Laura M. Gonnerman

The Role of the Posterior Fusiform Gyrus in Reading

Studies of skilled reading [Price, C. J., & Mechelli, A. Reading and reading disturbance. Current Opinion in Neurobiology, 15, 231238, 2005], its acquisition in children [Shaywitz, B. A., Shaywitz, S. E., Pugh, K. R., Mencl, W. E., Fulbright, R. K., Skudlarski, P., et al. Disruption of posterior brain systems for reading in children with developmental dyslexia. Biological Psychiatry, 52, 101110, 2002; Turkeltaub, P. E., Gareau, L., Flowers, D. L., Zeffiro, T. A., & Eden, G. F. Development of neural mechanisms for reading. Nature Neuroscience, 6, 767773, 2003], and its impairment in patients with pure alexia [Leff, A. P., Crewes, H., Plant, G. T., Scott, S. K., Kennard, C., & Wise, R. J. The functional anatomy of single word reading in patients with hemianopic and pure alexia. Brain, 124, 510521, 2001] all highlight the importance of the left posterior fusiform cortex in visual word recognition. We used visual masked priming and functional magnetic resonance imaging to elucidate the specific functional contribution of this region to reading and found that (1) unlike words, repetition of pseudowords (solst-solst) did not produce a neural priming effect in this region, (2) orthographically related words such as corner-corn did produce a neural priming effect, but (3) this orthographic priming effect was reduced when prime-target pairs were semantically related (teacher-teach). These findings conflict with the notion of stored visual word forms and instead suggest that this region acts as an interface between visual form information and higher order stimulus properties such as its associated sound and meaning. More importantly, this function is not specific to reading but is also engaged when processing any meaningful visual stimulus.

Graded semantic and phonological similarity effects in priming: evidence for a distributed connectionist approach to morphology.

A considerable body of empirical and theoretical research suggests that morphological structure governs the representation of words in memory and that many words are decomposed into morphological components in processing. The authors investigated an alternative approach in which morphology arises from the interaction of semantic and phonological codes. A series of cross-modal lexical decision experiments shows that the magnitude of priming reflects the degree of semantic and phonological overlap between words. Crucially, moderately similar items produce intermediate facilitation (e.g., lately-late). This pattern is observed for word pairs exhibiting different types of morphological relationships, including suffixed-stem (e.g., teacher-teach), suffixed-suffixed (e.g., saintly-sainthood), and prefixed-stem pairs (preheat-heat). The results can be understood in terms of connectionist models that use distributed representations rather than discrete morphemes.

Information content versus relational knowledge: Semantic deficits in patients with Alzheimer's disease

Studies of semantic impairment in Alzheimers disease (AD) have yielded conflicting results, some finding evidence of considerable deficits, others finding that semantic knowledge is relatively intact. How do we reconcile findings from picture naming tasks that seem to indicate semantic impairment in AD with results from certain sorting tasks that suggest intact semantics? To investigate the basis of the contradictory results described above, we conducted a study using two types of tasks: (1) picture naming; and (2) board sorting. The board sorting task we used is a simultaneous similarity judgment task, in which participants are asked to place more similar concepts closer together and less similar ones farther apart. We compared the performance of AD patients on these two tasks, using a number of different analyses that yield very different patterns of results. Our results indicate that whether patients show impairment or not depends on both the nature of the task and the subsequent analysis chosen. Specifically, tasks and analyses that focus on relational knowledge (e.g., dog is more related to cat than to camel) lead to different conclusions than those based on specific information about individual items. These findings suggest that the board sorting method, when coupled with multiple analyses, provides a more complete picture of the underlying semantic deficit in AD than previous studies have shown.

Speech articulation performance of francophone children in the early school years: Norming of the Test de Dépistage Francophone de Phonologie

Abstract Good quality normative data are essential for clinical practice in speech-language pathology but are largely lacking for French-speaking children. We investigated speech production accuracy by French-speaking children attending kindergarten (maternelle) and first grade (première année). The study aimed to provide normative data for a new screening test – the Test de Dépistage Francophone de Phonologie. Sixty-one children named 30 pictures depicting words selected to be representative of the distribution of phonemes, syllable shapes and word lengths characteristic of Québec French. Percent consonants’ correct was approximately 90% and did not change significantly with age although younger children produced significantly more syllable structure errors than older children. Given that the word set reflects the segmental and prosodic characteristics of spoken Québec French, and that ceiling effects were not observed, these results further indicate that phonological development is not complete by the age of seven years in French-speaking children.

Explicit and implicit semantic processing of verb–particle constructions by French–English bilinguals

Verb–particle constructions are a notoriously difficult aspect of English to acquire for second-language (L2) learners. The present study investigated whether L2 English speakers are sensitive to gradations in semantic transparency of verb–particle constructions (e.g., finish up vs. chew out). French–English bilingual participants (first language: French, second language: English) completed an off-line similarity ratings survey, as well as an on-line masked priming task. Results of the survey showed that bilinguals’ similarity ratings became more native-like as their English proficiency levels increased. Results from the masked priming task showed that response latencies from high, but not low-proficiency bilinguals were similar to those of monolinguals, with mid- and high-similarity verb–particle/verb pairs (e.g., finish up/finish) producing greater priming than low-similarity pairs (e.g., chew out/chew). Taken together, the results suggest that L2 English speakers develop both explicit and implicit understanding of the semantic properties of verb–particle constructions, which approximates the sensitivity of native speakers as English proficiency increases.

The Development of Morphological Representations in Young Readers: A Cross-Modal Priming Study.

The way children organize words in their memory has intrigued many researchers in the past 20 years. Given the large number of morphologically complex words in many languages, the influence of morphemes on this organization is being increasingly examined. The aim of this study was to understand how morphemic information influences English-speaking childrens word recognition. Children in grades 3 and 5 were asked to complete a lexical decision priming task. Prime-target pairs varied in semantic similarity, with low (e.g., belly-bell), moderate (e.g., lately-late), and high similarity relations (e.g., boldly-bold). There were also word pairs similar in form only (e.g., spinach-spin) and in semantics only (e.g., garbage-trash). Primes were auditory and targets were presented visually. Analyses of childrens lexical decision times revealed graded priming effects as a function of the convergence of form and meaning. These results indicate that developing readers do not necessarily need to lexicalize morphological units to facilitate word recognition. Their ability to process the morphological structure of words depends on their ability to develop connections between form and meaning.

The Factors Contributing to Teacher Predictions of Spelling Ability, and the Accuracy of Their Assessments

In this study, teachers of kindergarten and Grade 1 French-speaking students indicated the likelihood their students would develop later writing difficulties. Results showed that language measures, language background, the education levels of parents, and home literacy practices predicted whether children would be identified as at-risk. Moreover children’s oral language skills accounted for even more of the variance in teacher ratings than other variables. Spelling performance assessed 1-year later from a subset of children indicated that the teacher predictions were accurate. Thus, teachers appear to be an effective source for predicting children’s future literacy performance.