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BACKGROUND: Performing common computer tasks such as pointing, clicking, and dragging requires repetitive movements that cause musculoskeletal disorders in the wrists and hands. Given the growing use of touch screens and touch pens, further studies on the ergonomics of these devices are needed. This study aimed to compare a touch pen and an ordinary computer mouse in terms of movement time, error rate, wrist posture, and comfort of use. METHODS: Performance parameters (movement time and error rate), wrist postures, and comfort when using a mouse and a touch pen were measured based on ISO 9241-9 standard with the help of 27 participants. For data analysis, paired t test was performed using SPSS version 22. RESULTS: Using the touch pen resulted in better performance parameters than using the mouse (p:0.05). Wrist extension and flexion were lower when performing the task with the computer mouse than with the touch pen (p:0.05). When using the touch pen to perform the task, ulnar deviation and radial deviation were lower (p:0.05). The overall comfort was higher when using the mouse than the touch pen. CONCLUSION: Our results showed that the touch pen had better performance parameters than the ordinary mouse and also resulted in lower ulnar and radial deviations. Given the impact of habit and proficiency on users' comfort in using input devices, it is reasonable to expect users becoming more comfortable by using touch pens on the long term. © 2020 - IOS Press and the authors. All rights reserved.

Background Objective assessments of movement impairment are needed to support clinical trials and facilitate diagnosis. The objective of the current study was to determine if a rapid web‐based computer mouse test (Hevelius) could detect and accurately measure ataxia and parkinsonism. Methods Ninety‐five ataxia, 46 parkinsonism, and 29 control participants and 229,017 online participants completed Hevelius. We trained machine‐learning models on age‐normalized Hevelius features to (1) measure severity and disease progression and (2) distinguish phenotypes from controls and from each other. Results Regression model estimates correlated strongly with clinical scores (from r = 0.66 for UPDRS dominant arm total to r = 0.83 for the Brief Ataxia Rating Scale). A disease change model identified ataxia progression with high sensitivity. Classification models distinguished ataxia or parkinsonism from healthy controls with high sensitivity (≥0.91) and specificity (≥0.90). Conclusions Hevelius produces a granular and accurate motor assessment in a few minutes of mouse use and may be useful as an outcome measure and screening tool. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Switching between motor tasks requires accurate adjustments for changes in dynamics (grasping a cup) or sensorimotor transformations (moving a computer mouse). Dual-adaptation studies have investigated how learning of context-dependent dynamics or transformations is enabled by sensory cues. However, certain cues, such as color, have shown mixed results. We propose that these mixed results may arise from two major classes of cues: "direct" cues, which are part of the dynamic state and "indirect" cues, which are not. We hypothesized that explicit strategies would primarily account for the adaptation of an indirect color cue but would be limited to simple tasks, whereas a direct visual separation cue would allow implicit adaptation regardless of task complexity. To test this idea, we investigated the relative contribution of implicit and explicit learning in relation to contextual cue type (colored or visually shifted workspace) and task complexity (1 or 8 targets) in a dual-adaptation task. We found that the visual workspace location cue enabled adaptation across conditions primarily through implicit adaptation. In contrast, we found that the color cue was largely ineffective for dual adaptation, except in a small subset of participants who appeared to use explicit strategies. Our study suggests that the previously inconclusive role of color cues in dual adaptation may be explained by differential contribution of explicit strategies across conditions.

Prospective memory (PM) is typically measured using keypresses in laboratory paradigms, which therefore assess only discrete, stage-like processes. In the present study we manipulated focal and nonfocal PM cue conditions, as well as participants' focus on different aspects of the PM/ongoing task set, using the methodology to capture dynamic computer mouse movements. The software captured mouse trajectories during lexical decisions and PM responses. We replicated many findings typical in the PM literature, including the accuracy advantage for focal over nonfocal conditions and longer ongoing-task response times for nonfocal conditions. Participants' movement trajectories during PM responses revealed evidence for both spontaneous-retrieval and strategic-monitoring processes in focal and nonfocal PM retrieval conditions. During trials suggestive of spontaneous retrieval, mouse trajectories initially went toward the typical ongoing-task response but turned mid-trajectory toward the PM response field on the opposite side of the computer screen. In nonfocal conditions, these trajectory reversals had a wider arc and took longer to complete, reflecting the likely greater retrospective retrieval requirements of nonfocal conditions. Regarding what are more likely to be strategic-monitoring processes, a significant portion of responses traveled directly to the PM response field, as though people were prepared to make such a response.

The present study aimed to identify whether or not an increase in ciliary-muscle contraction force, when the eye-lens is adjusted for viewing at a near distance, results in an increase in trapezius muscle activity, while performing a natural work task. Twelve participants, ranging in age from 21 to 32 years, performed a computer-mouse work task during free gaze conditions. A moving visual target was tracked with a computer mouse on a screen placed at two different distances from the eyes, 25 cm and 50 cm. Tracking performance, eye accommodation, and bilateral trapezius muscle activity were measured continuously. Ciliary-muscle contraction force was computed according to a formula which takes into account the age-dependent, non-linear relationship between the contraction force of the ciliary muscle and the produced level of eye accommodation. Generalized estimating equations analyses were performed. On the dominant hand side and for the nearest screen distance, there was a significant effect of ciliary-muscle contraction force on the trapezius muscle activity (p 0.05). The results support the hypothesis that high visual demands, during computer mouse work, increase ciliary muscle contraction force and contribute to a raise of the sustained level of trapezius muscle activity. The current study specifically clarifies the validity of the relationship between ciliary-muscle contraction force and trapezius muscle activity and demonstrates that this relationship is not due to a general personality trait. We conclude that a high level of ciliary muscle contraction force can contribute to a development of musculoskeletal complaints in the neck–shoulder area.

Background Stress is a risk factor associated with physiological and mental health problems. Unobtrusive, continuous stress sensing would enable precision health monitoring and proactive interventions, but current sensing methods are often inconvenient, expensive, or suffer from limited adherence. Prior work has shown the possibility to detect acute stress using biomechanical models derived from passive logging of computer input devices. Objective Our objective is to detect acute stress from passive movement measurements of everyday interactions on a laptop trackpad: (1) click, (2) steer, and (3) drag and drop. Methods We built upon previous work, detecting acute stress through the biomechanical analyses of canonical computer mouse interactions and extended it to study similar interactions with the trackpad. A total of 18 participants carried out 40 trials each of three different types of movement—(1) click, (2) steer, and (3) drag and drop—under both relaxed and stressed conditions. Results The mean and SD of the contact area under the finger were higher when clicking trials were performed under stressed versus relaxed conditions (mean area: P=.009, effect size=0.76; SD area: P=.01, effect size=0.69). Further, our results show that as little as 4 clicks on a trackpad can be used to detect binary levels of acute stress (ie, whether it is present or not). Conclusions We present evidence that scalable, inexpensive, and unobtrusive stress sensing can be done via repurposing passive monitoring of computer trackpad usage.

In order to successfully interact with objects, we must maintain stable representations of their locations in the world. However, their images on our retina may be displaced several times per second by large, rapid eye movements. A number of studies have demonstrated that visual processing is heavily influenced by gaze-centered (retinotopic) information, including a recent finding that memory for an object’s location is more accurate and precise in gaze-centered (retinotopic) than world-centered (spatiotopic) coordinates (Golomb & Kanwisher, 2012b). This effect is somewhat surprising, given our intuition that behavior is successfully guided by spatiotopic representations. In the present experiment, we asked whether the visual system may rely on a more spatiotopic memory store depending on the mode of responding. Specifically, we tested whether reaching toward and tapping directly on an object’s location could improve memory for its spatiotopic location. Participants performed a spatial working memory task under four conditions: retinotopic vs. spatiotopic task, and computer mouse click vs. touchscreen reaching response. When participants responded by clicking with a mouse on the screen, we replicated Golomb & Kanwisher’s original results, finding that memory was more accurate in retinotopic than spatiotopic coordinates, and that the accuracy of spatiotopic memory deteriorated substantially more than retinotopic memory with additional eye movements during the memory delay. Critically, we found the same pattern of results when participants responded by using their finger to reach and tap the remembered location on the monitor. These results further support the hypothesis that spatial memory is natively retinotopic; we found no evidence that engaging the motor system improves spatiotopic memory across saccades.

Abstract. Though recent work in numerical cognition has supported a strong tie between numerical and spatial representations (e.g., a mental number line), less is known about such ties in multi-digit number representations. Along this line, Bloechle, Huber, and Moeller (2015) found that pointing positions in two-digit number comparison were biased leftward toward the decade digit. Moreover, this bias was reduced in unit-decade incompatible pairs. In the present study, we tracked computer mouse movements as participants compared two-digit numbers to a fixed standard (55). Similar to Bloechle et al. (2015) , we found that trajectories exhibited a leftward bias that was reduced for unit-decade incompatible comparisons. However, when positions of response labels were reversed, the biases reversed. That is, we found a rightward bias for compatible pairs that was reduced for incompatible pairs. This result calls into question a purely embodied representation of place value structure and instead supports a competition model of two-digit number representation.

Research on human motor adaptation has often focused on how people adapt to self-generated or externally-influenced errors. Trial-by-trial adaptation is a person’s response to self-generated errors. Externally-influenced errors applied as catch-trial perturbations are used to calculate a person’s perturbation adaptation rate. Although these adaptation rates are sometimes compared to one another, we show through simulation and empirical data that the two metrics are distinct. We demonstrate that the trial-by-trial adaptation rate, often calculated as a coefficient in a linear regression, is biased under typical conditions. We tested 12 able-bodied subjects moving a cursor on a screen using a computer mouse. Statistically different adaptation rates arise when sub-sets of trials from different phases of learning are analyzed from within a sequence of movement results. We propose a new approach to identify when a person’s learning has stabilized in order to identify steady-state movement trials from which to calculate a more reliable trial-by-trial adaptation rate. Using a Bayesian model of human movement, we show that this analysis approach is more consistent and provides a more confident estimate than alternative approaches. Constraining analyses to steady-state conditions will allow researchers to better decouple the multiple concurrent learning processes that occur while a person makes goal-directed movements. Streamlining this analysis may help broaden the impact of motor adaptation studies, perhaps even enhancing their clinical usefulness., Author summary By observing the learning rate of a person making a movement under new conditions, researchers can better understand how the nervous system handles uncertainty. Patients suffering from motor deficits or using prostheses will often display different motor abilities that can be observed as changes in error correction rates. Here we show that previous approaches to determining error correction rates are affected by the overall learning rate within the subset of trials selected for analysis. We use real-world data collected from people controlling a computer cursor and simulations of how a person’s nervous system operates to show the limitations of current approaches. We also present a new approach to limit some of the biases with current motor analysis techniques.

This paper introduces the “hybrid foraging” paradigm. In typical visual search tasks, observers search for one instance of one target among distractors. In hybrid search, observers search through visual displays for one instance of any of several types of target held in memory. In foraging search, observers collect multiple instances of a single target type from visual displays. Combining these paradigms, in hybrid foraging tasks observers search visual displays for multiple instances of any of several types of target (as might be the case in searching the kitchen for dinner ingredients or an X-ray for different pathologies). In the present experiment, observers held 8–64 targets objects in memory. They viewed displays of 60–105 randomly moving photographs of objects and used the computer mouse to collect multiple targets before choosing to move to the next display. Rather than selecting at random among available targets, observers tended to collect items in runs of one target type. Reaction time (RT) data indicate searching again for the same item is more efficient than searching for any other targets, held in memory. Observers were trying to maximize collection rate. As a result, and consistent with optimal foraging theory, they tended to leave 25–33% of targets uncollected when moving to the next screen/patch. The pattern of RTs shows that while observers were collecting a target item, they had already begun searching memory and the visual display for additional targets, making the hybrid foraging task a useful way to investigate the interaction of visual and memory search.

In a comparison task involving numbers, the size congruity effect refers to the general finding that responses are usually faster when there is a match between numerical size and physical size (e.g., 2-8) than when there is a mismatch (e.g., 2-8). In the present study, we used computer mouse tracking to test two competing models of the size congruity effect: an early interaction model, where interference occurs at an early representational stage, and a late interaction model, where interference occurs as dynamic competition between response options. In three experiments, we found that the curvature of responses for incongruent trials was greater than for congruent trials. In Experiment 2 we showed that this curvature effect was reliably modulated by the numerical distance between the two stimulus numbers, with large distance pairs exhibiting a larger curvature effect than small distance pairs. In Experiment 3 we demonstrated that the congruity effects persist into response execution. These findings indicate that incongruities between numerical and physical sizes are carried throughout the response process and result from competition between parallel and partially active response options, lending further support to a late interaction model of the size congruity effect.

Multiple object tracking (MOT) requires visually attending to dynamically moving targets and distractors. This cognitive ability is based on perceptual-attentional processes that are also involved in goal-directed movements. This study aimed to test the hypothesis that MOT affects the motor performance of aiming movements. Therefore, the participants performed pointing movements using their fingers or a computer mouse that controlled the movements of a cursor directed at the targets in the MOT task. The precision of the pointing movements was measured, and it was predicted that a higher number of targets and distractors in the MOT task would result in a lower pointing precision. The results confirmed this hypothesis, indicating that MOT might influence the performance of motor actions. The potential factors underlying this influence are discussed.

Objective Older adults evaluate faces as being more trustworthy than do younger adults. The present work examined whether aging is associated with changes in the dynamic activation of trustworthiness categories toward faces, and if category activation relates to enhanced trust. Method Younger and older adults categorized faces as trustworthy or untrustworthy while computer mouse trajectories were recorded to measure dynamic category activation. Results Older, but not younger, adults had more dynamic category activation (i.e., trustworthy and untrustworthy) when they viewed untrustworthy versus trustworthy faces. This tendency predicted a bias (pronounced with age) toward evaluating faces as being trustworthy. Discussion A pronounced trust bias in aging may be related to greater dynamic activation of trustworthiness (vs untrustworthiness) when perceiving faces.

Background Modern computer users use the mouse almost three times as much as the keyboard. As exposure rates are high, improving upper extremity posture while using a computer mouse is desirable due to the fact that posture is one risk factor for injury. Previous studies have found posture benefits associated with using alternative mouse designs, but at the cost of performance and preference. Objective To develop new computer mouse shapes, evaluate them versus benchmarks, and determine whether there are differences in wrist posture, pointing performance, and subjective measures. Methods Three concept mice were designed and evaluated relative to two existing benchmark models: a traditional flat mouse, and an alternative upright mouse. Using a repeated measures design, twelve subjects performed a standardized point-and-click task with each mouse. Pointing performance and wrist posture was measured, along with perceived fatigue ratings and subjective preferences pre and post use. Results All of the concept mice were shown to reduce forearm pronation relative to the traditional flat mouse. There were no differences in pointing performance between the traditional flat mouse and the concept mice. In contrast, the fully vertical mouse reduced pronation but had the poorest pointing performance. Perceived fatigue and subjective preferences were consistently better for one concept mouse. Conclusions Increasing mouse height and angling the mouse topcase can improve wrist posture without negatively affecting performance.

This study aimed to measure and compare sound and light source localization ability in young children and adults who have normal hearing and normal/corrected vision in order to determine the extent to which age, type of stimuli, and stimulus order affects sound localization accuracy.Two experiments were conducted. The first involved a group of adults only. The second involved a group of 30 children aged 3 to 5 years. Testing occurred in a sound-treated booth containing a semi-circular array of 15 loudspeakers set at 10° intervals from -70° to 70° azimuth. Each loudspeaker had a tiny light bulb and a small picture fastened underneath. Seven of the loudspeakers were used to randomly test sound and light source identification. The sound stimulus was the word "baseball". The light stimulus was a flashing of a light bulb triggered by the digital signal of the word "baseball". Each participant was asked to face 0° azimuth, and identify the location of the test stimulus upon presentation. Adults used a computer mouse to click on an icon; children responded by verbally naming or walking toward the picture underneath the corresponding loudspeaker or light. A mixed experimental design using repeated measures was used to determine the effect of age and stimulus type on localization accuracy in children and adults. A mixed experimental design was used to compare the effect of stimulus order (light first/last) and varying or fixed intensity sound on localization accuracy in children and adults.Localization accuracy was significantly better for light stimuli than sound stimuli for children and adults. Children, compared to adults, showed significantly greater localization errors for audition. Three-year-old children had significantly greater sound localization errors compared to 4- and 5-year olds. Adults performed better on the sound localization task when the light localization task occurred first.Young children can understand and attend to localization tasks, but show poorer localization accuracy than adults in sound localization. This may be a reflection of differences in sensory modality development and/or central processes in young children, compared to adults.

Perceptual learning is usually assumed to occur within sensory areas or when sensory evidence is mapped onto decisions. Subsequent procedural and motor processes, involved in most perceptual learning experiments, are thought to play no role in the learning process. Here, we show that this is not the case. Observers trained with a standard three-line bisection task and indicated the offset direction of the central line by pressing either a left or right push button. Before and after training, observers adjusted the central line of the same bisection stimulus using a computer mouse. As expected, performance improved through training. Surprisingly, learning did not transfer to the untrained mouse adjustment condition. The same was true for the opposite, i.e., training with mouse adjustments did not transfer to the push button condition. We found partial transfer when observers adjusted the central line with two different adjustment procedures. We suggest that perceptual learning is specific to procedural motor aspects beyond visual processing. Our results support theories were visual stimuli are coded together with their corresponding actions.

The present study was designed (1) to clarify the relationship between the flow experience and improvements in visuomotor skills, (2) to examine the effects of rotating the axis of a computer mouse on visuomotor skills, and (3) to investigate the effects of sleep for improving visuomotor skills. Participants (N = 18) responded to Perturbation and nap (PER+Nap), No-perturbation and nap (NoPER+Nap) and Perturbation and rest (PER+Rest) conditions. In the PER+Nap condition, participants conducted a visuomotor tracking task using a computer mouse, which was accompanied by perturbation caused by rotating the axis of their mouse. After the task, they took a 90 min nap. In NoPER+Nap condition, they conducted the same visuomotor task without any perturbation and took a nap. In the PER+Rest condition, participants conducted the task with the perturbation and took a 90 min break spent reading magazines instead of taking a nap. Results indicated (1) the flow experience did not occur when participants’ skills and the degree of the visuomotor challenge were matching, (2) improvements of visuomotor skills occurred regardless of the perturbation, (3) improvements of visuomotor skills occurred unrelated to the flow experience, or to mood states, and (4) improvements of visuomotor performance occurred regardless of sleep. These findings suggest that improvements of visuomotor skills occur regardless of mood status and occur independently of perturbations by axis rotation. The study also suggests that the acquisition of skills is related to merely the time elapsed since learning, rather than to sleep.

Repeated ingestion of small objects has been previously reported in the psychiatric literature. We recently had a patient with repeated intentional foreign body ingestion syndrome who developed complete airway obstruction and cardiac arrest after ingesting a computer mouse tracking ball. We use our case to suggest a pathway that can be used for similar emergent airway problems.

The use of forearm and palm supports has been associated with lower neck and shoulder muscle activity as well as reduced musculoskeletal discomfort during keyboard use, however, few studies have investigated their effect during computer mouse use. Eight men and eight women completed several computer mousing tasks in six arm support conditions: Forearm Support, Flat Palm Support, Raised Palm Support, Forearm + Flat Palm Support, Forearm + Raised Palm Support, and No Support. Concurrently, an infrared three-dimensional motion analysis system measured postures, six-degree-of-freedom force-torque sensors measured applied forces & torques, and surface electromyography measured muscle activity. The use of forearm support compared to the no support condition was significantly associated with less shoulder muscle activity & torque, and the raised palm support was associated with less wrist extension. Forearm supports reduced shoulder flexion torque by 90% compared to no support. The use of either support also resulted in lower applied forces to the mouse pad. Participants reported less musculoskeletal discomfort when using a support. These results provide recommendations for office workstation setup and inform ergonomists of effective ways to reduce musculoskeletal exposures.

Subjects searched for low- or high-prevalence targets among static nonoverlapping items or items piled in heaps that could be moved using a computer mouse. We replicated the classical prevalence effect both in visual search and when unpacking items from heaps, with more target misses under low prevalence. Moreover, we replicated our previous finding that while unpacking, people often move the target item without noticing (the unpacking error) and determined that these errors also increase under low prevalence. On the basis of a comparison of item movements during the manually-assisted search and eye movements during static visual search, we suggest that low prevalence leads to broadly reduced diligence during search but that the locus of this reduced diligence depends on the nature of the task. In particular, while misses during visual search often arise from a failure to inspect all of the items, misses during manually-assisted search more often result from a failure to adequately inspect individual items. Indeed, during manually-assisted search, over 90 % of target misses occurred despite subjects having moved the target item during search.

In the present study, we investigated how degree of certainty modulates anticipatory processes using a modified spatial cuing task in which participants made an anticipatory hand movement with the computer mouse toward one of two probabilistic targets. A cue provided information of the location of the upcoming target with 100% validity (certain condition), 75% validity (semicertain condition) or gave no information of the location (uncertain condition). We found that the degree of certainty associated with the probabilistic precue on the upcoming target location affected the spatiotemporal characteristics of the anticipatory hand movements in a systematic way. In the case of semicertainty, we found evidence that the anticipatory processes were modulated in a way consistent with a model of graded probability matching biased toward certainty. In the case of uncertainty regarding two equally likely locations, we observed large between- and within-subject variability in the patterns of anticipatory hand movements, suggesting that individual differences in the strategies employed may become relevant when the likelihoods of response options are equal.

We analyzed muscular activity for different computer mouse positions during the completion of a timed computer task and determined whether the different mouse positions could affect muscular activity, productivity and perceived fatigue.The subjects were nine healthy young men. Two mouse positions were studied: the distal position (DP), with the forearm rested on the desk; the proximal position (PP), with only the wrist rested on the desk. The subjects performed a 16-min task in each position. Surface electromyography data were recorded for the upper back and shoulder muscles. Work productivity and muscular activity were measured for each mouse position. A visual analog scale was used to assess subjective fatigue.Muscular activity was higher in muscle (m.) deltoideus (posterior) for the DP, while it was significantly higher in m. inferior infraspinatus for the PP. The visual analog scale score was significantly higher and work productivity was lower in the PP.We found that using a mouse in the DP rather than the PP leads to less activity of the external rotators, less perceived fatigue and more productivity. This suggests that the DP is preferable to the PP for computer work involving a mouse.

Perceptual learning is usually feature-specific. Recently, we showed that perceptual learning is even specific for the motor response type. In a three-line bisection task, participants indicated whether the central line was offset either to the left or right by pressing a left or a right button, respectively. We found no transfer when the same participants adjusted the offset by using a computer mouse. Here, we first show that perceptual learning with mouse adjustments transfers to the untrained hand, but only for the trained adjustment condition. There was no transfer to the button press conditions, neither for the trained nor the untrained hand. Second, we show that a double training procedure enables transfer from the mouse adjustment to the button press condition. Hence, the specificity of perceptual learning to the motor response type can be overcome by double training as it is the case for visual features. Our results suggest that during perceptual learning, perceptuo-decisional signals are encoded together with the corresponding actions.

This study investigated the relationship between computer mouse work and contact pressure around the pisiform. Commonly performed mouse work was simulated using 3 different-shaped mice with 3 forearm positions. When typical mouse work was performed, the contact pressure on the pisiform area was evaluated using a digital pressure sensor and compared with that of the thenar area. Six mouse tasks were simulated. Results indicate that mouse users should avoid wrist-snap dragging and resting their wrist on the edge of the desk to minimize the pressure concentration on the pisiform area.

Background and objectives Dual-process models suggest that automatic behavioral tendencies contribute to the development and maintenance of Obsessive Compulsive Disorder (OCD) symptoms. The aim of the present study was to investigate the potential of the Approach-Avoidance Task (AAT) to reduce OCD symptoms and associated distress. Methods The study was set up as an online intervention. Participants with OCD symptoms ( N = 101) were randomly assigned either to one of two experimental conditions or a waitlist control group upon completion of an online baseline survey. Participants were instructed to respond to contamination-related and neutral pictures by pulling or pushing a computer mouse, respectively. In one AAT condition, contamination-relevant pictures remained on the screen one second after pulling (lock condition), while pictures disappeared immediately after pulling in the standard AAT. Participants completed an online re-assessment four weeks after baseline. Results For analyses, only data of patients with contamination-related OCD symptoms were analyzed. A significant reduction in distress caused by OCD symptoms was found for both AAT training groups. Furthermore, a reduction in compulsions occurred for the group using the standard AAT. No significant effect was found for the control group. Limitations Implicit behavioral tendencies prior to and after training were not assessed. Conclusions Findings tentatively suggest that the AAT might be effective in reducing washing-/contamination-related OCD symptoms.

In this eye-tracking and drawing study, we investigate the perceptual grounding of different types of spatial dimensions such as dense-sparse and top-bottom, focusing both on the participants' experiences of the opposite regions, e.g., O1: dense; O2: sparse, and the region that is experienced as intermediate, e.g., INT: neither dense nor sparse. Six spatial dimensions expected to have three different perceptual structures in terms of the point and range nature of O1, INT and O2 were analysed. Presented with images, the participants were instructed to identify each region (O1, INT, O2), first by looking at the region, and then circumscribing it using the computer mouse. We measured the eye movements, identification times and various characteristics of the drawings such as the relative size of the three regions, overlaps and gaps. Three main results emerged. Firstly, generally speaking, intermediate regions were not different from the poles on any of the indicators: overall identification times, number of fixations, and locations. Some differences emerged with regard to the duration of fixations for point INTs and the number of fixations for range INTs between two range poles (O1, O2). Secondly, the analyses of the fixation locations showed that the poles support the identification of the intermediate region as much as the intermediate region supports the identification of the poles. Finally, the relative size of the three areas selected in the drawing task were consistent with the classification of the regions as points or ranges. The analyses of the gaps and the overlaps between the three areas showed that the intermediate is neither O1 nor O2, but an entity in its own right.

To investigate a new alternative interaction method, called circling interface, for manipulating on-screen objects. To specify a target, the user makes a circling motion around the target. To specify a desired pointing command with the circling interface, each edge of the screen is used. The user selects a command before circling the target.To evaluate the circling interface, we conducted an experiment with 16 participants, comparing the performance on pointing tasks with different combinations of selection method (circling interface, physical mouse and dwelling interface) and input device (normal computer mouse, head pointer and joystick mouse emulator).A circling interface is compatible with many types of pointing devices, not requiring physical activation of mouse buttons, and is more efficient than dwell-clicking. Across all common pointing operations, the circling interface had a tendency to produce faster performance with a head-mounted mouse emulator than with a joystick mouse. The performance accuracy of the circling interface outperformed the dwelling interface.It was demonstrated that the circling interface has the potential as another alternative pointing method for selecting and manipulating objects in a graphical user interface. Implications for Rehabilitation A circling interface will improve clinical practice by providing an alternative pointing method that does not require physically activating mouse buttons and is more efficient than dwell-clicking. The Circling interface can also work with AAC devices.

Target expansion, i.e., the increase of target size according to cursor movement, can be a practical scheme to improve the usability of target-selection tasks using a mouse. This study examined the effects of different user age groups and target-expansion methods on target-acquisition tasks with grouped icons. Twenty-eight subjects performed acquisition tasks under eight experimental conditions: combinations of four expansion areas (no, one-icon, fish-eye, and group expansion) and two expansion techniques (occlusion and push). Older users took longer to acquire targets than younger users; however, they showed no significant difference in accuracy. Target expansion did not substantially improve performance speed compared to the static condition. However, the error rate was lowest when group area was expanded with the push technique, and both age groups were most satisfied with one-icon area expansion with the occlusion technique. We suggest alternative guidelines in designing target-expansion schemes.

Our representation of the peripersonal space is tied to our representation of our bodies. This representation appears to be flexible and it can be updated to include the space in which tools work, particularly when the tool is actively used. One indicator of this update is the increased efficiency with which sensory events near the tool are processed. In the present study we examined the role of visuomotor control in extending peripersonal space to a common virtual tool—a computer mouse cursor. In particular, after participants were exposed to different spatial mappings between movements of the mouse cursor and movements of their hand, participants' performance in a motion-onset detection task was measured, with the mouse cursor as the stimulus. When participants, during exposure, had the ability to move the cursor efficiently and accurately (familiar hand-cursor mapping), they detected motion-onset targets more quickly than when they could not move the cursor at all during exposure (no hand-cursor mapping). Importantly, reversing the spatial correspondence between the movements of the hand and the cursor (unfamiliar hand-cursor mapping) during exposure, which was thought to preserve the ability to move the cursor (ie agency) while weakening the ability to make the movements efficiently and accurately (ie control), eliminated the detection-facilitation effect. These results provide evidence for the possible extension of peripersonal space to frequently used objects in the virtual domain. Importantly, these extensions seem to depend on the participant's knowledge of the dynamic spatial mapping between the acting limb and the visible virtual tool.

Background: Sensorimotor deficits are an important phenomenological facet observed in patients with bipolar disorder (BD). However, there is little research on this topic. We hypothesize that the MPraxis test can be used to screen for motor impairments in BD aiming movements. Method: The MPraxis, which is a quick and easy-to-apply computerized test, measures sensorimotor control. During the test, the participant must move the computer mouse cursor over an ever-shrinking green box and click on it once. We predict that the MPraxis test is capable of detecting differences in sensorimotor performance between patients with BD and controls. We assessed 21 euthymic type I BD patients, without DSM-IV-TR Axis I comorbidity, and 21 healthy controls. Results and conclusions: Compared to the controls, the patients with BD presented a lower response time in their movements in all conditions. Our results showed sensorimotor deficits in BD and suggested that the MPraxis test can be used to screen for motor impairments in patients with euthymic BD.

In the present study, we investigated how observers' control of stimulus change affects temporal and spatial aspects of visual perception. We compared the illusory flash-lag effects for automatic movement of the stimulus with stimulus movement that was controlled by the observers' active manipulation of a computer mouse (Experiments 1, 2, and 5), a keyboard (Experiment 3), or a trackball (Experiment 4). We found that the flash-lag effect was significantly reduced when the observer was familiar with the directional relationship between the mouse movement and stimulus movement on a front parallel display (Experiments 1 and 2) and that, although the unfamiliar directional relationship between the mouse movement and stimulus movement increased the flash-lag effect at the beginning of the experimental session, the repetitive observation with the same unfamiliar directional relationship reduced the flash-lag effect (Experiment 5). We found no consistent reduction of the flash-lag effect with the use of a keyboard or a trackball (Experiments 3 and 4). These results suggest that the learning of a specific directional relationship between a proprioceptive signal of hand movements and a visual signal of stimulus movements is necessary for the reduction of the flash-lag effect.

Auditory and tactile stimuli are integrated within a limited space around the body to form an auditory peripersonal space (APPS). Here we investigate whether the APPS representation around the hand can be extended through the use of a common technological tool such as the computer mouse. When using a mouse, an action occurring in the space around the hand has a distal effect in the space defined by the computer screen; thus, the mouse virtually links near and far space. Does prolonged experience with the mouse durably extend APPS representation to the far space? We examined 16 habitual mouse users to determine whether a sound presented near the right hand or near the computer screen affected reaction times to a tactile target at the hand. When subjects sat in front of the computer, without holding the mouse, they responded faster to tactile stimuli when sounds were presented near the hand rather than near the screen, consistent with a normal segregation of APPS around the hand. In contrast, when subjects either actively used or even passively held the mouse, the difference between the effects of near and far sounds disappeared, thus showing an extension of the APPS toward the far space. This effect was selective for the effector used to operate the mouse: if tactile stimuli were presented on the left hand, rarely used to act upon the mouse, a sound presented near the hand speeded up reactions times when subjects both held and did not hold the mouse in their left hand.

Converging evidence from neuroimaging and neuropsychological studies is essential for understanding human frontal cortical function. We introduce a new method for studying the effects of transient disruptions of frontal activity during transcranial magnetic stimulation (TMS). Using a novel combination of TMS and computer-mouse tracking, through two experiments we tested process models of semantic competition in left ventrolateral prefrontal cortex (VLPFC). On TMS stimulation of left mid-VLPFC just after presentation of an ambiguous stimulus, participants' mouse-movement trajectories deviated more toward the incorrect target for weak associate trials than for any other trial type. This effect was extinguished when participants were simultaneously shown both target and cue stimuli. Results suggest that left mid-VLPFC is necessary to resolve semantic competition when a response is underdetermined by the stimulus and the interpretive context of the stimulus is ambiguous. Computer-mouse movements reveal the dynamics of competitive interactions as they resolve, making this technique ideally suited for studying cognitive control processes and a more sensitive index of TMS disruption than reaction time and accuracy alone.

Brosnan and de Waal (Nature 425:297-299, 2003) claimed that if a capuchin sees another capuchin receiving a superior food, she tends to reject an inferior, previously acceptable food. They related this phenomenon to human inequity aversion. This phyletic extension is "down linkage," because nonhuman research is interpreted in terms of human research. The present experiment makes an "up-linkage" test of this claimed connection by attempting to reproduce the capuchin-inequity effect in humans. In Experiment 1's equity condition, a subject and an adjacent confederate each clicked a computer mouse to mark the number "7" from a random numbers table, earning 0.5 yen per mark. In the inequity condition, the confederate's pay rate was twice that of the subject. There was no between-condition difference in quitting times or likelihoods. Experiment 2 replicated Experiment 1 except, before beginning, the subject and confederate clicked a mouse over a rapidly switching message that said they would earn either 0.5 or 1 yen per marked seven. For the equity condition in this rigged test, subject and confederate stopped the message at 0.5 yen, while in the inequity condition, these values were 0.5 and 1 yen, respectively. Now, inequity-condition subjects quit sooner than equity-condition subjects. Experiment 1 found no inequity effect, but Experiment 2 did. These results show that: (a) a sense of control/responsibility may be critical to an inequity effect and (b) the inequity effect putatively present in capuchins cannot be reproduced in an up-linkage human analog of that research, thereby calling this linkage into question. This report exemplifies that up- and down-linkage tests are often requisite to establish commonality of psychological process between nonhuman primates and humans.

Brain-computer interface (BCI) technology can provide nonmuscular communication and control to people who are severely paralyzed. BCIs can use noninvasive or invasive techniques for recording the brain signals that convey the user's commands. Although noninvasive BCIs are used for simple applications, it has frequently been assumed that only invasive BCIs, which use electrodes implanted in the brain, will be able to provide multidimensional sequential control of a robotic arm or a neuroprosthesis. The present study shows that a noninvasive BCI using scalp-recorded electroencephalographic (EEG) activity and an adaptive algorithm can provide people, including people with spinal cord injuries, with two-dimensional cursor movement and target selection. Multiple targets were presented around the periphery of a computer screen, with one designated as the correct target. The user's task was to use EEG to move a cursor from the center of the screen to the correct target and then to use an additional EEG feature to select the target. If the cursor reached an incorrect target, the user was instructed not to select it. Thus, this task emulated the key features of mouse operation. The results indicate that people with severe motor disabilities could use brain signals for sequential multidimensional movement and selection.

Two types of computer input devices, a conventional mouse and a roller bar one, were studied in terms of muscular activitiy in m. trapezius dexter, m. deltoideus anterior dexter and m. extensor digitorum dexter, and comfort rating. Fifteen university students and employees participated in this study. The order of the devices was random. While a task was performed, electromyography (EMG) data were recorded for each test. Muscular activity was found to be significantly lower for the roller bar mouse than for the conventional one. Comfort rating indicated there was a significant difference in moving a cursor with the conventional mouse compared to the roller bar one. It is concluded that a roller bar mouse allowed the subjects to work closer to the body compared to the conventional one, thus the former can be recommended as a general means of reducing upper extremity musculoskeletal disorders.

Random dot cinematograms were used to probe motion perception in human observers ranging from 23 to 81 years of age. Stimuli were either broadband directional Noise, which produces no experience of global motion flow, or a narrower band directional Signal, which tended to produce experiences of coherent, global direction flow. On each trial, subjects rated their certainty that a Signal had been presented, and used a computer mouse to indicate the direction of perceived global flow. At all ages, sensitivity to motion and accuracy of perceived direction improved significantly as stimulus duration increased from 75 to 470 ms. However, older subjects (>70 years of age) were significantly less sensitive to motion, and were significantly less accurate at identifying the direction of movement. A control experiment, which found that older subjects accurately perceived and remembered the orientation of a line, ruled out the possibility that the observed deficits in motion perception were due to an inability on the part of older subjects to manipulate the computer mouse. Those control results also showed that both younger and older observers maintained robust visual representations over durations ranging from .24 to 6.0 s. The motion detection and identification results obtained from subjects less than 70 years of age were well fit by a simple multichannel model of motion, although different levels of additive internal noise were needed to fit detection data and direction-identification data, suggesting that motion direction and identification are constrained by different mechanisms. To fit the data from the oldest subjects, however, the values of model parameters had to be significantly altered, either by increasing the level of additive internal noise substantially, or by a smaller increase in noise coupled with an increase in the bandwidth of the model’s directionally selective channels. These results are qualitatively consistent with recent neurophysiological studies showing weaker directional selectivity and higher spontaneous noise in visual neurons of senescent monkeys and cats. � 2007 Elsevier Ltd. All rights reserved.

An individual's cardiovascular health is important. The measurement of blood pressure (BP) can be performed nonintrusively during normal daily activities. A study was designed to estimate systolic BP by measuring pulse arrival time (PAT) nonintrusively. PAT was obtained nonintrusively to estimate each individual's BP while he or she worked at a computer. Electrocardiogram (ECG) was measured with a capacitive-coupled electrocardiogram (CC-ECG) system and photoplethysmogram (PPG) was measured using specially installed circuits in a computer mouse. PAT was calculated from CC-ECG and PPG, and compared to PAT measured by the standard method. Three individuals participated in this study. Results correlated well. An equation to estimate BP from the measured PAT was derived for each of three individuals during a training period. Estimated BP was compared with measured BP in a series of experiments under varied BP conditions. For each individual, the estimated BP followed the measured BP within a tolerable error range. This method was also used for long-term BP monitoring. Results showed that this method could be useful for monitoring BP for telemedicine and e-health.

Computer work is characterized by sedentary static workload with low-intensity energy metabolism. The aim of our study was to evaluate the dynamics of skin surface temperature in the hand during prolonged computer mouse work under different ergonomic setups. Digital infrared imaging of the right forearm and wrist was performed during three hours of continuous computer work (measured at the start and every 15 minutes thereafter) in a laboratory with controlled ambient conditions. Four people participated in the study. Three different ergonomic computer mouse setups were tested on three different days (horizontal computer mouse without mouse pad, horizontal computer mouse with mouse pad and padded wrist support, vertical computer mouse without mouse pad). The study revealed a significantly strong negative correlation between the temperature of the dorsal surface of the wrist and time spent working with a computer mouse. Hand skin temperature decreased markedly after one hour of continuous computer mouse work. Vertical computer mouse work preserved more stable and higher temperatures of the wrist (&gt, 30 °C), while continuous use of a horizontal mouse for more than two hours caused an extremely low temperature (&lt, 28 °C) in distal parts of the hand. The preliminary observational findings indicate the significant effect of the duration and ergonomics of computer mouse work on the development of hand hypothermia.

Non-neutral wrist positions and external pressure leading to increased carpal tunnel pressure during computer use have been associated with a heightened risk of carpal tunnel syndrome (CTS). This study investigated whether commonly used ergonomic devices reduce carpal tunnel pressure in patients with CTS. Carpal tunnel pressure was measured in twenty-one patients with CTS before, during and after a computer mouse task using a standard mouse, a vertical mouse, a gel mouse pad and a gliding palm support. Carpal tunnel pressure increased while operating a computer mouse. Although the vertical mouse significantly reduced ulnar deviation and the gel mouse pad and gliding palm support decreased wrist extension, none of the ergonomic devices reduced carpal tunnel pressure. The findings of this study do therefore not endorse a strong recommendation for or against any of the ergonomic devices commonly recommended for patients with CTS. Selection of ergonomic devices remains dependent on personal preference.

This study tested the notion that an equivalence relation may include a response when differential responses are paired with stimuli presented during training. Eight normal adults learned three kinds of computer mouse movements as differential response topographies (R1, R2, and R3). Next, in matching-to-sample training, one of the response topographies was used to select a comparison stimulus B (B1, B2, or B3) conditionally upon presentation of sample stimulus A (A1, A2, or A3), and to select stimulus D (D1, D2, or D3) conditionally upon presentation of stimulus C (C1, C2, or C3). After two sample–comparison–response relations (ABR and CDR) were established, 18 sample–comparison relations were tested (BA, DC, RA, RB, RC, RD, AC, CA, AD, DA, BC, CB, BD, DB, AA, BB, CC, and DD). In the RA, RB, RC, and RD tests, the differential responses (R1, R2, and R3) were used as sample stimuli. All subjects made class-consistent comparison selections in the tests. This study provides evidence that responses may become members of an equivalence class.

Many researchers have recommended the focus-window tracking (FWT) technique to study the course of information acquisition and visual attention. In FWT, the stimulus is blurred, and the subject scans for information by moving a clear window with a computer mouse. We show that poor calibration of the blur filter will bias search behavior in FWT because diagnostically useful information may leak through a filter even though the subjects are unaware of it. To provide a valid index of information acquisition, FWT requires an information filter that is calibrated to the task.

The objective of the present study was to gain insight into the effects of precision demands and mental pressure on the load of the upper extremity. Two computer mouse tasks were used: an aiming and a tracking task. Upper extremity loading was operationalized as the myo-electric activity of the wrist flexor and extensor and of the trapezius descendens muscles and the applied grip- and click-forces on the computer mouse. Performance measures, reflecting the accuracy in both tasks and the clicking rate in the aiming task, indicated that the levels of the independent variables resulted in distinguishable levels of accuracy and work pace. Precision demands had a small effect on upper extremity loading with a significant increase in the EMG-amplitudes (21%) of the wrist flexors during the aiming tasks. Precision had large effects on performance. Mental pressure had substantial effects on EMG-amplitudes with an increase of 22% in the trapezius when tracking and increases of 41% in the trapezius and 45% and 140% in the wrist extensors and flexors, respectively, when aiming. During aiming, grip- and click-forces increased by 51% and 40% respectively. Mental pressure had small effects on accuracy but large effects on tempo during aiming. Precision demands and mental pressure in aiming and tracking tasks with a computer mouse were found to coincide with increased muscle activity in some upper extremity muscles and increased force exertion on the computer mouse. Mental pressure caused significant effects on these parameters more often than precision demands. Precision and mental pressure were found to have effects on performance, with precision effects being significant for all performance measures studied and mental pressure effects for some of them. The results of this study suggest that precision demands and mental pressure increase upper extremity load, with mental pressure effects being larger than precision effects. The possible role of precision demands as an indirect mental stressor in working conditions is discussed.

With the spread of visual display terminals (VDT) in offices, the numbers of workers using VDT and the working hours at such equipment have increased rapidly in recent years. Also, preventive measures for fatigue have been proposed and the office-working environment has been improved. To examine the effects of the rapid changes in working conditions and environment on the health of VDT workers, we conducted a questionnaire survey in 2002. A self-reported questionnaire was distributed to 3,927 office workers; 2,374 (60.5%) responded. Subjects whose questionnaires had missing data were excluded from analysis. As a result, 1,406 (male: 1,069, female: 337) workers aged 20 to 59 were subjected to analysis. By a logistic regression model, we examined the association between VDT use and visual and musculoskeletal symptoms. Prevalence of eye strain and/or pain (72.1%) was the highest, followed by neck stiffness and/or pain (59.3%), low back stiffness and/or pain (30.0%) and hand or arm strain and/or pain (13.9%). Women consistently reported more discomfort than men. As a result of the logistic regression model, eye strain and/or pain was associated with dissatisfaction with airflow, but not with factors affecting visual symptoms as reported in previous studies, for example, reflection of light and blurred characters on the screen. It was thought that airflow appeared as a risk factor because the lighting environment had been improved in offices to prevent reflection of light on the screen. Neck stiffness and/or pain was associated with raising the shoulders during VDT work, the unsuitable shape of the computer mouse for a hand, and the inconvenient arrangement of the mouse in relation to the body. Hand or arm strain and/or pain were associated with the arrangement of the mouse and inappropriate height of the desk. Low back stiffness and/or pain were associated with dissatisfaction with the chair and using the keyboard without a wrist rest. Although measures to prevent fatigue had been implemented for VDT workers, risk factors for musculoskeletal symptoms would be the same as in previous studies.

The Cinderella hypothesis postulates the continuous activity of specific motor units (MUs) during low-level muscle contraction. The MUs may become metabolically overloaded, with the subject developing muscle pain and strain. The hypothesis requires MUs that are active for a time long enough to actually damage muscle fibers. The aim of this study was to determine if there are continuously active MUs in the right trapezius muscle during normal computer work using a computer mouse. Fourteen healthy subjects executed an interactive computer-learning program (ErgoLight) for 30 min. Six-channel intramuscular EMG and two-channel surface EMG signals were recorded from two positions of the trapezius muscle. Decomposition was achieved with automated, multi-channel, long-term decomposition software (EMG-LODEC). In two out of the 14 subjects, three MUs were continuously active throughout the 30 min. Although the majority of the MUs were active during only part of the experimental session, an ordered on–off behavior (e.g. substitution) pattern was not observed. As long-lasting activity was verified in some subjects, the results support the Cinderella hypothesis. However, it cannot be concluded here how long the MUs could stay active. If continuous activity overloads low threshold MUs, the potential exists for selective fibre injuries in low threshold MUs of the trapezius muscle in subjects exposed to long-term computer work.

Purpose : To improve the operating speed of the traditional row-column scanning computer keyboard-mouse composite panel controlled using a single key. Method : Using a single mouse input control window can avoid scanning unnecessary keyboard characters, thereby increasing the speed in performing mouse commands. In addition, the surface electromyographic (SEMG) sensing input can also be used to provide an input option for the disabled. Results : Eleven volunteers operated the single mouse input control window using the SEMG input and the traditional computer keyboard-mouse composite panel controlled using a single key. The average operating times were 121.3 &#45 8.9 sec and 208.6 &#45 10.7 sec, respectively. The difference was statistically significant ( p

Beliefs about memory play a role in older adults' concerns about aging and can influence their performance on memory tasks. Visual analog scales can capture beliefs about how aging affects memory in general (the General Beliefs About Memory Instrument [GBMI]) and one's own memory (the Personal Beliefs About Memory Instrument [PBMI]). Data were combined across four cross-sectional studies of adults who had completed the two measures, contrasting traditional paper-and-pencil versions of the questionnaires with newer computerized versions that use a computer mouse for visual analog scaling. This scaling method is easy to use and automates scoring of graphic rating scale responses. Adults of all ages produced GBMI responses reflecting their belief that memory declines with advancing age. Older adults' PBMI responses indicated that they perceived their memory ability more negatively than those of young adults and middle-aged adults. Adults of all ages were able to use the computerized questionnaires without difficulty, making these measures suitable for use in adult developmental research.

The goal was to examine whether visuomotor control and choice response time shared age-related developmental trajectories, and if prior computer experience played an important role in control processes. Children (6–7, 8–9, 10–11 yr.), younger adults (24 yr.) and older adults (76 yr.) performed the cursor pointing and choice response time (CRT) tasks with a computer mouse. Participants moved the mouse cursor back and forth to click two targets on the screen as fast and accurately as possible. In the CRT, based on visual stimuli, participants moved and clicked one of the three targets on the screen as fast and accurately as possible; the time between stimulus onset and clicking the correct target was recorded as the choice response time. Visuomotor performance increased with age to younger adulthood but was worse in the older adult group. CRT performance was also positively related to age among the groups of children, with scores leveling off in the young adult group. Computer experience was statistically significantly related only to visuomotor control, but not to CRT. Optimal CRT performance required only sub-optimal visuomotor control. Cognitive and sensory age declines may be related to the poorer CRT performance in the oldest age group.

Motor unit (MU) activity pattern was examined in the right-hand extensor digitorum communis muscle (EDC) during standardised finger movements simulating actual computer mouse tasks. Intramuscular recordings were performed with a quadripolar needle electrode. Nine women performed four lifts of their right-hand index finger, middle finger or both as well as a number of double clicks. Additionally, the subjects performed contra lateral activity with their left-hand fingers and for three subjects recordings were also obtained during an interview with no physical activity. Besides the expected close coupling of MU activity with finger movement, activity was observed in three different situations with no physical requirements. Attention related activity was found before or after performance of the finger movement task, contra lateral activity in right EDC during left-hand finger tasks, and activity during mental activity without any finger movements involved. A relatively large number of doublet occurrences suggest they are a natural part of the activation pattern during performance of the rapid finger movement required to perform an efficient double click on the computer mouse.

In 3 experiments, the authors investigated and described how individuals control manual interceptive movements to slowly moving targets. Participants (N = 8 in each experiment) used a computer mouse and a graphics tablet assembly to manually intercept targets moving across a computer screen toward a marked target zone. They moved the cursor so that it would arrive in the target zone simultaneously with the target. In Experiment 1, there was a range of target velocities, including some very slow targets. In Experiment 2, there were 2 movement distance conditions. Participants moved the cursor either the same distance as the target or twice as far. For both experiments, hand speed was found to be related to target speed, even for the very slowly moving targets and when the target-to-cursor distance ratios were altered, suggesting that participants may have used a strategy similar to tracking. To test that notion, in Experiment 3, the authors added a tracking task in which the participants tracked the target cursor into the target zone. Longer time was spent planning the interception movements; however, there was a longer time in deceleration for the tracking movements, suggesting that more visually guided trajectory updates were made in that condition. Thus, although participants scaled their interception movements to the cursor speed, they were using a different strategy than they used in tracking. It is proposed that during target interception, anticipatory mechanisms are used rather than the visual feedback mechanism used when tracking and when pointing to stationary targets.