Protracted Neural Development of Dorsal Motor Systems During Handwriting and the Relation to Early Literacy Skills.

Handwriting is a complex visual-motor skill that affects early reading development. A large body of work has demonstrated that handwriting is supported by a widespread neural system comprising ventral-temporal, parietal, and frontal motor regions in adults. Recent work has demonstrated that this neural system is largely established by 8 years of age, suggesting that the development of this system occurs in young children who are still learning to read and write.

The Effects of Frequency, Variability, and Co-occurrence on Category Formation in Neural Systems.

Objects are grouped into categories through a complex combination of statistical and structural regularities. We sought to better understand the neural responses to the structural features of object categories that result from implicit learning. Adult participants were exposed to 32 object categories that contained three structural properties: frequency, variability, and co-occurrences, during an implicit learning task.

Category structure guides the formation of neural representations.

Perceptual variability is often viewed as having multiple benefits in object learning and categorization. Despite the abundant results demonstrating benefits such as increased transfer of knowledge, the neural mechanisms underlying variability as well as the developmental trajectories of how variability precipitates changes to category boundaries are unknown. By manipulating an individual's exposure to variability of novel, metrically organized categories during an fMRI-adaptation paradigm, we were able to assess the functional differences between similarity and variability in category learning and generalization across two time-points in development: adulthood (n = 14) and late childhood (n = 13).

"Neural differences in expert guitarists during over-learned non-standard visuomotor mapping of abstract versus concrete information".

Using visual information to perform actions is a fundamental aspect of human behavior. Musicians commonly translate visual information into action using both concrete and abstract visual information. We exposed expert guitarists to four types of familiar visual depictions of action instruction including musical notation (very abstract), tablature (abstract), chord diagrams (more concrete), and actual pictures of guitars chords being formed (very concrete).

Ecological validity of experimental set-up affects parietal involvement during letter production.

Studies of symbol production using fMRI often use techniques that introduce an artificial pairing between motor production and visual perception. These techniques allow participants to see their own output by recording their pen trajectories using a touchscreen-only tablet and displaying these productions on a mirror placed above their head. We recently developed an MR-safe writing tablet with video display that allows participants to see their own hand and their own productions while producing symbols in real time on the surface where they are producing them-allowing for more ecologically valid fMRI studies of production.

Constraining Stroke Order During Manual Symbol Learning Hinders Subsequent Recognition in Children Under 4 1/2 Years.

In the age of technology, writing by hand has become less common than texting and keyboarding. Learning letters by hand, however, has been shown to have profound developmental importance. One aspect of writing by hand that has been understudied is the effect of learning symbols stroke-by-stroke, a dynamic action that does not occur with keyboarding.

Visual experiences during letter production contribute to the development of the neural systems supporting letter perception.

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.

Learning math by hand: The neural effects of gesture-based instruction in 8-year-old children.

Producing gesture can be a powerful tool for facilitating learning. This effect has been replicated across a variety of academic domains, including algebra, chemistry, geometry, and word learning. Yet the mechanisms underlying the effect are poorly understood.

An Analysis of the Brain Systems Involved with Producing Letters by Hand.

Complex visual-motor behaviors dominate human-environment interactions. Letter production, writing individual letters by hand, is an example of a complex visual-motor behavior composed of numerous behavioral components, including the required motor movements and the percepts that those motor movements create. By manipulating and isolating components of letter production, we provide experimental evidence that this complex visual-motor behavior is supported by a widespread neural system that is composed of smaller subsystems related to different sensorimotor components.

Functional fixedness in tool use: Learning modality, limitations and individual differences.

Functional fixedness is a cognitive bias that describes how previous knowledge of a tool's function can negatively impact the use of this tool in novel contexts. As such, functional fixedness disturbs the use of tools during mechanical problem solving. Little is known about whether this bias emerges from different experiences with tools, whether it occurs regardless of problem difficulty, or whether there are protective factors against it.

Gesture for generalization: gesture facilitates flexible learning of words for actions on objects.

Verb learning is difficult for children (Gentner, ), partially because children have a bias to associate a novel verb not only with the action it represents, but also with the object on which it is learned (Kersten & Smith, ). Here we investigate how well 4- and 5-year-old children (N = 48) generalize novel verbs for actions on objects after doing or seeing the action (e.g.

A new statistical model for analyzing rating scale data pertaining to word meaning.

The concrete-abstract categorization scheme has guided several research programs. A popular way to classify words into one of these categories is to calculate a word's mean value in a Concreteness or Imageability rating scale. However, this procedure has several limitations.

Dorsal stream function in the young child: an fMRI investigation of visually guided action.

Visually guided action is a ubiquitous component of human behavior, but the neural substrates that support the development of this behavior are unknown. Here we take an initial step in documenting visual-motor system development in the young (4- to 7-year-old) child. Through functional MRI and by using a new technique to measure the mechanisms underlying real-time visually guided action in the MRI environment, we demonstrate that children rely primarily on the IPS and cerebellum for this complex behavior.

Handwriting generates variable visual output to facilitate symbol learning.

Recent research has demonstrated that handwriting practice facilitates letter categorization in young children. The present experiments investigated why handwriting practice facilitates visual categorization by comparing 2 hypotheses: that handwriting exerts its facilitative effect because of the visual-motor production of forms, resulting in a direct link between motor and perceptual systems, or because handwriting produces variable visual instances of a named category in the environment that then changes neural systems. We addressed these issues by measuring performance of 5-year-old children on a categorization task involving novel, Greek symbols across 6 different types of learning conditions: 3 involving visual-motor practice (copying typed symbols independently, tracing typed symbols, tracing handwritten symbols) and 3 involving visual-auditory practice (seeing and saying typed symbols of a single typed font, of variable typed fonts, and of handwritten examples).

Crossmodal enhancement in the LOC for visuohaptic object recognition over development.

Research has provided strong evidence of multisensory convergence of visual and haptic information within the visual cortex. These studies implement crossmodal matching paradigms to examine how systems use information from different sensory modalities for object recognition. Developmentally, behavioral evidence of visuohaptic crossmodal processing has suggested that communication within sensory systems develops earlier than across systems; nonetheless, it is unknown how the neural mechanisms driving these behavioral effects develop.

Effects of learning with gesture on children's understanding of a new language concept.

Asking children to gesture while being taught a concept facilitates their learning. Here, we investigated whether children benefitted equally from producing gestures that reflected speech (speech-gesture matches) versus gestures that complemented speech (speech-gesture mismatches), when learning the concept of palindromes. As in previous studies, we compared the utility of each gesture strategy to a speech alone strategy.

Neural substrates of sensorimotor processes: letter writing and letter perception.

Writing and perceiving letters are thought to share similar neural substrates; however, what constitutes a neural representation for letters is currently debated. One hypothesis is that letter representation develops from sensorimotor experience resulting in an integrated set of modality-specific regions, whereas an alternative account suggests that letter representations may be abstract, independent of modality. Studies reviewed suggest that letter representation consists of a network of modality-responsive brain regions that may include an abstract component.

Using the axis of elongation to align shapes: developmental changes between 18 and 24 months of age.

An object's axis of elongation serves as an important frame of reference for forming three-dimensional representations of object shape. By several recent accounts, the formation of these representations is also related to experiences of acting on objects. Four experiments examined 18- to 24-month-olds' (N=103) sensitivity to the elongated axis in action tasks that required extracting, comparing, and physically rotating an object so that its major axis was aligned with that of a visual standard.

Some views are better than others: evidence for a visual bias in object views self-generated by toddlers.

How objects are held determines how they are seen, and may thereby play an important developmental role in building visual object representations. Previous research suggests that toddlers, like adults, show themselves a disproportionate number of planar object views - that is, views in which the objects' axes of elongation are perpendicular or parallel to the line of sight. Here, three experiments address three explanations of this bias: (1) that the locations of interesting features of objects determine how they are held and thus how they are viewed; (2) that ease of holding determines object views; and (3) that there is a visual bias for planar views that exists independently of holding and of interesting surface properties.

Brain activation patterns resulting from learning letter forms through active self-production and passive observation in young children.

Although previous literature suggests that writing practice facilitates neural specialization for letters, it is unclear if this facilitation is driven by the perceptual feedback from the act of writing or the actual execution of the motor act. The present study addresses this issue by measuring the change in BOLD signal in response to hand-printed letters, unlearned cursive letters, and cursive letters that 7-year-old children learned actively, by writing, and passively, by observing an experimenter write. Brain activation was assessed using fMRI while perceiving letters-in both cursive and manuscript forms.

Neural correlates of gesture processing across human development.

Co-speech gesture facilitates learning to a greater degree in children than in adults, suggesting that the mechanisms underlying the processing of co-speech gesture differ as a function of development. We suggest that this may be partially due to children's lack of experience producing gesture, leading to differences in the recruitment of sensorimotor networks when comparing adults to children. Here, we investigated the neural substrates of gesture processing in a cross-sectional sample of 5-, 7.

The effects of handwriting experience on functional brain development in pre-literate children.

In an age of increasing technology, the possibility that typing on a keyboard will replace handwriting raises questions about the future usefulness of handwriting skills. Here we present evidence that brain activation during letter perception is influenced in different, important ways by previous of letters versus previous of those same letters. Preliterate, five-year old children printed, typed, or traced letters and shapes, then were shown images of these stimuli while undergoing functional MRI scanning.

Expert individuation of objects increases activation in the fusiform face area of children.

The role of experience in the development of brain mechanisms for face recognition is intensely debated. Experience with subordinate- and individual-level classification of faces is thought, by some, to be foundational in the development of the specialization of face recognition. Studying children with extremely intense interests (EII) provides an opportunity to examine experience-related changes in non-face object recognition in a population where face expertise is not fully developed.

The Lateralizer: a tool for students to explore the divided brain.

Despite a profusion of popular misinformation about the left brain and right brain, there are functional differences between the left and right cerebral hemispheres in humans. Evidence from split-brain patients, individuals with unilateral brain damage, and neuroimaging studies suggest that each hemisphere may be specialized for certain cognitive processes. One way to easily explore these hemispheric asymmetries is with the divided visual field technique, where visual stimuli are presented on either the left or right side of the visual field and task performance is compared between these two conditions; any behavioral differences between the left and right visual fields may be interpreted as evidence for functional asymmetries between the left and right cerebral hemispheres.