Search

Formation of neural mechanisms for morphosyntactic processing in young children is still poorly understood. Here, we addressed neural processing and rapid online acquisition of familiar and unfamiliar combinations of morphemes. Three different types of morphologically complex words — derived, inflected, and novel (pseudostem + real suffix) — were presented in a passive listening setting to 16 typically developing 3–4-year old children (as part of a longitudinal Helsinki SLI follow-up study). The mismatch negativity (MMN) component of event-related potentials (ERP), an established index of long-term linguistic memory traces in the brain, was analysed separately for the initial and final periods of the exposure to these items. We found MMN response enhancement for the inflected words towards the end of the recording session, whereas no response change was observed for the derived or novel complex forms. This enhancement indicates rapid build-up of a new memory trace for the combination of real morphemes, suggesting a capacity for online formation of whole-form lexicalized representations as one of the morphological mechanisms in the developing brain. Furthermore, this enhancement increased with age, suggesting the development of automatic morphological processing circuits in the age range of 3–4 years.

Purpose: The aim of this study was to investigate developmental and noise-induced changes in central auditory processing indexed by event-related potentials in typically developing children. Method: P1, N2, and N4 responses as well as mismatch negativities (MMNs) were recorded for standard syllables and consonants, frequency, intensity, vowel, and vowel duration changes in silent and noisy conditions in the same 14 children at the ages of 2 and 4 years. Results: The P1 and N2 latencies decreased and the N2, N4, and MMN amplitudes increased with development of the children. The amplitude changes were strongest at frontal electrodes. At both ages, background noise decreased the P1 amplitude, increased the N2 amplitude, and shortened the N4 latency. The noise-induced amplitude changes of P1, N2, and N4 were strongest frontally. Furthermore, background noise degraded the MMN. At both ages, MMN was significantly elicited only by the consonant change, and at the age of 4 years, also by the vowel duration change during noise. Conclusions: Developmental changes indexing maturation of central auditory processing were found from every response studied. Noise degraded sound encoding and echoic memory and impaired auditory discrimination at both ages. The older children were as vulnerable to the impact of noise as the younger children.

Background: Developmental language disorder (DLD, also called specific language impairment, SLI) is a common developmental disorder comprising the largest disability group in pre-school-aged children. Approximately 7% of the population is expected to have developmental language difficulties. However, the specific etiological factors leading to DLD are not yet known and even the typical linguistic features appear to vary by language. We present here a project that investigates DLD at multiple levels of analysis and aims to make the reliable prediction and early identification of the difficulties possible. Following the multiple deficit model of developmental disorders, we investigate the DLD phenomenon at the etiological, neural, cognitive, behavioral, and psychosocial levels, in a longitudinal study of preschool children. Methods: In January 2013, we launched the Helsinki Longitudinal SLI study (HelSLI) at the Helsinki University Hospital (http://tiny.cc/HelSLI). We will study 227 children aged 3–6 years with suspected DLD and their 160 typically developing peers. Five subprojects will determine how the child’s psychological characteristics and environment correlate with DLD and how the child’s well-being relates to DLD, the characteristics of DLD in monolingual versus bilingual children, nonlinguistic cognitive correlates of DLD, electrophysiological underpinnings of DLD, and the role of genetic risk factors. Methods include saliva samples, EEG, computerized cognitive tasks, neuropsychological and speech and language assessments, video-observations, and questionnaires. Discussion: The project aims to increase our understanding of the multiple interactive risk and protective factors that affect the developing heterogeneous cognitive and behavioral profile of DLD, including factors affecting literacy development. This accumulated knowledge will form a heuristic basis for the development of new interventions targeting linguistic and non-linguistic aspects of

To be able to acquire, produce, and comprehend language, precise central auditory processing (CAP), neural processes utilized for managing auditory input, is essential. However, the auditory environments are not always optimal for CAP because noise levels in children’s daily environments can be surprisingly high. In young children, CAP and its developmental trajectory as well as the influence of noise on it have scarcely been investigated. Event-related potentials (ERPs) offer promising means to study different stages of CAP in small children. Sound processing, preattentive auditory discrimination, and attention shifting processes can be addressed with obligatory responses, mismatch negativity (MMN), and novelty P3 of ERPs, respectively. In this thesis the developmental trajectory of CAP from 2 to 4 years of age as well as noise-induced changes on it, were investigated. In addition, the feasibility of the multi-feature paradigm with syllable stimuli and novel sounds in children was evaluated. To this end, obligatory responses (P1, N2, and N4) and MMNs for consonant, frequency, intensity, vowel, and vowel duration changes, as well as novelty P3 responses, were recorded in a silent condition and with babble noise using the multi-feature paradigm. The participants were voluntary, typically developing children. Significant P1, N2, N4, and MMN responses were elicited at both ages. Also a significant novelty P3, studied at the age of 2 years, was found. From 2 to 4 years, the P1 and N2 latencies shortened. The amplitudes of N2, N4, and MMNs increased and the increment was the largest at frontal electrode locations. During noise, P1 decreased, N2 increased, and the latency of N4 diminished as well as MMNs degraded. The noise-induced changes were largely similar at both ages. In conclusion, the multi-feature paradigm with five syllable deviant types and novel sounds was found to be an appropriate measure of CAP in toddlers. The changes in ERP morphology from 2 to 4, Tiivistelmä Kielen omaksumiselle, tuottamiselle sekä ymmärtämiselle on tärkeää tarkka keskushermostollinen kuulotiedon käsittely eli ne hermostolliset prosessit, joita käytetään kuullun aineksen käsittelyyn. Kuunteluympäristöt eivät kuitenkaan aina ole optimaalisia kuulotiedon käsittelylle, sillä melutasot lasten elinympäristöissä voivat olla hyvinkin korkeita. Pienten lasten kuulotiedon käsittelyä, sen kehittymistä ja melun vaikutusta siihen on tutkittu vähän. Kuuloherätevasteet ovat toimiva tapa tarkastella pienten lasten kuulotiedon käsittelyä eri näkökulmista. Äänen käsittelyä, esitietoista kuuloerottelua ja tarkkaavuuden siirtymistä voidaan tarkastella obligatoristen vasteiden, poikkeavuusnegatiivisuuden ja novelty P3 -vasteiden avulla. Tässä väitöskirjassa tarkastellaan kuulotiedon käsittelyn kehittymistä kahden vuoden iästä neljän vuoden ikään sekä melun vaikutusta siihen. Lisäksi arvioidaan tavuärsykkeitä ja poikkeavia ääniä sisältävän monipiirreparadigman soveltuvuutta lapsitutkimuksiin. Tutkimuksissa rekisteröitiin monipiirreparadigman avulla obligatorisia vasteita (P1, N2 ja N4); konsonantin, taajuuden, intensiteetin, vokaalin ja vokaalin keston muutokselle syntyneitä MMN-vasteita sekä novelty P3 -vasteita hiljaisuudessa ja taustamelussa. Tutkimuksen osallistujat olivat vapaaehtoisia tyypillisesti kehittyviä lapsia. Molemmilla tutkimuskerroilla P1, N2, N4 ja MMN poikkesivat merkitsevästi nollatasosta samoin kuin kaksivuotiailta tutkittu novelty P3. Kahden vuoden iästä neljään vuoteen P1- ja N2-vasteiden latenssi lyheni sekä N2, N4 ja MMN vahvistuivat, muutoksen ollessa suurinta frontaalisilla elektrodeilla. Melun aikana P1 heikkeni, N2 vahvistui ja N4-vasteen latenssi lyhentyi. Lisäksi MMN-vaste heikkeni. Melun aiheuttamat muutokset olivat samankaltaisia sekä kahden että neljän vuoden iässä. Johtopäätöksenä voidaan todeta viittä eri tavuärsyketyyppiä ja yllättäviä ääniä sisältävän monipiirreparadigman olevan toimiva menetelmä taaperoiden kuulotiedon käsit

The purpose of this study was to evaluate the effect of antibiotic treatment and surgery on acute otitis media (AOM), and to evaluate quality of life (QoL) among children with AOM and their parents. To evaluate the effectiveness of antibiotics, a total of 82 children with AOM were randomized for antibiotic or placebo treatment for 7 days. The duration of middle ear effusion was measured by daily tympanometry screenings at home over 2 weeks. Duration was also measured at clinical visits, including at entry, after 3 days, after 7 days, and then weekly until both ears were healthy according to pneumatic otoscopy or otomicroscopy, or for a maximum of 2 months. Among the group receiving antibiotics, middle ear effusion disappeared 2.0 weeks earlier than among those receiving placebo (P<0.02). On day 14, 69% of children in the antibiotic group and 38% in the placebo group had normal tympanometry findings (P=0.02). On day 60, 5% of children in the antibiotic group and 24% in the placebo group had persistent middle ear effusion (P=0.01). The effect of surgery was assessed by randomly assigning 300 children with recurrent AOM, aged 10 months to 2 years, into 3 groups: 1. to receive ventilation tubes (VTs), 2. to receive VTs and adenoidectomy and 3. non-surgery. Follow-up of children occurred at clinical visits every 4 months for a 1-year period. If children suffered from upper respiratory symptoms or their parents suspected AOM during this period they were encouraged to receive additional follow-up care. Intervention was considered unsuccessful if a child had 2 AOM episodes in 2 months, 3 episodes in 6 months or persistent effusion lasting for 2 months. Intervention failed in 34% of children in the non-surgery group, 21% in the VT group (P=0.04 compared to non-surgery) and 16% in the group with VT and adenoidectomy (P=0.004 compared to non-surgery). QoL was assessed among 159 children participating in the study on the effect of surgery in children with recurrent, Tiivistelmä Työn tavoitteena oli tutkia antibiootin ja kirurgian vaikutusta äkilliseen välikorvatulehdukseen sekä tutkia välikorvatulehduksia sairastavien lasten ja heidän vanhempiensa elämänlaatua. 82 äkillistä välikorvatulehdusta sairastavaa lasta satunnaistettiin saamaan joko antibiootti- tai lumelääkettä. Välikorvaeritteen poistumista seurattiin kotona päivittäisillä tympanometriamittauksilla kahden viikon ajan. Seurantakäynnit olivat yhden, kolmen ja seitsemän päivän kuluttua sekä viikoittain, kunnes korvat oli todettu terveiksi pneumaattisella otoskoopilla tai korvamikroskoopilla tai kahden kuukauden seuranta-aika päättyi. Välikorvaerite poistui kaksi viikkoa aikaisemmin antibiootti- kuin lumelääkkeellä (P<0.02). Tympanometria normalisoitui kahden viikon kuluttua 69 %:lla antibioottiryhmästä ja 38 %:lla lumelääkeryhmästä (P=0.02). 60 päivän kuluttua välikorvaeritettä oli 5 %:lla antibioottiryhmästä ja 24 %:lla lumelääkeryhmästä (P=0.02). Kirurgian vaikuttavuutta toistuviin äkillisiin välikorvatulehduksiin tutkittiin satunnaistamalla 300 10–24 kk:n ikäistä lasta saamaan ilmastointiputket tai sekä ilmastointiputket että kitarisanpoisto tai ei kumpaakaan. Seurantakäynnit olivat neljän kuukauden välein vuoden ajan tai aina kun lapset sairastuivat ylähengitystietulehdukseen tai vanhemmat epäilivät välikorvatulehdusta. Interventio katsottiin epäonnistuneeksi (äkillisiä välikorvatulehduksia 2 / 2 kk, 3 / 6 kk tai jatkuva erite 2 kk) 34 %:lla ilman kirurgiaa hoidetuista lapsista, 21 %:lla ilmastointiputkiryhmän lapsista (P=0.04 verrattuna ilman kirurgiaa hoidettuihin) ja 16 %:lla lapsista, joille tehtiin sekä kitarisan poisto että asetettiin ilmastointiputket (P=0.004 verrattuna ilman kirurgiaa hoidettuihin). Elämänlaadun, äkillisen välikorvatulehduksen sekä siihen liittyvän kirurgian välistä yhteyttä selvitettiin 159 lapsella, jotka osallistuivat kirurgian vaikuttavuutta selvittävään tutkimukseen. Elämänlaatua mitattiin sekä tautikohtaisilla (Otitis Media-6) että

Learning, the foundation of adaptive and intelligent behavior, is based on plastic changes in neural assemblies, reflected by the modulation of electric brain responses. In infancy, auditory learning implicates the formation and strengthening of neural long-term memory traces, improving discrimination skills, in particular those forming the prerequisites for speech perception and understanding. Although previous behavioral observations show that newborns react differentially to unfamiliar sounds vs. familiar sound material that they were exposed to as fetuses, the neural basis of fetal learning has not thus far been investigated. Here we demonstrate direct neural correlates of human fetal learning of speech-like auditory stimuli. We presented variants of words to fetuses; unlike infants with no exposure to these stimuli, the exposed fetuses showed enhanced brain activity (mismatch responses) in response to pitch changes for the trained variants after birth. Furthermore, a significant correlation existed between the amount of prenatal exposure and brain activity, with greater activity being associated with a higher amount of prenatal speech exposure. Moreover, the learning effect was generalized to other types of similar speech sounds not included in the training material. Consequently, our results indicate neural commitment specifically tuned to the speech features heard before birth and their memory representations.