming task. In Experiment 1, subjects ( n=5) practised a manual aiming task that emphasised the central visual information available during the final homing-in phase, for a moderate number of trials in either a target-only or normal-vision condition. Following the practice phase, subjects were transferred to the other condition. Spatial accuracy data indicated that the subjects' error increased following the removal and addition of the relevant central visual information. In Experiment 2, the task constraints were manipulated such that the relevant visual information was available through the peripheral retina only. Subjects ( n=5) practised the task for a moderate and extensive number of trials in either a target-only or normal-vision condition. Following each practice phase, subjects were transferred to the other condition. Spatial accuracy data indicated that while subjects' error increased following the removal of peripheral vision, there were no detrimental effects following its addition. Spatial error was reduced when transferring to the normal-vision condition. Kinematic data indicated that, on transferring to the normal-vision condition, subjects adapted their response to exploit the added visual information, as evidenced by an increased number of movement corrections in the deceleration phase. The positive effects of the addition of peripheral vision are not consistent with the notion of increasing specificity to the information available during practice. PsycINFO classification: 2300; 2320; 2323

Catching With Both Hands: An Evaluation of Neural Cross-Talk and Coordinative Structure Models of Bimanual Coordination

Kelso, Southard, and Goodman (1979) and Marteniuk and MacKenzie (1980) have each proposed a different theoretical model for bimanual coordination. In the model of Kelso et al., a close temporal relationship between the hands in a bimanual task is predicted, even when each hand is required to move different distances. In Marteniuk and MacKenzie's model, separate motor commands are issued so that each limb will arrive simultaneously at the specified movement endpoint, leading to low temporal associations between limbs. In most previous work on bimanual coordination, manual aiming tasks with differing constraints have been used by subjects in individual studies. In this study, the usefulness of existing models for predicting performance in a real-world catching task in which the required movement pattern was constrained by ball flight characteristics was examined. Eleven university students caught tennis balls with both hands in the following 3 conditions: Condition 1. Ball projected to the right shoulder area (left hand moved a greater distance than the right); Condition 2. Ball projected to center of the chest area, (both hands moved same distance); and Condition 3. Ball projected to left shoulder area (right hand moved a greater distance). Kinematic data (time to peak velocity, movement initiation time) indicating significant cross-correlations between the left and right limbs in all 3 conditions concurred with the data of Kelso et al. (1979) on manual aiming. Timing appeared to be an essential variable coordinating bimanual interceptive actions. Although the limbs moved at different speeds when each was required to move different distances, times to peak velocity showed strong associations, suggesting the presence of a coordinative structure.

Aging and motor control.

The goal of the two experiments of the present study was to determine whether in an aiming task performed within a relatively long movement time (MT) bandwidth, older adults make similar use of visual information for motor control as younger adults. Older and younger subjects practiced a manual aiming task toward one (Experiment 1), or one of many (Experiment 2) small target(s) while only the target to be reached was visible (proprioception only: P) or under normal lighting condition (proprioception+vision: PV). Following practice, all subjects were transferred to the P conditions. The results of both experiments indicate that the older subjects were, during practice, as accurate as the younger ones in the PV condition. Moreover, both groups suffered a large and similar increase in aiming error in the transfer condition. This underlines that a useful source of sensory information, namely vision, has been withdrawn in transfer. This result is different from those of earlier studies in which a shorter target MT had been used (Chaput & Proteau, 1996; Proteau, Charest, & Chaput, 1994). This suggests that older adults process the sensory information available in that type of task similarly to younger subjects but at a lower speed. However, when the temporal constraints of the task are stringent, older adults might rely more on modes of control in which sensory information plays a minimal role when compared to younger subjects. Finally, the results of the second experiment suggest that, when multiple targets are used, older adults appear to program a response which is optimally suited for a "central" target.

Effects of Skill Level, Hand Laterality and Movement Direction during Visuomotor Processing of Female Athletes Performing Manual Aiming Tasks

Hand laterality research efforts have shown a performance advantage in terms of pointing accuracy and limb speed (movement time—MVT) for the preferred hand (right-hand), and a slight reaction time (RT) performance advantage for the non-preferred hand (left-hand) for rapid manual aiming movements (Flowers, 1975; Roy, 1983; Roy & Elliott, 1986). These performance advantages for the right and left-hands, respectively, are considered an enigma in the motor behavior literature (Magill, 1993) and were investigated. The purpose of this study was to determine the effects of skill level, hand laterality, and movement direction during visuomotor processing of female athletes performing manual aiming tasks. Results showed that skill level and hand laterality did not influence the initiation of manual aiming movements; but, left direction movements were initiated faster than right direction movements. Right-hand MVT was faster than left-hand MVT; but, main effects skill level and movement direction were not significant for MVT. Skill level did interact with hand laterality and movement direction for MVT. Also, right-hand right direction movements were the easiest manual aiming tasks to complete while left-hand right direction movements were the most difficult manual aiming tasks to complete. Differences in hemispheric visuomotor processing when performing manual aiming movements based on skill level and hand laterality were discussed. Training implications for manual aiming movements were also discussed.

Vision of the Stylus in a Manual Aiming Task: The Effects of Practice

Nearly a decade ago, Carlton (1981) showed that in a manual aiming task, vision of the ongoing stylus led to a better accuracy than when that source of information was not available. However, Elliott (1988) recently failed to replicate that finding and, rather, showed that being able to see an ongoing stylus did not result in a significant improvement of accuracy over a conventional no-vision condition. In the experiment to be reported here, we, on the one hand, replicated Elliott's results for the low level of practice condition (15 acquisition trials). On the other hand, the results obtained after moderate practice (150 acquisition trials) supported Carlton's earlier conclusion. These results therefore indicate that after sufficient practice one is able to use effectively the information provided by the ongoing stylus to help control his/her movement. This conclusion was further substantiated by the results obtained in a transfer task. Collectively, the results gave added support to a specificity of learning hypothesis (Proteau, Marteniuk, Girouard, & Dugas, 1987; Proteau, Marteniuk, & Lévesque, 1990).

The contribution of vision to asymmetries in manual aiming

An experiment was conducted to examine the hypothesis that the right hand system is superior in the processing of visual information. A manual aiming task utilizing four visual conditions was employed. In the full-vision (FV) condition subjects were afforded vision of both the hand and the target throughout the course of the movement. In the ambient-illumination-off (AO) condition, the room lights were extinguished at movement initiation, thus preventing vision of the moving limb. The target remained illuminated. In the target-off (TO) condition, the target was extinguished upon initiation of the movement. Ambient illumination and thus vision of the hand remained present. Finally there was a no-vision (NV) condition in which ambient illumination was removed and the target was extinguished upon initiation of the response movement. Although the manipulation of vision had potent effects upon terminal accuracy, and influenced reaction and movement time measures, the hands did not differ in the extent to which these characteristics were expressed. A left hand advantage for reaction time was observed. This may reflect a relative increase in right hemisphere involvement prior to aiming movements which are spatially complex.