Word Recognition and Word Prediction in Preschoolers With (a Suspicion of) a Developmental Language Disorder: Evidence From Eye Tracking.

Purpose This study compares online word recognition and prediction in preschoolers with (a suspicion of) a developmental language disorder (DLD) and typically developing (TD) controls. Furthermore, it investigates correlations between these measures and the link between online and off-line language scores in the DLD group. Method Using the visual world paradigm, Dutch children ages 3;6 (years;months) with (a suspicion of) DLD (n = 51) and TD peers (n = 31) listened to utterances such as, "Kijk, een hoed!" (Look, a hat!) in a word recognition task, and sentences such as, "Hé, hij leest gewoon een boek" (literal translation: Hey, he reads just a book) in a word prediction task, while watching a target and distractor picture. Results Both groups demonstrated a significant word recognition effect that looked similar directly after target onset. However, the DLD group looked longer at the target than the TD group and shifted slower from the distractor to target pictures. Within the DLD group, word recognition was linked to off-line expressive language scores. For word prediction, the DLD group showed a smaller effect and slower shifts from verb onset compared to the TD group. Interestingly, within the DLD group, prediction behavior varied considerably, and was linked to receptive and expressive language scores. Finally, slower shifts in word recognition were related to smaller prediction effects. Conclusions While the groups' word recognition abilities looked similar, and only differed in processing speed and dwell time, the DLD group showed atypical verb-based prediction behavior. This may be due to limitations in their processing capacity and/or their linguistic knowledge, in particular of verb argument structure.

Semantic Processing of Sentences in Preschoolers With Specific Language Impairment: Evidence From the N400 Effect.

Purpose: Given the complexity of sentence processing and the specific problems that children with specific language impairment (SLI) experience, we investigated the time course and characteristics of semantic processing at the sentence level in Dutch preschoolers with SLI. Method: We measured N400 responses to semantically congruent and incongruent spoken sentences (e.g., "My father is eating an apple/*blanket") in a group of 37 Dutch preschoolers with SLI and in a group of 25 typically developing (TD) peers. We compared the time course and amplitude of the N400 effect between the two groups. Results: The TD group showed a strong posterior N400 effect in time windows 300-500 ms and 500-800 ms. In contrast, the SLI group demonstrated only a reliable N400 effect in the later time window, 500-800 ms, and did not show a stronger presence at posterior electrodes. Conclusion: The findings suggest that the neuronal processing of semantic information at sentence level is atypical in preschoolers with SLI compared with TD children.

Task-related influences on neurophysiological assessment of auditory rhyme: implications for clinical studies.

OBJECTIVE: The present study investigated whether implicit rhyme detection, as an implicit measure of phonological processing, can be assessed using a passive ERP paradigm. METHODS: Pseudoword pairs were presented to healthy adults while their EEG was recorded. Participants were either instructed to (a) indicate by a button press after each pseudoword pair whether the words rhymed or not (active paradigm) or (b) ignore the speech stimuli (passive paradigm). RESULTS: In the active rhyme paradigm, a typical phonological N400 effect was elicited with non-rhyming targets showing more negative ERPs at posterior sites during 400-600 ms compared to rhyming targets. In the passive paradigm, an anterior positive effect was elicited for non-rhyming targets during 350-750 ms compared to rhyming targets. CONCLUSIONS: Auditory rhyme processing can be studied at the group level by a passive neurophysiological measurement. In such a test, one should focus on the anterior positivity, which seems to reflect automatic rhyme detection. Future research is needed to make this task more reliable for studying rhyme detection at the individual level. SIGNIFICANCE: A passive ERP measurement of implicit phonological processing could possibly function as an indicator of future success in learning to read in children from clinical populations.

The nature of auditory discrimination problems in children with specific language impairment: an MMN study.

Many children with specific language impairment (SLI) show impairments in discriminating auditorily presented stimuli. The present study investigates whether these discrimination problems are speech specific or of a general auditory nature. This was studied using a linguistic and nonlinguistic contrast that were matched for acoustic complexity in an active behavioral task and a passive ERP paradigm, known to elicit the mismatch negativity (MMN). In addition, attention skills and a variety of language skills were measured. Participants were 25 five-year-old Dutch children with SLI having receptive as well as productive language problems and 25 control children with typical speech- and language development. At the behavioral level, the SLI group was impaired in discriminating the linguistic contrast as compared to the control group, while both groups were unable to distinguish the non-linguistic contrast. Moreover, the SLI group tended to have impaired attention skills which correlated with performance on most of the language tests. At the neural level, the SLI group, in contrast to the control group, did not show an MMN in response to either the linguistic or nonlinguistic contrast. The MMN data are consistent with an account that relates the symptoms in children with SLI to non-speech processing difficulties.

Towards neurophysiological assessment of phonemic discrimination: context effects of the mismatch negativity.

OBJECTIVE: This study focusses on the optimal paradigm for simultaneous assessment of auditory and phonemic discrimination in clinical populations. We investigated (a) whether pitch and phonemic deviants presented together in one sequence are able to elicit mismatch negativities (MMNs) in healthy adults and (b) whether MMN elicited by a change in pitch is modulated by the presence of the phonemic deviants. METHODS: Standard stimuli [i] were intermixed with small, medium or large pitch deviants or with pitch deviants of the same magnitude together with small and large phonemic deviants, [y] and [u], respectively. RESULTS: When pitch and phonemic deviants were presented together, only the large pitch and phonemic contrasts elicited significant MMNs. When only pitch deviants were presented, the medium and large pitch contrasts elicited significant MMNs. The MMNs, in response to the medium and large pitch contrasts, were of similar magnitude across the two contexts. CONCLUSIONS: Pitch and phonemic deviants can be tested together provided the pitch contrast is relatively large. SIGNIFICANCE: A combined neurophysiological test of phonemic and pitch discrimination, as measured by the MMN, is a time-effective tool that may provide valuable information about the underlying cause of poorly specified phonemic representations in clinical populations.