Basic and supplementary sensory feedback in handwriting

International audienceThe mastering of handwriting is so essential in our society that it is important to try to find new methods for facilitating its learning and rehabilitation. The ability to control the graphic movements clearly impacts on the quality of the writing. This control allows both the programming of letter formation before movement execution and the online adjustments during execution, thanks to diverse sensory feedback (FB). New technologies improve existing techniques or enable new methods to supply the writer with real-time computer-assisted FB. The possibilities are numerous and various. Therefore, two main questions arise: (1) What aspect of the movement is concerned and (2) How can we best inform the writer to help them correct their handwriting? In a first step, we report studies on FB naturally used by the writer. The purpose is to determine which information is carried by each sensory modality, how it is used in handwriting control and how this control changes with practice and learning. In a second step, we report studies on supplementary FB provided to the writer to help them to better control and learn how to write. We suggest that, depending on their contents, certain sensory modalities will be more appropriate than others to assist handwriting motor control. We emphasize particularly the relevance of auditory modality as online supplementary FB on handwriting movements. Using real-time supplementary FB to assist in the handwriting process is probably destined for a brilliant future with the growing availability and rapid development of tablets

Digitizing Literacy: Reflections on the Haptics of Writing

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Comparing comprehension of a long text read in print book and on Kindle: Where in the text and when in the story?

Digital reading devices such as Kindle differ from paper books with respect to the kinesthetic and tactile feedback provided to the reader, but the role of these features in reading is rarely studied empirically. This experiment compares reading of a long text on Kindle DX and in print. Fifty participants (24 years old) read a 28 page (∼1 h reading time) long mystery story on Kindle or in a print pocket book and completed several tests measuring various levels of reading comprehension: engagement, recall, capacities to locate events in the text and reconstructing the plot of the story. Results showed that on most tests subjects performed identically whatever the reading medium. However, on measures related to chronology and temporality, those who had read in the print pocket book, performed better than those who had read on a Kindle. It is concluded that, basically comprehension was similar with both media, but, because kinesthetic feedback is less informative with a Kindle, readers were not as efficient to locate events in the space of the text and hence in the temporality of the story. We suggest that, to get a correct spatial representation of the text and consequently a coherent temporal organization of the story, readers would be reliant on the sensorimotor cues which are afforded by the manipulation of the book.publishedVersio

Spatial coding of voluntary saccades in man

International audienceThree experiments are described in which human subjects must direct the gaze to previously memorized point in visual space after the initial position of the eyes has been displaced voluntarily

How does interior car noise alter driver's perception of motion? Multisensory integration in speed perception

International audienceAcoustic feedback inside a car is composed of different sources, which give information on the drivers actions and the dynamic state of the car. This acoustic feedback influences the drivers perception of movement in a multisensory integration. The development of electric motorizations brings new balance between noise sources inside the car, due to the loss of engine sound that is present in traditional internal combustion engine cars. To study the influence of this modified noise source balance on driving, we focused on speed perception. A car simulator was used for this purpose. 24 participants were asked to accelerate up to a given target speed, while the speedometer was hidden. We studied the speed they actually reached with three acoustic feedbacks (engine, electric motor, no sound), in two visual conditions (night and day). We found out that acoustic feedback can alter the drivers speed perception

Handwriting in Children and Adults With Down Syndrome: Developmental Delay or Specific Features?

International audienceWhile there is a long history and tradition of behavioral research on basic motor skills in Down syndrome (DS), there has been only limited research on handwriting ability. We analyzed the spatiotemporal features of handwriting produced by children and adults with DS (n = 24), and compared their productions with those of comparison groups matched for developmental (n = 24) or chronological (n = 24) age. Results indicated that the participants with DS performed an alphabet letter-writing task just as efficiently as the children of the same developmental age, in terms of the length, duration and speed of their handwriting, and the number and duration of their pauses. Our study highlights a substantial delay in the stages of writing acquisition

From shape to sound: sonification of two dimensional curves by reenaction of biological movements

International audienceSonifying two dimensional data is a common problem. In this study, we propose a method to synthesize sonic metaphors of two dimensional curves based on the mental representation of the sound produced by the friction of the pencil when somebody is drawing or writing on a paper. The relevance of such approach is firstly presented. Secondly, synthesis of friction sounds allows to investigate the relevance of the kinematics in the perception of a gesture underlying a sound. In third part, a biological law linking the curvature of a shape to the velocity of the gesture which have draw the shape is calibrated from the auditory point of view. It enables to generate friction sounds with a physically based synthesis model from a given shape

Sonifying drawings: characterization of perceptual attributes of sounds produced by human gestures

International audienceFriction sounds produced by the pencil of a person who is drawing on a paper are audible and could bring information about his/her gestures. This study firstly focuses on the perceptual significance of the morphology of such sounds, and to what extent gestures could be retrieved by sounds. Sounds recorded during drawing sessions were used in association tests where subjects had to univocally associate friction sounds with different shapes. Results showed that subjects were able to associate sounds with correct shapes and that the auditory characterization of the shape depended on the velocity profile.\\ A sonification strategy was then proposed for human drawings using a friction sound synthesis model. Inspired by the work of Viviani et al. (1982) who exhibited a 2/3-power law relation between kinetics and shape curvature for visual perception, experiments were carried out with the synthesis model, where subjects were asked to adjust the power law exponent so that the most realistic sound was obtained. Results revealed an exponent close to 2/3 as previously found in vision and thus highlighted a similar power law in the auditory modality, providing an ecological way to determine velocity profiles from static shapes and to generate sounds coherent with human gestures

Music Training Positively Influences the Preattentive Perception of Voice Onset Time in Children with Dyslexia: A Longitudinal Study

Previous results showed a positive influence of music training on linguistic abilities at both attentive and preattentive levels. Here, we investigate whether six months of active music training is more efficient than painting training to improve the preattentive processing of phonological parameters based on durations that are often impaired in children with developmental dyslexia (DD). Results were also compared to a control group of Typically Developing (TD) children matched on reading age. We used a Test-Training-Retest procedure and analysed the Mismatch Negativity (MMN) and the N1 and N250 components of the Event-Related Potentials to syllables that differed in Voice Onset Time (VOT), vowel duration, and vowel frequency. Results were clear-cut in showing a normalization of the preattentive processing of VOT in children with DD after music training but not after painting training. They also revealed increased N250 amplitude to duration deviant stimuli in children with DD after music but not painting training, and no training effect on the preattentive processing of frequency. These findings are discussed in view of recent theories of dyslexia pointing to deficits in processing the temporal structure of speech. They clearly encourage the use of active music training for the rehabilitation of children with language impairments