Does modifying visual feedback facilitate learning to write new pseudoletters?

Learning to write relies on the efficient integration of visual and proprioceptive feedback, with a transition from a control, based on the visual inspection of the written trace at the beginning of the learning process to a more predictive control, based mainly on handwriting movement, in proficient writers. The aim of this study was to test the effect of a partial deletion of the written trace, as well as the effect of supplementary visual information, on handwriting kinematics in a learning task. Twenty-four adults learned to write six new pseudoletters using their non-dominant hand on a touch screen digital tablet. Three pseudoletters were trained with modified visual feedback conditions and the other three, in the control condition, i.e. without any visual modification. Results revealed that, in the short-term, the pseudoletters learned with modified visual feedback were traced faster and more fluently than those learned in the control condition, without spatial accuracy reduction. This method seems to be efficient in adults, which is a prerequisite before testing a method with children.

Overpressure on fingertips prevents state estimation of the pen grip force and movement accuracy.

We tested the hypothesis that the inability to move a pen accurately in a graphic task is partly due to a decrease of afferent somatosensory information resulting from overpressure on the tactile receptors of the fingers holding the pen. To disentangle the depressed somatosensory origin from an altered motor command, we compared a condition in which the participant actively produces pressure on the pen (active grip) with a condition in which pressure is passively applied (passive grip, no grip-related motor command). We expected that the response of the somatosensory cortex to electric stimulation of the wrist's tactile nerve (i.e., SEP) would be greater in the natural pen grip (baseline condition) than in the two overpressure conditions (actively or passively induced). Fifteen adults were required to trace a geometrical shape in the three grip conditions. The SEP amplitude was not significantly different between the baseline and both overpressure conditions. However, behavioral results showed that drawing accuracy is impaired when the pressure on the pen is increased (passively or actively). Cortical source analyses revealed that the activity of the superior parietal areas (SPL) increased in both overpressure conditions. Our findings suggest that the SPL is critical for sensorimotor integration, by maintaining an internal representation of pen holding. These cortical changes might witness the impaired updating of the finger-pen interaction force for such drawing actions under visual guidance.

Imagining How Lines Were Drawn: The Appreciation of Calligraphy and the Facilitative Factor Based on the Viewer's Rating and Heart Rate.

For this study, we examined how recognizing the writing process of calligraphy influences the cognitive and affective processes related to appreciating it, with the aim of contributing to both graphonomics and the psychology of aesthetics. To this end, we conducted two Web-based experiments in which some participants were instructed to view calligraphy by tracing it with their eyes (the tracing method), while others were told to feel free to think and imagine whatever they wanted. Study 1 (N = 103) revealed that the tracing method elicits stronger admiration, inspiration, and empathy in viewers. Study 2 (N = 87) showed that the tracing method decreases the average heart rate of those who do not frequently engage in calligraphy appreciation as they gaze at calligraphy for a minute-and-a-half (during the second half of the stimulus duration); this suggests that the tracing method could keep viewers from becoming bored while looking at calligraphy. In sum, the tracing method has positive effects on viewing calligraphy. From a broader perspective, the results imply that how in detail viewers recognize the process of creating an artwork will be a key determinant of art appreciation. In addition, our findings demonstrate how we can measure cardiac activities using the emerging technology of the photoplethysmogram (PPG).

Cancelling discrete and stopping ongoing rhythmic movements: Do they involve the same process of motor inhibition?

Motor inhibition is considered to be an important process of executive control and to be implicated in numerous activities in order to cancel prepared actions and, supposedly, to suppress ongoing ones. Usually, it is evaluated using a "stop-signal task" in which participants have to inhibit prepared discrete movements. However, it is unknown whether other movement types involve the same inhibition process. We therefore investigated whether the inhibition process for discrete movements is involved in stopping ongoing rhythmic movements as well. Twenty healthy adults performed two counterbalanced tasks. The first task was used to estimate the stop-signal reaction time (SSRTd) needed to inhibit prepared discrete key-pressing movements. In the second task, participants drew graphic patterns on a tablet and had to stop the movement when a stop-signal occurred. We calculated the rhythmic stop signal-reaction time as the time needed to initiate stopping such ongoing rhythmic movement (SSRTr) and the same latency relative to the period of the rhythmic movement (relSSRTr). We measured these delays under different movement frequencies and motor coordination conditions and further investigated whether they varied as a function of several parameters of the rhythmic movements (speed, mean and variance of the relative phase, and movement phase at several time events). We found no correlation between inhibition measures in the two tasks. In contrast, generalized linear models showed a moderate yet significant influence of the motion parameters on the inhibition of ongoing rhythmic movements. We therefore conclude that the motor inhibition processes involved in cancelling prepared discrete movements and stopping ongoing rhythmic movements are dissimilar.

Digitalized spiral drawing in Parkinson's disease: A tool for evaluating beyond the written trace.

One of the current scientific challenges is to propose novel tools and tasks designed to identify new motor biomarkers in Parkinson's disease (PD). Among these, a focus has placed on drawing tasks. Independently from clinical ratings, this study aimed to evaluate the pen movement and holding in digitalized spiral drawing in individuals with PD without and with medical treatment and in healthy controls. A three-step data-driven analysis was conducted. First, the effects of spatial and temporal constraints on several variables were determined. Second, the relationship between handedness and dominance of PD symptoms was investigated for the most relevant variables. Finally, a third analysis was conducted to assess the occurrence of changes associated with PD. The first analysis revealed that the number of velocity peaks and pen altitude variations were the most relevant variables in spiral drawing for evaluating the effect of the disease and medication. The second analysis revealed that the effect of medication was present for the movement fluency only, when spirals with spatial constraints were produced at a spontaneous speed by the hand on the side of dominant PD signs. Finally, the third analysis showed that the effect of medication was greater at the beginning of drawing than at the end. Digitalized spiral drawing makes it possible to observe precisely when the kinematic changes related to the disease occur during the task. Such a simple and quick task might be of great relevance to contribute to the diagnosis and follow-up of PD.

Computerized spiral analysis using the iPad.

BACKGROUND: Digital analysis of writing and drawing has become a valuable research and clinical tool for the study of upper limb motor dysfunction in patients with essential tremor, Parkinson's disease, dystonia, and related disorders. We developed a validated method of computerized spiral analysis of hand-drawn Archimedean spirals that provides insight into movement dynamics beyond subjective visual assessment using a Wacom graphics tablet. While the Wacom tablet method provides robust data, more widely available mobile technology platforms exist. NEW METHOD: We introduce a novel adaptation of the Wacom-based method for the collection of hand-drawn kinematic data using an Apple iPad. This iPad-based system is stand-alone, easy-to-use, can capture drawing data with either a finger or capacitive stylus, is precise, and potentially ubiquitous. RESULTS: The iPad-based system acquires position and time data that is fully compatible with our original spiral analysis program. All of the important indices including degree of severity, speed, presence of tremor, tremor amplitude, tremor frequency, variability of pressure, and tightness are calculated from the digital spiral data, which the application is able to transmit. COMPARISON WITH EXISTING METHOD: While the iPad method is limited by current touch screen technology, it does collect data with acceptable congruence compared to the current Wacom-based method while providing the advantages of accessibility and ease of use. CONCLUSIONS: The iPad is capable of capturing precise digital spiral data for analysis of motor dysfunction while also providing a convenient, easy-to-use modality in clinics and potentially at home.

Handwriting Development in Spanish Children With and Without Learning Disabilities: A Graphonomic Approach.

The central purpose of this study was to analyze the dynamics of handwriting movements in real time for Spanish students in early grades with and without learning disabilities. The sample consisted of 120 children from Grades 1 through 3 (primary education), classified into two groups: with learning disabilities and without learning disabilities. The Early Grade Writing Assessment tasks selected for this purpose were writing the alphabet in order from memory, alphabet copying in cursive and manuscript, and allograph selection. The dynamics of these four handwriting tasks were recorded using graphonomic tablets (type Wacom Intuos-4), Intuos Inking pens, and Eye and Pen 2 software. Several events were recorded across four different tasks: velocity, pressure, time invested in pauses, and automaticity. The results demonstrated significant graphonomic variations between groups across grades, depending on the type of task.

Co-variation between graphic pattern stability and attentional cost: a clue for the difficulty to produce handwritten traces.

Attentional cost incurred for generating handwritten graphic patterns was investigated using a classic dual-task procedure, in which a concurrent reaction time (RT) task was used as an index of the attentional cost incurred by the primary graphic task. Eight right-handed adults had to trace graphic patterns, characterized by a 0°, 45°, 90°, 135° or 180° relative phase and corresponding to shapes ranging from lines to ellipses to circles, while responding by a key press as fast as possible to an auditory signal. The results evidenced a strong and significant correlation between the stability of the produced pattern and the associated attentional cost. The amplitude of the minor and major axes of the produced ellipsoids decreased with the increase of movement frequency, as expected by nonlinear models of oscillatory pattern generation. These findings pave the way to the study for the (coordinative) processes for letter (mal)formation in cursive handwriting.