EXPRESS: Orthographic and feature-level contributions to letter identification

Word recognition is facilitated by primes containing visually similar letters (dentjst-dentist, Marcet & Perea, 2017), suggesting that letter identities are encoded with initial uncertainty. Orthographic knowledge also guides letter identification, as readers are more accurate at identifying letters in words compared to pseudowords (Reicher, 1969; Wheeler, 1970). We investigated how higher-level orthographic knowledge and low-level visual feature analysis operate in combination during letter identification. We conducted a Reicher-Wheeler task to compare readers' ability to discriminate between visually similar and dissimilar letters across different orthographic contexts (words, pseudowords, and consonant strings). Orthographic context and visual similarity had independent effects on letter identification, and there was no interaction between these factors. The magnitude of these effects indicated that higher-level orthographic information plays a greater role than lower-level visual feature information in letter identification. We propose that readers use orthographic knowledge to refine potential letter candidates while visual feature information is accumulated. This combination of higher-level knowledge and low-level feature analysis may be essential in permitting the flexibility required to identify visual variations of the same letter (e.g. N-n) whilst maintaining enough precision to tell visually similar letters apart (e.g. n-h). These results provide new insights on the integration of visual and linguistic information and highlight the need for greater integration between models of reading and visual processing. This study was pre-registered on the Open Science Framework. Pre-registration, stimuli, instructions, trial-level data, and analysis scripts are openly available (https://osf.io/p4q9u/)

Early cranial ultrasound findings among infants with neonatal encephalopathy in Uganda: an observational study.

BACKGROUND: In sub-Saharan Africa, the timing and nature of brain injury and their relation to mortality in neonatal encephalopathy (NE) are unknown. We evaluated cranial ultrasound (cUS) scans from term Ugandan infants with and without NE for evidence of brain injury. METHODS: Infants were recruited from a national referral hospital in Kampala. Cases (184) had NE and controls (100) were systematically selected unaffected term infants. All had cUS scans <36 h reported blind to NE status. RESULTS: Scans were performed at median age 11.5 (interquartile range (IQR): 5.2-20.2) and 8.4 (IQR: 3.6-13.5) hours, in cases and controls respectively. None had established antepartum injury. Major evolving injury was reported in 21.2% of the cases vs. 1.0% controls (P < 0.001). White matter injury was not significantly associated with bacteremia in encephalopathic infants (odds ratios (OR): 3.06 (95% confidence interval (CI): 0.98-9.60). Major cUS abnormality significantly increased the risk of neonatal death (case fatality 53.9% with brain injury vs. 25.9% without; OR: 3.34 (95% CI: 1.61-6.95)). CONCLUSION: In this low-resource setting, there was no evidence of established antepartum insult, but a high proportion of encephalopathic infants had evidence of major recent and evolving brain injury on early cUS imaging, suggesting prolonged or severe acute exposure to hypoxia-ischemia (HI). Early abnormalities were a significant predictor of death

Masked transposition priming effects are observed in Korean in the same-different task

Research suggests that readers of Korean Hangul demonstrate precise orthographic coding. In contrast to findings from many other languages, the identification of Hangul words is not speeded by prior masked presentation of transposition primes relative to substitution primes. The present studies asked whether evidence for precise orthographic coding is also observed in the same–different task—a task claimed to reflect pre-lexical orthographic representations. Experiments tested whether masked transposed-letter (Experiment 1) or transposed-syllable-block (Experiment 2) primes facilitate judgements about whether a target matches a reference stimulus. In contrast to previous results using lexical decision, significant transposition effects were observed in both cases. These findings add weight to the proposition that apparent differences across writing systems in the precision of orthographic coding may reflect demands of the word identification process rather than properties of orthographic representations themselves

Shaping the precision of letter position coding by varying properties of a writing system

There is substantial debate around the nature of letter position coding in reading. Research on a variety of Indo-European languages suggests uncertainty in position coding; for example, readers perceive transposed-letter stimuli (jugde) as similar to their base words (judge). However, these effects are not apparent for all languages. We developed a powerful new method to delineate how specific properties of a writing system shape the representation of letter position. Two groups of 24 adults learned to read novel words printed in artificial scripts. One group learned a dense orthography (i.e. with many anagrams) and one group learned a sparse orthography (i.e. no anagrams). Following four days of training, participants showed a larger transposed-letter effect in the sparse orthography than in the dense orthography. These results challenge existing models of orthographic processing in reading, and support the claim that orthographic representations are shaped by the nature of the writing system