Cynthia P. Roesler

Using Early Standardized Language Measures to Predict Later Language and Early Reading Outcomes in Children at High Risk for Language-Learning Impairments

The aim of the study was to examine the profiles of children with a family history (FH+) of language-learning impairments (LLI) and a control group of children with no reported family history of LLI (FH—) and identify which language constructs (receptive or expressive) and which ages (2 or 3 years) are related to expressive and receptive language abilities, phonological awareness, and reading abilities at ages 5 and 7 years. Participants included 99 children (40 FH+ and 59 FH—) who received a standardized neuropsychological battery at 2, 3, 5, and 7 years of age. As a group, the FH+ children had significantly lower scores on all language measures at 2 and 3 years, on selected language and phonological awareness measures at 5 years, and on phonological awareness and nonword reading at 7 years. Language comprehension at 3 years was the best predictor of later language and early reading for both groups. These results support past work suggesting that children with a positive family history of LLI are at greater risk for future language and reading problems through their preschool and early school-age years. Furthermore, language comprehension in the early years is a strong predictor of future language-learning status.

Plasticity in developing brain: active auditory exposure impacts prelinguistic acoustic mapping.

A major task across infancy is the creation and tuning of the acoustic maps that allow efficient native language processing. This process crucially depends on ongoing neural plasticity and keen sensitivity to environmental cues. Development of sensory mapping has been widely studied in animal models, demonstrating that cortical representations of the sensory environment are continuously modified by experience. One critical period for optimizing human language mapping is early in the first year; however, the neural processes involved and the influence of passive compared with active experience are as yet incompletely understood. Here we demonstrate that, while both active and passive acoustic experience from 4 to 7 months of age, using temporally modulated nonspeech stimuli, impacts acoustic mapping, active experience confers a significant advantage. Using event-related potentials (ERPs), we show that active experience increases perceptual vigilance/attention to environmental acoustic stimuli (e.g., larger and faster P2 peaks) when compared with passive experience or maturation alone. Faster latencies are also seen for the change discrimination peak (N2*) that has been shown to be a robust infant predictor of later language through age 4 years. Sharpening is evident for both trained and untrained stimuli over and above that seen for maturation alone. Effects were also seen on ERP morphology for the active experience group with development of more complex waveforms more often seen in typically developing 12- to 24-month-old children. The promise of selectively “fine-tuning” acoustic mapping as it emerges has far-reaching implications for the amelioration and/or prevention of developmental language disorders.

Oscillatory support for rapid frequency change processing in infants.

Rapid auditory processing and auditory change detection abilities are crucial aspects of speech and language development, particularly in the first year of life. Animal models and adult studies suggest that oscillatory synchrony, and in particular low-frequency oscillations play key roles in this process. We hypothesize that infant perception of rapid pitch and timing changes is mediated, at least in part, by oscillatory mechanisms. Using event-related potentials (ERPs), source localization and time-frequency analysis of event-related oscillations (EROs), we examined the neural substrates of rapid auditory processing in 4-month-olds. During a standard oddball paradigm, infants listened to tone pairs with invariant standard (STD, 800-800 Hz) and variant deviant (DEV, 800-1200 Hz) pitch. STD and DEV tone pairs were first presented in a block with a short inter-stimulus interval (ISI) (Rapid Rate: 70 ms ISI), followed by a block of stimuli with a longer ISI (Control Rate: 300 ms ISI). Results showed greater ERP peak amplitude in response to the DEV tone in both conditions and later and larger peaks during Rapid Rate presentation, compared to the Control condition. Sources of neural activity, localized to right and left auditory regions, showed larger and faster activation in the right hemisphere for both rate conditions. Time-frequency analysis of the source activity revealed clusters of theta band enhancement to the DEV tone in right auditory cortex for both conditions. Left auditory activity was enhanced only during Rapid Rate presentation. These data suggest that local low-frequency oscillatory synchrony underlies rapid processing and can robustly index auditory perception in young infants. Furthermore, left hemisphere recruitment during rapid frequency change discrimination suggests a difference in the spectral and temporal resolution of right and left hemispheres at a very young age.

An operantly conditioned looking task for assessing infant auditory processing ability

In this paper, we describe the design and evaluation of a gaze-driven interface for the assessment of rapid auditory processing abilities in infants aged 4 to 6 months. A cross-modal operant conditioning procedure is used to reinforce anticipatory eye movements in response to changes in a continuous auditory stream. Using this procedure, we hope to develop a clinical tool that will enable early identification of individuals at risk for language-based learning impairments. Some of the unique opportunities and challenges inherent to designing for infant-computer interaction are discussed.

Auditory event-related responses in children with semi-lobar holoprosencephaly.

The purpose of this study was to evaluate auditory sensory and discrimination responses in children with semi-lobar holoprosencephaly (HPE). Event-related potential (ERP) signals were recorded to tone pair stimuli at 62 electrode sites from the scalp using an oddball paradigm (a two-block design, inter-stimulus interval=70 or 300 ms; frequency of tone pair=100 vs. 100 Hz for the frequent and 100 vs. 300 Hz for the infrequent). Latencies and amplitudes of P150, N250, and mismatch negativity (MMN)-like components were compared between children with HPE and controls. Our results revealed less organized ERP waveforms to both stimuli in children with HPE, with diminished P150 and N250 components across brain area. Robust and delayed MMN-like responses were elicited from the children with HPE, with decreased MMN amplitudes in the central, parietal, occipital, and posterior temporal areas. Our results suggest that while brain sensory responses to auditory tones may be impaired in children with semi-lobar HPE, subcomponents of auditory discrimination processes remain functional.

Active auditory experience in infancy promotes brain plasticity in Theta and Gamma oscillations

Highlights • Active acoustic experience (AEx) in infancy impacts cortical oscillations.• AEx infants show left Theta- and Gamma-band activity to complex tone pairs.• Passive and naïve infants yield less distinct, more bilateral responses.

Infant Auditory Processing and Event-related Brain Oscillations

Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral and temporal changes that are characteristic of human language. These abilities lay the foundation for effective language acquisition; allowing infants to hone in on the sounds of their native language. Invasive procedures in animals and scalp-recorded potentials from human adults suggest that simultaneous, rhythmic activity (oscillations) between and within brain regions are fundamental to sensory development; determining the resolution with which incoming stimuli are parsed. At this time, little is known about oscillatory dynamics in human infant development. However, animal neurophysiology and adult EEG data provide the basis for a strong hypothesis that rapid auditory processing in infants is mediated by oscillatory synchrony in discrete frequency bands. In order to investigate this, 128-channel, high-density EEG responses of 4-month old infants to frequency change in tone pairs, presented in two rate conditions (Rapid: 70 msec ISI and Control: 300 msec ISI) were examined. To determine the frequency band and magnitude of activity, auditory evoked response averages were first co-registered with age-appropriate brain templates. Next, the principal components of the response were identified and localized using a two-dipole model of brain activity. Single-trial analysis of oscillatory power showed a robust index of frequency change processing in bursts of Theta band (3 - 8 Hz) activity in both right and left auditory cortices, with left activation more prominent in the Rapid condition. These methods have produced data that are not only some of the first reported evoked oscillations analyses in infants, but are also, importantly, the product of a well-established method of recording and analyzing clean, meticulously collected, infant EEG and ERPs. In this article, we describe our method for infant EEG net application, recording, dynamic brain response analysis, and representative results.

Sensory Desensitization Training for Successful Net Application and EEG/ERP Acquisition in Difficult to Test Children

This study examined the effectiveness of sensory desensitization training for 12 nonverbal children with autism to facilitate participation in an electrophysiological study assessing linguistic processing. Sensory desensitization was achieved for 10 of the 12 children and thus allowed collection of usable data in a passive linguistic paradigm. Application of such desensitization methods may be useful as a precursor to other assessment protocols for individuals who are difficult to test.

Effects of noise and age on the infant brainstem response to speech

OBJECTIVE Background noise makes hearing speech difficult for people of all ages. This difficulty can be exacerbated by co-occurring developmental deficits that often emerge in childhood. Sentence-type speech-in-noise (SIN) tests are available clinically but cannot be administered to very young individuals. Our objective was to examine the use of an electrophysiological test of SIN, suitable for infants, to track developmental trajectories. METHODS Speech-evoked brainstem potentials were recorded from 30 typically-developing infants in quiet and +10 dB SNR background noise. Infants were divided into two age groups (7-12 and 18-24 months) and examined across development. Spectral power of the frequency following response (FFR) was computed using a fast Fourier Transform. Cross-correlations between quiet and noise responses were computed to measure encoding resistance to noise. RESULTS Older infants had more robust FFR encoding in noise and had higher quiet-noise correlations than their younger counterparts. No group differences were observed in the quiet condition. CONCLUSIONS By two years of age, infants show less vulnerability to the disruptive effects of background noise, compared to infants under 12 months. SIGNIFICANCE Speech-in-noise electrophysiology can be easily recorded across infancy and provides unique insights into developmental differences that tests conducted in quiet may miss.

A Modulatory Effect of Brief Passive Exposure to Non-linguistic Sounds on Intrinsic Functional Connectivity: Relevance to Cognitive Performance

Abstract A growing literature on resting‐state fMRI (R‐fMRI) has explored the impact of preceding sensory experience on intrinsic functional connectivity (iFC). However, it remains largely unknown how passive exposure to irrelevant auditory stimuli, which is a constant in everyday life, reconfigures iFC. Here, we directly compared pre‐ and post‐exposure R‐fMRI scans to examine: 1) modulatory effects of brief passive exposure to repeating non‐linguistic sounds on subsequent iFC, and 2) associations between iFC modulations and cognitive abilities. We used an exploratory regional homogeneity (ReHo) approach that indexes local iFC, and performed a linear mixed‐effects modeling analysis. A modulatory effect (increase) in ReHo was observed in the right superior parietal lobule (R.SPL) within the parietal attention network. Post hoc seed‐based correlation analyses provided further evidence for increased parietal iFC (e.g., R.SPL with the right inferior parietal lobule). Notably, less iFC modulation was associated with better cognitive performance (e.g., word reading). These results suggest that: 1) the parietal attention network dynamically reconfigures its iFC in response to passive (thus irrelevant) non‐linguistic sounds, but also 2) minimization of iFC modulation in the same network characterizes better cognitive performance. Our findings may open up new avenues for investigating cognitive disorders that involve impaired sensory processing.