Impact of Prematurity on Auditory Processing in Children.

Prematurity is one of the most crucial risk factors negatively affecting the maturation of the auditory system. Children born preterm demonstrate high rates of hearing impairments. Auditory processing difficulties in preterm children might be a result of disturbances in the central auditory system development and/or sensory deprivation due to peripheral hearing loss. To investigate auditory processing in preterm children, we utilized a set of psychoacoustic tests to assess temporal processing and speech intelligibility. A total of 241 children aged 6-11 years old (136 born preterm and 105 healthy full-term children forming the control group) were assessed. The preterm children were divided into three groups based on their peripheral hearing status: 74 normal hearing (NH group); 30 children with bilateral permanent sensorineural hearing loss (SNHL group) and 32 children with bilateral auditory neuropathy spectrum disorder (ANSD group). The results showed significantly worse performance in all tests in premature children compared with full-term children. NH and SNHL groups showed significant age-related improvement in speech recognition thresholds in noise that might signify a "bottom-up" auditory processing maturation effect. Overall, all premature children had signs of auditory processing disorders of varying degrees. Analyzing and understanding the auditory processing specificity in preterm children can positively contribute to the more effective implementation of rehabilitation programs.

Auditory Mismatch Negativity Response in Institutionalized Children.

The attunement of speech perception/discrimination to the properties of one's native language is a crucial step in speech and language development at early ages. Studying these processes in young children with a history of institutionalization is of great interest, as being raised in institutional care (IC) may lead to lags in language development. The sample consisted of 82 children, split into two age groups. The younger age group (<12 months) included 17 children from the IC and 17 children from the biological-family-care (BFC) group. The older group (>12 months) consisted of 23 children from the IC group, and 25 children from the BFC group. A double-oddball paradigm with three consonant-vowel syllables was used, utilizing native (Russian) and foreign (Hindi) languages. A Mismatch Negativity (MMN) component was elicited within a 125-225 ms time window in the frontal-central electrode. Findings demonstrate the absence of MMN effect in the younger age group, regardless of the living environment. Children in the older group are sensitive to native deviants and do not differentiate foreign language contrasts. No significant differences were observed between the IC and BFC groups for children older than 12 months, indicating that children in the IC have typical phonological processing. The results show that the MMN effect is not registered in Russian speaking children before the age of 12 months, regardless of their living environment. At 20 months of age, institutionally reared children show no evidence of delays in phonetic development despite a limited experience of language.

Neurophysiological Correlates of Fast Mapping of Novel Words in the Adult Brain.

Word acquisition could be mediated by the neurocognitive mechanism known as fast mapping (FM). It refers to a process of incidental exclusion-based learning and is believed to be a critical mechanism for the rapid build-up of lexicon, although its neural mechanisms are still poorly understood. To investigate the neural bases of this key learning skill, we used event-related potentials (ERPs) and employed an audio-visual paradigm that included a counterbalanced set of familiar and novel spoken word forms presented, in a single exposure, in conjunction with novel and familiar images. To define learning-related brain dynamics, passive auditory ERPs, known to index long-term memory trace activation, were recorded before and after the FM task. Following the single FM learning exposure, we found a significant enhancement in neural activation elicited by the newly trained word form, which was expressed at ~200-400 ms after the word onset. No similar amplitude increase was found either for the native familiar word used as a control stimulus in the same learning paradigm or for similar control stimuli which were not subject to training. Topographic analysis suggested a left-lateral shift of the ERP scalp distribution for the novel FM word form, underpinned by fronto-temporal cortical sources, which may indicate the involvement of pre-existing neurolinguistic networks for mastering new word forms with native phonology. Overall, the near-instant changes in neural activity after a single-shot novel word training indicate that FM could promote rapid integration of newly learned items into the brain's neural lexicon, even in adulthood.

The Effect of a Social-Emotional Intervention on the Development of Preterm Infants in Institutions.

This study examined the effect of a social-emotional intervention implemented in one St. Petersburg (Russian Federation) institution (called a Baby Home, BH) on the general behavioral development of preterm children (gestational ages of 30-36 weeks) during their first two years of life. The intervention consisted of training caregivers and implementing structural changes to create a more family-like environment. The study included preterm (N = 56) and full-term (N = 93) children from one BH that implemented the intervention and from another BH with no intervention. Children were assessed at 3, 6, 9, 12, 18 and 24 months of age with the Battelle Development Inventory (LINC Associates, 1988). The results showed that the intervention positively influenced the general behavioral development of BH preterm children throughout their first two years of life compared to preterms from the no-intervention BH. Also, results indicated that the intervention effect was developmentally similar for preterm and for full-term children, but preterm children consistently scored lower than full-terms during their first two years living in the BH. In general, our research emphasizes the crucial role of warm, sensitive, and responsive interactions with a constant and emotionally available caregiver for healthy child development for both term and preterm children.