Biomedical subjects

Conrad Perry

Publications and source records attributed to Conrad Perry.

13 recordsLinked to original sources

PubMed2005

Prosody and lemma selection.

In three picture-naming experiments, we examined the effect of prosodic context on the synonyms people use to name pictures in Mandarin Chinese. This was done without time pressure. The results showed that when monosyllabic and bisyllabic synonyms (e.g., hen/chicken) were embedded in a context of pictures with either bisyllabic or trisyllabic names, participants gave bisyllabic responses to the synonyms more often than they did in a condition without such a context. The difference was very similar in magnitude in both the bisyllabic and trisyllabic contextual conditions. These results suggest that people are biased toward using synonyms that have numbers of syllables equal or similar to those of the prosodic context. If it is assumed that prosodic effects originate at a stage of processing beyond the lemma level, then this suggests either that multiple phonological forms of synonyms can be activated or that there is feedback from prosodic processing that influences lemma selection.

Humans↗

PubMed2004

fMRI evidence for the automatic phonological activation of briefly presented words.

Functional magnetic resonance imaging was used to investigate whether people generate the phonology of briefly presented words that they do not attend. This was done in Chinese by examining the effect of orthography-phonology regularity (i.e., how predictable the phonology of a word is from its components rather than whole-word form) with high- and low-frequency words, and by using a task that diverted participants' attention to a mask, rather than the words. The results showed that there was a significant interaction between regularity and word frequency in blood oxygen level-dependent (BOLD) signal, which mirrored the pattern found in behavioral data. Specifically, for low-frequency characters, bilateral fusiform gyri, the posterior superior temporal gyrus, and inferior parietal regions were more active when using irregular compared to regular characters. There were no significant differences when high-frequency characters were used. These results support the possibility that at least for low-frequency words, phonology is automatically generated when reading, even when people do not attend to the words and even in a language where the orthography-phonology mapping is extremely irregular.

Adolescent↗

PubMed2004

Do current connectionist learning models account for reading development in different languages?

Learning to read a relatively irregular orthography, such as English, is harder and takes longer than learning to read a relatively regular orthography, such as German. At the end of grade 1, the difference in reading performance on a simple set of words and nonwords is quite dramatic. Whereas children using regular orthographies are already close to ceiling, English children read only about 40% of the words and nonwords correctly. It takes almost 4 years for English children to come close to the reading level of their German peers. In the present study, we investigated to what extent recent connectionist learning models are capable of simulating this cross-language learning rate effect as measured by nonword decoding accuracy. We implemented German and English versions of two major connectionist reading models, Plaut et al.'s (Plaut, D. C., McClelland, J. L., Seidenberg, M. S., & Patterson, K. (1996). Understanding normal and impaired word reading: computational principles in quasi-regular domains. Psychological Review, 103, 56-115) parallel distributed model and Zorzi et al.'s (Zorzi, M., Houghton, G., & Butterworth, B. (1998a). Two routes or one in reading aloud? A connectionist dual-process model. Journal of Experimental Psychology: Human Perception and Performance, 24, 1131-1161); two-layer associative network. While both models predicted an overall advantage for the more regular orthography (i.e. German over English), they failed to predict that the difference between children learning to read regular versus irregular orthographies is larger earlier on. Further investigations showed that the two-layer network could be brought to simulate the cross-language learning rate effect when cross-language differences in teaching methods (phonics versus whole-word approach) were taken into account. The present work thus shows that in order to adequately capture the pattern of reading acquisition displayed by children, current connectionist models must not only be sensitive to the statistical structure of spelling-to-sound relations but also to the way reading is taught in different countries.

Child↗

PubMed2004

Beyond the two-strategy model of skilled spelling: effects of consistency, grain size, and orthographic redundancy.

Most models of spelling assume that people rely on two procedures when engaging in spelling: a lexical look-up procedure that retrieves spellings in their entirety, and a nonlexical procedure that constructs spellings with a set of phoneme-grapheme rules. In the present research, we investigated whether larger sized subsyllabic relationships also play a role in spelling, and how they compare to small-sized phoneme-grapheme relationships. In addition, we investigated whether purely orthographic units can explain some of the variance typically attributed to the mapping between sound and spelling. To do this, we ran five spelling experiments, two using real words and three using nonwords. Results from the experiments showed that there were independent contributions of both phoneme-grapheme and larger sized subsyllabic sound-spelling relationships, although the effect of phoneme-grapheme-sized relationships was always stronger and more reliable than larger sized subsyllabic sound-spelling relationships. Purely orthographic effects were also shown to affect word spelling, but no significant effects were found with nonword spelling. Together, the results support the hypothesis that a major constraint on spelling comes from phoneme-grapheme-sized relationships.

Choice Behavior↗

PubMed2003

Neural mechanisms underlying semantic and orthographic processing in Chinese-English bilinguals.

Brain activation underlying language processing in Chinese-English bilinguals was examined using fMRI in an orthographic search and a semantic classification task. In both tasks, brain areas activated by Chinese characters and English words were very similar to tasks examining Chinese reading using Chinese pinyin (an alphabetic Chinese script) and Chinese characters. However, the degree of later-alization was different, with English words (second language) causing much more right hemisphere activation than Chinese characters (native language). These differences support the hypothesis that second language usage causes more right hemisphere activation than native language usage.

Adult↗

PubMed2003

Neural basis of the non-attentional processing of briefly presented words.

The neural basis of the automatic activation of words was investigated in an fMRI study. In the study, words were presented briefly (51 or 151 msec) followed by a mask. To prevent attentional processing, subjects attended to the masks and not the words, and were required to make perceptual judgment about the masks. We found that a distributed neural network (including the frontal, temporal, occipital, parietal lobes, and the cerebellum) was activated during non-attentional processing of words in both exposure durations. A significant main effect of presentation duration was found in bilateral cerebellum and the right fusiform gyrus, suggesting their role in the later (151 msec) processing of words. In addition, a significant interaction between presentation duration and word frequency was obtained. When the presentation duration was 151 msec, no significant difference in activation was found between high- and low-frequency words. Alternatively, when the presentation duration was 51 msec, high-frequency words evoked significantly greater activation in bilateral fusiform gyri, cerebellum, right inferior parietal lobe, medial frontal gyrus (BA 45/46/9), and the right temporal-occipital junction (BA 21/37). These results suggest that these regions are sensitive to word frequency, and are related to both the attentional and non-attentional access of lexical representations.

Adolescent↗

PubMed2003

Developmental dyslexia in different languages: language-specific or universal?

Most of the research on developmental dyslexia comes from English-speaking countries. However, there is accumulating evidence that learning to read English is harder than learning to read other European orthographies (Seymour, Aro, & Erskine, 2003). These findings therefore suggest the need to determine whether the main English findings concerning dyslexia can be generalized to other European orthographies, all of which have less irregular spelling-to-sound correspondences than English. To do this, we conducted a study with German- and English-speaking children (n=149) in which we investigated a number of theoretically important marker effects of the reading process. The results clearly show that the similarities between dyslexic readers using different orthographies are far bigger than their differences. That is, dyslexics in both countries exhibit a reading speed deficit, a nonword reading deficit that is greater than their word reading deficit, and an extremely slow and serial phonological decoding mechanism. These problems were of similar size across orthographies and persisted even with respect to younger readers that were at the same reading level. Both groups showed that they could process larger orthographic units. However, the use of this information to supplement grapheme-phoneme decoding was not fully efficient for the English dyslexics.

Adolescent↗

PubMed2003

The neural substrate of analogical reasoning: an fMRI study.

This study investigated the anatomical substrate of analogical reasoning using functional magnetic resonance imaging. In the study, subjects performed a verbal analogy task (e.g., soldier is to army as drummer is to band) and, to control for activation caused by purely semantic access, a semantic judgment task. Significant activation differences between the verbal analogy and the semantic judgment task were found bilaterally in the prefrontal cortex (right BA 11/BA 47 and left BA45), the fusiform gyrus, and the basal ganglia; left lateralized in the postero-superior temporal gyrus (BA 22) and the (para) hippocampal region; and right lateralized in the anterior cingulate. The role of these areas in analogical reasoning is discussed.

Adult↗

PubMed2003

Priming the rules of spelling.

This paper reports three spelling experiments that examined the effect of lexical priming through intervening items. In the first and second experiments, a strong effect of word priming on nonword spelling was found, even when two intervening filler items separated primetarget pairs. In addition, the absolute size of the effect was similar when one intervening item separated primetarget pairs and when two intervening items separated primetarget pairs. A much larger effect was found when no intervening items were used, however. This effect did not appear to be related to filler type, as Experiment 1 used nonword fillers, and Experiment 2 used word fillers. The third experiment examined the same effect with two intervening filler items, but instead used nonwords as primes (and thus examined a subsyllabic repetition effect). A similar-sized effect as that of the first and second experiments was found. The most plausible explanation of these results, which is consistent with the interactive dual-route model of spelling, is that they reflect the priming of soundspelling rules that people use to spell nonwords.

Humans↗

PubMed2003

A phoneme-grapheme feedback consistency effect.

Recent studies examining the feedback consistency effect have been criticized for poor item selection (Peereman, Content, & Bonin, 1998). In the present study, an experiment was run with a new set of items, in which feedback consistency was manipulated at a phoneme-grapheme level. The results suggested that participants responded faster to feedback-consistent words than to feedback-inconsistent words. This was despite the feedback-consistent and feedback-inconsistent word groups' being matched on many other dimensions, including word frequency and subjective orthographic frequency. These results may differ from those of previous studies, since previous studies in English have measured feedback consistency at the rime-body level.

Choice Behavior↗

PubMed2003

Speed of lexical and nonlexical processing in French: the case of the regularity effect.

Words with irregular spelling-sound correspondences are read aloud more slowly than words with regular spelling-sound correspondences. This so-called regularity effect is modulated by word frequency, with low-frequency words showing larger costs than do high-frequency words. Because French has more regular spelling-to-sound correspondences than English, we expected a different pattern in French than in English. This was indeed the case, since regularity effects were obtained for both high- and low-frequency words in French. We further showed that a French implementation of the dual-route cascaded model could not account for this pattern. In additional simulations, we investigated whether this failure was due to lexical processes being too fast (leaving little time for the nonlexical route to interfere) or nonlexical processes being too slow. The results showed that only speeding up the nonlexical route allowed the model to capture the data. This suggests that the delayed phonology assumption that characterizes nonlexical processing in the original model needs to be abandoned in a more regular orthography.

Humans↗

PubMed2002

How predictable is spelling? Developing and testing metrics of phoneme-grapheme contingency.

Prior research has purported to show that words with infrequent phoneme-grapheme correspondences are more difficult to spell than words with frequent phoneme-grapheme correspondences. Defining exactly what a phoneme-grapheme relationship is, however, is not necessarily straightforward. There are a number of different assumptions that can be made. In this study, we developed four metrics of sound-spelling contingency based on all monosyllabic English words, including those with complex morphology. These metrics differed in the extent to which they included assumptions about spelling. The psychological reality of these different metrics was evaluated against data from a large-scale study of skilled adult spelling and a nonword spelling experiment. The results suggest that when spelling, people are sensitive to positional information, morphological status, vowel type, and a number of more idiosyncratic constraints.

Humans↗

PubMed2002

Cross-language computational investigation of the length effect in reading aloud.

The authors examined whether 2 computational models of reading, the dual-route cascaded model (M. Coltheart, K. Rastle, C. Perry, R. Langdon, & J. C. Ziegler, 2001) and the connectionist 2-layer model (M. Zorzi, G. Houghton, & B. Butterworth, 1998), were able to predict the pattern that the length effect found in reading aloud is larger in German than in English (J. C. Ziegler, C. Perry, A. M. Jacobs, & M. Braun, 2001). The results showed that the dual-route cascaded model, which uses a serial mechanism for assembling phonology, successfully predicted this cross-language difference. In contrast, the connectionist model of Zorzi et al. (1998) predicted the opposite: a larger length effect in English than in German. Both the success of one model and the failure of the other highlight fundamental differences between 2 major classes of computational models.

Electronic Data Processing↗