OS_12. Orthographic processing

Friday, September 30th,   2011 [14:20 - 16:00]

TALKS

OS_12.1 - An ERP investigation of location-specific and location-independent orthographic priming

Ktori, M. ^{1, 2} , Grainger, J. ^{1, 2} , Dufau, S. ^{1, 2} & Holcomb, P. J. ³

1 CNRS, France
2 Laboratoire de Psychology Cognitive (LPC), Aix-Marseille University, Marseille, France
3 Department of Psychology, Tufts University, Medford, Massachusetts, U.S.A.

The present study used event-related potentials (ERPs) to examine the time-course of location-specific and location-independent orthographic priming. In a masked sandwich priming experiment, changes in the relative positions of letters in prime and target stimuli combined with shifts of prime location relative to target location were manipulated. In particular, relative-position primes formed by concatenated subsets of the target stimuli (e.g., ‘grdn/GARDEN’) and absolute-position primes formed by hyphenated equivalent subsets (e.g., ‘g-rd-n/GARDEN’) were presented either centrally or displaced by two letter positions to the right or to the left (targets were always central). ERP waveforms were modulated starting at around 100 ms post-target onset and extending into the N400 component. Early priming effects were seen between 100-200 ms post-target onset, where priming effects were only apparent with centrally presented hyphenated primes. By 200-300 ms post-target onset, priming effects were present for both concatenated and hyphenated primes, with the latter still showing sensitivity to prime location. Finally, on N400 amplitude, both prime types revealed priming of similar size and scalp distribution independently of prime location. These results are consistent with an early activation of location-specific letter detectors, between 100 and 200 ms after stimulus onset, that subsequently map onto location-independent orthographic representations.

OS_12.2 - Orthographic knowledge affects the processing of unattended spoken words: mismatch negativity evidence

Pattamadilok, C. ¹ , Colin, C. ¹ , Morais, J. ¹ & Kolinsky, R. ^{1, 2}

1 Université Libre de Bruxelles, Belgium
2 Fonds de la Recherche Scientifique-FNRS, Belgium

Behavioral and brain-imaging studies demonstrated the influence of orthographic knowledge on active and high-level speech processing tasks even when written words are not presented. No studies, however, have successfully shown that such influence could be observed at a very low processing level: when speech is unattended. Here, the Mismatch Negativity, a specific ERP component that is an automatic index of experience-dependent auditory memory traces, was used to investigate this issue. An ‘‘odd-ball’’ sequence of acoustic stimuli containing a frequent-standard word /tRi/-“TRI”, an orthographically congruent infrequent-deviant word, /kRi/-“CRI”, and an orthographically incongruent infrequent-deviant word, /pRi/-“PRIX”, was presented to 14 participants in a passive listening situation where participants watched silent movies and ignored the auditory stimuli. Both deviant words elicited a typical MMN over the fronto-central regions, reflecting automatic discrimination of standard and deviant stimuli. Most interestingly, the MMN elicited by the orthographically incongruent deviant word showed higher peak and mean amplitude than the one elicited by the orthographically congruent deviant word. We concluded that orthographic knowledge qualitatively changes the nature of spoken words. Once reading is acquired, the “phonological” representations might become “phonographic” representations. The implication of this observation on the architecture of the speech processing models will be discussed.

OS_12.3 - How does reading experience shape letter processing? Behavioral and electrophysiological evidence from preschoolers and novel readers

Dimitropoulou, M. ^{1, 2, 3} , Carreiras, M. ^{1, 4, 5} & Duñabeitia, J. A. ¹

1 Basque Center on Cognition, Brain and Language, BCBL, Donostia, Spain
2 * Project awarded with the 2010 Early Career Stimulus Award, ESCoP
3 Facultad de Psicologia, Universidad de La Laguna, Tenerife, Spain
4 University of the Basque Country, Bilbao, Spain
5 IKERBASQUE, Basque Foundation for Science, Bilbao, Spain

Reading acquisition depends on accurate letter identification. Studies testing experienced readers have identified two discrete stages of letter processing: featural decomposition (enabling the discrimination of similar-looking letters; e.g., c-o) and abstract letter identity assignment (enabling the assignment of the same identity to visually dissimilar graphemes; e.g., A-a). By combining behavioral and ERP measures we investigated how processes underlying letter perception are modified by exposure to print during the initial phases of reading. Pre-readers, with knowledge of the letters, and first-graders, with regular exposure to print, performed same/different judgments on letter-pairs. Behavioral results showed that both pre-readers and first-graders tended to judge as identical letter-pairs differing by one-similar looking same-case letter (e.g., za-ze) as well as pairs only differing by an upper and a lowercase version of the same letter (e.g., za-zA). However, the cost for the latter pairs was significantly greater for first-graders than for pre-readers, suggesting that letter identities become automatically activated as a function of increased exposure. ERPs closely mimicked the pattern of behavioral effects, showing larger waveform differences for first-graders than for pre-readers with the latter pairs. These findings support a cognitive shift in letter processing induced by reading experience at the earliest stages of reading acquisition.

OS_12.4 - Orthographic learning during reading: The role of whole-word visual processing

Bosse, M. ¹ , Chaves, N. ² & Largy, P. ²

1 LPNC, Lab. of Psychology and Neuro Cognition, University Pierre Mendès-France, Grenoble France
2 LPDPS, Lab. of Developmental Psychology and Socialisation Processes, University Toulouse le Mirail, Toulouse France

The self teaching hypothesis suggests that most knowledge about the orthographic structure of words is acquired incidentally during reading through phonological recoding. The current study assessed whether visual processing skills during reading further contribute to orthographic learning. French children were asked to read pseudo-words, in a context of stories. The whole pseudo-word letter-string was available at once for half of the targets and the pseudo-word’s sublexical units were discovered in turn for the other half. Presentation time and total time of processing were controlled. The memorisation of target orthographic forms was assessed immediately after reading or seven days after. Results showed that more orthographic learning occurred when pseudo-words have been seen in their whole. The whole-word presentation effect was significant whatever the delay between reading and orthographic restitution. This effect depended on neither target reading accuracy nor target reading speed during the reading phase. Moreover, analyses revealed that orthographic learning was independent of presentation time. Beyond recoding skills, the ability to process the entire orthographic letter string at once during reading appears as a significant factor of efficient orthographic learning. This new finding opens the way for a better understanding of the visual-orthographic factor in the self-teaching hypothesis.

OS_12.5 - Consistency effects in visual lexical decision task: Influence of item’s presentation

Petrova, A. & Gaskell, G.

University of York, UK

Several studies carried out using the lexical decision task suggest that words with consistent (one-to-one) phonology-to-spelling mappings are easier to recognise than inconsistent words (one-to-several mapping). However, these effects appear less reliable in the visual than the auditory modality. This pattern of results could indicate a qualitative difference between the recognition systems, but alternative possibilities rely on differences in informational availability between modalities. The current study addressed the latter explanation using a range of different procedures and a set of items that did not show consistency effects in the classic version of the task. We found phonology-to-spelling consistency effects in visual lexical decision task using three different item presentation methods: Experiment 1 used a short item presentation duration (100 ms), Experiment 2 used letter-by-letter presentation and Experiment 3 used presentation with visual noise. This study suggests that interactions between phonology and spelling are present not only in the auditory modality but also in the visual modality. Consistency effects may be observable easily in visual word recognition only in noisier conditions that make the recognition process more similar to auditory processing. Importantly, our results also suggest that the underlying substrates for spoken and visual word recognition operate in broadly comparable ways.