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Letter production through handwriting creates visual experiences that may be important for the development of visual letter perception. We sought to better understand the neural responses to different visual percepts created during handwriting at different levels of experience. Three groups of participants, younger children, older children, and adults, ranging in age from 4.5 to 22 years old, were presented with dynamic and static presentations of their own handwritten letters, static presentations of an age-matched control's handwritten letters, and typeface letters during fMRI. First, data from each group were analyzed through a series of contrasts designed to highlight neural systems that were most sensitive to each visual experience in each age group. We found that younger children recruited ventral-temporal cortex during perception and this response was associated with the variability present in handwritten forms. Older children and adults also recruited ventral-temporal cortex; this response, however, was significant for typed letter forms but not variability. The adult response to typed letters was more distributed than in the children, including ventral-temporal, parietal, and frontal motor cortices. The adult response was also significant for one's own handwritten letters in left parietal cortex. Second, we compared responses among age groups. Compared to older children, younger children demonstrated a greater fusiform response associated with handwritten form variability. When compared to adults, younger children demonstrated a greater response to this variability in left parietal cortex. Our results suggest that the visual perception of the variability present in handwritten forms that occurs during handwriting may contribute to developmental changes in the neural systems that support letter perception.

Previous research has suggested that handwriting letters may be an important exerciser to facilitate early letter understanding. Experimental studies to date, however, have not investigated whether this effect is general to any visual-motor experience or specific to handwriting letters. In the present work, we addressed this issue by testing letter knowledge using three measures in preschool children before and after a school-based intervention. Participants were divided into four training groups (letter-writing, digit-writing, letter-viewing, digit-viewing) that either wrote letters or digits or viewed letters or digits, twice a week for 6 weeks. We hypothesized that the visual-motor experience of handwriting letters or digits would improve letter knowledge more than viewing experience and that this effect would not be specific to training with letters. Our results demonstrated that the writing groups improved in letter recognition--one component of letter knowledge--significantly more than the viewing groups. The letter-writing group did not improve significantly more than the digit-writing group. These results suggest that visual-motor practice with any symbol could lead to increases in letter recognition. We interpret this novel finding as suggesting that any handwriting will increase letter recognition in part because it facilitates gains in visual-motor coordination.

Fetal Alcohol Syndrome (FAS) is a developmental disorder caused by maternal drinking during pregnancy. Computerize imaging techniques have been applied to study human facial dysmorphology associated with FAS. This paper describes a new facial image analysis method based on a multi-angle image classification technique using micro-video images of mouse embryo. Images taken from several different angles are analyzed separately, and the results are combined for classifications that separate embryos with and without alcohol exposures. Analysis results from animal models provide critical references for the understanding of FAS and potential therapy solutions for human patients.