Comprehension and processing of the universal quantifier in children, adolescents and adults.

Quantifier spreading (Q-spreading), children's incorrect falsification of a universally-quantified sentence based on an 'extra-object' picture, may persist beyond childhood, and children adhere to Q-spreading without changing responses throughout testing. We examined the error patterns across wider age groups (aged 4-79) with a picture-sentence verification eye-tracking task. We also examined whether prosodic emphasis affects their comprehension and processing of universally-quantified sentences. Whereas adults' comprehension was ceiling, children/adolescents (aged 4-17) showed various comprehension patterns, splitting into: 'Adult-like responders' (consistently adult-like), 'Q-spreaders' (consistently showing Q-spreading), and 'Switchers' (shifted from Q-spreading to adult-like). While adults rarely looked at the extra-object, 'Q-spreaders' showed frequent looks throughout testing, and both 'Switchers' and 'Adult-like responders' exhibited reduced looks to the extra-object, suggesting that avoidance and correction of Q-spreading requires inhibition of the visual attention to the extra-object. The effect of prosodic emphasis on eye movement emerged later for children/adolescents than adults.

Early L2 Spoken Word Recognition Combines Input-Based and Knowledge-Based Processing.

This study examines the perceptual trade-off between knowledge of a language's statistical regularities and reliance on the acoustic signal during L2 spoken word recognition. We test how early learners track and make use of segmental and suprasegmental cues and their relative frequencies during non-native word recognition. English learners of Mandarin were taught an artificial tonal language in which a tone's informativeness for word identification varied according to neighborhood density. The stimuli mimicked Mandarin's uneven distribution of syllable+tone combinations by varying syllable frequency and the probability of particular tones co-occurring with a particular syllable. Use of statistical regularities was measured by four-alternative forced-choice judgments and by eye fixations to target and competitor symbols. Half of the participants were trained on one speaker, that is, low speaker variability while the other half were trained on four speakers. After four days of learning, the results confirmed that tones are processed according to their informativeness. Eye movements to the newly learned symbols demonstrated that L2 learners use tonal probabilities at an early stage of word recognition, regardless of speaker variability. The amount of variability in the signal, however, influenced the time course of recovery from incorrect anticipatory looks: participants exposed to low speaker variability recovered from incorrect probability-based predictions of tone more rapidly than participants exposed to greater variability. These results motivate two conclusions: early L2 learners track the distribution of segmental and suprasegmental co-occurrences and make predictions accordingly during spoken word recognition; and when the acoustic input is more variable because of multi-speaker input, listeners rely more on their knowledge of tone-syllable co-occurrence frequency distributions and less on the incoming acoustic signal.

Contrast-marking prosodic emphasis in Williams syndrome: results of detailed phonetic analysis.

BACKGROUND: Past reports on the speech production of individuals with Williams syndrome (WS) suggest that their prosody is anomalous and may lead to challenges in spoken communication. While existing prosodic assessments confirm that individuals with WS fail to use prosodic emphasis to express contrast, those reports typically lack detailed phonetic analysis of speech data. The present study examines the acoustic properties of speech prosody, aiming for the future development of targeted speech interventions. AIMS: The study examines the three primary acoustic correlates of prosodic emphasis (duration, intensity, F0) and determines whether individuals with WS have difficulty in producing all or a particular set of the three prosodic cues. METHODS & PROCEDURES: Speech produced by 12 individuals with WS and 12 chronological age (CA)-matched typically developing individuals were recorded. A sequential picture-naming task elicited production of target phrases in three contexts: (1) no contrast: gorilla with a racket → rabbit with a balloon; (2) contrast on the animal: fox with a balloon → rabbit with a balloon; and (3) contrast on the object: rabbit with a ball → rabbit with a balloon. The three acoustic correlates of prosodic prominence (duration, intensity and F0) were compared across the three referential contexts. OUTCOMES & RESULTS: The two groups exhibited striking similarities in their use of word duration and intensity for expressing contrast. Both groups showed the reduction and enhancement of final lengthening, and the enhancement and reduction of intensity difference for the animal contrast and for the object contrast conditions, respectively. The two groups differed in their use of F0: the CA group produced higher F0 for the animal than for the object regardless of the context, and this difference was enhanced when the animal noun was contrastive. In contrast, the WS group produced higher F0 for the object than for the animal when the object was contrastive. CONCLUSIONS & IMPLICATIONS: The present data contradict previous assessment results that report a lack of prosodic skills to mark contrast in individuals with WS. The methodological differences that may account for this variability are discussed. The present data suggest that individuals with WS produce appropriate prosodic cues to express contrast, although their use of pitch may be somewhat atypical. Additional data and future speech comprehension studies will determine whether pitch modulation can be targeted for speech intervention in individuals with WS.

Interpretation of contrastive pitch accent in six- to eleven-year-old English-speaking children (and adults).

Both off-line and on-line comprehension studies suggest not only toddlers and preschoolers, but also older school-age children have trouble interpreting contrast-marking pitch prominence. To test whether children achieve adult-like proficiency in processing contrast-marking prosody during school years, an eye-tracking experiment examined the effect of accent on referential resolution in six- to eleven-year-old children and adults. In all age groups, a prominent accent facilitated the detection of a target in contrastive discourse sequences (pink cat → green cat), whereas it led to a garden path in non-contrastive sequences (pink rabbit → green monkey: the initial fixations were on rabbits). While the data indicate that children as young as age six immediately interpret contrastive accent, even the oldest child group showed delayed fixations compared to adults. We argue that the children's slower recovery from the garden path reflects the gradual development in cognitive flexibility that matures independently of general oculomotor control.

Anticipatory effects of intonation: Eye movements during instructed visual search.

Three eye-tracking experiments investigated the role of pitch accents during online discourse comprehension. Participants faced a grid with ornaments, and followed pre-recorded instructions such as "Next, hang the blue ball" to decorate holiday trees. Experiment 1 demonstrated a processing advantage for felicitous as compared to infelicitous uses of L+H* on the adjective noun pair (e.g. blue ball followed by GREEN ball vs. green BALL). Experiment 2 confirmed that L+H* on a contrastive adjective led to 'anticipatory' fixations, and demonstrated a "garden path" effect for infelicitous L+H* in sequences with no discourse contrast (e.g. blue angel followed by GREEN ball resulted in erroneous fixations to the cell of angels). Experiment 3 examined listeners' sensitivity to coherence between pitch accents assigned to discourse markers such as 'And then,' and those assigned to the target object noun phrase.