Practice and the dynamics of handwriting performance: evidence for a shift of motor programming load

Sixteen adult subjects were served in an experiment in which the writing of six unfamiliar graphemes was practiced. To investigate the learning process, we analyzed the absolute and relative changes of movement time of the first three consecutive segments as a function of practice. The results showed that movement time of all three segments decreased. This decrease was significantly less in the first segment that it was in the second and third segment, however. We interpret these effects of practice, from an information-processing viewpoint, as follows: (a) Initially separate response segments become integrated in more comprehensive response chunks, and (b) the preparation of later segments of the grapheme is realized more and more during the real-time execution of the initial segment. The results further revealed that these learning effects were more pronounced in graphemes composed of familiar segments than in graphemes that contained unfamiliar segments. Finally, it turned out that similarity between initial and final segments hindered the writing speed of the first segment; the effect of similarity was independent of the above-mentioned effects of practice. The latter effect is interpreted as confirming evidence for the view that the preparation of later segments of a grapheme is reflected by changes of movement time of the first segments of a grapheme.     

Structural complexity of motor patterns: A study on reaction times and movement times of handwritten letters

This study investigates the effects of psychomotor complexity on latencies for beginning to write single letters and numerals, and on times taken to complete the first strokes of letters and numerals. An experiment measured simple and choice reaction times for writing homogeneous graphemes (i.e., letters or numerals made up of similar strokes) and for writing heterogeneous graphemes (i.e., characters made up of dissimilar strokes). It was assumed that the motor programme for writing a letter is retrieved from long-term memory and briefly held, until it is used, in a short-term buffer store. The experiment examined the hypothesis that it is more difficult to read out homogeneous than heterogeneous stroke-structures from this store. For three out of four allographic grapheme pairs, homogeneous graphemes required longer initiation times or longer movement times for completion of the first stroke than did heterogeneous graphemes. These results are discussed in relation to recent findings on motor programming based on the use of reaction-time paradigms.     

Graphemes are perceptual reading units

Graphemes are commonly defined as the written representation of phonemes. For example, the word 'BREAD' is composed of the four phonemes /b/, /r/, /e/ and /d/, and consequently, of the four graphemes 'B', 'R', 'EA', and 'D'. Graphemes can thus be considered the minimal 'functional bridges' in the mapping between orthography and phonology. In the present study, we investigated the hypothesis that graphemes are processed as perceptual units by the reading system. If the reading system processes graphemes as units, then detecting a letter in a word should be harder when this letter is embedded in a multi-letter grapheme than when it corresponds to a single-letter grapheme. In Experiment 1A, done in English, participants were slower to detect a target letter in a word when the target letter was embedded in multi-letter grapheme (i.e. 'A' in 'BEACH') than when it corresponded to a single-letter grapheme (i.e. 'A' in 'PLACE'). In Experiment 1B, this effect was replicated in French. In Experiment 2, done in English, this grapheme effect remained when phonemic similarity between the target letter alone and the target letter inside the word was controlled. Together, the results are consistent with the assumption that graphemes are processed as perceptual reading units in alphabetic writing systems such as English or French.     

Decreased load on general motor preparation and visual-working memory while preparing familiar as compared to unfamiliar movement sequences

Learning movement sequences is thought to develop from an initial controlled attentive phase to a more automatic inattentive phase. Furthermore, execution of sequences becomes faster with practice, which may result from changes at a general motor processing level rather than at an effector specific motor processing level. In the current study, we examined whether these changes are already present during preparation. Fixed series of six keypresses, either familiar or unfamiliar, had to be prepared and executed/withheld after a go/nogo signal. Reaction time results confirmed that familiar sequences were executed faster than unfamiliar sequences. Results derived from the electroencephalogram showed a decreased demand on general motor preparation and visual-working memory before familiar sequences as compared to unfamiliar sequences. We propose that with familiar sequences the presetting segments of responses is less demanding than with unfamiliar sequences, as familiar sequences can be regarded as less complex than unfamiliar sequences. Finally, the decreasing demand on visual-working memory before familiar sequences suggests that sequence learning indeed develops from an attentive to an automatic phase.     

Movement segmentation and visual perturbation increase developmental differences in motor control and learning

We examined the developmental differences in motor control and learning of a two‐segment movement. One hundred and five participants (53 female) were divided into three age groups (7–8 years, 9–10 years and 19–27 years). They performed a two‐segment movement task in four conditions (full vision, fully disturbed vision, disturbed vision in the first movement segment and disturbed vision in the second movement segment). The results for movement accuracy and overall movement time show that children, especially younger children, are more susceptible to visual perturbations than adults. The adults’ movement time in one of the movement segments could be increased by disturbing the vision of the other movement segment. The children's movement time for the second movement segment increased when their vision of the first movement segment was disturbed. Disturbing the vision of the first movement segment decreased the percentage of central control of the second movement in younger children, but not in the other two age groups. The children's normalized jerk was more easily increased by visual perturbations. The children showed greater improvement after practice in the conditions of partial vision disturbance. As the participants’ age increased, practice tended to improve their feedforward motor control rather than their feedback motor control. These results suggest that children's central movement control improves with age and practice. We discuss the theoretical implications and practical significance of the differential effects of visual perturbation and movement segmentation upon motor control and learning from a developmental viewpoint.     

Processing complex graphemes in handwriting production

Recent studies on handwriting production and neuropsychological data have suggested that orthographic representations are multilevel structures that encode information on letter identity and order, but also on intermediate-grained processing units such as syllables and morphemes. This study on handwriting production examined whether orthographic representations also include a graphemic-processing level. French adults wrote words containing an embedded one-, two-, or three-letter grapheme (e.g., a in clavier, ai in prairie, ain in plainte) on a digitizer. The results for letter duration revealed that the timing of movement processing depends on grapheme length (e.g., the duration of a for one-letter graphemes was shorter than that for two-letter graphemes, which, in turn, was shorter than that for three-letter graphemes). Two- and three-letter graphemes start to be processed before we start to write them. The results therefore revealed that orthographic representations also encode information on grapheme complexity.     

The Modulation of Visual and Task Characteristics of a Writing System on Hemispheric Lateralization in Visual Word Recognition—A Computational Exploration

Through computational modeling, here we examine whether visual and task characteristics of writing systems alone can account for lateralization differences in visual word recognition between different languages without assuming influence from left hemisphere (LH) lateralized language processes. We apply a hemispheric processing model of face recognition to visual word recognition; the model implements a theory of hemispheric asymmetry in perception that posits low spatial frequency biases in the right hemisphere and high spatial frequency (HSF) biases in the LH. We show two factors that can influence lateralization: (a) Visual similarity among words: The more similar the words in the lexicon look visually, the more HSF/LH processing is required to distinguish them, and (b) Requirement to decompose words into graphemes for grapheme‐phoneme mapping: Alphabetic reading (involving grapheme‐phoneme conversion) requires more HSF/LH processing than logographic reading (no grapheme‐phoneme mapping). These factors may explain the difference in lateralization between English and Chinese orthographic processing.     

Precision of synesthetic color matching resembles that for recollected colors rather than physical colors

Grapheme-color synesthesia is an atypical condition in which individuals experience sensations of color when reading printed graphemes such as letters and digits. For some grapheme-color synesthetes, seeing a printed grapheme triggers a sensation of color, but hearing the name of a grapheme does not. This dissociation allowed us to compare the precision with which synesthetes are able to match their color experiences triggered by visible graphemes, with the precision of their matches for recalled colors based on the same graphemes spoken aloud. In six synesthetes, color matching for printed graphemes was equally variable relative to recalled experiences. In a control experiment, synesthetes and age-matched controls either matched the color of a circular patch while it was visible on a screen, or they judged its color from memory after it had disappeared. Both synesthetes and controls were more variable when matching from memory, and the variance of synesthetes' recalled color judgments matched that associated with their synesthetic judgments for visible graphemes in the first experiment. Results suggest that synesthetic experiences of color triggered by achromatic graphemes are analogous to recollections of color. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

阅读障碍儿童的形音捆绑缺陷及其脑神经机制

形音捆绑缺陷研究是国内外阅读障碍研究领域的一个新方向。本文阐述了形音捆绑加工的理论与定义,综述了国内外研究者经常采用的三种形音捆绑的研究范式:配对联想学习、变化检测范式和线索回忆任务,介绍并分析了各研究范式的优缺点、适用范围及主要研究发现。同时,综述与评价了国内外有关阅读障碍形音捆绑缺陷的脑机制研究的主要结论及不足。最后,本文讨论了现有研究在实验设计和理论上的贡献与不足,提出了今后的研究方向和改进建议。     

Colours sometimes count: Awareness and bidirectionality in grapheme–colour synaesthesia

Three experiments were conducted with 10 grapheme–colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme–colour synaesthesia may be bidirectional in the sense that not only do graphemes induce colours, but that colours influence the processing of graphemes. Using attentional blink and Stroop paradigms with digit targets, we found that some synaesthetes did report “seeing” synaesthetic colours even when they were not able to report the inducing digit. Moreover, congruency effects (effects of matching the colour of digit presentation with the synaesthetic colour associated with that digit) suggested that grapheme–colour synaesthesia can be bidirectional, at least for some synaesthetes.     

Seeing double: the role of meaning in alphanumeric-colour synaesthesia

When PD, an alphanumeric-colour synaesthete, is shown black digits or letters, each grapheme elicits a highly specific colour, called a "photism" (e.g., a 2 induces green, a Z induces brown). Previous experiments showed that photisms interfere with video-colour naming when the photism colour and the video colour are incongruent. Here we used coloured ambiguous graphemes that could be interpreted as either digits or letters depending on context (e.g., an ambiguous grapheme was interpreted as a 2 if presented within a block of digit trials, but as a Z if presented within a block of letter trials). Ambiguous graphemes were presented in video colours that were either congruent or incongruent with PD's photisms. Crucially, what was a congruent trial in one context was an incongruent trial in the other context. PD's pattern of response times indicated that identical graphemes could induce differently coloured photisms depending on their interpretation. This suggests that the meaning of graphemes ultimately determines their synaesthetic colour.     

Biases and regularities of grapheme–colour associations in Japanese nonsynaesthetic population

Associations between graphemes and colours in a nonsynaesthetic Japanese population were investigated. Participants chose the most suitable colour from 11 basic colour terms for each of 40 graphemes from the four categories of graphemes used in the Japanese language (kana characters, English alphabet letters, and Arabic and kanji numerals). This test was repeated after a three-week interval. In their responses, which were not as temporally consistent as those of grapheme–colour synaesthetes, participants showed biases and regularities that were comparable to those of synaesthetes reported in past studies. Although it has been believed that only synaesthetes, and not nonsynaesthetes, tended to associate graphemes with colours based on grapheme frequency, Berlin and Kay's colour typology, and colour word frequency, participants in this study tended in part to associate graphemes with colours based on the above factors. Moreover, participants that were nonsynaesthetes tended to associate different graphemes that shared sounds and/or meanings (e.g., Arabic and kanji numerals representing the same number) with the same colours, which was analogous to the findings in Japanese synaesthetes. These results support the view that grapheme–colour synaesthesia might have its origins in cross-modal association processes that are shared with the general population.     

Interactions among end-effectors and movement parameters influence reaction time in discrete, rapid aimed movements.

Two reliable findings in discrete, rapid aimed movements are that reaction time increases with decrease in target diameter (for the short-length movements), and reaction time is not affected by movement length [Journal of Experimental Psychology, Human Perception and Performance 104 (2) (1975) 147]. Participants normally use a short stylus (SS) to tap targets located on either side of a central (aligned with body midline) start-point with no restrictions imposed on the initial posture of the limb or segmental recruitment except as determined by movement conditions. Thus, the effects of movement parameters on reaction time in previous work are potentially confounded with the effect of initial posture of the limb at the start-point, along with order and amount of the contribution of segments recruited in response execution. Two experiments were performed to resolve the confounding between initial posture and recruitment of limb segments. In the first experiment a conventional stylus (pen-like) was employed and the starting position of the limb was aligned either with the body midline or with the participant's right shoulder. The effect of starting position on reaction time was not significant. In the second experiment the starting position was in line with the right shoulder. Two groups participated. One group used a conventional stylus. For the second group a modified (lengthened) stylus was used that permitted initial limb posture and number of limb segments recruited to be held constant across an extended range of movement lengths. When similar sets of limb segments were used, reaction time increased with decreasing movement length and diminishing target diameter. These findings suggest that uncontrolled initial limb posture, uncontrolled order of joint(s) recruitment, and the subsequent inclusion of reaction time values from incompatible sources may, in the final analysis, have confounded previous work investigating movement amplitude and target diameter effects on reaction time.     

Spoken language planning and the initiation of articulation

Minimalist theories of spoken language planning hold that articulation starts when the first speech segment has been planned, whereas non-minimalist theories assume larger units (e.g., Levelt, Roelofs, & Meyer, 1999a). Three experiments are reported, which were designed to distinguish between these views using a new hybrid task that factorially manipulated preparation and auditory priming of spoken language production. Minimalist theories predict no effect from priming of non-initial segments when the initial segment of an utterance is already prepared; observing such a priming effect would support non-minimalist theories. In all three experiments, preparation and priming yielded main effects, and together their effects were additive. Preparation of initial segments does not eliminate priming effects for later segments. These results challenge the minimalist view. The findings are simulated by WEAVER++ (Roelofs, 1997b), which employs the phonological word as the lower limit for articulation initiation.     

Implication des fonctions exécutives dans le décodage en lecture : étude comparative entre normolecteurs et faibles lecteurs de CE2

The implication of executive functions in reading was studied. Normo and poor third grade readers were compared in an illusory conjunction task using the selection of a letter features embedded in a grapheme or risen to the syllable boundary. Executive task of updating or shifting were then added to this task. According to decoding progress from graphemes to syllables we suppose that the cost of executive processing will be more important for poor readers. Results showed that addition of an executive control task to a selection task, led to an increase in response times for poor readers whatever the presentation (grapheme, syllable).     

Grapheme-color synaesthesia benefits rule-based Category learning

Researchers have long suspected that grapheme-color synaesthesia is useful, but research on its utility has so far focused primarily on episodic memory and perceptual discrimination. Here we ask whether it can be harnessed during rule-based Category learning. Participants learned through trial and error to classify grapheme pairs that were organized into categories on the basis of their associated synaesthetic colors. The performance of synaesthetes was similar to non-synaesthetes viewing graphemes that were physically colored in the same way. Specifically, synaesthetes learned to categorize stimuli effectively, they were able to transfer this learning to novel stimuli, and they falsely recognized grapheme-pair foils, all like non-synaesthetes viewing colored graphemes. These findings demonstrate that synaesthesia can be exploited when learning the kind of material taught in many classroom settings.     

Temporal Distribution of Attention During a Throwing Motion

A reaction-time measure of attention was employed during five segments of a simultaneous dart throw: premovement decision, immediately after recoil was begun, maximum recoil, immediately after forward movement was begun, and after release of the dart. Reaction time was significantly longer when the stimulus was presented during the first or second segment than during later segments. Reaction time during premovement was not consistently greater than that immediately after movement was begun, indicating that information is being sampled at a high rate after movement commences. It appears that monitoring of proprioceptive feedback after movement has begun, and initiation of corrective submovements, is necessary for skillful performance of dart throwing.     

Effects of orthographic consistency, frequency, and letter knowledge on children's vowel spelling development

This study investigated children's sensitivity to spelling consistency, and lexical and sublexical (rime) frequency, and their use of explicitly learned canonical vowel graphemes in the early stages of learning to spell. Vowel spellings produced by 78 British children at the end of reception year (mean age 5 years, 7 months) and 6 months later in mid-Year 1 were assessed. Regression analyses revealed that, at both test times, knowledge of sound-letter correspondences influenced spelling performance; however, unconditional consistency of vowel spellings affected children's spelling most strongly, over and above additional effects of word and rime frequency and the complexity of the target vowel grapheme. The effect of conditional consistency of vowel spellings given coda contexts was not significant. Thus, young children are sensitive to various statistical properties of the orthography from the earliest phases of spelling development and, in particular, to the unconditional consistency of the vowel spelling pattern.     

The dual role of vision in sequential aiming movements

Previous research has demonstrated that movement times to the first target in sequential aiming movements are influenced by the properties of subsequent segments. Based on this finding, it has been proposed that individual segments are not controlled independently. The purpose of the current study was to investigate the role of visual feedback in the interaction between movement segments. In contrast to past research in which participants were instructed to minimize movement time, participants were set a criterion movement time and the resulting errors and limb trajectory kinematics were examined under vision and no vision conditions. Similar to single target movements, the results indicated that vision was used within each movement segment to correct errors in the limb trajectory. In mediating the transition between segments, visual feedback from the first movement segment was used to adjust the parameters of the second segment. Hence, increases in variability that occurred from the first to the second target in the no vision condition were curtailed when visual feedback was available. These results are discussed along the lines of the movement constraint and movement integration hypotheses.