Adult-child discourse: Developmental interaction between information processing and linguistic knowledge

In the present study, the discourse interaction between adult and child was examined in terms of the content of their utterances, and the linguistic and contextual relations between their messages, in order to investigate how children use the information from adults' input sentences to form contingent responses. The analyses described were based on longitudinal data from four children from approximately 21 to 36 months of age. Categories of child discourse, their development and their interactions with aspects of prior adult utterances form the major results of the study. Child utterances were identified as adjacent (immediately preceded by an adult utterance), or as nonadjacent (not immediately preceded by an adult utterance). Adjacent utterances were either contingent (shared the same topic and added new information relative to the topic of the prior utterance), imitative (shared the same topic but did not add new information), or noncontingent (did not share the same topic). From the beginning, the adjacent speech was greater than nonadjacent speech. Contingent speech increased over time; in particular, linguistically contingent speech (speech that expanded the verb relation of the prior adult utterance with added or replaced constituents within a clause) showed the greatest developmental increase. Linguistically contingent speech occurred more often after questions than nonquestions. The results are discussed in terms of how the differential requirements for processing information in antecedent messages is related to language learning.     

Brain network interactions in auditory, visual and linguistic processing

In the paper, we discuss the importance of network interactions between brain regions in mediating performance of sensorimotor and cognitive tasks, including those associated with language processing. Functional neuroimaging, especially PET and fMRI, provide data that are obtained essentially simultaneously from much of the brain, and thus are ideal for enabling one to assess interregional functional interactions. Two ways to use these types of data to assess network interactions are presented. First, using PET, we demonstrate that anterior and posterior perisylvian language areas have stronger functional connectivity during spontaneous narrative production than during other less linguistically demanding production tasks. Second, we show how one can use large-scale neural network modeling to relate neural activity to the hemodynamically-based data generated by fMRI and PET. We review two versions of a model of object processing - one for visual and one for auditory objects. The regions comprising the models include primary and secondary sensory cortex, association cortex in the temporal lobe, and prefrontal cortex. Each model incorporates specific assumptions about how neurons in each of these areas function, and how neurons in the different areas are interconnected with each other. Each model is able to perform a delayed match-to-sample task for simple objects (simple shapes for the visual model; tonal contours for the auditory model). We find that the simulated electrical activities in each region are similar to those observed in nonhuman primates performing analogous tasks, and the absolute values of the simulated integrated synaptic activity in each brain region match human fMRI/PET data. Thus, this type of modeling provides a way to understand the neural bases for the sensorimotor and cognitive tasks of interest.     

Developmental trends in recall of central and incidental auditory material

An auditory recall task, involving central and incidental stimuli and designed to correspond to that used in visual selective attention studies, was developed and presented to second-, fourth-, sixth-, and eighth-graders. There were significant differences in favor of older compared to younger Ss and girls compared to boys. In addition, Ss performed better when animals were the relevant and foods the irrelevant stimuli than vice versa. The nature of the developmental increase in auditory recall of central vs incidental stimuli demonstrated in this task was discussed in terms of developmental trends found in the visual modality. The sex differences and differences found for the animals vs foods condition were discussed with regard to differential short-term memory strategies.     

Electrophysiological correlates of rapid auditory and linguistic processing in adolescents with specific language impairment

Brief tonal stimuli and spoken sentences were utilized to examine whether adolescents (aged 14;3-18;1) with specific language impairments (SLI) exhibit atypical neural activity for rapid auditory processing of non-linguistic stimuli and linguistic processing of verb-agreement and semantic constraints. Further, we examined whether the behavioral and electrophysiological indices for rapid auditory processing were correlated with those for linguistic processing. Fifteen adolescents with SLI and 15 adolescents with normal language met strict criteria for displaying consistent diagnoses from kindergarten through the eighth grade. The findings provide evidence that auditory processing for non-linguistic stimuli is atypical in a significant number of adolescents with SLI compared to peers with normal language and indicate that reduced efficiency in auditory processing in SLI is more vulnerable to rapid rates (200ms ISI) of stimuli presentation (indexed by reduced accuracy, a tendency for longer RTs, reduced N100 over right anterior sites, and reduced amplitude P300). Many adolescents with SLI displayed reduced behavioral accuracy for detecting verb-agreement violations and semantic anomalies, along with less robust P600s elicited by verb-agreement violations. The results indicate that ERPs elicited by morphosyntactic aspects of language processing are atypical in many adolescents with SLI. Additionally, correlational analyses between behavioral and electrophysiological indices of processing non-linguistic stimuli and verb-agreement violations suggest that the integrity of neural functions for auditory processing may only account for a small proportion of the variance in morphosyntactic processing in some adolescents.     

Decision interaction between auditory channels

Observers detected signals presented in a two-channel, simultaneous detection task at 630 and 1,400 Hz. The familiar pattern of interference between the frequency channels was observed: detectability in one channel was depressed on trials when a signal or a yes response occurred in the other channel. On each trial, measures were made of the energy within specified frequency bands around each signal frequency. The relationships between these measures and performance in each channel were studied. There was no consistent relationship between the magnitude of the measure in one channel and performance in the other. Interactions between the channels probably originate in the response process of the interfering channel     

Orthographic depth and the interaction of visual and auditory processing in word recognition

We studied the influence of word frequency and orthographic depth on the interaction of orthographic and phonetic information in word perception. Native speakers of English and Serbo-Croatian were presented with simultaneous printed and spoken verbal stimuli and had to decide whether they were equivalent. Decision reaction time was measured in three experimental conditions: Clear print and clear speech, degraded print and clear speech, and clear print and degraded speech. Within each language, the effects of visual and auditory degradation were measured, relative to the undegraded presentation. Both effects of degradation were much stronger in English than in Serbo-Croatian. Moreover, they were the same for high- and low-frequency words in both languages. These results can be accounted for by a parallel interactive processing model that assumes lateral connections between the orthographic and phonological systems at all of their levels. The structure of these lateral connections is independent of word frequency and is determined by the relationship between spelling and phonology in the language: simple isomorphic connections between graphemes and phonemes in Serbo-Croatian, but more complex, many-to-one, connections in English.     

The relationship between the frequency and the processing complexity of linguistic structure

In this paper the relative frequencies of the possible resolutions of ambiguities involving noun phrase attachment sites are compared to the results of off-line psycholinguistic measurements of syntactic complexity. A lack of correlation between the two is observed. It is therefore argued that the comprehension system is distinct from what is driving the frequencies in the corpora. A production heuristic separate from the comprehension system is proposed to account for the observed frequencies.We would like to thank Susanne Tunstall for providing linguistic judgments in the corpus analyses reported in Sec. 3.3. We also wish to thank the following people for helpful, comments and discussions on earlier presentations of this paper: the audience at the Eighth Human Sentence Processing Conference, in Tucson Arizona, Maria Babyonyshev, Tom Bever, Martin Corley, Danny Fox, Don Mitchell, Edson Miyamoto, Janet Nicol, Colin Phillips, Gregg Solomon, Michael Spivey-Knowlton, James Thomas, and Tom Wasow. All remaining errors are our own. The second author was supported by the Research Training Grant Language: Acquisition and Computation awarded by the National Science Foundation (U.S.) to the Massachusetts Institute of Technology (DIR 9113607), and by a fellowship from the Social Sciences and Humanities Research Council of Canada.     

Developmental changes in the linguistic brain after puberty

The development of reading skills is a complex and very long-lasting process. In an influential study Booth et al. demonstrated age-related changes in the activation of a network of left hemisphere regions, including the inferior frontal area, the superior temporal gyrus, and the angular gyrus. Interestingly, they found that the angular gyrus, which is involved in the mapping between phonological and orthographic representation, is automatically activated in adults during visual orthographic tasks not requiring this operation.     

Developmental course of auditory processing interactions: Garner interference and Simon interference.

Previous research suggests that with increasing age children become more efficient in inhibiting conflicting responses and in resisting interference from irrelevant information. We assessed the abilities of 100 children (ages 3-16 years) and 20 adults to resist interference during the processing of 2 auditory dimensions of speech, namely the speaker's gender and spatial location. The degree of interference from irrelevant variability in either dimension did not vary with age. Apparently, young children do not have more difficulty in resisting interference when the nontarget and the target are both perceptual attributes. We also assessed the participants' abilities to inhibit conflicting task-irrelevant information from spatial location and to resist interference from spatial variability in the context of conflict. In the presence of conflicting task-irrelevant information, both interference effects declined significantly with age. Developmental change in auditory processing seems to vary as a function of (1) the nature of the target-nontarget combination and (2) the presence/absence of conflicting task-irrelevant information.     

Developmental changes in the linguistic performance correlates of reading achievement

The present study evaluated the hypothesis that measures of linguistic skills differentially contribute to the variability in reading achievement at different ages. Linguistic skills that develop earlier and are more important for earlier phases of reading were predicted to contribute more to the variability of reading achievement at earlier ages (5–7) than at older ages (10–12). Conversely, linguistic skills that develop later and are more important for later phases of reading were predicted to contribute more to the variability in reading achievement at older ages (10–12) than at younger ages (5–7). To test these developmental hypotheses, measures of language skills with different developmental rates were administered to cross-sectional samples of disabled and nondisabled readers at three mean ages: 5.5, 8.5, and 11 years. Reading group differences were apparent at each age on measures assumed to develop earlier, thus failing to confirm the first prediction. However, these measures may not have been sensitive to linguistic skills important for beginning reading. Reading group differences on measures of later developing language skills were apparent only for older readers, thus confirming the second prediction. The latter age-dependent relationships provided additional evidence for developmental changes in the linguistic correlates of reading achievement.     

Relationships between three auditory inspection time tasks and processing speed

This study investigated the relationship between a spatial auditory inspection time task and previous versions of AIT, as well as the relationships of these tasks with visual inspection time (VIT) and general speediness (Gs). A total of 96 university undergraduates (age mean (M) = 20.0 years, standard deviation (SD) = 4.0 years) completed three AIT tasks, VIT, auditory reaction time (ART) and visual reaction time (VRT), and two Gs marker tests. Auditory inspection time‐spatial (AIT‐S) did not relate to VIT, but it did relate to the Gs marker tests. It also loaded moderately on a Gs factor along with VIT. Neither of the alternate AIT tasks showed any consistent relationships to reaction time (RT) or Gs measures. The AIT‐S task did, however, share substantial variance with its predecessors, suggesting that performance on all AIT tasks relies to some extent on similar processes. Further research is required to determine the nature of these processes.     

Developmental trends in dichhaptic lateralization

Two studies on developmental trends in dichhaptic lateralization for nonlinguistic stimuli were conducted on school-aged children. Study 1 included 60 students in Grades 1, 5, and 9. Study 2 included 200 students from Grades 2, 4, 6, 8, and 10. Both studies showed significant age-related increases in over-all dichhaptic accuracy. In Study 2 a significant left-hand advantage for all subjects as well as an over-all advantage for boys were noted. Significant interactions indicated different developmental trends for boys and girls but did not show clear patterns in the development of lateralization.     

The interaction between duration, velocity and repetitive auditory stimulation

Repetitive auditory stimulation (with click trains) and visual velocity signals both have intriguing effects on the subjective passage of time. Previous studies have established that prior presentation of auditory clicks increases the subjective duration of subsequent sensory input, and that faster moving stimuli are also judged to have been presented for longer (the time dilation effect). However, the effect of clicks on velocity estimation is unknown, and the nature of the time dilation effect remains ambiguous. Here were present a series of five experiments to explore these phenomena in more detail. Participants viewed a rightward moving grating which traveled at velocities ranging from 5 to 15°/s and which lasted for durations of 500 to 1500 ms. Gratings were preceded by clicks, silence or white noise. It was found that both clicks and higher velocities increased subjective duration. It was also found that the time dilation effect was a constant proportion of stimulus duration. This implies that faster velocity increases the rate of the pacemaker component of the internal clock. Conversely, clicks increased subjective velocity, but the magnitude of this effect was not proportional to actual velocity. Through considerations of these results, we conclude that clicks independently affect velocity and duration representations.