A dual-route cascaded model of reading by deaf adults: evidence for grapheme to viseme conversion

The time course of Cantonese and Hong Kong Sign Language phonological activation: An ERP study of deaf bimodal bilingual readers of Chinese

This study investigated Cantonese and Hong Kong Sign Language (HKSL) phonological activation patterns in Hong Kong deaf readers using the ERP technique. Two experiments employing the error disruption paradigm were conducted while recording participants' EEGs. Experiment 1 focused on orthographic and speech-based phonological processing, while Experiment 2 examined sign-phonological processing. ERP analyses focused on the P200 (180-220 ms) and N400 (300-500 ms) components. The results of Experiment 1 showed that hearing readers exhibited both orthographic and phonological effects in the P200 and N400 windows, consistent with previous studies on Chinese reading. In deaf readers, significant speech-based phonological effects were observed in the P200 window, and orthographic effects spanned both the P200 and N400 windows. Comparative analysis between the two groups revealed distinct spatial distributions for orthographic and speech-based phonological ERP effects, which may indicate the engagement of different neural networks during early processing stages. Experiment 2 found evidence of sign-phonological activation in both the P200 and N400 windows among deaf readers, which may reflect the involvement of sign-phonological representations in early lexical access and later semantic integration. Furthermore, exploratory analysis revealed that higher reading fluency in deaf readers correlated with stronger orthographic effects in the P200 window and diminished effects in the N400 window, indicating that efficient orthographic processing during early lexical access is a distinguishing feature of proficient deaf readers.

Deafness and early language deprivation influence arithmetic performances

It has been consistently reported that deaf individuals experience mathematical difficulties compared to their hearing peers. However, the idea that deafness and early language deprivation might differently affect verbal (i.e., multiplication) vs. visuospatial (i.e., subtraction) arithmetic performances is still under debate. In the present paper, three groups of 21 adults (i.e., deaf signers, hearing signers, and hearing controls) were therefore asked to perform, as fast and as accurately as possible, subtraction and multiplication operations. No significant group effect was found for accuracy performances. However, reaction time results demonstrated that the deaf group performed both arithmetic operations slower than the hearing groups. This group difference was even more pronounced for multiplication problems than for subtraction problems. Weaker language-based phonological representations for retrieving multiplication facts, and sensitivity to interference are two hypotheses discussed to explain the observed dissociation.

Orthographic, Phonological, and Semantic Dynamics During Visual Word Recognition in Deaf Versus Hearing Adults

Purpose Studies on reading in individuals with severe-to-profound hearing loss (deaf) raise the possibility that, due to deficient phonological coding, deaf individuals may rely more on orthographic-semantic links than on orthographic-phonological links. However, the relative contribution of phonological and semantic information to visual word recognition in deaf individuals was not directly assessed in these studies. The aim of the present study, therefore, was to examine the interplay between orthographic, phonological, and semantic representations during visual word recognition, in deaf versus hearing adults. Method Deaf and hearing participants were asked to perform a visual lexical decision task in Hebrew. The critical stimuli consisted of three types of Hebrew words, which differ in terms of their relationship between orthography, phonology, and semantics: unambiguous words, homonyms, and homographs. Results In the hearing group, phonological effects were more pronounced than semantic effects: Homographs (multiple pronunciations) were recognized significantly slower than homonyms or unambiguous words (one pronunciation). However, there was no significant difference between homonyms (multiple meanings) and unambiguous words (one meaning). In contrast, in the deaf group, there was no significant difference among the three word types, indicating that visual word recognition, in these participants, is driven primarily by orthography. Conclusion While visual word recognition in hearing readers is accomplished mainly via orthographic-phonological connections, deaf readers rely mainly on orthographic-semantic connections.

Sign phonological parameters modulate parafoveal preview effects in deaf readers

Research has found that deaf readers unconsciously activate sign translations of written words while reading. However, the ways in which different sign phonological parameters associated with these sign translations tie into reading processes have received little attention in the literature. In this study on Chinese reading, we used a parafoveal preview paradigm to investigate how four different types of sign phonologically related preview affect reading processes in adult deaf signers of Hong Kong Sign Language (HKSL). The four types of sign phonologically related preview-target pair were: (1) pairs with HKSL translations that overlapped in three parameters-handshape, location, and movement; (2) pairs that overlapped in only handshape and location; (3) pairs that only overlapped in handshape and movement; and (4) pairs that only overlapped in location and movement. Results showed that the handshape parameter was of particular importance as only sign translation pairs that had handshape among their overlapping sign phonological parameters led to early sign activation. Furthermore, we found that, compared to control previews, deaf readers took longer to read targets when the sign translation previews overlapped with targets in either handshape and movement or handshape, movement, and location. In contrast, fixation times on targets were shorter when previews and targets overlapped location and any single additional parameter-either handshape or movement. These results indicate that the phonological parameters of handshape, location, and movement are activated via orthography during Chinese reading and can have different effects on parafoveal processing in deaf signers of HKSL.

Visual word recognition in deaf readers: lexicality is modulated by communication mode

Evidence indicates that adequate phonological abilities are necessary to develop proficient reading skills and that later in life phonology also has a role in the covert visual word recognition of expert readers. Impairments of acoustic perception, such as deafness, can lead to atypical phonological representations of written words and letters, which in turn can affect reading proficiency. Here, we report an experiment in which young adults with different levels of acoustic perception (i.e., hearing and deaf individuals) and different modes of communication (i.e., hearing individuals using spoken language, deaf individuals with a preference for sign language, and deaf individuals using the oral modality with less or no competence in sign language) performed a visual lexical decision task, which consisted of categorizing real words and consonant strings. The lexicality effect was restricted to deaf signers who responded faster to real words than consonant strings, showing over-reliance on whole word lexical processing of stimuli. No effect of stimulus type was found in deaf individuals using the oral modality or in hearing individuals. Thus, mode of communication modulates the lexicality effect. This suggests that learning a sign language during development shapes visuo-motor representations of words, which are tuned to the actions used to express them (phono-articulatory movements vs. hand movements) and to associated perceptions. As these visuo-motor representations are elicited during on-line linguistic processing and can overlap with the perceptual-motor processes required to execute the task, they can potentially produce interference or facilitation effects.