Visual similarity effects on masked priming

We investigated the role of the visual similarity of masked primes to targets in a lexical decision experiment. In the primes, some letters in the target (e.g., A in ABANDON) had either visually similar letters (e.g., H), dissimilar letters (D), visually similar digits (4), or dissimilar digits (6) substituted for them. The similarities of the digits and letters to the base letter were equated and verified in a two-alternative forced choice (2AFC) perceptual identification task. Using targets presented in lowercase (e.g., abandon) and primes presented in uppercase, visually similar digit primes (e.g., 484NDON) produced more priming than did visually dissimilar digit primes (676NDON), but little difference was found between the visually similar and dissimilar letter primes (HRHNDON vs. DWDNDON). These results were explained in terms of task-driven competition between the target letter and the visually similar letter.     

Bedding down new words: Sleep promotes the emergence of lexical competition in visual word recognition

Lexical competition processes are widely viewed as the hallmark of visual word recognition, but little is known about the factors that promote their emergence. This study examined for the first time whether sleep may play a role in inducing these effects. A group of 27 participants learned novel written words, such as banara, at 8 am and were tested on their learning at 8 pm the same day (AM group), while 29 participants learned the words at 8 pm and were tested at 8 am the following day (PM group). Both groups were retested after 24 hours. Using a semantic categorization task, we showed that lexical competition effects, as indexed by slowed responses to existing neighbor words such as banana, emerged 12 h later in the PM group who had slept after learning but not in the AM group. After 24 h the competition effects were evident in both groups. These findings have important implications for theories of orthographic learning and broader neurobiological models of memory consolidation.     

Item-specific adaptation and the conflict-monitoring hypothesis: a computational model

M. M. Botvinick, T. S. Braver, D. M. Barch, C. S. Carter, and J. D. Cohen (2001) implemented their conflict-monitoring hypothesis of cognitive control in a series of computational models. The authors of the current article first demonstrate that M. M. Botvinick et al.'s (2001) conflict-monitoring Stroop model fails to simulate L. L. Jacoby, D. S. Lindsay, and S. Hessels's (2003) report of an item-specific proportion-congruent (ISPC) effect in the Stroop task. The authors then implement a variant of M. M. Botvinick et al.'s model based on the assumption that control must be able to operate at the item level. This model successfully simulates the ISPC effect. In addition, the model provides an alternative to M. M. Botvinick et al.'s explanation of the list-level proportion-congruent effect in terms of an ISPC effect. Implications of the present modeling effort are discussed.     

Constraints on computational models of basic processes in reading

There are numerous reports in the visual word recognition literature that the joint effects of various factors are additive on reaction time. A central claim by D. C. Plaut and J. R. Booth (2000, 2006) is that their parallel distributed processing model simulates additive effects of stimulus quality and word frequency in the context of lexical decision. If correct, this success would have important implications for computational accounts of reading processes. However, the results of further simulations with this model undermine this claim given that the joint effects of stimulus quality and word frequency yield a nonmonotonic function (underadditivity, additivity, and overadditivity) depending on the size of the stimulus quality effect, whereas skilled readers yield additivity more broadly. The implications of these results both locally and more globally are discussed, and a number of other issues are noted. Additivity of factor effects constitutes a benchmark that computational accounts should strive to meet.     

Children reading spoken words: interactions between vocabulary and orthographic expectancy

There is an established association between children's oral vocabulary and their word reading but its basis is not well understood. Here, we present evidence from eye movements for a novel mechanism underlying this association. Two groups of 18 Grade 4 children received oral vocabulary training on one set of 16 novel words (e.g., ‘nesh’, ‘coib’), but no training on another set. The words were assigned spellings that were either predictable from phonology (e.g., nesh) or unpredictable (e.g., koyb). These were subsequently shown in print, embedded in sentences. Reading times were shorter for orally familiar than unfamiliar items, and for words with predictable than unpredictable spellings but, importantly, there was an interaction between the two: children demonstrated a larger benefit of oral familiarity for predictable than for unpredictable items. These findings indicate that children form initial orthographic expectations about spoken words before first seeing them in print. A video abstract of this article can be viewed at: https://youtu.be/jvpJwpKMM3E .