Cursor Location Research Articles

New and Simplified Manual Controls for Projection and Slice Tours, With Application to Exploring Classification Boundaries in High Dimensions

This article describes new user controls for examining high-dimensional data using low-dimensional linear projections and slices. A user can interactively change the contribution of a given variable to a low-dimensional projection, which is useful for exploring the sensitivity of structure to particular variables. The user can also interactively shift the center of a slice, for example, to explore how structure changes in local subspaces. The Mathematica package as well as example notebooks are provided, which contain functions enabling the user to experiment with these new manual controls, with one specifically for exploring regions and boundaries produced by classification models. The advantage of Mathematica is its linear algebra capabilities and interactive cursor location controls. Some limited implementation has also been made available in the R package tourr. Supplementary materials for this article are available online.

Timing is everything: Event-related transcranial direct current stimulation improves motor adaptation

BackgroundThere is a current discord between the foundational theories underpinning motor learning and how we currently apply transcranial direct current stimulation (TDCS): the former is dependent on tight coupling of events while the latter is conducted with very low temporal resolution. ObjectiveHere we aimed to investigate the temporal specificity of stimulation by applying TDCS in short epochs, and coincidentally with movement, during a motor adaptation task. MethodsParticipants simultaneously adapted a reaching movement to two opposing velocity-dependent force-fields (clockwise and counter-clockwise), distinguished by a contextual leftward or rightward shift in the task display and cursor location respectively. Brief bouts (<3 s) of event-related TDCS (er-TDCS) were applied over M1 or the cerebellum during movements for only one of these learning contexts. ResultsWe show that when short duration stimulation is applied to the cerebellum and yoked to movement, only those reaching movements performed simultaneously with stimulation are selectively enhanced, whilst similar and interleaved movements are left unaffected. We found no evidence of improved adaptation following M1 er-TDCS, as participants displayed equivalent levels of error during both stimulated and unstimulated movements. Similarly, participants in the sham stimulation group adapted comparably during left and right-shift trials. ConclusionsIt is proposed that the coupling of cerebellar stimulation and movement influences timing-dependent (i.e. Hebbian-like) mechanisms of plasticity to facilitate enhanced learning in the stimulated context.

Use of an EMG-Controlled Game as a Therapeutic Tool to Retrain Hand Muscle Activation Patterns Following Stroke: A Pilot Study.

To determine the feasibility of training with electromyographically (EMG) controlled games to improve control of muscle activation patterns in stroke survivors. Twenty chronic stroke survivors (>6 months) with moderate hand impairment were randomized to train either unilaterally (paretic only) or bilaterally over 9 one-hour training sessions. EMG signals from the unilateral or bilateral limbs controlled a cursor location on a computer screen for gameplay. The EMG muscle activation vector was projected onto the plane defined by the first 2 principal components of the activation workspace for the nonparetic hand. These principal components formed the x- and y-axes of the computer screen. The recruitment goal (n = 20) was met over 9 months, with no screen failure, no attrition, and 97.8% adherence rate. After training, both groups significantly decreased the time to move the cursor to a novel sequence of targets (P = 0.006) by reducing normalized path length of the cursor movement (P = 0.005), and improved the Wolf Motor Function Test (WMFT) quality score (P = 0.01). No significant group difference was observed. No significant change was seen in the WMFT time or Box and Block Test. Stroke survivors could successfully use the EMG-controlled games to train control of muscle activation patterns. While the nonparetic limb EMG was used in this study to create target EMG patterns, the system supports various means for creating target patterns per user desires. Future studies will employ training with the EMG-controlled games in conjunction with functional task practice for a longer intervention duration to improve overall hand function.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A379).

Bayesian integration during sensorimotor estimation in elite athletes.

An experiment was designed to determine the effects of sensory uncertainty on sensorimotor estimation in elite athletes compared to non-athletes. Nineteen elite athletes and 16 non-athletes were required to estimate when and where a cursor arrived at a target location. The cursor position was displayed through its entire trajectory in the certain condition while only briefly in the uncertain condition. Accuracy and variability in time and spatial domains were calculated. A Bayesian analysis using subsets of subjects' total spatial variance was also performed. The results indicated that athletes and non-athletes used estimation strategies consistent with Bayesian integration. The results also showed a decrease in variability for spatial performance for both groups during the uncertain condition compared to the certain condition, especially when the cursor location was further away from the prior mean. This decrease in variability was significantly greater for non-athletes. By concentrating performance around the end-point mean location, an increase in spatial error occurred. More spatial and timing errors were observed in non-athletes than athletes, indicating athletes were more certain about likelihood information or their interpretation of likelihood information than non-athletes. These results suggest that athletic experience may facilitate the use of probabilistic information for optimal sensorimotor estimations.

Exploring Accessibility in DOAJ: A Case Study

This study explores the accessibility of HTML articles indexed in the Directory of Open Access Journals (DOAJ). The researchers tested a random sample of journals that possessed the DOAJ seal of approval, added content in 2019, were published in English and had 50 or more indexed articles. From this sample, HTML full-text articles were randomly selected for accessibility testing, using the W3C Easy Checks. 131 journals on 22 platforms were reviewed. All content reviewed provided unique web page titles. The majority of articles reviewed allowed for increases in text size and had meaningful heading structure. The application of alternative text tags for images and form labels was inconsistent, as was the ability to use keyboard controls for page navigation. Further, most content did not clearly indicate cursor location. The most egregious accessibility issues came from design choices, which generated a variety of contrast errors. More in-depth studies of DOAJ and other OA indexes and content providers are recommended, as is requiring adherence to WCAG 2.0 accessibility criteria as a condition of article submission.

Частотні перетворювачі СВІП-генератора на основі ЗІГ-резонатора

Improving the accuracy of measuring the frequency characteristics of electronic devices and communication lines is an important task. In order to solve it for panoramic microwave devices, sweep-generators based on a YIG resonator with improved metrological characteristics are being developed. The article describes a new approach to creating a sweep generator. The self-oscillator at the YIG resonator is not covered by reverse control connections, and the circuit is supplemented with a frequency converter with reference oscillators. As a result, the error of setting the frequency of the sweep generator, which is caused by the instability of the parameters of the YIG resonator, is compensated. In addition, the output voltage of the oscillator has a minimum level of phase noise. A frequency converter with a range reference oscillator, a frequency converter based on a quad and a frequency converter of a sweep generator in the swing stop mode are proposed. The principle of their work is explained, temporary waveforms and calculated expressions are given. &nbsp;In a sweep generator with a frequency converter containing a range reference generator, it is additionally possible, in addition to the coordinate marks on the monitor screen, to form a measuring mark with any frequency. The high linearity of the dependence of the generation frequency of the YIG resonator on the control current makes it possible, using a piecewise linear approximation, to obtain information about the frequency at the cursor location on the monitor screen. Quad-based frequency converters are installed in sweep-generators operating in linear and non-linear frequency change modes. The scheme of the frequency converter of the sweep-generator in the swing-out mode is also constructed on the basis of a quad. The microcontroller of the sweep-generator with installed frequency converters adjusts the digital control code of the oscillator. As a result, the accuracy of determining the frequency increases i.e. decreases the measurement error of various frequency characteristics of devices and communication lines.

Relação entre comportamento supersticioso e estímulo reforçador condicionado: uma replicação sistemática de Lee (1996).

O objetivo foi verificar se um estímulo reforçador condicionado pode instalar comportamento supersticioso, replicando sistematicamente Lee (1996). A tarefa de doze participantes era mudar a disposição de cinco ícones dispostos no canto esquerdo da tela do computador, clicando o mouse; as mudanças não dependiam da localização do cursor na tela, quando os cliques ocorriam, mas sim do número de cliques. Na Fase 1, mudança na disposição dos ícones ocorria em um esquema de razão variável, as quatro primeiras mudanças apenas alteravam a disposição de cinco ícones diferentes e a quinta, produzia 5 ícones iguais. Pontos eram liberados, quando os ícones se igualavam. Na Fase 2, após alguns cliques no mouse (que podiam ser de 1 a 30), em que não produziam mudança nos ícones, os próximos quatro cliques produziam mudanças na disposição de cinco ícones diferentes e o quinto clique produzia a igualação dos ícones. Na Fase 3, a igualação ocorria diretamente, após “n” cliques. Dois tipos de respostas supersticiosas foram identificados: respostas de clicar sobre zonas de localização que continham ou não, os ícones e respostas de variar a localização dos cliques, após ausência de mudança ou de mudança nos ícones.

Using TRIZ for Minimizing Cursor Movements in GUI

Although a GUI is a revolutionary development over its predecessors, it suffers from a typical shortcoming that it requires a lot of pointer movements. As pointer movement is a slow process it affects the overall performance of a GUI operation. Besides too much pointer movement can frustrate a user. Hence, it is desirable to reduce the pointer movements while performing any action through a typical GUI. Ideally the user need not move the pointer to initiate a GUI based operation. In other words the pointer itself should automatically move onto the desired location on the graphical user interface (Ideal Final Result). This article analyzes the problems involved in pointer movements, finds out the specific GUI activities that demands more pointer movements and suggests specific methods that can reduce pointer movements. The methods include reducing the distance to access the remote menu items, automating the process of resizing and relocating windows and toolboxes, bringing the desired menu or command near to the cursor location instead of needing the cursor to move to the menu or command location.

Tonal interface to MacroMolecules (TIMMol)

We developed the three-dimensional visualization software, Tonal Interface to MacroMolecules or TIMMol, for studying atomic coordinates of protein structures. Key features include audio tones indicating x, y, z location, identification of the cursor location in one-dimensional and three-dimensional space, textual output that can be easily linked to speech or Braille output, and the ability to scroll along the main chain backbone of a protein structure. This program was initially designed for visually impaired users, and it already has shown its effectiveness in helping a blind researcher study X-ray crystal structure data. Subsequently, TIMMol has been enhanced with a graphical display to act as a bridge to ease communication between sighted and visually impaired users as well as to serve users with spatial visualization difficulties. We performed a pilot study to assess the efficacy of the program in conveying three-dimensional information about proteins with and without graphical output to a general scientific audience. Attitudes regarding using TIMMol were assessed using Rasmol, a common visualization package, for comparison. With the use of text and tones exclusively, a majority of users were able to identify specific secondary structure elements, three-dimensional relationships among atoms, and atoms coordinating a ligand. In addition, a majority of users saw benefits in using TIMMol and would recommend it to those having difficulty with standard tools.

Contributions of Online Visual Feedback to the Learning and Generalization of Novel Finger Coordination Patterns

We explored how people learn new ways to move objects through space using neuromuscular control signals having more degrees of freedom than needed to unambiguously specify object location. Subjects wore an instrumented glove that recorded finger motions. A linear transformation matrix projected joint angle signals (a high-dimensional control vector) onto a two-dimensional cursor position on a video monitor. We assessed how visual information influences learning and generalization of novel finger coordination patterns as subjects practiced using hand gestures to manipulate cursor location. Three groups of test subjects practiced moving a visible cursor between different sets of screen targets. The hand-to-screen transformation was designed such that the different sets of targets (which we called implicit spatial cues) varied in how informative they were about the gestures to be learned. A separate control group practiced gesturing with explicit cues (pictures of desired gestures) without ongoing cursor feedback. Another control group received implicit spatial cueing and feedback only of final cursor position. We found that test subjects and subjects provided with explicit cues could learn to produce desired gestures, although training efficacy decreased as the amount of task-relevant feedback decreased. Although both control groups learned to associate screen targets with specific gestures, only subjects provided with online feedback of cursor motion learned to generalize in a manner consistent with the internal representation of an inverse hand-to-screen mapping. These findings suggest that spatial learning and generalization require dynamic feedback of object motion in response to control signal changes; static information regarding geometric relationships between controller and endpoint configurations does not suffice.

Remapping Hand Movements in a Novel Geometrical Environment

The issue of how the Euclidean properties of space are represented in the nervous system is a main focus in the study of visual perception, but is equally relevant to motor learning. The goal of our experiments was to investigate how the properties of space guide the remapping of motor coordination. Subjects wore an instrumented data glove that recorded the finger motions. Signals generated by the glove operated a remotely controlled endpoint: a cursor on a computer monitor. The subjects were instructed to execute movements of this endpoint with controlled motions of the fingers. This required inverting a highly redundant map from fingers to cursor motions. We found that 1) after training with visual feedback of the final error (but not of the ongoing cursor motion), subjects learned to map cursor locations into configurations of the fingers; 2) extended practice of movement led to more rectilinear cursor movement, a trend facilitated by training under continuous visual feedback of cursor motions; 3) with practice, subjects reduced motion in the degrees of freedom that did not contribute to the movements of the cursor; 4) with practice, subjects reduced variability of both cursor and hand movements; and 5) the reduction of errors and the increase in linearity generalized beyond the set of movements used for training. These findings suggest that subjects not only learned to produce novel coordinated movement to control the placement of the cursor, but they also developed a representation of the Euclidean space on which hand movements were remapped.

How the lack of visuomotor feedback affects even the early stages of goal-directed pointing movements.

Pointing movements made with a hidden cursor from the center of gaze to a stationary, visible target overshot the actual target location. The systematic error decreased when the final cursor location from the previous trial was shown, which likely led to the creation of an internal sensorimotor model of movement. However, the putative model had a short memory, and could not substitute for on-line visuomotor feedback on subsequent trials. Contrary to common belief, the effect of a lack of visuomotor feedback was seen even in the early acceleration stage of the movement trajectory. Unchecked in the absence of visual monitoring, the acceleration stage of the movement lasted longer, as was evidenced by the significantly larger value of the peak cursor speed. Moreover, the speed peaked much later in the course of the movement. Speed declined more rapidly thereafter. Consequently, the delayed deceleration stage lasted far less than the acceleration stage. In the absence of visual feedback, the shift rightward in time of the peak speed position (PSP) in relation to total movement duration and other changes in the trajectory imply that visual feedback must play a significant role in determining when acceleration ceases (d V/d t=0), and argue against the traditional notion that visuomotor feedback is unavailable until the later stages of movement. Moreover, our data suggest that non-visual modalities, e.g., proprioception, may be too slow to make up for the absence of vision.

Weaving a web

Suppose, you want to implement a structured editor for some term type, so that the user can navigate through a given term and perform edit actions on subterms. In this case you are immediately faced with the problem of how to keep track of the cursor movements and the user's edits in a reasonably efficient manner. In a previous pearl, Huet (1997) introduced a simple data structure, the Zipper, that addresses this problem – we will explain the Zipper briefly in section 2. A drawback of the Zipper is that the type of cursor locations depends on the structure of the term type, i.e. each term type gives rise to a different type of location (unless you are working in an untyped environment). In this pearl, we present an alternative data structure, the web, that serves the same purpose, but that is parametric in the underlying term type. Sections 3–6 are devoted to the new data structure. Before we unravel the Zipper and explore the web, let us first give a taste of their use.

Characteristics of cursor trajectories controlled by the computer mouse

An analysis of computer screen cursor trajectories can provide insights into the factors limiting efficient cursor positioning and can assist in the design of humancomputer interfaces. Cursor locations as controlled by a Microsoft computer mouse with standard settings were therefore sampled at 5ms intervals and kinematic analyses addressed the proportions of time spent in the initiation, accelerative and terminal guidance phases of cursor positioning. Twelve participants used a computer mouse to move a cursor over different distances (7.5cm, 15cm) from a home location in the lower centre of the screen to targets of different diameters (8mm, 16mm), situated to the left, middle or right of the computer screen. Cursor trajectories were irregular, and participants regularly overshot their targets, spending 70% of movement duration in terminal guidance. Participants appeared to use the initial part of their movement to establish mappings between controller and display. Interventions should seek to reduce the terminal guidance phase of cursor positioning.

Voice recognition system

A text locating system recognizes spoken utterances, uses the recognized words as a search string, and searches text for words matching that search string. The probability that a given vocabulary word is selected as a search word is altered both by limiting the recognizable vocabulary to words in the text to the searched, and by altering the probability that individual recognizable words will be selected as a function of the number of time they occur in that text. The system performs incremental searches by adding successively recognized words to the search string and searching for the next occurrence of the string in response to each such addition. The invention can be used in a text editing system which enables a user to switch between a dictation mode, which inserts recognized words into text, and a search mode, which uses them to search for new cursor locations. Broadly speaking, the invention provides a computer system which recognizes spoken words, which has a data structure representing words; which uses that data structure for a purpose other than speech recognition; and which alters the probability that a given vocabulary word will be recognized as a function of the frequency of that word in the data structure.

Leukocyte immunophenotyping by flow cytometry in a multisite study: Standardization, quality control, and normal values in the Transfusion Safety Study

The Transfusion Safety Study (TSS) is a multicenter, cooperative investigation of factors that may determine the occurrence and modify the expression of transusion-transmitted infections. A flow cytometry laboratory was established in each of the six participating centers in order to avoid alterations in cell phenotypes which may be caused by shipping delays, temperature changes, and handling. As a consequence, in order to assure compatibility of results, stringent standardization, quality control, and proficiency testing procedures were developed. This paper documents (i) the effect of time from phlebotomy to specimen staining and then to analysis for the antibodies used in the study; (ii) the effects of variations in light scatter cursor location for certain antibodies; (iii) a quality control program and data management and analysis system, each specifically designed for the study; and (iv) presents extensive data on age- and sex-related reference (normal) ranges for the several individual and paired monoclonal antibodies used in the study. Problems encountered, including obtaining reliable absolute lymphocyte counts, interference by nucleated erythrocytes, and sources of variability in results, are discussed. This study is meant to serve as a reference for future TSS publications.

Incremental evaluation for attribute grammars with unrestricted movement between tree modifications

This paper concerns the design of editors that perform checks on a language's context-dependent constraints. Our particular concern is the design of an efficient, incremental analysis algorithm for systems based on the attribute-grammar model of editing. With previous incremental evaluation algorithms for arbitrary noncircular attribute grammars, the editing model required there to be a restriction on the operation that moves the editing cursor: moving the cursor was limited to just a single step in the tree — either to the parent node or to one of the child nodes of the current cursor location. This paper describes a new updating algorithm that can be used when an arbitrary movement of the cursor in the tree is permitted. After an operation that restructures the tree, the tree's attributes can be updated with a cost of 0 ((1+¦AFFECTED¦)·√m), where m is the size of the tree and AFFECTED is the subset of the tree's attributes that require new values, when the cost is amortized over a sequence of tree modifications. the editing cursor may be moved from its current location to any other node of the tree in a single, unit-cost operation. CR Categories and Subject Descriptors: D.2.3 [Software Engineering]: Coding — program editors; D.2.6 [Software Engineering]: Programming Environments; D.3.1 [Programming Languages]: Formal Definitions and Theory — semantics, syntax D.3.4 [Programming Languages]: Processors — translator writing systems and compiler generators F.3.2 [Logics and Meanings of Programs]: Semantics of Programming Languages — denotational semantics.

Incremental evaluation for attribute grammars with unrestricted movement between tree modifications

This paper concerns the design of editors that perform checks on a language's context-dependent constraints. Our particular concern is the design of an efficient, incremental analysis algorithm for systems based on the attribute-grammar model of editing. With previous incremental evaluation algorithms for arbitrary noncircular attribute grammars, the editing model required there to be a restriction on the operation that moves the editing cursor: moving the cursor was limited to just a single step in the tree — either to the parent node or to one of the child nodes of the current cursor location. This paper describes a new updating algorithm that can be used when an arbitrary movement of the cursor in the tree is permitted. After an operation that restructures the tree, the tree's attributes can be updated with a cost of 0 ((1+¦AFFECTED¦)·√m), where m is the size of the tree and AFFECTED is the subset of the tree's attributes that require new values, when the cost is amortized over a sequence of tree modifications. the editing cursor may be moved from its current location to any other node of the tree in a single, unit-cost operation. CR Categories and Subject Descriptors: D.2.3 [Software Engineering]: Coding — program editors; D.2.6 [Software Engineering]: Programming Environments; D.3.1 [Programming Languages]: Formal Definitions and Theory — semantics, syntax D.3.4 [Programming Languages]: Processors — translator writing systems and compiler generators F.3.2 [Logics and Meanings of Programs]: Semantics of Programming Languages — denotational semantics.