Karin Harman James

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 handwriting of letters versus previous typing or tracing 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. A previously documented “reading circuit” was recruited during letter perception only after handwriting—not after typing or tracing experience. These findings demonstrate that handwriting is important for the early recruitment in letter processing of brain regions known to underlie successful reading. Handwriting therefore may facilitate reading acquisition in young children.

Since Broca’s studies on language processing, cortical functional specialization has been considered to be integral to efficient neural processing. A fundamental question in cognitive neuroscience concerns the type of learning that is required for functional specialization to develop. To address this issue with respect to the development of neural specialization for letters, we used functional magnetic resonance imaging (fMRI) to compare brain activation patterns in pre‐school children before and after different letter‐learning conditions: a sensori‐motor group practised printing letters during the learning phase, while the control group practised visual recognition. Results demonstrated an overall left‐hemisphere bias for processing letters in these pre‐literate participants, but, more interestingly, showed enhanced blood oxygen‐level‐dependent activation in the visual association cortex during letter perception only after …

Behavioral, neuropsychological and neuroimaging research suggest a distributed network that is recruited when we interact with letters. For the first time, we combine several letter processing tasks in a single experiment to study why letters seem to engage such disparate processing areas. Using fMRI, we investigate how the brain responds to letters using tasks that should recruit systems for letter perception, letter writing, letter copying and letter imagery. We describe a network of five cortical regions including the left fusiform gyrus, two left pre-central areas, left cuneus and the left inferior frontal gyrus that are all selectively engaged during a 1-back matching paradigm with letters. Our results suggest involvement of these regions to different extents in different tasks. However, the regions also form an integrated network such that letter perception also engages motor regions while writing recruits letter-specific visual …

One would expect that a lifetime of experience recognizing letters would have an important influence on the visual system. Surprisingly, there is limited evidence of a specific neural response to letters over visual control stimuli. We measured brain activation during a sequential matching task using isolated characters (Roman letters, digits, and Chinese characters) and strings of characters. We localized the visual word form area (VWFA) by contrasting the response to pseudowords against that for letter strings, but this region did not show any other sign of visual specialization for letters. In addition, a left fusiform area posterior to the VWFA was selective for letter strings, whereas a more anterior left fusiform region showed selectivity for single letters. The results of different analyses using both large regions of interest and inspections of individual patterns of response reveal a dissociation between selectivity for …

Functional specialization in the brain is considered a hallmark of efficient processing. It is therefore not surprising that there are brain areas specialized for processing letters. To better understand the causes of functional specialization for letters, we explore the emergence of this pattern of response in the ventral processing stream through a training paradigm. Previously, we hypothesized that the specialized response pattern seen during letter perception may be due in part to our experience in writing letters. The work presented here investigates whether or not this aspect of letter processing—the integration of sensorimotor systems through writing—leads to functional specialization in the visual system. To test this idea, we investigated whether or not different types of experiences with letter-like stimuli (“pseudoletters”) led to functional specialization similar to that which exists for letters. Neural activation patterns were …

Lors d'une étude antérieure (Harman, Humphrey et Goodale, 1999), nous avons démontré que les observateurs qui effectuaient eux-mêmes la rotation d'objets tridimensionnels nouveaux, présentés à l'écran d'un ordinateur, affichaient une reconnaissance visuelle de ces objets plus rapide que ne le faisaient les observateurs qui avaient passivement visionné la même suite d'images illustrant ces objets virtuels. Dans l'expérience 1 de la présente étude, nous avons montré que, par rapport à l'observation passive, l'exploration active de la structure d'un objet tridimensionnel accélère la performance lors d'une tâche de «rotation mentale» qui met en jeu les objets explorés. De plus, nous avons évalué le temps que les observateurs consacraient à différentes vues particulières des objets pendant l'exploration active. Comme dans notre précédente étude, ils ont consacré la majorité de leur temps aux vues de côté et de …

We used a fully immersive virtual reality environment to study whether actively interacting with objects would effect subsequent recognition, when compared with passively observing the same objects. We found that when participants learned object structure by actively rotating the objects, the objects were recognized faster during a subsequent recognition task than when object structure was learned through passive observation. We also found that participants focused their study time during active exploration on a limited number of object views, while ignoring other views. Overall, our results suggest that allowing active exploration of an object during initial learning can facilitate recognition of that object, perhaps owing to the control that the participant has over the object views upon which they can focus. The virtual reality environment is ideal for studying such processes, allowing realistic interaction with …

Previous research shows that sensory and motor systems interact during perception, but how these connections among systems are created during development is unknown. The current work exposes young children to novel ‘verbs’ and objects through either (a) actively exploring the objects or (b) by seeing an experimenter interact with the objects. Results demonstrate that the motor system is recruited during auditory perception only after learning involved self‐generated interactions with objects. Action observation itself led to above‐baseline activation in one motor region during visual perception, but was still significantly less active than after self‐generated action. Therefore, in the developing brain, associations are built upon real‐world interactions of body and environment, leading to sensori‐motor representations of both objects and words.

This study investigated neural activation patterns during verb processing in children, using fMRI (functional Magnetic Resonance Imaging). Preschool children (aged 4–6) passively listened to lists of verbs and adjectives while neural activation was measured. Findings indicated that verbs were processed differently than adjectives, as the verbs recruited motor systems in the frontal cortex during auditory perception, but the adjectives did not. Further evidence suggested that different types of verbs activated different regions in the motor cortex. The results demonstrate that the motor system is recruited during verb perception in the developing brain, reflecting the embodied nature of language learning and processing.

O bjects can be recognized using any of our sensory modalities. For instance, a bumblebee can be recognized by seeing its characteristic yellow and black colors, by hearing its distinctive buzzing sound, by feeling the fuzzy surface of its body as it walks across our hand, by experiencing the pain as it stings our finger, or by any combination of these cues. But, it is only by using vision and touch that the complex three-dimensional (3-D) geometric properties of particular objects can be recognized. Of these two senses, vision is the one we use most often to identify objects—although the tactile system (or haptics) is also useful, particularly in situations where the objects cannot be seen. Haptics can also provide information about the weight, compliance, and tem-perature of an object—as well as information about its surface features, such

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. Results showed that active training led to increased recruitment of the sensori-motor network associated with letter perception as well as the insula and claustrum, but passive observation did not. This suggests that perceptual networks for newly learned cursive letters are driven by motor execution rather than by perceptual feedback.

We performed an event-related fMRI study comparing attempts at suppressing recall of negative versus neutral memories. The hippocampus is crucial for successful explicit recall. Hippocampal activation has been shown to decrease during the suppression of previously learned neutral words. However, different effects may occur in the case of emotional memories. Participants first learned 40 word pairs consisting of a cue and either a neutral or a negative target. During fMRI scanning, the participants were shown the cues and were instructed to recall the targets or to suppress the targets, using attentional distraction. Similar right-lateralized frontoparietal regions were activated more during suppression than during recall, regardless of emotion. However, we show for the first time that lowered hippocampal activation occurs during the suppression of neutral, but not negative, words. Coinciding with this …

Millennia ago Pythagoras noted a simple but remarkably powerful rule for the aesthetics of tone combinations: pairs of tones^ intervals^ with simple ratios such as an octave (ratio 2: 1) or a¢ fth (ratio 3: 2) were pleasant sounding (consonant), whereas intervals with complex ratios such as the major seventh (ratio 243: 128) were harsh (dissonant). These Pythagorean ratio rules are the building blocks of Western classical music; however, their neurophysiologic basis is not known. Using functional MRI we have found the neurophysiologic correlates of the ratio rules. In musicians, the inferior frontal gyrus, superior temporal gyrus, medial frontal gyrus, inferior parietal lobule and anterior cingulate respond with progressively more activation to perfect consonances, imperfect consonances and dissonances. In nonmusicians only the right inferior frontal gyrus follows this pattern. NeuroReport 18: 1521^ 1525 c 2007 Wolters …

The effect of writing on the concurrent visual perception of letters was investigated in a series of studies using an interference paradigm. Participants drew shapes and letters while simultaneously visually identifying letters and shapes embedded in noise. Experiments 1–3 demonstrated that letter perception, but not the perception of shapes, was affected by motor interference. This suggests a strong link between the perception of letters and the neural substrates engaged during writing. The overlap both in category (letter vs. shape) and in the perceptual similarity of the features (straight vs. curvy) of the seen and drawn items determined the amount of interference. Experiment 4 demonstrated that intentional production of letters is not necessary for the interference to occur, because passive movement of the hand in the shape of letters also interfered with letter perception. When passive movements were used …

Object recognition depends on the seen views of objects. These views depend in part on the perceivers' own actions as they select and show object views to themselves. The self-selection of object views from manual exploration of objects during infancy and childhood may be particularly informative about the human object recognition system and its development. Here, we report for the first time on the structure of object views generated by 12 to 36 month old children (N= 54) and for comparison adults (N= 17) during manual and visual exploration of objects. Object views were recorded via a tiny video camera placed low on the participant's forehead. The findings indicate two viewing biases that grow rapidly in the first three years: a bias for planar views and for views of objects in an upright position. These biases also strongly characterize adult viewing. We discuss the implications of these findings for a developmentally complete theory of object recognition.